Claire M. Rickard, RN, PhD

Peripherally inserted central catheters (PICCs) have evolved since their inception in the early 1970s and are used with increasing frequency for pediatric inpatients and outpatients.^1-3 Emerging literature, including a meta-analysis of international observational studies,⁴ reports PICC failure (complications necessitating premature removal) occurs in up to 30% of PICCs, most commonly due to infection, thrombosis, occlusion, and fracture.^4-7 Raffini et al.⁷ report the increasing incidence of pediatric PICC-related thrombosis increases morbidity and mortality⁸ and negatively impacts future vessel health and preservation.⁹

PICCs have progressed from relatively simple, silicone-based catheters with an external clamp to chemically engineered polyurethane with pressure-activated valves placed at the proximal or distal catheter hub with the intent to reduce occlusion.¹⁰ Further modernization of PICC material occurred with the incorporation of antithrombogenic (AT) material (Endexo^®). These PICCs are designed to contain a nonstick polymer, which is designed to reduce the adherence of blood components (platelets and clotting factors) and inhibit thrombus formation (and hence prevent deep vein thrombosis andocclusion, as well as inhibit microbial biofilm attachment [and subsequent infection]).¹¹

In addition to new materials, other aspects of this PICC design have been the addition of a pressure-activated safety valve (PASV^®) built into the proximal hub. Pressure-activated valve technology promises to prevent catheter occlusion by reducing blood reflux into the PICC; the valve opens with pressure during infusion and aspiration and remains closed with normal venous pressure, circumventing the need for clinicians to manually clamp the PICC and reducing human error and the potential for thrombosis, occlusion, and fracture development.¹² Hoffer et al.¹³ reported half as many occlusions of valved PICCs (3.3%) compared with nonvalved or clamped PICCs (7.1%); although not statistically significant (P = .10), perhaps due to the small sample, overall complications, including occlusion and infection, were significantly lessened with the valved PICC (35% vs 79%; P = .02). Comparatively, Pittiruti et al.¹⁴ conducted a trial of 2 types of valved PICCs with an open-ended, nonvalved PICC and found no reduction in PICC occlusion or catheter malfunction.

Today, PICC use is common for patients who require short-to-medium intravenous therapy. PICCs are increasingly recognized for their significant complications, including thrombosis and infection.¹⁵ Novel PICC technology, including the incorporation of AT material such as Endexo^® and PASV^®, may reduce complications; however, the clinical efficacy, cost-effectiveness, and acceptability of these innovations have not been tested through randomized trials in pediatric patients. In accordance with Medical Research Council guidelines¹⁶ for developing interventions, we pilot tested the feasibility of the BioFlo^® PICC, including intervention acceptability, compliance, recruitment, and initial estimates of effect, in anticipation of a subsequent full-scale efficacy randomized controlled trial. Our secondary aim was to compare the effectiveness of the BioFlo^® PICC with Endexo^® and PASV^® technology in reducing PICC complications and failure.

Design

We undertook a pilot randomized controlled trial comparing the standard polyurethane PICC (with external clamp) with the BioFlo^® PICC (with internal valve) in preventing catheter failure in pediatric patients. The study was prospectively registered with the Australian Clinical Trials Registry (ACTRN12615001290583), and the research protocol was published.¹⁷

Study Setting

The study commenced in March 2016 at the Lady Cilento Children’s Hospital in South Brisbane, Australia, a tertiary-level, specialist, pediatric teaching hospital in Queensland, Australia, providing full-spectrum health services to children and young people from birth to 18 years of age. Recruitment, including data collection, was completed in November 2016.

Sample

The target sample size was 110 participants, 50 participants per group plus 10% for potential attrition, as determined by standard pilot trial sample size recommendations.¹⁸ With ethics approval, the sample size was later increased to 150 participants in order to adequately pilot a microbiological substudy method (published separately).¹⁷ Participants were consecutively recruited if they met the inclusion criteria: PICC insertion, age <18 years, predicted hospital stay >24 hours, single-lumen PICC, and written informed consent by an English-speaking, legal parent or guardian. Patients were excluded if they had a current (<48 hours) blood stream infection (BSI), vessel size <2 mm, could not speak English without an interpreter, required a multilumen PICC, or were previously enrolled in the study.

Interventions

Participants were randomized to receive either of the following PICCs: (1) standard care: Cook™ polyurethane, turbo-ject, power-injectable PICC (Cook Medical, Bloomington, IN) or (2) comparison: BioFlo^® polyurethane with Endexo^® technology (AngioDynamics Inc, Queensbury, NY).

Outcomes

The primary outcome was feasibility of a full-efficacy trial established by composite analysis of the elements of eligibility (>70% of patients will be eligible), recruitment (>70% of patients will agree to enroll), retention and attrition (<15% of participants are lost to follow-up or withdraw from the study), protocol adherence (>80% of participants receive their allocated, randomly assigned study product), missing data (<10% of data are missed during data collection), parent and healthcare staff satisfaction, and PICC failure effect size estimates to allow sample size calculations.^18,19 PICC failure was defined as the following complications associated with PICC removal: (1) catheter-associated BSI,^8,20-22 (2) local site infection,²² (3) venous thrombosis,²³ (4) occlusion,^24,25 (5) PICC fracture, or (6) PICC dislodgement.^25,26 Parents (or caregivers) and healthcare staff were asked to rate their level of confidence with the study product and ease of PICC removal by using a 0 to 100 numeric rating scale (NRS) of increasing confidence and/or ease. These data were collected at the time of PICC removal. Operators were also asked to rate their levels of satisfaction with the insertion equipment and ease of PICC insertion immediately upon completion of the insertion procedure (both 0-100 NRS of increasing satisfaction and/or ease). Secondary outcomes included individual PICC complications (eg, occlusion) occurring at any time point during the PICC dwell (including at removal), adverse events, pain, redness at the insertion site, and overall PICC dwell.

Study Procedures

The research nurse (ReN) screened operating theater lists for patients, obtained written informed consent, and initiated the randomization. Randomization was computer generated, and web based via Griffith University (https://www151.griffith.edu.au/random) to ensure allocation concealment until study entry. Patients were randomly assigned in a 1:1 ratio with computer-generated and randomly varied block sizes of 2 and 4. Data were collected by the ReN on the day of insertion, at day 1 postinsertion, then every 2 to 3 days thereafter so that PICCs were checked at least twice per week until study completion. Participants were included in the trial until 12 weeks post-PICC insertion, study withdrawal or PICC removal (whichever came first), with an additional 48 hours follow-up for infection outcomes. Patient review was face to face during the inpatient stay, with discharged patients’ follow-up occurring via outpatient clinics, hospital-in-the-home service, or telephone.

Data collection was via Research Electronic Data Capture (http://project-redcap.org/). The ReN collected data on primary and secondary outcomes by using the predefined criteria. Demographic and clinical data were collected to assess the success of randomization, describe the participant group, and display characteristics known to increase the risk of PICC complication and thrombosis. A blinded radiologist and infectious disease specialist reviewed and diagnosed thrombosis of deep veins and catheter-associated BSI outcomes, respectively.

PICC Procedures

Extensive prestudy education for 2 months prior to trial commencement was provided to all clinicians involved with the insertion and care of PICCs, including the study products. PICCs were inserted in an operating theater environment by a qualified consultant pediatric anesthetist, a senior anesthetic registrar or fellow in an approved anesthetic training program, or pediatric vascular access nurse practitioner. Ultrasound guidance was used to assess a patient’s vasculature and puncture the vessel. The operator chose the PICC size on the basis of clinical judgment of vessel size and patient needs and then inserted the allocated PICC.²⁷ Preferred PICC tip location was the cavoatrial junction. All PICC tip positions were confirmed with a chest x-ray before use.

Postinsertion, PICCs were managed by local interdisciplinary clinicians in accordance with local practice guidelines.^27-31 PICC care and management includes the use of 2% chlorhexidine gluconate in 70% alcohol for site antisepsis and neutral displacement needleless connectors (TUTA Pulse; Medical Australia Limited, Lidcombe, New South Wales, Australia); normal saline was used to flush after medication administration, and if the device was not in use for 6 hours or longer, heparin is instilled with securement via bordered polyurethane dressing (Tegaderm 1616; 3M, St Paul, Minnesota) and a sutureless securement device (Statlock VPPCSP; Bard, Georgia).

Statistical Analyses

Data were exported to Stata 15³² for cleaning and analysis. Data cleaning of outlying figures and missing and implausible data was undertaken prior to analysis. Missing data were not imputed. The PICC was the unit of measurement, and all randomly assigned patients were analyzed on an intention-to-treat basis.³³ Descriptive statistics (frequencies and percentages) were used to ascertain the primary outcome of feasibility for the larger trial. Incidence rates (per 1,000 catheter days) and rate ratios, including 95% confidence intervals (CIs), were calculated. The comparability of groups at baseline was described across demographic, clinical, and device characteristics. Kaplan-Meier survival curves (with log-rank tests) were used to compare PICC failure between study groups over time. Associations between baseline characteristics and failure were described by calculating hazard ratios (HRs). Univariable Cox regression was performed only due to the relatively low number of outcomes. P values of <.05 were considered statistically significant.

Ethics

The Children’s Health Service District, Queensland (Human Research Ethics Committee/15/QRCH/164), and Griffith University (2016/077) Human Research Ethics Committees provided ethics and governance approval. Informed consent was obtained from parents or legal guardians, with children providing youth assent if they were 7 years or older, dependent upon cognitive ability.

Participant and PICC Characteristics

Feasibility Outcomes

PICC Failure and Complications

DISCUSSION

This is the first pilot feasibility trial of new PICC materials and valve design incorporated in the BioFlo^® PICC in the pediatric population. The trial incorporated best practice for randomized trials, including using a concurrent control group, centralized and concealed randomization, predetermined feasibility criteria, and a registered and published trial protocol.¹⁷ As in other studies,^15,24,34 PICC failure and complication prevalence was unacceptably high for this essential device. Standard care PICCs failed twice as often as the new BioFlo^® PICCs (22% vs 11%), which is a clinically important difference. As researchers in a pilot study, we did not expect to detect statistically significant differences; however, we found that overall complications during the dwell occurred significantly more with the standard care than BioFlo^® PICCs (P = .009).

BioFlo^® PICC material offers a major advancement in PICC material through the incorporation of AT technologies into catheter materials, such as PICCs. Endexo^® is a low molecular–weight, fluoro-oligomeric additive that self-locates to the top few nanometers of the material surface. When added to power-injectable polyurethane, the additive results in a strong but passive, nonstick, fluorinated surface in the base PICC material. This inhibits platelet adhesion, suppresses protein procoagulant conformation, and thereby reduces thrombus formation in medical devices. Additionally, Endexo^® is not a catheter coating; rather, it is incorporated within the polyurethane of the PICC, thereby ensuring these AT properties are present on the internal, external, and cut surfaces of the PICC. If this technology can reduce complication during treatment and reduce failure from infection, thrombosis, occlusion, fracture, and dislodgement, it will improve patient outcomes considerably and lower health system costs. Previous studies investigating valve technology in PICC design to reduce occlusion have been inconclusive.^12-14,35,36 Occlusion (both partial and complete) was less frequent in our study with the BioFlo^® group (n = 3; 4%) compared to the standard care group (n = 6; 8%). The results of this pilot study suggest that either the Endexo^® material or PASV^® technology has a positive association with occlusion reduction during PICC treatment.

Thrombosis was the primary failure type for the standard care PICCs, comprising one-third of failures. All but one patient with radiologically confirmed thrombosis required the removal of the PICC prior to completion of treatment. The decision to remove the PICC or retain and treat conservatively remained with the treating team. Raffini et al.⁷ found thrombosis to increase in patients with one or more coexisting chronic medical condition. Slightly more standard care than BioFlo^® patients were free of such comorbidities (25% vs 16%), yet standard care patients still had the higher number of thromboses (7% vs 3%). Morgenthaler and Rodriguez³⁷ reported vascular access-associated thrombosis in pediatrics to be less common than in adults but higher in medically complex children. Worryingly, Menendez et al.³⁸ reported pediatric thrombosis to be largely asymptomatic, so the true incidence in our study is likely higher because only radiologically confirmed thromboses were recorded.

Occlusion (partial or complete) was the predominant complication across the study, being associated with one-third of all failures. When occlusion complications during the dwell (some of which were resolved with treatment), in addition to those causing failure, were considered, this number was even greater. Occlusion complications are prevalent and costly. Smith et al.²⁴ reported that occlusion was the most common reason for PICC removal and the most likely complication to delay treatment. Both the BioFlo^® and standard care PICCs are pressure rated with good tensile strength; however, fracture occurred in 4% (n = 3) of standard care PICCs compared to no fractures in BioFlo^® PICCs. Although the numbers are small, it may suggest a superior tensile strength of the BioFlo^® material.

This study reinforces previously published results^24,38 that PICC tip position is important and can influence complications, such as occlusion and thrombosis. In addition, we found a significant association with failure when PICCs did not have a continuous infusion. These findings reinforce the need for optimal tip location at insertion and ongoing flushing and maintenance of PICCs not used for infusions.

Limitations of this study include the small sample size, which was not designed to detect statistical differences in the primary outcome between groups. Despite randomization, there were slight imbalances at baseline for inserter type and leukocyte count, although these were not significantly associated with PICC failure in the Cox regression (data not shown), and thus were unlikely to influence findings. Additionally, a difference of <10% was associated with PICC tip position, favoring the BioFlo^® group. PICC tip position outside the cavoatrial junction was positively associated with failure; therefore, the effect of tip positioning on outcomes is difficult to ascertain given the small sample size and feasibility nature of the study. Further study is warranted to further explore this effect. The population sampled was pediatric medical and surgical inpatients with a vessel size >2 mm attending the operating theater suite for PICC insertion, thereby limiting the study’s generalizability to adults and other populations, including neonates and those with PICCs inserted in the pediatric intensive care unit. The study could not be blinded because study products had to be visible to the clinical and research staff. However, it is unlikely that staff would intentionally sabotage PICCs to bias the study. Blinding was possible for the assessment of blood culture and ultrasound reports to diagnose infection and thrombosis. Strengths of this study included 100% protocol adherence, and no patients were lost to follow-up.

These results confirm that PICC failure is unacceptably high and suggest that the innovative BioFlo^® PICC material and design holds promise to improve PICC outcomes by reducing complications and overall PICC failure. Trials of this technology are feasible, safe, and acceptable to healthcare staff and parents. Further trials are required, including in other patient populations, to definitively identify clinical, cost-effective methods to prevent PICC failure and improve reliability during treatment.

Acknowledgments

The authors thank the children and parents of Lady Cilento Children’s Hospital for participating in this important research. A special thank you goes to the nurses within the Vascular Assessment and Management Service and to Karen Turner, Julieta Woosley, and Anna Dean for their efforts in data collecting and ensuring protocol adherence.

Disclosure

Griffith University has received unrestricted, investigator-initiated research or educational grants to support the research of T. K., A. J. U., and C. R. M. from product manufacturers 3M, Adhezion Inc, AngioDynamics, Bard Medical, Baxter, B. Braun Medical Inc, Becton Dickinson, CareFusion, Centurion Medical Products, Cook Medical, Entrotech, FloMedical, ICU Medical Inc, Medical Australia Limited, Medtronic, Smiths Medical, and Teleflex. Griffith University has received consultancy payments on behalf of C. R. M., A. J. U., and T. K. from manufacturers 3M, AngioDynamics, Bard Medical, B. Braun Medical Inc, Becton Dickinson, CareFusion, Mayo Healthcare Inc, ResQDevices, and Smiths Medical. AngioDynamics (the BioFlo^® PICC manufacturer) provided partial funds to undertake this research via an unrestricted donation to Griffith University (but not the study authors). Queensland Health provided in-kind support to fund the remainder of the trial. The funders had no role in the study design, collection, analysis, or interpretation of the data, writing of the report, or decision to submit the article for publication.

Peripherally inserted central catheters (PICCs) have evolved since their inception in the early 1970s and are used with increasing frequency for pediatric inpatients and outpatients.^1-3 Emerging literature, including a meta-analysis of international observational studies,⁴ reports PICC failure (complications necessitating premature removal) occurs in up to 30% of PICCs, most commonly due to infection, thrombosis, occlusion, and fracture.^4-7 Raffini et al.⁷ report the increasing incidence of pediatric PICC-related thrombosis increases morbidity and mortality⁸ and negatively impacts future vessel health and preservation.⁹

PICCs have progressed from relatively simple, silicone-based catheters with an external clamp to chemically engineered polyurethane with pressure-activated valves placed at the proximal or distal catheter hub with the intent to reduce occlusion.¹⁰ Further modernization of PICC material occurred with the incorporation of antithrombogenic (AT) material (Endexo^®). These PICCs are designed to contain a nonstick polymer, which is designed to reduce the adherence of blood components (platelets and clotting factors) and inhibit thrombus formation (and hence prevent deep vein thrombosis andocclusion, as well as inhibit microbial biofilm attachment [and subsequent infection]).¹¹

In addition to new materials, other aspects of this PICC design have been the addition of a pressure-activated safety valve (PASV^®) built into the proximal hub. Pressure-activated valve technology promises to prevent catheter occlusion by reducing blood reflux into the PICC; the valve opens with pressure during infusion and aspiration and remains closed with normal venous pressure, circumventing the need for clinicians to manually clamp the PICC and reducing human error and the potential for thrombosis, occlusion, and fracture development.¹² Hoffer et al.¹³ reported half as many occlusions of valved PICCs (3.3%) compared with nonvalved or clamped PICCs (7.1%); although not statistically significant (P = .10), perhaps due to the small sample, overall complications, including occlusion and infection, were significantly lessened with the valved PICC (35% vs 79%; P = .02). Comparatively, Pittiruti et al.¹⁴ conducted a trial of 2 types of valved PICCs with an open-ended, nonvalved PICC and found no reduction in PICC occlusion or catheter malfunction.

Today, PICC use is common for patients who require short-to-medium intravenous therapy. PICCs are increasingly recognized for their significant complications, including thrombosis and infection.¹⁵ Novel PICC technology, including the incorporation of AT material such as Endexo^® and PASV^®, may reduce complications; however, the clinical efficacy, cost-effectiveness, and acceptability of these innovations have not been tested through randomized trials in pediatric patients. In accordance with Medical Research Council guidelines¹⁶ for developing interventions, we pilot tested the feasibility of the BioFlo^® PICC, including intervention acceptability, compliance, recruitment, and initial estimates of effect, in anticipation of a subsequent full-scale efficacy randomized controlled trial. Our secondary aim was to compare the effectiveness of the BioFlo^® PICC with Endexo^® and PASV^® technology in reducing PICC complications and failure.

Design

We undertook a pilot randomized controlled trial comparing the standard polyurethane PICC (with external clamp) with the BioFlo^® PICC (with internal valve) in preventing catheter failure in pediatric patients. The study was prospectively registered with the Australian Clinical Trials Registry (ACTRN12615001290583), and the research protocol was published.¹⁷

Study Setting

The study commenced in March 2016 at the Lady Cilento Children’s Hospital in South Brisbane, Australia, a tertiary-level, specialist, pediatric teaching hospital in Queensland, Australia, providing full-spectrum health services to children and young people from birth to 18 years of age. Recruitment, including data collection, was completed in November 2016.

Sample

The target sample size was 110 participants, 50 participants per group plus 10% for potential attrition, as determined by standard pilot trial sample size recommendations.¹⁸ With ethics approval, the sample size was later increased to 150 participants in order to adequately pilot a microbiological substudy method (published separately).¹⁷ Participants were consecutively recruited if they met the inclusion criteria: PICC insertion, age <18 years, predicted hospital stay >24 hours, single-lumen PICC, and written informed consent by an English-speaking, legal parent or guardian. Patients were excluded if they had a current (<48 hours) blood stream infection (BSI), vessel size <2 mm, could not speak English without an interpreter, required a multilumen PICC, or were previously enrolled in the study.

Interventions

Participants were randomized to receive either of the following PICCs: (1) standard care: Cook™ polyurethane, turbo-ject, power-injectable PICC (Cook Medical, Bloomington, IN) or (2) comparison: BioFlo^® polyurethane with Endexo^® technology (AngioDynamics Inc, Queensbury, NY).

Outcomes

The primary outcome was feasibility of a full-efficacy trial established by composite analysis of the elements of eligibility (>70% of patients will be eligible), recruitment (>70% of patients will agree to enroll), retention and attrition (<15% of participants are lost to follow-up or withdraw from the study), protocol adherence (>80% of participants receive their allocated, randomly assigned study product), missing data (<10% of data are missed during data collection), parent and healthcare staff satisfaction, and PICC failure effect size estimates to allow sample size calculations.^18,19 PICC failure was defined as the following complications associated with PICC removal: (1) catheter-associated BSI,^8,20-22 (2) local site infection,²² (3) venous thrombosis,²³ (4) occlusion,^24,25 (5) PICC fracture, or (6) PICC dislodgement.^25,26 Parents (or caregivers) and healthcare staff were asked to rate their level of confidence with the study product and ease of PICC removal by using a 0 to 100 numeric rating scale (NRS) of increasing confidence and/or ease. These data were collected at the time of PICC removal. Operators were also asked to rate their levels of satisfaction with the insertion equipment and ease of PICC insertion immediately upon completion of the insertion procedure (both 0-100 NRS of increasing satisfaction and/or ease). Secondary outcomes included individual PICC complications (eg, occlusion) occurring at any time point during the PICC dwell (including at removal), adverse events, pain, redness at the insertion site, and overall PICC dwell.

Study Procedures

The research nurse (ReN) screened operating theater lists for patients, obtained written informed consent, and initiated the randomization. Randomization was computer generated, and web based via Griffith University (https://www151.griffith.edu.au/random) to ensure allocation concealment until study entry. Patients were randomly assigned in a 1:1 ratio with computer-generated and randomly varied block sizes of 2 and 4. Data were collected by the ReN on the day of insertion, at day 1 postinsertion, then every 2 to 3 days thereafter so that PICCs were checked at least twice per week until study completion. Participants were included in the trial until 12 weeks post-PICC insertion, study withdrawal or PICC removal (whichever came first), with an additional 48 hours follow-up for infection outcomes. Patient review was face to face during the inpatient stay, with discharged patients’ follow-up occurring via outpatient clinics, hospital-in-the-home service, or telephone.

Data collection was via Research Electronic Data Capture (http://project-redcap.org/). The ReN collected data on primary and secondary outcomes by using the predefined criteria. Demographic and clinical data were collected to assess the success of randomization, describe the participant group, and display characteristics known to increase the risk of PICC complication and thrombosis. A blinded radiologist and infectious disease specialist reviewed and diagnosed thrombosis of deep veins and catheter-associated BSI outcomes, respectively.

PICC Procedures

Extensive prestudy education for 2 months prior to trial commencement was provided to all clinicians involved with the insertion and care of PICCs, including the study products. PICCs were inserted in an operating theater environment by a qualified consultant pediatric anesthetist, a senior anesthetic registrar or fellow in an approved anesthetic training program, or pediatric vascular access nurse practitioner. Ultrasound guidance was used to assess a patient’s vasculature and puncture the vessel. The operator chose the PICC size on the basis of clinical judgment of vessel size and patient needs and then inserted the allocated PICC.²⁷ Preferred PICC tip location was the cavoatrial junction. All PICC tip positions were confirmed with a chest x-ray before use.

Postinsertion, PICCs were managed by local interdisciplinary clinicians in accordance with local practice guidelines.^27-31 PICC care and management includes the use of 2% chlorhexidine gluconate in 70% alcohol for site antisepsis and neutral displacement needleless connectors (TUTA Pulse; Medical Australia Limited, Lidcombe, New South Wales, Australia); normal saline was used to flush after medication administration, and if the device was not in use for 6 hours or longer, heparin is instilled with securement via bordered polyurethane dressing (Tegaderm 1616; 3M, St Paul, Minnesota) and a sutureless securement device (Statlock VPPCSP; Bard, Georgia).

Statistical Analyses

Data were exported to Stata 15³² for cleaning and analysis. Data cleaning of outlying figures and missing and implausible data was undertaken prior to analysis. Missing data were not imputed. The PICC was the unit of measurement, and all randomly assigned patients were analyzed on an intention-to-treat basis.³³ Descriptive statistics (frequencies and percentages) were used to ascertain the primary outcome of feasibility for the larger trial. Incidence rates (per 1,000 catheter days) and rate ratios, including 95% confidence intervals (CIs), were calculated. The comparability of groups at baseline was described across demographic, clinical, and device characteristics. Kaplan-Meier survival curves (with log-rank tests) were used to compare PICC failure between study groups over time. Associations between baseline characteristics and failure were described by calculating hazard ratios (HRs). Univariable Cox regression was performed only due to the relatively low number of outcomes. P values of <.05 were considered statistically significant.

Ethics

The Children’s Health Service District, Queensland (Human Research Ethics Committee/15/QRCH/164), and Griffith University (2016/077) Human Research Ethics Committees provided ethics and governance approval. Informed consent was obtained from parents or legal guardians, with children providing youth assent if they were 7 years or older, dependent upon cognitive ability.

Participant and PICC Characteristics

Feasibility Outcomes

PICC Failure and Complications

DISCUSSION

This is the first pilot feasibility trial of new PICC materials and valve design incorporated in the BioFlo^® PICC in the pediatric population. The trial incorporated best practice for randomized trials, including using a concurrent control group, centralized and concealed randomization, predetermined feasibility criteria, and a registered and published trial protocol.¹⁷ As in other studies,^15,24,34 PICC failure and complication prevalence was unacceptably high for this essential device. Standard care PICCs failed twice as often as the new BioFlo^® PICCs (22% vs 11%), which is a clinically important difference. As researchers in a pilot study, we did not expect to detect statistically significant differences; however, we found that overall complications during the dwell occurred significantly more with the standard care than BioFlo^® PICCs (P = .009).

BioFlo^® PICC material offers a major advancement in PICC material through the incorporation of AT technologies into catheter materials, such as PICCs. Endexo^® is a low molecular–weight, fluoro-oligomeric additive that self-locates to the top few nanometers of the material surface. When added to power-injectable polyurethane, the additive results in a strong but passive, nonstick, fluorinated surface in the base PICC material. This inhibits platelet adhesion, suppresses protein procoagulant conformation, and thereby reduces thrombus formation in medical devices. Additionally, Endexo^® is not a catheter coating; rather, it is incorporated within the polyurethane of the PICC, thereby ensuring these AT properties are present on the internal, external, and cut surfaces of the PICC. If this technology can reduce complication during treatment and reduce failure from infection, thrombosis, occlusion, fracture, and dislodgement, it will improve patient outcomes considerably and lower health system costs. Previous studies investigating valve technology in PICC design to reduce occlusion have been inconclusive.^12-14,35,36 Occlusion (both partial and complete) was less frequent in our study with the BioFlo^® group (n = 3; 4%) compared to the standard care group (n = 6; 8%). The results of this pilot study suggest that either the Endexo^® material or PASV^® technology has a positive association with occlusion reduction during PICC treatment.

Thrombosis was the primary failure type for the standard care PICCs, comprising one-third of failures. All but one patient with radiologically confirmed thrombosis required the removal of the PICC prior to completion of treatment. The decision to remove the PICC or retain and treat conservatively remained with the treating team. Raffini et al.⁷ found thrombosis to increase in patients with one or more coexisting chronic medical condition. Slightly more standard care than BioFlo^® patients were free of such comorbidities (25% vs 16%), yet standard care patients still had the higher number of thromboses (7% vs 3%). Morgenthaler and Rodriguez³⁷ reported vascular access-associated thrombosis in pediatrics to be less common than in adults but higher in medically complex children. Worryingly, Menendez et al.³⁸ reported pediatric thrombosis to be largely asymptomatic, so the true incidence in our study is likely higher because only radiologically confirmed thromboses were recorded.

Occlusion (partial or complete) was the predominant complication across the study, being associated with one-third of all failures. When occlusion complications during the dwell (some of which were resolved with treatment), in addition to those causing failure, were considered, this number was even greater. Occlusion complications are prevalent and costly. Smith et al.²⁴ reported that occlusion was the most common reason for PICC removal and the most likely complication to delay treatment. Both the BioFlo^® and standard care PICCs are pressure rated with good tensile strength; however, fracture occurred in 4% (n = 3) of standard care PICCs compared to no fractures in BioFlo^® PICCs. Although the numbers are small, it may suggest a superior tensile strength of the BioFlo^® material.

This study reinforces previously published results^24,38 that PICC tip position is important and can influence complications, such as occlusion and thrombosis. In addition, we found a significant association with failure when PICCs did not have a continuous infusion. These findings reinforce the need for optimal tip location at insertion and ongoing flushing and maintenance of PICCs not used for infusions.

Limitations of this study include the small sample size, which was not designed to detect statistical differences in the primary outcome between groups. Despite randomization, there were slight imbalances at baseline for inserter type and leukocyte count, although these were not significantly associated with PICC failure in the Cox regression (data not shown), and thus were unlikely to influence findings. Additionally, a difference of <10% was associated with PICC tip position, favoring the BioFlo^® group. PICC tip position outside the cavoatrial junction was positively associated with failure; therefore, the effect of tip positioning on outcomes is difficult to ascertain given the small sample size and feasibility nature of the study. Further study is warranted to further explore this effect. The population sampled was pediatric medical and surgical inpatients with a vessel size >2 mm attending the operating theater suite for PICC insertion, thereby limiting the study’s generalizability to adults and other populations, including neonates and those with PICCs inserted in the pediatric intensive care unit. The study could not be blinded because study products had to be visible to the clinical and research staff. However, it is unlikely that staff would intentionally sabotage PICCs to bias the study. Blinding was possible for the assessment of blood culture and ultrasound reports to diagnose infection and thrombosis. Strengths of this study included 100% protocol adherence, and no patients were lost to follow-up.

These results confirm that PICC failure is unacceptably high and suggest that the innovative BioFlo^® PICC material and design holds promise to improve PICC outcomes by reducing complications and overall PICC failure. Trials of this technology are feasible, safe, and acceptable to healthcare staff and parents. Further trials are required, including in other patient populations, to definitively identify clinical, cost-effective methods to prevent PICC failure and improve reliability during treatment.

Acknowledgments

The authors thank the children and parents of Lady Cilento Children’s Hospital for participating in this important research. A special thank you goes to the nurses within the Vascular Assessment and Management Service and to Karen Turner, Julieta Woosley, and Anna Dean for their efforts in data collecting and ensuring protocol adherence.

Disclosure

Griffith University has received unrestricted, investigator-initiated research or educational grants to support the research of T. K., A. J. U., and C. R. M. from product manufacturers 3M, Adhezion Inc, AngioDynamics, Bard Medical, Baxter, B. Braun Medical Inc, Becton Dickinson, CareFusion, Centurion Medical Products, Cook Medical, Entrotech, FloMedical, ICU Medical Inc, Medical Australia Limited, Medtronic, Smiths Medical, and Teleflex. Griffith University has received consultancy payments on behalf of C. R. M., A. J. U., and T. K. from manufacturers 3M, AngioDynamics, Bard Medical, B. Braun Medical Inc, Becton Dickinson, CareFusion, Mayo Healthcare Inc, ResQDevices, and Smiths Medical. AngioDynamics (the BioFlo^® PICC manufacturer) provided partial funds to undertake this research via an unrestricted donation to Griffith University (but not the study authors). Queensland Health provided in-kind support to fund the remainder of the trial. The funders had no role in the study design, collection, analysis, or interpretation of the data, writing of the report, or decision to submit the article for publication.

Peripherally inserted central catheters (PICCs) have evolved since their inception in the early 1970s and are used with increasing frequency for pediatric inpatients and outpatients.^1-3 Emerging literature, including a meta-analysis of international observational studies,⁴ reports PICC failure (complications necessitating premature removal) occurs in up to 30% of PICCs, most commonly due to infection, thrombosis, occlusion, and fracture.^4-7 Raffini et al.⁷ report the increasing incidence of pediatric PICC-related thrombosis increases morbidity and mortality⁸ and negatively impacts future vessel health and preservation.⁹

PICCs have progressed from relatively simple, silicone-based catheters with an external clamp to chemically engineered polyurethane with pressure-activated valves placed at the proximal or distal catheter hub with the intent to reduce occlusion.¹⁰ Further modernization of PICC material occurred with the incorporation of antithrombogenic (AT) material (Endexo^®). These PICCs are designed to contain a nonstick polymer, which is designed to reduce the adherence of blood components (platelets and clotting factors) and inhibit thrombus formation (and hence prevent deep vein thrombosis andocclusion, as well as inhibit microbial biofilm attachment [and subsequent infection]).¹¹

In addition to new materials, other aspects of this PICC design have been the addition of a pressure-activated safety valve (PASV^®) built into the proximal hub. Pressure-activated valve technology promises to prevent catheter occlusion by reducing blood reflux into the PICC; the valve opens with pressure during infusion and aspiration and remains closed with normal venous pressure, circumventing the need for clinicians to manually clamp the PICC and reducing human error and the potential for thrombosis, occlusion, and fracture development.¹² Hoffer et al.¹³ reported half as many occlusions of valved PICCs (3.3%) compared with nonvalved or clamped PICCs (7.1%); although not statistically significant (P = .10), perhaps due to the small sample, overall complications, including occlusion and infection, were significantly lessened with the valved PICC (35% vs 79%; P = .02). Comparatively, Pittiruti et al.¹⁴ conducted a trial of 2 types of valved PICCs with an open-ended, nonvalved PICC and found no reduction in PICC occlusion or catheter malfunction.

Today, PICC use is common for patients who require short-to-medium intravenous therapy. PICCs are increasingly recognized for their significant complications, including thrombosis and infection.¹⁵ Novel PICC technology, including the incorporation of AT material such as Endexo^® and PASV^®, may reduce complications; however, the clinical efficacy, cost-effectiveness, and acceptability of these innovations have not been tested through randomized trials in pediatric patients. In accordance with Medical Research Council guidelines¹⁶ for developing interventions, we pilot tested the feasibility of the BioFlo^® PICC, including intervention acceptability, compliance, recruitment, and initial estimates of effect, in anticipation of a subsequent full-scale efficacy randomized controlled trial. Our secondary aim was to compare the effectiveness of the BioFlo^® PICC with Endexo^® and PASV^® technology in reducing PICC complications and failure.

Design

We undertook a pilot randomized controlled trial comparing the standard polyurethane PICC (with external clamp) with the BioFlo^® PICC (with internal valve) in preventing catheter failure in pediatric patients. The study was prospectively registered with the Australian Clinical Trials Registry (ACTRN12615001290583), and the research protocol was published.¹⁷

Study Setting

The study commenced in March 2016 at the Lady Cilento Children’s Hospital in South Brisbane, Australia, a tertiary-level, specialist, pediatric teaching hospital in Queensland, Australia, providing full-spectrum health services to children and young people from birth to 18 years of age. Recruitment, including data collection, was completed in November 2016.

Sample

The target sample size was 110 participants, 50 participants per group plus 10% for potential attrition, as determined by standard pilot trial sample size recommendations.¹⁸ With ethics approval, the sample size was later increased to 150 participants in order to adequately pilot a microbiological substudy method (published separately).¹⁷ Participants were consecutively recruited if they met the inclusion criteria: PICC insertion, age <18 years, predicted hospital stay >24 hours, single-lumen PICC, and written informed consent by an English-speaking, legal parent or guardian. Patients were excluded if they had a current (<48 hours) blood stream infection (BSI), vessel size <2 mm, could not speak English without an interpreter, required a multilumen PICC, or were previously enrolled in the study.

Interventions

Participants were randomized to receive either of the following PICCs: (1) standard care: Cook™ polyurethane, turbo-ject, power-injectable PICC (Cook Medical, Bloomington, IN) or (2) comparison: BioFlo^® polyurethane with Endexo^® technology (AngioDynamics Inc, Queensbury, NY).

Outcomes

The primary outcome was feasibility of a full-efficacy trial established by composite analysis of the elements of eligibility (>70% of patients will be eligible), recruitment (>70% of patients will agree to enroll), retention and attrition (<15% of participants are lost to follow-up or withdraw from the study), protocol adherence (>80% of participants receive their allocated, randomly assigned study product), missing data (<10% of data are missed during data collection), parent and healthcare staff satisfaction, and PICC failure effect size estimates to allow sample size calculations.^18,19 PICC failure was defined as the following complications associated with PICC removal: (1) catheter-associated BSI,^8,20-22 (2) local site infection,²² (3) venous thrombosis,²³ (4) occlusion,^24,25 (5) PICC fracture, or (6) PICC dislodgement.^25,26 Parents (or caregivers) and healthcare staff were asked to rate their level of confidence with the study product and ease of PICC removal by using a 0 to 100 numeric rating scale (NRS) of increasing confidence and/or ease. These data were collected at the time of PICC removal. Operators were also asked to rate their levels of satisfaction with the insertion equipment and ease of PICC insertion immediately upon completion of the insertion procedure (both 0-100 NRS of increasing satisfaction and/or ease). Secondary outcomes included individual PICC complications (eg, occlusion) occurring at any time point during the PICC dwell (including at removal), adverse events, pain, redness at the insertion site, and overall PICC dwell.

Study Procedures

The research nurse (ReN) screened operating theater lists for patients, obtained written informed consent, and initiated the randomization. Randomization was computer generated, and web based via Griffith University (https://www151.griffith.edu.au/random) to ensure allocation concealment until study entry. Patients were randomly assigned in a 1:1 ratio with computer-generated and randomly varied block sizes of 2 and 4. Data were collected by the ReN on the day of insertion, at day 1 postinsertion, then every 2 to 3 days thereafter so that PICCs were checked at least twice per week until study completion. Participants were included in the trial until 12 weeks post-PICC insertion, study withdrawal or PICC removal (whichever came first), with an additional 48 hours follow-up for infection outcomes. Patient review was face to face during the inpatient stay, with discharged patients’ follow-up occurring via outpatient clinics, hospital-in-the-home service, or telephone.

Data collection was via Research Electronic Data Capture (http://project-redcap.org/). The ReN collected data on primary and secondary outcomes by using the predefined criteria. Demographic and clinical data were collected to assess the success of randomization, describe the participant group, and display characteristics known to increase the risk of PICC complication and thrombosis. A blinded radiologist and infectious disease specialist reviewed and diagnosed thrombosis of deep veins and catheter-associated BSI outcomes, respectively.

PICC Procedures

Extensive prestudy education for 2 months prior to trial commencement was provided to all clinicians involved with the insertion and care of PICCs, including the study products. PICCs were inserted in an operating theater environment by a qualified consultant pediatric anesthetist, a senior anesthetic registrar or fellow in an approved anesthetic training program, or pediatric vascular access nurse practitioner. Ultrasound guidance was used to assess a patient’s vasculature and puncture the vessel. The operator chose the PICC size on the basis of clinical judgment of vessel size and patient needs and then inserted the allocated PICC.²⁷ Preferred PICC tip location was the cavoatrial junction. All PICC tip positions were confirmed with a chest x-ray before use.

Postinsertion, PICCs were managed by local interdisciplinary clinicians in accordance with local practice guidelines.^27-31 PICC care and management includes the use of 2% chlorhexidine gluconate in 70% alcohol for site antisepsis and neutral displacement needleless connectors (TUTA Pulse; Medical Australia Limited, Lidcombe, New South Wales, Australia); normal saline was used to flush after medication administration, and if the device was not in use for 6 hours or longer, heparin is instilled with securement via bordered polyurethane dressing (Tegaderm 1616; 3M, St Paul, Minnesota) and a sutureless securement device (Statlock VPPCSP; Bard, Georgia).

Statistical Analyses

Data were exported to Stata 15³² for cleaning and analysis. Data cleaning of outlying figures and missing and implausible data was undertaken prior to analysis. Missing data were not imputed. The PICC was the unit of measurement, and all randomly assigned patients were analyzed on an intention-to-treat basis.³³ Descriptive statistics (frequencies and percentages) were used to ascertain the primary outcome of feasibility for the larger trial. Incidence rates (per 1,000 catheter days) and rate ratios, including 95% confidence intervals (CIs), were calculated. The comparability of groups at baseline was described across demographic, clinical, and device characteristics. Kaplan-Meier survival curves (with log-rank tests) were used to compare PICC failure between study groups over time. Associations between baseline characteristics and failure were described by calculating hazard ratios (HRs). Univariable Cox regression was performed only due to the relatively low number of outcomes. P values of <.05 were considered statistically significant.

Ethics

The Children’s Health Service District, Queensland (Human Research Ethics Committee/15/QRCH/164), and Griffith University (2016/077) Human Research Ethics Committees provided ethics and governance approval. Informed consent was obtained from parents or legal guardians, with children providing youth assent if they were 7 years or older, dependent upon cognitive ability.

Participant and PICC Characteristics

Feasibility Outcomes

PICC Failure and Complications

DISCUSSION

This is the first pilot feasibility trial of new PICC materials and valve design incorporated in the BioFlo^® PICC in the pediatric population. The trial incorporated best practice for randomized trials, including using a concurrent control group, centralized and concealed randomization, predetermined feasibility criteria, and a registered and published trial protocol.¹⁷ As in other studies,^15,24,34 PICC failure and complication prevalence was unacceptably high for this essential device. Standard care PICCs failed twice as often as the new BioFlo^® PICCs (22% vs 11%), which is a clinically important difference. As researchers in a pilot study, we did not expect to detect statistically significant differences; however, we found that overall complications during the dwell occurred significantly more with the standard care than BioFlo^® PICCs (P = .009).

BioFlo^® PICC material offers a major advancement in PICC material through the incorporation of AT technologies into catheter materials, such as PICCs. Endexo^® is a low molecular–weight, fluoro-oligomeric additive that self-locates to the top few nanometers of the material surface. When added to power-injectable polyurethane, the additive results in a strong but passive, nonstick, fluorinated surface in the base PICC material. This inhibits platelet adhesion, suppresses protein procoagulant conformation, and thereby reduces thrombus formation in medical devices. Additionally, Endexo^® is not a catheter coating; rather, it is incorporated within the polyurethane of the PICC, thereby ensuring these AT properties are present on the internal, external, and cut surfaces of the PICC. If this technology can reduce complication during treatment and reduce failure from infection, thrombosis, occlusion, fracture, and dislodgement, it will improve patient outcomes considerably and lower health system costs. Previous studies investigating valve technology in PICC design to reduce occlusion have been inconclusive.^12-14,35,36 Occlusion (both partial and complete) was less frequent in our study with the BioFlo^® group (n = 3; 4%) compared to the standard care group (n = 6; 8%). The results of this pilot study suggest that either the Endexo^® material or PASV^® technology has a positive association with occlusion reduction during PICC treatment.

Thrombosis was the primary failure type for the standard care PICCs, comprising one-third of failures. All but one patient with radiologically confirmed thrombosis required the removal of the PICC prior to completion of treatment. The decision to remove the PICC or retain and treat conservatively remained with the treating team. Raffini et al.⁷ found thrombosis to increase in patients with one or more coexisting chronic medical condition. Slightly more standard care than BioFlo^® patients were free of such comorbidities (25% vs 16%), yet standard care patients still had the higher number of thromboses (7% vs 3%). Morgenthaler and Rodriguez³⁷ reported vascular access-associated thrombosis in pediatrics to be less common than in adults but higher in medically complex children. Worryingly, Menendez et al.³⁸ reported pediatric thrombosis to be largely asymptomatic, so the true incidence in our study is likely higher because only radiologically confirmed thromboses were recorded.

Occlusion (partial or complete) was the predominant complication across the study, being associated with one-third of all failures. When occlusion complications during the dwell (some of which were resolved with treatment), in addition to those causing failure, were considered, this number was even greater. Occlusion complications are prevalent and costly. Smith et al.²⁴ reported that occlusion was the most common reason for PICC removal and the most likely complication to delay treatment. Both the BioFlo^® and standard care PICCs are pressure rated with good tensile strength; however, fracture occurred in 4% (n = 3) of standard care PICCs compared to no fractures in BioFlo^® PICCs. Although the numbers are small, it may suggest a superior tensile strength of the BioFlo^® material.

This study reinforces previously published results^24,38 that PICC tip position is important and can influence complications, such as occlusion and thrombosis. In addition, we found a significant association with failure when PICCs did not have a continuous infusion. These findings reinforce the need for optimal tip location at insertion and ongoing flushing and maintenance of PICCs not used for infusions.

Limitations of this study include the small sample size, which was not designed to detect statistical differences in the primary outcome between groups. Despite randomization, there were slight imbalances at baseline for inserter type and leukocyte count, although these were not significantly associated with PICC failure in the Cox regression (data not shown), and thus were unlikely to influence findings. Additionally, a difference of <10% was associated with PICC tip position, favoring the BioFlo^® group. PICC tip position outside the cavoatrial junction was positively associated with failure; therefore, the effect of tip positioning on outcomes is difficult to ascertain given the small sample size and feasibility nature of the study. Further study is warranted to further explore this effect. The population sampled was pediatric medical and surgical inpatients with a vessel size >2 mm attending the operating theater suite for PICC insertion, thereby limiting the study’s generalizability to adults and other populations, including neonates and those with PICCs inserted in the pediatric intensive care unit. The study could not be blinded because study products had to be visible to the clinical and research staff. However, it is unlikely that staff would intentionally sabotage PICCs to bias the study. Blinding was possible for the assessment of blood culture and ultrasound reports to diagnose infection and thrombosis. Strengths of this study included 100% protocol adherence, and no patients were lost to follow-up.

These results confirm that PICC failure is unacceptably high and suggest that the innovative BioFlo^® PICC material and design holds promise to improve PICC outcomes by reducing complications and overall PICC failure. Trials of this technology are feasible, safe, and acceptable to healthcare staff and parents. Further trials are required, including in other patient populations, to definitively identify clinical, cost-effective methods to prevent PICC failure and improve reliability during treatment.

Acknowledgments

The authors thank the children and parents of Lady Cilento Children’s Hospital for participating in this important research. A special thank you goes to the nurses within the Vascular Assessment and Management Service and to Karen Turner, Julieta Woosley, and Anna Dean for their efforts in data collecting and ensuring protocol adherence.

Disclosure

Griffith University has received unrestricted, investigator-initiated research or educational grants to support the research of T. K., A. J. U., and C. R. M. from product manufacturers 3M, Adhezion Inc, AngioDynamics, Bard Medical, Baxter, B. Braun Medical Inc, Becton Dickinson, CareFusion, Centurion Medical Products, Cook Medical, Entrotech, FloMedical, ICU Medical Inc, Medical Australia Limited, Medtronic, Smiths Medical, and Teleflex. Griffith University has received consultancy payments on behalf of C. R. M., A. J. U., and T. K. from manufacturers 3M, AngioDynamics, Bard Medical, B. Braun Medical Inc, Becton Dickinson, CareFusion, Mayo Healthcare Inc, ResQDevices, and Smiths Medical. AngioDynamics (the BioFlo^® PICC manufacturer) provided partial funds to undertake this research via an unrestricted donation to Griffith University (but not the study authors). Queensland Health provided in-kind support to fund the remainder of the trial. The funders had no role in the study design, collection, analysis, or interpretation of the data, writing of the report, or decision to submit the article for publication.

Peripheral intravenous catheter (PIV) insertion is the fastest, simplest, and most cost-effective method to gain vascular access, and it is used for short-term intravenous (IV) fluids, medications, blood products, and contrast media.¹ It is the most common invasive device in hospitalized patients,² with up to 70% of hospital patients receiving a PIV.³ Unacceptable PIV failure rates have been reported as high as 69%.^4-7 Failure is most frequently due to phlebitis (vein wall irritation/inflammation), occlusion (blockage), infiltration or extravasation (IV fluids/vesicant therapy entering surrounding tissue), partial dislodgement or accidental removal, leakage, and infection.^4,6,8 These failures have important implications for patients, who endure the discomfort of PIV complications and catheter replacements, and healthcare staff and budgets.

To reduce the incidence of catheter failure and avoid preventable PIV replacements, a clear understanding of why catheters fail is required. Previous research has identified that catheter gauge,^9-11 insertion site,^12-14 and inserter skill^10,15 have an impact on PIV failure. Limitations of existing research are small study sizes,^16-18 retrospective design,¹⁹ or secondary analysis of an existing data set; all potentially introduce sampling bias.^10,20

To overcome these potential biases, we developed a data collection instrument based on the catheter-associated risk factors described in the literature,^9-11,13 and other potential insertion and maintenance risks for PIV failure (eg, multiple insertion attempts, medications administered), with data collected prospectively. The study aim was to improve patient outcomes by identifying PIV insertion and maintenance risk factors amenable to modification through education or alternative clinical interventions, such as catheter gauge selection or insertion site.

Study Design and Participants

We conducted this prospective cohort study in a large tertiary hospital in Queensland, Australia. Ethics committee approval was obtained from the hospital (HREC/14/QRBW/76) and Griffith University (NRS/26/14/HREC). The study was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12615000738527). Patients in medical and surgical wards were screened Monday, Wednesday, and Friday between October 2014 and December 2015. Patients over 18 years with a PIV (BD Insyte^TM Autoguard^TM BC; Becton Dickinson, Franklin Lakes, NJ) inserted within 24 hours, and who were able to provide written informed consent, were eligible and recruited sequentially. Patients classified as palliative by the treating clinical team were excluded.

Sample Size Calculation

The “10 events per variable” rule was used to determine the sample size required to study 50 potential risk factors.^21,22 This determined that 1000 patients, with an average of 1.5 PIVs each and an expected PIV failure of 30% (500 events), were required.

Data Collection

At recruitment, baseline patient information was collected by a research nurse (ReNs) (demographics, admitting diagnosis, comorbidities, skin type,²³ and vein condition) and entered into an electronic data platform supported by Research Electronic Data Capture (REDCap).²⁴ Baseline data also included catheter variables (eg, gauge, insertion site, catheterized vein) and insertion details (eg, department of insertion, inserting clinician, number of insertion attempts). We included every PIV the participant had during their admission until hospital discharge or insertion of a central venous access device. PIV sites were reviewed Monday, Wednesday, and Friday by ReNs for site complications (eg, redness, pain, swelling, palpable cord). Potential risk factors for failure were also recorded (eg, infusates and additives, antibiotic type and dosage, flushing regimen, number of times the PIV was accessed each day for administration of IV medications or fluids, dressing type and condition, securement method for the catheter and tubing, presence of extension tubing or 3-way taps, patient mobility status, and delirium). A project manager trained and supervised ReNs for protocol compliance and audited study data quality. We considered PIV failure to have occurred if the catheter had complications at removal identified by the ReNs assessment, from medical charts, or by speaking to the patient and beside nurse. We grouped the failures in 1 of 3 types: (1) occlusion or infiltration, defined as blockage, IV fluids moving into surrounding tissue, induration, or swelling greater than 1 cm from the insertion site at or within 24 hours of removal; (2) phlebitis, defined as per clinicians’ definitions or one or more of the following signs and symptoms: pain or tenderness scored at 2 or more on a 1 to 10 increasing severity pain scale, or redness or a palpable cord (either extending greater than 1 cm from the insertion site) at or within 24 hours of PIV removal; and (3) dislodgement (partial or complete). If multiple complications were present, all were recorded.

Statistical Analysis

Data were downloaded from REDcap to Stata 14.2 (StataCorp., College Station, TX) for data management and analysis. Missing data were not imputed. Nominal data observations were collapsed into a single observation per device. Patient and device variables were described as frequencies and proportions, means and standard deviations, or medians and interquartile ranges. Failure incidence rates were calculated, and a Kaplan-Meier survival curve was plotted. In general, Cox proportional hazards models were fitted (Efron method) to handle tied failures (clustering by patient). Variables significant at P < 0.20 on univariable analyses were subjected to multivariable regression. Generally, the largest category was set as referent. Correlations between variables were checked (Spearman’s rank for binary variables, R-squared value of linear regressions for continuous/categorical or continuous/continuous variables). Correlations were considered significant if r > 0.5 and the lower bound of the 95% confidence interval (CI) was >0.5 (where calculated). Covariate interactions were explored, and effects at P < 0.05 noted. The 4 steps of multivariable model building were (1) baseline covariates only with manual stepwise removal of covariates at P ≥ 0.05, (2) treatment covariates only with manual stepwise removal of covariates at P ≥ 0.05, (3) a combination of the derived models from (1) and (2) and manual stepwise removal of covariates at P ≥ 0.05, and (4) manual stepwise addition and removal (at P ≥ 0.05) of variables dropped during the previous steps and interaction testing. Final models were checked as follows: global proportional-hazards assumption test, concordance probability (that predictions and outcomes were in agreement), and Nelson-Aalen cumulative hazard function plotted against the Cox-Snell residuals.

Patient Characteristics

In total, 1000 patients with 1578 PIVs were recruited. The average age was 54 years and the majority were surgical patients (673; 67%). Almost half of patients (455; 46%) had 2 or more comorbidities, and 334 (33%) were obese (body mass index greater than 30). Sample characteristics are shown by the type of catheter failure in Table 1.

PIV Characteristics

All 1578 PIVs were followed until removal, with only 7 PIVs (0.44%) having missing data for the 3 outcomes of interest (these were coded as nonfailures for analysis). Sixty percent of participants had more than 1 PIV followed in the study. Doctors and physicians inserted 1278 (83%) catheters. A total of 550 (35%) were placed in the ward, with 428 (28%) inserted in the emergency department or ambulance. A third of the catheters (540; 34%) were 18-gauge or larger in diameter, and 1000 (64%) were located in the cubital fossa or hand. Multiple insertion attempts were required to place 315 (23%) PIVs. No PIVs were inserted with ultrasound, as this is rarely used in this hospital. The flushing policy was for the administration of 9% sodium chloride every 8 hours if no IV medications or fluids were ordered. Table 2 contains further details of device-related characteristics. Although the hospital policy was for catheter removal by 72 hours, dwell time ranged from <1 to 14 days, with an average of 2.4 days.

PIV Complications

Catheter failure (any cause) occurred in 512 (32%) catheters, which is a failure rate of 136 per 1000 catheter days (95% CI, 125-148). A total of 346 patients out of 1000 (35%) had at least 1 failed PIV during the study. Failures were 267 phlebitis (17%), 228 occlusion/infiltration (14%), and/or 154 dislodgement (10%; Figure), with some PIVs exhibiting multiple concurrent complications (Table 2).

Multivariable AnalysisOcclusion/Infiltration

The multivariable analysis (Table 3) showed occlusion or infiltration was statistically significantly associated with female patients (hazard ratio [HR], 1.48; 95% CI, 1.10-2.00), with a 22-gauge catheter (HR, 1.43; 95% CI, 1.02-2.00), IV flucloxacillin (HR, 1.98; 95% CI, 1.19-3.31), and with frequent PIV access (HR, 1.12; 95% CI, 1.04-1.21; ie, with each increase of 1 in the mean medications/fluids administrations per day, relative PIV failure increased 112%). Less occlusion and infiltration were statistically significantly associated with securement by using additional nonsterile tape (HR, 0.46; 95% CI, 0.33-0.63), elasticized tubular bandages (HR, 0.49; 95% CI, 0.35-0.70 ), or other types of additional securement for the PIV (HR, 0.35; 95% CI, 0.26-0.47).

Phlebitis

Phlebitis was statistically significantly associated with female patients (HR, 1.81; 95% CI, 1.40-2.35), bruising at the insertion site (HR, 2.16; 95% CI, 1.26-3.71), insertion in patients’ dominant side (HR, 1.39; 95% CI, 1.09-1.77), IV flucloxicillin (HR, 2.01; 95% CI, 1.26-3.21), or with frequent PIV access (HR, 1.14; 95% CI, 1.08-1.21). Older age, (HR, 0.99; 95% CI, 0.98-0.99; ie, each year older was associated with 1% less phlebitis), securement with additional nonsterile tape (HR, 0.63; 95% CI, 0.48-0.82) or with any other additional securement (HR, 0.53; 95% CI, 0.39-0.70), or the administration of IV cephazolin (HR, 0.63; 95% CI, 0.44-0.89) were associated with lower phlebitis risk.

Dislodgement

Statistically significant predictors associated with an increased risk of PIV dislodgement included paramedic insertion (HR, 1.78; 95% CI, 1.03-3.06) and frequent PIV access (HR, 1.11; 95% CI, 1.03-1.20). A decreased risk was associated with the additional securement of the PIV, including nonsterile tape (HR, 0.44; 95% CI, 0.31-0.63) or other forms of additional securement (HR, 0.32; 95% CI, 0.22-0.46).

One in 3 PIVs failed in this study, with phlebitis as the most common cause of PIV failure. The 17% phlebitis rate reflected clinician-reported phlebitis or phlebitis observed by research staff using a 1-criteria definition because any sign or symptom can trigger PIV removal (eg, pain), even if other signs or symptoms are not present. Reported phlebitis rates are lower if definitions require 2 signs or symptoms.^4,6 With over 71 different phlebitis assessment scales in use, and none well validated, the best method for diagnosing phlebitis remains unclear and explains the variation in reported rates.²⁵ Occlusion/infiltration and dislodgement were also highly prevalent forms of PIV failure at 14% and 10%, respectively. Occlusion and infiltration were combined because clinical staff use these terms interchangeably, and differential diagnostic tools are not used in practice. Both result in the same outcome (therapy interruption and PIV removal), and this combination of outcomes has been used previously.²³ No PIV-associated bloodstream infections occurred, despite the heightened awareness of these infections in the literature.³

Females had significantly more occlusion/infiltration and phlebitis than males, in keeping with previous studies.^7,9,10 This could be because of females’ smaller vein caliber, although the effect remained after adjustment for PIV gauge.^7,26 The effect of aging on vascular endothelium and structural integrity may explain the observed decrease in phlebitis of 1% with each older year of age.²⁷ However, gender and age effects could be explained by psychosocial factors (eg, older people may be less likely to admit pain, or we may question them less sympathetically), but, regardless, women and younger patients should be monitored more closely.

We found 22-gauge catheters were more likely to fail from occlusion/infiltration than other sizes. This confirms similar findings from Abolfotouh et al.⁹ PIV gauge selection for this study was made at the inserter’s discretion and may be confounded by smaller vein size, which was not measured. In addition, risk may be because of smaller gauge alone or also more influenced by the shorter length of the studied 22-gauge (25 mm) than the <20-gauge catheters (30 mm). These results question international guidelines, which currently recommend the smallest gauge peripheral catheter possible,^28,29 and randomized trials are needed. Although practice varies between inserters, some preferentially cannulate the nondominant limb. We are not aware of previous studies on this practice; however, our results support this approach.

Flucloxacillin was associated with a 2-fold increase in occlusion/infiltration and phlebitis. Although multiple studies have reported IV medications^9,11 and IV antibiotics^10,30,31 as risk factors for PIV failure, none have identified flucloxacillin as an independent risk factor. IV flucloxacillin is recommended for reconstitution as 1 g in 15 mL to 20 mL of sterile water, and injection over 3 to 4 minutes, although this may not be adhered to in practice. Alternative administration regimes or improved adherence to current policy may be needed. An exception to the relationship between IV antibiotics and catheter failure was IV cephazolin, associated with 40% relatively less phlebitis. This may be a spurious finding because the administration, pH, and osmolality of cephazolin are similar to other IV antibiotics.

The more PIVs that were accessed per day, whether for infusions or medications, the more failure occurred from occlusion/infiltration, phlebitis, and dislodgement. This suggests that peripheral veins are easily damaged and/or inflamed by the influx of fluids or medications. Lower injection pressures or the timely transfer to oral medications may limit this problem. Flushing regimens may also assist because practice varies greatly, and questions on whether slow continuous flush infusion or intermittent manual flushing are more vein-protective, and the optimal flush volume, frequency, and technique (eg, pulsatile) remain.^32,33 Manual handling for frequent access may loosen dressings and securement, thus explaining the observed association between frequent access and catheter dislodgement. Finally, the association between use and failure may indicate that many of these patients were not suitable for a PIV, and different approaches (eg, ultrasound-guided insertion) or a midline may have been a superior option. There is growing emphasis on the need for better preinsertion assessment and selection of the most appropriate device for the patient and the IV treatment required.³⁴

Suboptimal dressings or securements are not unusual in hospitals.³⁵ Despite our policy of PIV securement with bordered transparent dressings, we found 4 dressing types in use. In addition, we found almost 50% of PIVs had an additional (secondary) securement, and this was associated with significantly less PIV failure of all 3 types. This suggests that 1 or more of nonsterile tape, elasticized tubular bandages, or other securement (eg, bandage or second transparent dressing) can reduce PIV failure, although a randomized trial is lacking.³⁶ Whether the dressing was failing and required reinforcement or hospital staff lacked confidence in the dressing and placed additional securement preventatively is unclear. Both PIV failure and PIV dressing failure are common, and further research into superior PIV products and practices is urgently needed. Paramedic insertions had a higher risk of dislodgement, suggesting that the increased emphasis on securement should start in the prehospital setting.

While multiple or difficult insertion attempts were not associated with PIV failure, insertions were not directly observed, and clinicians may have underreported attempts. In contrast, insertion-related bruising (a surrogate for difficult insertion) was associated with more than double the incidence of phlebitis. The long-term implications of multiple insertion attempts on patient’s vasculature are unclear, but we believe first time PIV insertion is important to patients and of interest to clinicians. A recent systematic review of strategies associated with first attempt PIV insertion success in an emergency department found little evidence for effective strategies and recommended further research.³⁷

The overall PIV failure rate in our study was 32%, lower than the 35% to 40% failure observed in our previous randomized controlled trials, which had more stringent inclusion and exclusion criteria (eg, longer predicted duration of therapy).^6,38 The implications for patients and costs to the organization of frequent catheter replacement demonstrate urgent need for further research in this area of practice.³⁹ A strength of this study is that all PIVs, regardless of the expected length of dwell time or reason for insertion, were eligible for inclusion, providing more generalizable results. The PIV failure rate of 32% is concerning because these failures trigger treatment delays and replacement insertions, with significant increased labor and equipment costs. The mean cost of PIV replacement has been costed at AUD $69.30 or US $51.92 (as per 2010 $ value) per episode of IV treatment.⁴⁰ For our hospital, which uses 200,000 PIVs per year, the current level of PIV failure suggests almost AU $5.5 (US $4.1) million in waste annually at this site alone.

The additional strengths of this study include the extensive information collected prospectively about PIV insertion and maintenance, including information on who inserted the PIV, IV medications administered, and PIV dressings used. Limitations were the population of surgical and medical patients in 1 tertiary hospital, which may not be generalizable to other settings.

Our study confirms the high rate of catheter failure in acute care hospitals, validates existing evidence related to PIV failure, and identifies new, potentially modifiable risk factors to improve PIV insertion and management. Implications for future research were also identified.

Acknowledgments

The researchers acknowledge and thank the nurses and patients involved in this study. The authors would also like to acknowledge Becton Dickinson for partly funding this study in the form of an unrestricted grant-in-aid paid to Griffith University. Becton Dickinson did not design the study protocol, collect or analyze data, and did not prepare or review the manuscript.

Disclosure

 On behalf of NM and CMR, Griffith University has received unrestricted educational and research grants and consultancy payment for lectures from 3M and Becton Dickinson. On behalf of NM, MC, and CMR, Griffith University has received unrestricted investigator-initiated research grants from Centurion Medical Products and Entrotech Lifesciences (manufacturers of PIV dressings) and Becton Dickinson (manufacturer of PIVs). On behalf of MC, Griffith University has received a consultancy payment to develop education material from Baxter. On behalf of CMR, Griffith University has received unrestricted donations or investigator initiated research grants unrelated to this research from Adhezion, Angiodynamics, Baxter, Carefusion, Cook Medical, Hospira, Mayo, Smiths Medical, and Vygon. On behalf of CMR, Griffith University has received consultancy payments for educational lectures or professional opinion from B. Braun, Bard, Carefusion, Mayo, ResQDevices, and Smiths Medical. On behalf of EL, Griffith University has received consultancy payments for educational lecture from 3M. On behalf of MC, Griffith University has received a consultancy payment to develop education material from Baxter. As this was an observational study, no products were trialed in this study. JW and GM have no conflicts of interest.

Peripheral intravenous catheter (PIV) insertion is the fastest, simplest, and most cost-effective method to gain vascular access, and it is used for short-term intravenous (IV) fluids, medications, blood products, and contrast media.¹ It is the most common invasive device in hospitalized patients,² with up to 70% of hospital patients receiving a PIV.³ Unacceptable PIV failure rates have been reported as high as 69%.^4-7 Failure is most frequently due to phlebitis (vein wall irritation/inflammation), occlusion (blockage), infiltration or extravasation (IV fluids/vesicant therapy entering surrounding tissue), partial dislodgement or accidental removal, leakage, and infection.^4,6,8 These failures have important implications for patients, who endure the discomfort of PIV complications and catheter replacements, and healthcare staff and budgets.

To reduce the incidence of catheter failure and avoid preventable PIV replacements, a clear understanding of why catheters fail is required. Previous research has identified that catheter gauge,^9-11 insertion site,^12-14 and inserter skill^10,15 have an impact on PIV failure. Limitations of existing research are small study sizes,^16-18 retrospective design,¹⁹ or secondary analysis of an existing data set; all potentially introduce sampling bias.^10,20

To overcome these potential biases, we developed a data collection instrument based on the catheter-associated risk factors described in the literature,^9-11,13 and other potential insertion and maintenance risks for PIV failure (eg, multiple insertion attempts, medications administered), with data collected prospectively. The study aim was to improve patient outcomes by identifying PIV insertion and maintenance risk factors amenable to modification through education or alternative clinical interventions, such as catheter gauge selection or insertion site.

Study Design and Participants

We conducted this prospective cohort study in a large tertiary hospital in Queensland, Australia. Ethics committee approval was obtained from the hospital (HREC/14/QRBW/76) and Griffith University (NRS/26/14/HREC). The study was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12615000738527). Patients in medical and surgical wards were screened Monday, Wednesday, and Friday between October 2014 and December 2015. Patients over 18 years with a PIV (BD Insyte^TM Autoguard^TM BC; Becton Dickinson, Franklin Lakes, NJ) inserted within 24 hours, and who were able to provide written informed consent, were eligible and recruited sequentially. Patients classified as palliative by the treating clinical team were excluded.

Sample Size Calculation

The “10 events per variable” rule was used to determine the sample size required to study 50 potential risk factors.^21,22 This determined that 1000 patients, with an average of 1.5 PIVs each and an expected PIV failure of 30% (500 events), were required.

Data Collection

At recruitment, baseline patient information was collected by a research nurse (ReNs) (demographics, admitting diagnosis, comorbidities, skin type,²³ and vein condition) and entered into an electronic data platform supported by Research Electronic Data Capture (REDCap).²⁴ Baseline data also included catheter variables (eg, gauge, insertion site, catheterized vein) and insertion details (eg, department of insertion, inserting clinician, number of insertion attempts). We included every PIV the participant had during their admission until hospital discharge or insertion of a central venous access device. PIV sites were reviewed Monday, Wednesday, and Friday by ReNs for site complications (eg, redness, pain, swelling, palpable cord). Potential risk factors for failure were also recorded (eg, infusates and additives, antibiotic type and dosage, flushing regimen, number of times the PIV was accessed each day for administration of IV medications or fluids, dressing type and condition, securement method for the catheter and tubing, presence of extension tubing or 3-way taps, patient mobility status, and delirium). A project manager trained and supervised ReNs for protocol compliance and audited study data quality. We considered PIV failure to have occurred if the catheter had complications at removal identified by the ReNs assessment, from medical charts, or by speaking to the patient and beside nurse. We grouped the failures in 1 of 3 types: (1) occlusion or infiltration, defined as blockage, IV fluids moving into surrounding tissue, induration, or swelling greater than 1 cm from the insertion site at or within 24 hours of removal; (2) phlebitis, defined as per clinicians’ definitions or one or more of the following signs and symptoms: pain or tenderness scored at 2 or more on a 1 to 10 increasing severity pain scale, or redness or a palpable cord (either extending greater than 1 cm from the insertion site) at or within 24 hours of PIV removal; and (3) dislodgement (partial or complete). If multiple complications were present, all were recorded.

Statistical Analysis

Data were downloaded from REDcap to Stata 14.2 (StataCorp., College Station, TX) for data management and analysis. Missing data were not imputed. Nominal data observations were collapsed into a single observation per device. Patient and device variables were described as frequencies and proportions, means and standard deviations, or medians and interquartile ranges. Failure incidence rates were calculated, and a Kaplan-Meier survival curve was plotted. In general, Cox proportional hazards models were fitted (Efron method) to handle tied failures (clustering by patient). Variables significant at P < 0.20 on univariable analyses were subjected to multivariable regression. Generally, the largest category was set as referent. Correlations between variables were checked (Spearman’s rank for binary variables, R-squared value of linear regressions for continuous/categorical or continuous/continuous variables). Correlations were considered significant if r > 0.5 and the lower bound of the 95% confidence interval (CI) was >0.5 (where calculated). Covariate interactions were explored, and effects at P < 0.05 noted. The 4 steps of multivariable model building were (1) baseline covariates only with manual stepwise removal of covariates at P ≥ 0.05, (2) treatment covariates only with manual stepwise removal of covariates at P ≥ 0.05, (3) a combination of the derived models from (1) and (2) and manual stepwise removal of covariates at P ≥ 0.05, and (4) manual stepwise addition and removal (at P ≥ 0.05) of variables dropped during the previous steps and interaction testing. Final models were checked as follows: global proportional-hazards assumption test, concordance probability (that predictions and outcomes were in agreement), and Nelson-Aalen cumulative hazard function plotted against the Cox-Snell residuals.

Patient Characteristics

In total, 1000 patients with 1578 PIVs were recruited. The average age was 54 years and the majority were surgical patients (673; 67%). Almost half of patients (455; 46%) had 2 or more comorbidities, and 334 (33%) were obese (body mass index greater than 30). Sample characteristics are shown by the type of catheter failure in Table 1.

PIV Characteristics

All 1578 PIVs were followed until removal, with only 7 PIVs (0.44%) having missing data for the 3 outcomes of interest (these were coded as nonfailures for analysis). Sixty percent of participants had more than 1 PIV followed in the study. Doctors and physicians inserted 1278 (83%) catheters. A total of 550 (35%) were placed in the ward, with 428 (28%) inserted in the emergency department or ambulance. A third of the catheters (540; 34%) were 18-gauge or larger in diameter, and 1000 (64%) were located in the cubital fossa or hand. Multiple insertion attempts were required to place 315 (23%) PIVs. No PIVs were inserted with ultrasound, as this is rarely used in this hospital. The flushing policy was for the administration of 9% sodium chloride every 8 hours if no IV medications or fluids were ordered. Table 2 contains further details of device-related characteristics. Although the hospital policy was for catheter removal by 72 hours, dwell time ranged from <1 to 14 days, with an average of 2.4 days.

PIV Complications

Catheter failure (any cause) occurred in 512 (32%) catheters, which is a failure rate of 136 per 1000 catheter days (95% CI, 125-148). A total of 346 patients out of 1000 (35%) had at least 1 failed PIV during the study. Failures were 267 phlebitis (17%), 228 occlusion/infiltration (14%), and/or 154 dislodgement (10%; Figure), with some PIVs exhibiting multiple concurrent complications (Table 2).

Multivariable AnalysisOcclusion/Infiltration

The multivariable analysis (Table 3) showed occlusion or infiltration was statistically significantly associated with female patients (hazard ratio [HR], 1.48; 95% CI, 1.10-2.00), with a 22-gauge catheter (HR, 1.43; 95% CI, 1.02-2.00), IV flucloxacillin (HR, 1.98; 95% CI, 1.19-3.31), and with frequent PIV access (HR, 1.12; 95% CI, 1.04-1.21; ie, with each increase of 1 in the mean medications/fluids administrations per day, relative PIV failure increased 112%). Less occlusion and infiltration were statistically significantly associated with securement by using additional nonsterile tape (HR, 0.46; 95% CI, 0.33-0.63), elasticized tubular bandages (HR, 0.49; 95% CI, 0.35-0.70 ), or other types of additional securement for the PIV (HR, 0.35; 95% CI, 0.26-0.47).

Phlebitis

Phlebitis was statistically significantly associated with female patients (HR, 1.81; 95% CI, 1.40-2.35), bruising at the insertion site (HR, 2.16; 95% CI, 1.26-3.71), insertion in patients’ dominant side (HR, 1.39; 95% CI, 1.09-1.77), IV flucloxicillin (HR, 2.01; 95% CI, 1.26-3.21), or with frequent PIV access (HR, 1.14; 95% CI, 1.08-1.21). Older age, (HR, 0.99; 95% CI, 0.98-0.99; ie, each year older was associated with 1% less phlebitis), securement with additional nonsterile tape (HR, 0.63; 95% CI, 0.48-0.82) or with any other additional securement (HR, 0.53; 95% CI, 0.39-0.70), or the administration of IV cephazolin (HR, 0.63; 95% CI, 0.44-0.89) were associated with lower phlebitis risk.

Dislodgement

Statistically significant predictors associated with an increased risk of PIV dislodgement included paramedic insertion (HR, 1.78; 95% CI, 1.03-3.06) and frequent PIV access (HR, 1.11; 95% CI, 1.03-1.20). A decreased risk was associated with the additional securement of the PIV, including nonsterile tape (HR, 0.44; 95% CI, 0.31-0.63) or other forms of additional securement (HR, 0.32; 95% CI, 0.22-0.46).

One in 3 PIVs failed in this study, with phlebitis as the most common cause of PIV failure. The 17% phlebitis rate reflected clinician-reported phlebitis or phlebitis observed by research staff using a 1-criteria definition because any sign or symptom can trigger PIV removal (eg, pain), even if other signs or symptoms are not present. Reported phlebitis rates are lower if definitions require 2 signs or symptoms.^4,6 With over 71 different phlebitis assessment scales in use, and none well validated, the best method for diagnosing phlebitis remains unclear and explains the variation in reported rates.²⁵ Occlusion/infiltration and dislodgement were also highly prevalent forms of PIV failure at 14% and 10%, respectively. Occlusion and infiltration were combined because clinical staff use these terms interchangeably, and differential diagnostic tools are not used in practice. Both result in the same outcome (therapy interruption and PIV removal), and this combination of outcomes has been used previously.²³ No PIV-associated bloodstream infections occurred, despite the heightened awareness of these infections in the literature.³

Females had significantly more occlusion/infiltration and phlebitis than males, in keeping with previous studies.^7,9,10 This could be because of females’ smaller vein caliber, although the effect remained after adjustment for PIV gauge.^7,26 The effect of aging on vascular endothelium and structural integrity may explain the observed decrease in phlebitis of 1% with each older year of age.²⁷ However, gender and age effects could be explained by psychosocial factors (eg, older people may be less likely to admit pain, or we may question them less sympathetically), but, regardless, women and younger patients should be monitored more closely.

We found 22-gauge catheters were more likely to fail from occlusion/infiltration than other sizes. This confirms similar findings from Abolfotouh et al.⁹ PIV gauge selection for this study was made at the inserter’s discretion and may be confounded by smaller vein size, which was not measured. In addition, risk may be because of smaller gauge alone or also more influenced by the shorter length of the studied 22-gauge (25 mm) than the <20-gauge catheters (30 mm). These results question international guidelines, which currently recommend the smallest gauge peripheral catheter possible,^28,29 and randomized trials are needed. Although practice varies between inserters, some preferentially cannulate the nondominant limb. We are not aware of previous studies on this practice; however, our results support this approach.

Flucloxacillin was associated with a 2-fold increase in occlusion/infiltration and phlebitis. Although multiple studies have reported IV medications^9,11 and IV antibiotics^10,30,31 as risk factors for PIV failure, none have identified flucloxacillin as an independent risk factor. IV flucloxacillin is recommended for reconstitution as 1 g in 15 mL to 20 mL of sterile water, and injection over 3 to 4 minutes, although this may not be adhered to in practice. Alternative administration regimes or improved adherence to current policy may be needed. An exception to the relationship between IV antibiotics and catheter failure was IV cephazolin, associated with 40% relatively less phlebitis. This may be a spurious finding because the administration, pH, and osmolality of cephazolin are similar to other IV antibiotics.

The more PIVs that were accessed per day, whether for infusions or medications, the more failure occurred from occlusion/infiltration, phlebitis, and dislodgement. This suggests that peripheral veins are easily damaged and/or inflamed by the influx of fluids or medications. Lower injection pressures or the timely transfer to oral medications may limit this problem. Flushing regimens may also assist because practice varies greatly, and questions on whether slow continuous flush infusion or intermittent manual flushing are more vein-protective, and the optimal flush volume, frequency, and technique (eg, pulsatile) remain.^32,33 Manual handling for frequent access may loosen dressings and securement, thus explaining the observed association between frequent access and catheter dislodgement. Finally, the association between use and failure may indicate that many of these patients were not suitable for a PIV, and different approaches (eg, ultrasound-guided insertion) or a midline may have been a superior option. There is growing emphasis on the need for better preinsertion assessment and selection of the most appropriate device for the patient and the IV treatment required.³⁴

Suboptimal dressings or securements are not unusual in hospitals.³⁵ Despite our policy of PIV securement with bordered transparent dressings, we found 4 dressing types in use. In addition, we found almost 50% of PIVs had an additional (secondary) securement, and this was associated with significantly less PIV failure of all 3 types. This suggests that 1 or more of nonsterile tape, elasticized tubular bandages, or other securement (eg, bandage or second transparent dressing) can reduce PIV failure, although a randomized trial is lacking.³⁶ Whether the dressing was failing and required reinforcement or hospital staff lacked confidence in the dressing and placed additional securement preventatively is unclear. Both PIV failure and PIV dressing failure are common, and further research into superior PIV products and practices is urgently needed. Paramedic insertions had a higher risk of dislodgement, suggesting that the increased emphasis on securement should start in the prehospital setting.

While multiple or difficult insertion attempts were not associated with PIV failure, insertions were not directly observed, and clinicians may have underreported attempts. In contrast, insertion-related bruising (a surrogate for difficult insertion) was associated with more than double the incidence of phlebitis. The long-term implications of multiple insertion attempts on patient’s vasculature are unclear, but we believe first time PIV insertion is important to patients and of interest to clinicians. A recent systematic review of strategies associated with first attempt PIV insertion success in an emergency department found little evidence for effective strategies and recommended further research.³⁷

The overall PIV failure rate in our study was 32%, lower than the 35% to 40% failure observed in our previous randomized controlled trials, which had more stringent inclusion and exclusion criteria (eg, longer predicted duration of therapy).^6,38 The implications for patients and costs to the organization of frequent catheter replacement demonstrate urgent need for further research in this area of practice.³⁹ A strength of this study is that all PIVs, regardless of the expected length of dwell time or reason for insertion, were eligible for inclusion, providing more generalizable results. The PIV failure rate of 32% is concerning because these failures trigger treatment delays and replacement insertions, with significant increased labor and equipment costs. The mean cost of PIV replacement has been costed at AUD $69.30 or US $51.92 (as per 2010 $ value) per episode of IV treatment.⁴⁰ For our hospital, which uses 200,000 PIVs per year, the current level of PIV failure suggests almost AU $5.5 (US $4.1) million in waste annually at this site alone.

The additional strengths of this study include the extensive information collected prospectively about PIV insertion and maintenance, including information on who inserted the PIV, IV medications administered, and PIV dressings used. Limitations were the population of surgical and medical patients in 1 tertiary hospital, which may not be generalizable to other settings.

Our study confirms the high rate of catheter failure in acute care hospitals, validates existing evidence related to PIV failure, and identifies new, potentially modifiable risk factors to improve PIV insertion and management. Implications for future research were also identified.

Acknowledgments

The researchers acknowledge and thank the nurses and patients involved in this study. The authors would also like to acknowledge Becton Dickinson for partly funding this study in the form of an unrestricted grant-in-aid paid to Griffith University. Becton Dickinson did not design the study protocol, collect or analyze data, and did not prepare or review the manuscript.

Disclosure

 On behalf of NM and CMR, Griffith University has received unrestricted educational and research grants and consultancy payment for lectures from 3M and Becton Dickinson. On behalf of NM, MC, and CMR, Griffith University has received unrestricted investigator-initiated research grants from Centurion Medical Products and Entrotech Lifesciences (manufacturers of PIV dressings) and Becton Dickinson (manufacturer of PIVs). On behalf of MC, Griffith University has received a consultancy payment to develop education material from Baxter. On behalf of CMR, Griffith University has received unrestricted donations or investigator initiated research grants unrelated to this research from Adhezion, Angiodynamics, Baxter, Carefusion, Cook Medical, Hospira, Mayo, Smiths Medical, and Vygon. On behalf of CMR, Griffith University has received consultancy payments for educational lectures or professional opinion from B. Braun, Bard, Carefusion, Mayo, ResQDevices, and Smiths Medical. On behalf of EL, Griffith University has received consultancy payments for educational lecture from 3M. On behalf of MC, Griffith University has received a consultancy payment to develop education material from Baxter. As this was an observational study, no products were trialed in this study. JW and GM have no conflicts of interest.

Peripheral intravenous catheter (PIV) insertion is the fastest, simplest, and most cost-effective method to gain vascular access, and it is used for short-term intravenous (IV) fluids, medications, blood products, and contrast media.¹ It is the most common invasive device in hospitalized patients,² with up to 70% of hospital patients receiving a PIV.³ Unacceptable PIV failure rates have been reported as high as 69%.^4-7 Failure is most frequently due to phlebitis (vein wall irritation/inflammation), occlusion (blockage), infiltration or extravasation (IV fluids/vesicant therapy entering surrounding tissue), partial dislodgement or accidental removal, leakage, and infection.^4,6,8 These failures have important implications for patients, who endure the discomfort of PIV complications and catheter replacements, and healthcare staff and budgets.

To reduce the incidence of catheter failure and avoid preventable PIV replacements, a clear understanding of why catheters fail is required. Previous research has identified that catheter gauge,^9-11 insertion site,^12-14 and inserter skill^10,15 have an impact on PIV failure. Limitations of existing research are small study sizes,^16-18 retrospective design,¹⁹ or secondary analysis of an existing data set; all potentially introduce sampling bias.^10,20

To overcome these potential biases, we developed a data collection instrument based on the catheter-associated risk factors described in the literature,^9-11,13 and other potential insertion and maintenance risks for PIV failure (eg, multiple insertion attempts, medications administered), with data collected prospectively. The study aim was to improve patient outcomes by identifying PIV insertion and maintenance risk factors amenable to modification through education or alternative clinical interventions, such as catheter gauge selection or insertion site.

Study Design and Participants

We conducted this prospective cohort study in a large tertiary hospital in Queensland, Australia. Ethics committee approval was obtained from the hospital (HREC/14/QRBW/76) and Griffith University (NRS/26/14/HREC). The study was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12615000738527). Patients in medical and surgical wards were screened Monday, Wednesday, and Friday between October 2014 and December 2015. Patients over 18 years with a PIV (BD Insyte^TM Autoguard^TM BC; Becton Dickinson, Franklin Lakes, NJ) inserted within 24 hours, and who were able to provide written informed consent, were eligible and recruited sequentially. Patients classified as palliative by the treating clinical team were excluded.

Sample Size Calculation

The “10 events per variable” rule was used to determine the sample size required to study 50 potential risk factors.^21,22 This determined that 1000 patients, with an average of 1.5 PIVs each and an expected PIV failure of 30% (500 events), were required.

Data Collection

At recruitment, baseline patient information was collected by a research nurse (ReNs) (demographics, admitting diagnosis, comorbidities, skin type,²³ and vein condition) and entered into an electronic data platform supported by Research Electronic Data Capture (REDCap).²⁴ Baseline data also included catheter variables (eg, gauge, insertion site, catheterized vein) and insertion details (eg, department of insertion, inserting clinician, number of insertion attempts). We included every PIV the participant had during their admission until hospital discharge or insertion of a central venous access device. PIV sites were reviewed Monday, Wednesday, and Friday by ReNs for site complications (eg, redness, pain, swelling, palpable cord). Potential risk factors for failure were also recorded (eg, infusates and additives, antibiotic type and dosage, flushing regimen, number of times the PIV was accessed each day for administration of IV medications or fluids, dressing type and condition, securement method for the catheter and tubing, presence of extension tubing or 3-way taps, patient mobility status, and delirium). A project manager trained and supervised ReNs for protocol compliance and audited study data quality. We considered PIV failure to have occurred if the catheter had complications at removal identified by the ReNs assessment, from medical charts, or by speaking to the patient and beside nurse. We grouped the failures in 1 of 3 types: (1) occlusion or infiltration, defined as blockage, IV fluids moving into surrounding tissue, induration, or swelling greater than 1 cm from the insertion site at or within 24 hours of removal; (2) phlebitis, defined as per clinicians’ definitions or one or more of the following signs and symptoms: pain or tenderness scored at 2 or more on a 1 to 10 increasing severity pain scale, or redness or a palpable cord (either extending greater than 1 cm from the insertion site) at or within 24 hours of PIV removal; and (3) dislodgement (partial or complete). If multiple complications were present, all were recorded.

Statistical Analysis

Data were downloaded from REDcap to Stata 14.2 (StataCorp., College Station, TX) for data management and analysis. Missing data were not imputed. Nominal data observations were collapsed into a single observation per device. Patient and device variables were described as frequencies and proportions, means and standard deviations, or medians and interquartile ranges. Failure incidence rates were calculated, and a Kaplan-Meier survival curve was plotted. In general, Cox proportional hazards models were fitted (Efron method) to handle tied failures (clustering by patient). Variables significant at P < 0.20 on univariable analyses were subjected to multivariable regression. Generally, the largest category was set as referent. Correlations between variables were checked (Spearman’s rank for binary variables, R-squared value of linear regressions for continuous/categorical or continuous/continuous variables). Correlations were considered significant if r > 0.5 and the lower bound of the 95% confidence interval (CI) was >0.5 (where calculated). Covariate interactions were explored, and effects at P < 0.05 noted. The 4 steps of multivariable model building were (1) baseline covariates only with manual stepwise removal of covariates at P ≥ 0.05, (2) treatment covariates only with manual stepwise removal of covariates at P ≥ 0.05, (3) a combination of the derived models from (1) and (2) and manual stepwise removal of covariates at P ≥ 0.05, and (4) manual stepwise addition and removal (at P ≥ 0.05) of variables dropped during the previous steps and interaction testing. Final models were checked as follows: global proportional-hazards assumption test, concordance probability (that predictions and outcomes were in agreement), and Nelson-Aalen cumulative hazard function plotted against the Cox-Snell residuals.

Patient Characteristics

In total, 1000 patients with 1578 PIVs were recruited. The average age was 54 years and the majority were surgical patients (673; 67%). Almost half of patients (455; 46%) had 2 or more comorbidities, and 334 (33%) were obese (body mass index greater than 30). Sample characteristics are shown by the type of catheter failure in Table 1.

PIV Characteristics

All 1578 PIVs were followed until removal, with only 7 PIVs (0.44%) having missing data for the 3 outcomes of interest (these were coded as nonfailures for analysis). Sixty percent of participants had more than 1 PIV followed in the study. Doctors and physicians inserted 1278 (83%) catheters. A total of 550 (35%) were placed in the ward, with 428 (28%) inserted in the emergency department or ambulance. A third of the catheters (540; 34%) were 18-gauge or larger in diameter, and 1000 (64%) were located in the cubital fossa or hand. Multiple insertion attempts were required to place 315 (23%) PIVs. No PIVs were inserted with ultrasound, as this is rarely used in this hospital. The flushing policy was for the administration of 9% sodium chloride every 8 hours if no IV medications or fluids were ordered. Table 2 contains further details of device-related characteristics. Although the hospital policy was for catheter removal by 72 hours, dwell time ranged from <1 to 14 days, with an average of 2.4 days.

PIV Complications

Catheter failure (any cause) occurred in 512 (32%) catheters, which is a failure rate of 136 per 1000 catheter days (95% CI, 125-148). A total of 346 patients out of 1000 (35%) had at least 1 failed PIV during the study. Failures were 267 phlebitis (17%), 228 occlusion/infiltration (14%), and/or 154 dislodgement (10%; Figure), with some PIVs exhibiting multiple concurrent complications (Table 2).

Multivariable AnalysisOcclusion/Infiltration

The multivariable analysis (Table 3) showed occlusion or infiltration was statistically significantly associated with female patients (hazard ratio [HR], 1.48; 95% CI, 1.10-2.00), with a 22-gauge catheter (HR, 1.43; 95% CI, 1.02-2.00), IV flucloxacillin (HR, 1.98; 95% CI, 1.19-3.31), and with frequent PIV access (HR, 1.12; 95% CI, 1.04-1.21; ie, with each increase of 1 in the mean medications/fluids administrations per day, relative PIV failure increased 112%). Less occlusion and infiltration were statistically significantly associated with securement by using additional nonsterile tape (HR, 0.46; 95% CI, 0.33-0.63), elasticized tubular bandages (HR, 0.49; 95% CI, 0.35-0.70 ), or other types of additional securement for the PIV (HR, 0.35; 95% CI, 0.26-0.47).

Phlebitis

Phlebitis was statistically significantly associated with female patients (HR, 1.81; 95% CI, 1.40-2.35), bruising at the insertion site (HR, 2.16; 95% CI, 1.26-3.71), insertion in patients’ dominant side (HR, 1.39; 95% CI, 1.09-1.77), IV flucloxicillin (HR, 2.01; 95% CI, 1.26-3.21), or with frequent PIV access (HR, 1.14; 95% CI, 1.08-1.21). Older age, (HR, 0.99; 95% CI, 0.98-0.99; ie, each year older was associated with 1% less phlebitis), securement with additional nonsterile tape (HR, 0.63; 95% CI, 0.48-0.82) or with any other additional securement (HR, 0.53; 95% CI, 0.39-0.70), or the administration of IV cephazolin (HR, 0.63; 95% CI, 0.44-0.89) were associated with lower phlebitis risk.

Dislodgement

Statistically significant predictors associated with an increased risk of PIV dislodgement included paramedic insertion (HR, 1.78; 95% CI, 1.03-3.06) and frequent PIV access (HR, 1.11; 95% CI, 1.03-1.20). A decreased risk was associated with the additional securement of the PIV, including nonsterile tape (HR, 0.44; 95% CI, 0.31-0.63) or other forms of additional securement (HR, 0.32; 95% CI, 0.22-0.46).

One in 3 PIVs failed in this study, with phlebitis as the most common cause of PIV failure. The 17% phlebitis rate reflected clinician-reported phlebitis or phlebitis observed by research staff using a 1-criteria definition because any sign or symptom can trigger PIV removal (eg, pain), even if other signs or symptoms are not present. Reported phlebitis rates are lower if definitions require 2 signs or symptoms.^4,6 With over 71 different phlebitis assessment scales in use, and none well validated, the best method for diagnosing phlebitis remains unclear and explains the variation in reported rates.²⁵ Occlusion/infiltration and dislodgement were also highly prevalent forms of PIV failure at 14% and 10%, respectively. Occlusion and infiltration were combined because clinical staff use these terms interchangeably, and differential diagnostic tools are not used in practice. Both result in the same outcome (therapy interruption and PIV removal), and this combination of outcomes has been used previously.²³ No PIV-associated bloodstream infections occurred, despite the heightened awareness of these infections in the literature.³

Females had significantly more occlusion/infiltration and phlebitis than males, in keeping with previous studies.^7,9,10 This could be because of females’ smaller vein caliber, although the effect remained after adjustment for PIV gauge.^7,26 The effect of aging on vascular endothelium and structural integrity may explain the observed decrease in phlebitis of 1% with each older year of age.²⁷ However, gender and age effects could be explained by psychosocial factors (eg, older people may be less likely to admit pain, or we may question them less sympathetically), but, regardless, women and younger patients should be monitored more closely.

We found 22-gauge catheters were more likely to fail from occlusion/infiltration than other sizes. This confirms similar findings from Abolfotouh et al.⁹ PIV gauge selection for this study was made at the inserter’s discretion and may be confounded by smaller vein size, which was not measured. In addition, risk may be because of smaller gauge alone or also more influenced by the shorter length of the studied 22-gauge (25 mm) than the <20-gauge catheters (30 mm). These results question international guidelines, which currently recommend the smallest gauge peripheral catheter possible,^28,29 and randomized trials are needed. Although practice varies between inserters, some preferentially cannulate the nondominant limb. We are not aware of previous studies on this practice; however, our results support this approach.

Flucloxacillin was associated with a 2-fold increase in occlusion/infiltration and phlebitis. Although multiple studies have reported IV medications^9,11 and IV antibiotics^10,30,31 as risk factors for PIV failure, none have identified flucloxacillin as an independent risk factor. IV flucloxacillin is recommended for reconstitution as 1 g in 15 mL to 20 mL of sterile water, and injection over 3 to 4 minutes, although this may not be adhered to in practice. Alternative administration regimes or improved adherence to current policy may be needed. An exception to the relationship between IV antibiotics and catheter failure was IV cephazolin, associated with 40% relatively less phlebitis. This may be a spurious finding because the administration, pH, and osmolality of cephazolin are similar to other IV antibiotics.

The more PIVs that were accessed per day, whether for infusions or medications, the more failure occurred from occlusion/infiltration, phlebitis, and dislodgement. This suggests that peripheral veins are easily damaged and/or inflamed by the influx of fluids or medications. Lower injection pressures or the timely transfer to oral medications may limit this problem. Flushing regimens may also assist because practice varies greatly, and questions on whether slow continuous flush infusion or intermittent manual flushing are more vein-protective, and the optimal flush volume, frequency, and technique (eg, pulsatile) remain.^32,33 Manual handling for frequent access may loosen dressings and securement, thus explaining the observed association between frequent access and catheter dislodgement. Finally, the association between use and failure may indicate that many of these patients were not suitable for a PIV, and different approaches (eg, ultrasound-guided insertion) or a midline may have been a superior option. There is growing emphasis on the need for better preinsertion assessment and selection of the most appropriate device for the patient and the IV treatment required.³⁴

Suboptimal dressings or securements are not unusual in hospitals.³⁵ Despite our policy of PIV securement with bordered transparent dressings, we found 4 dressing types in use. In addition, we found almost 50% of PIVs had an additional (secondary) securement, and this was associated with significantly less PIV failure of all 3 types. This suggests that 1 or more of nonsterile tape, elasticized tubular bandages, or other securement (eg, bandage or second transparent dressing) can reduce PIV failure, although a randomized trial is lacking.³⁶ Whether the dressing was failing and required reinforcement or hospital staff lacked confidence in the dressing and placed additional securement preventatively is unclear. Both PIV failure and PIV dressing failure are common, and further research into superior PIV products and practices is urgently needed. Paramedic insertions had a higher risk of dislodgement, suggesting that the increased emphasis on securement should start in the prehospital setting.

While multiple or difficult insertion attempts were not associated with PIV failure, insertions were not directly observed, and clinicians may have underreported attempts. In contrast, insertion-related bruising (a surrogate for difficult insertion) was associated with more than double the incidence of phlebitis. The long-term implications of multiple insertion attempts on patient’s vasculature are unclear, but we believe first time PIV insertion is important to patients and of interest to clinicians. A recent systematic review of strategies associated with first attempt PIV insertion success in an emergency department found little evidence for effective strategies and recommended further research.³⁷

The overall PIV failure rate in our study was 32%, lower than the 35% to 40% failure observed in our previous randomized controlled trials, which had more stringent inclusion and exclusion criteria (eg, longer predicted duration of therapy).^6,38 The implications for patients and costs to the organization of frequent catheter replacement demonstrate urgent need for further research in this area of practice.³⁹ A strength of this study is that all PIVs, regardless of the expected length of dwell time or reason for insertion, were eligible for inclusion, providing more generalizable results. The PIV failure rate of 32% is concerning because these failures trigger treatment delays and replacement insertions, with significant increased labor and equipment costs. The mean cost of PIV replacement has been costed at AUD $69.30 or US $51.92 (as per 2010 $ value) per episode of IV treatment.⁴⁰ For our hospital, which uses 200,000 PIVs per year, the current level of PIV failure suggests almost AU $5.5 (US $4.1) million in waste annually at this site alone.

The additional strengths of this study include the extensive information collected prospectively about PIV insertion and maintenance, including information on who inserted the PIV, IV medications administered, and PIV dressings used. Limitations were the population of surgical and medical patients in 1 tertiary hospital, which may not be generalizable to other settings.

Our study confirms the high rate of catheter failure in acute care hospitals, validates existing evidence related to PIV failure, and identifies new, potentially modifiable risk factors to improve PIV insertion and management. Implications for future research were also identified.

Acknowledgments

The researchers acknowledge and thank the nurses and patients involved in this study. The authors would also like to acknowledge Becton Dickinson for partly funding this study in the form of an unrestricted grant-in-aid paid to Griffith University. Becton Dickinson did not design the study protocol, collect or analyze data, and did not prepare or review the manuscript.

Disclosure

 On behalf of NM and CMR, Griffith University has received unrestricted educational and research grants and consultancy payment for lectures from 3M and Becton Dickinson. On behalf of NM, MC, and CMR, Griffith University has received unrestricted investigator-initiated research grants from Centurion Medical Products and Entrotech Lifesciences (manufacturers of PIV dressings) and Becton Dickinson (manufacturer of PIVs). On behalf of MC, Griffith University has received a consultancy payment to develop education material from Baxter. On behalf of CMR, Griffith University has received unrestricted donations or investigator initiated research grants unrelated to this research from Adhezion, Angiodynamics, Baxter, Carefusion, Cook Medical, Hospira, Mayo, Smiths Medical, and Vygon. On behalf of CMR, Griffith University has received consultancy payments for educational lectures or professional opinion from B. Braun, Bard, Carefusion, Mayo, ResQDevices, and Smiths Medical. On behalf of EL, Griffith University has received consultancy payments for educational lecture from 3M. On behalf of MC, Griffith University has received a consultancy payment to develop education material from Baxter. As this was an observational study, no products were trialed in this study. JW and GM have no conflicts of interest.

Up to a billion peripheral intravenous catheters (PIVCs) are inserted annually; therefore, the importance of this invasive device in modern medicine cannot be argued.¹ The insertion of a PIVC is a clinical procedure undertaken by a range of clinical staff and in a variety of patient populations and settings. In many clinical environments (for example, the emergency department [ED]), PIVCs are the predominant first-choice vascular access device (VAD).^2,3 Researchers in one study estimated over 25 million PIVCs are used in French EDs each year,³ and intravenous therapy is the leading ED treatment in the United States.⁴

First-time insertion success (FTIS) for PIVCs has been reported at 18% to 98% in adult populations.^5,6 The variability of FTIS likely reflects not just a variety of clinician groups and patient populations but also the absence of uniform approaches to PIVC insertion. Terms frequently used to describe or formalize a pattern of care or a clinical procedure include the following: diagnostic and prognostic tools and/or plans, frameworks, predictive assessment tools, prediction models, rules, decision-making rules, scores, scales, risk factors, risk algorithms, and algorithms.^7-12 In this paper, we use the terms tools, clinical prediction rules, and algorithms (TRAs) to review such frameworks that have been reported in the context of promoting FTIS for PIVCs.

The purpose of this systematic scoping review was to investigate what PIVC decision-making approaches exist to facilitate FTIS of PIVCs in adult hospitalized patients. Our intention was to systematically synthesize the research on TRAs, to review significant associations identified with these TRAs, and to critique TRA validity and reliability.

Scoping Review

We selected a scoping review method that, by definition, maps the evidence to identify gaps,^13,14 set research agendas, and identify implications for decision making. This allowed a targeted approach to answering our 3 research questions:

• What published clinical TRAs exist to facilitate PIVC insertion in adults?
• What clinical, patient and/or product variables have been identified using TRAs as having significant associations with FTIS for PIVCs in adult patients?
• What is the reported reliability, validity, responsiveness, clinical feasibility, and utility of existing TRAs for PIVC insertion in adults?

Our aim was to identify the amount, variety and essential qualities of TRA literature rather than to critically appraise and evaluate the effectiveness of TRAs, a process reserved for systematic review and meta-analysis of interventional studies.^13,14 We followed scoping review guidelines published by members and collaborators of the Joanna Briggs Institute, an internationally recognized leader in research synthesis, evidence use, and implementation. The guidance is based on 5 steps: (i) scoping review objective and question, (ii) background of the topic to support scoping review, (iii) study selection, (iv) charting the results, and (v) collating and summarizing results.¹⁵ Clinicometric assessment of a TRA or any clinical prediction rule requires 4 specific phases: (i) development (identification of predictors from data), (ii) validation (testing the rule in a separate population for reliability), (iii) impact analysis or responsiveness (How clinically useful is the rule in the clinical setting? Is it resource heavy or light? Is it cost effective?), and (iv) implementation and adoption (uptake into clinical practice).¹⁶

Search Strategy

We included studies that described the use or development of any TRA regarding PIVC insertion in the adult hospitalized population.

Inclusion Criteria

Studies were included if they were published in the English Language, included TRAs for PIVC insertion in adult hospital patients, and prospectively assessed a clinical category of patient for PIVC insertion using a traditional approach. We defined a traditional PIVC insertion approach as an assessment and/or insertion with touch and feel, therefore, without vessel-locating technology such as ultrasound and/or near infrared technology.

Exclusion Criteria

Exclusion criteria included pediatric studies, authors’ personal (nonresearch) experience of tools, TRAs focused on postinsertion assessment of the cannula (such as phlebitis, infiltration, and/or dressing failure), and papers with a focus on VADs other than PIVCs. We excluded studies using PIVC ultrasound and/or near infrared technology because these are not standard in all insertions and greatly change the information available for pre-insertion assessment as well as the likelihood of insertion success.

In June 2016, a systematic search of the Cochrane library, Ovid Medline® In-process & Other Non-Indexed Citations and Ovid MEDLINE(R) <1946 to Present>, EBSCO CINAHL databases, and Google Scholar with specific keywords to identify publications that identified or defined TRAs was undertaken. Medical subject headings were created with assistance from a research librarian using tailored functions within individual databases. With key search terms, we limited studies to those related to our inclusion criteria. See Appendix 1 for our search strategy for Medline and CINAHL.

We used Covidence, a web-based application specifically designed for systematic reviews to screen and evaluate eligible publications.¹⁷ Two authors (PJC and NSH) screened the initial retrieved searches based upon the predetermined inclusion and exclusion criteria.

Data Extraction

A paper template was developed and used by 2 reviewers (P.J.C. and N.S.H.). Data included the following: study sample, aim(s), design, setting and country in which the study took place, clinical and patient variables, and how the TRAs were developed and tested. Studies were categorized by TRA type. We also sought to identify if clinical trial registration (where appropriate) was evidenced, in addition to evidence of protocol publication and what standardized reporting guidelines were used (such as those outlined by the EQUATOR Network).¹⁸

Data Synthesis

Formal meta-analysis was beyond the scope and intention of this review. However, we provide the FTIS rate and the ranges of odds ratios (ORs) with 95% confidence intervals (CIs) for certain independent predictors.

Thirty-six references were imported for screening against title and abstract content, with 11 studies excluded and 25 studies assessed for full-text eligibility (see Figure, PRISMA Flowchart). We then excluded a further 12 studies (6 did not meet inclusion criteria, 2 were focused on the prehospital setting, 2 were personal correspondence and focused on another type of VAD, 1 was a protocol to establish a TRA, and 1 was a framework for all device types), leaving 13 studies included in the final review (see Figure). These studies presented data on 4 tools,^19-22 4 predictive models^3,23-25 (of which 3 present receiver operating characteristic/area under the curve scores),^3,23,24 2 framed as risk factor studies,^26,27 and 1 of each of the following: a scale,²⁸ a score,²⁹ and an estimation of the incidence report rate (Table 1).³⁰ Seven studies had “difficult” or “difficulty” in their title as a term to use to describe insertion failure.^{3,19,24-27,30} One study was titled exclusively for the nursing profession,²⁰ 5 studies were reported in medical journals,^{3,24,26,29,30} and 6 were reported in nursing journals,^19-22,25,27 with the remainder published in a vascular access journal.^23,28

General Characteristics of Included Studies

One TRA which was registered as a clinical trial²⁴ involved a standardized reporting tool as is recommended by the EQUATOR Network.¹⁸

Nine of the 13 papers reported that TRA components were chosen based on identified predictors of successful insertion from observational data^{3,19,23-28,30}, with 5 papers using multivariate logistic regression to identify independent predictors.^3,23,24,26,2 At least 4330 insertion attempts on patients were reported. Seven papers reported FTIS, which ranged from 61%-90%.^3,23-27,30

Two clinical settings accounted for 10 of the 13 included studies. We identified 5 papers from the ED setting^{3,23,26,29,30} and 5 studies specific to cancer settings.^19-22,28 Two ED papers identified clinical predictors of insertion difficulty, with 1 identifying an existing medical diagnosis (such as sickle cell disease, diabetes, or intravenous drug abuse) and the other reporting a pragmatic patient self-report of difficulty.^26,30 Three studies focused on patient-exclusive variables (such as vein characteristics)^19,21,28 and some with a combined clinician and patient focus.^{3,23-25,27,30}Relatively few studies reported interobserver measurements to describe the reliability of clinical assessments made.^3,19,21,28 Webster et al. in Australia assessed interrater reliability of a vein assessment tool (VAT) and found high agreement (kappa 0.83 for medical imaging nurses and 0.93 for oncology nurses).²¹ Wells compared reliability with Altman’s K scores obtained from a different VAT when compared with the Deciding on Intravenous Access tool and found good agreement.²² Vein deterioration was proposed as a variable for inclusion when developing an assessment tool within an oncological context.³¹ In Spain, de la Torre and colleagues²⁸ demonstrated good interrater agreement (with kappa, 0.77) for the Venous International Assessment (VIA) tool. The VIA offers a grading system scale to predict the patient’s declining vessel size while undergoing chemotherapy via peripheral veins with PIVCs. Grade I suggests little or no insertion failure, whereas a Grade V should predict insertion failure.

Patient Variables

Vein characteristics were significant independent factors associated with insertion success in a number of studies.^{3,19,23,24,27,28} These included the number of veins, descriptive quality (eg, small, medium, large), size, location, visible veins, and palpable veins. Other factors appear to be patient specific (such as chronic conditions), including diabetes (OR, 2.1 [adjusted to identify demographic risk factors]; 95% CI, 1.3-3.4), sickle cell disease (OR, 3.5; 95% CI, 1.4-4.8), and intravenous drug abuse (OR, 2.4; 95% CI, 1.1-5.3).²⁶ It is unclear if a consistent relationship between weight classification and insertion outcomes exists. Despite a finding that BMI was not independently associated with insertion difficulty,²⁶ one study reports that BMI was independently associated with insertion failure (BMI <18.5 [OR, 2.24; 95% CI, 1.07-4.67], BMI >30 [OR, 1.98; 95% CI, 1.9-3.60])³ and another reports emaciated patients were associated with greater failure when compared to normal weight patients (OR, 0.07; 95% CI, 0.02-0.34).²³ Consequently, extremes of BMI appear to be associated with insertion outcomes despite 1 study reporting no significant association with BMI as an independent factor of insertion failure.²⁶ A history of difficult intravenous access (DIVA) was reported in 1 study and independently associated with insertion failure (OR, 3.86; 95% CI, 2.39-6.25; see Table 2). DIVA appears to be the motivating factor in the title of 7 studies. When defined, the definitions of DIVA are heterogeneous and varied and include the following: >1 minute to insert a PIVC and requiring >1 attempt²⁷; 2 failed attempts³⁰; 3 or more PIVC attempts.²⁶ In the remaining 4 studies, variables associated with difficulty are identified and, therefore, TRAs to target those in future with predicted difficulty prior to any attempts are proposed.^3,19,24,25

Clinician Variables

Specialist nurse certification, years of experience, and self-report skill level (P < 0.001) appear to be significantly associated with successful insertions.²⁵ This is in part validated in another study reporting greater procedural inserting PIVCs as an independent predictor of success (OR, 4.404; 95% CI, 1.61-12-06; see Table 2).²³ Two studies involved simple pragmatic percentage cut offs for PIVCs: likelihood of use²⁹ and likelihood of insertion success.²³ One paper using a cross-sectional design that surveyed ED clinicians suggested if the clinician’s predicted likelihood of the patient needing a PIVC was >80%, this was a reasonable trigger for PIVC insertion.²⁹ The other, in a self-report cohort study, reported that a clinician’s likelihood estimation of PIVC FTIS prior to insertion is independently associated with FTIS (OR, 1.06; 95% CI, 1.04-1.07).²³

Product Variables

In this review, higher failure rates were identified in smaller sizes (22-24 g).²⁶ One study revealed gauge size was significantly associated with a failed first attempt in a univariate analysis (OR, 0.44; 95% CI, 0.34-0.58), but this was not retained in a multivariate model.²⁴ Matching the PIVC size with vein assessment is considered in the VIA tool.²⁸ It suggests a large PIVC (18 g) can be considered in patients with at least 6 vein options; smaller PIVCs of 22 to 24 g are recommended when 3 or fewer veins are found.²⁸ One paper describes a greater proportion of success between PIVC brands.²⁵

The published evidence for TRAs for PIVCs is limited, with few studies using 2 or more reliability, validity, responsiveness, clinical feasibility, or utility measurements in their development. There is a clear need to assess the clinical utility and clinical feasibility of these approaches so they can be externally validated prior to clinical adoption.¹⁶ For this reason, a validated TRA is likely required but must be appropriate for the capability of the healthcare services to use it. We suggest the consistent absence of all of these phases is owing to the variety of healthcare practitioners who are responsible for the insertion, the care and surveillance of peripheral cannulae, and the fragmentation of clinical approaches that exist.³²

Previously, a comprehensive systematic review on the subject of PIVCs found that the presence of a visible and/or palpable vein is usually associated with FTIS.³³ This current review found evidence of simple scores or cutoff percentage estimates in 2 TRA reports to predict either appropriate PIVC insertion or FTIS.^23,29 If such methods are supported by future experimental trials, then such simple approaches could initiate huge clinical return, particularly given that idle or unused PIVCs are of substantial clinical concern.^34-36 PIVCs transcend a variety of clinical environments with excessive use identified in the ED, where it may be performed for blood sampling alone and, hence, are labeled as “just in case” PIVCs and contribute to the term “idle PIVC.”^23,34 Therefore, a clinical indication to perform PIVC insertion in the first instance must be embedded into any TRA; for example, clinical deterioration is likely and the risks are outweighed by benefit, intravenous fluids and/or medicines are required, and/or diagnostic or clinical procedures are requested (such as contrast scans or procedural sedation).

In the majority of papers reviewed, researchers described how to categorize patients into levels of anticipated and predicted difficulty, but none offered corresponding detailed recommendations for strategies to increase insertion success, such as insertion with ultrasound or vascular access expert. Hypothetically, adopting a TRA may assist with the early identification of difficult to cannulate patients who may require a more expert vascular access clinician. However, in this review, we identify that a uniform definition for DIVA is lacking. Both Webster et al.²¹ and Wells²² suggest that an expert inserter is required if difficult access is identified by their tools, but there is no clear description of the qualities of an expert inserter in the literature.³⁷ Recently, consensus recommendations for the definition of vascular access specialist add to discussions about defining vascular access as an interdisciplinary specialist role.³⁸ This is supported by other publications that highlight the association between PIVC procedural experience and increased insertion success.^6,23,39-41With regards to products, PIVC gauge size may or may not be significantly associated with insertion success. For identifying a relationship of PIVC gauge with vein quality, both the vein diameter and description will help with the clinical interpretation of results. For example, it may be the case that bigger veins are easier to insert a PIVC and, thus, larger PIVCs are inserted. The opposite can occur when the veins are small and poorly visualized; hence, one may select a small gauge catheter. This argument is supported by Prottengeier et al.⁴² in a prehospital study that excluded PIVC size in a multivariate analysis because of confounding. However, gauge size is very likely to influence postinsertion complications. Prospective studies are contradictory and suggest 16 to 18 g PIVCs are more likely to contribute to superficial thrombus,⁴³ phlebitis, and, thus, device failure, in contrast to others reporting more frequent dislodgement with smaller 22 g PIVCs.^6,44Finally, the studies included did not assess survival times of the inserted PIVCs, given postinsertion failure in the hospitalized patient is prevalent⁴⁵ and, importantly, modifiable.⁴⁶ A TRA may yield initial insertion success, but if postinsertion the PIVC fails because of a modifiable reason that the TRA has not acknowledged, then it may be of negligible overall benefit. Therefore, TRAs for PIVC insertion need calibration, further development, and ongoing refinement prior to external validation testing.²⁴ Future research should also examine the role of TRAs in settings where ultrasound or other insertion technology is routinely used.

This review identifies a clinically significant gap in vascular access science. The findings of this review support recent work on vessel health and preservation^47-49 and appropriate device insertion.⁵⁰ It also points to the need for further research on the development and testing of an appropriate clinical TRA to improve vascular access outcomes in clinical practice.

Acknowledgments

The authors thank Ms. Kylie Black and Mr. Simon Lewis, who are medical research librarians at The University of Western Australia.

Disclosure

 Mr. Carr has received “speakers bureau” payment form CareFusion in 2013 and Becton Dickinson (BD) in 2014 for lectures on the subject of vascular access. He received a grant from CareFusion (facilitated by his institution at the time) to attend a scientific meeting on vascular access in the USA in 2012. Griffith University has received unrestricted investigator initiated research or educational grants on Marie Cooke’s behalf from product manufacturers: Baxter; Becton, Dickinson and Company; Centurion Medical Products and Entrotech Lifesciences. Griffith University has received unrestricted investigator initiated research or educational grants on Claire M. Rickard’s behalf from product manufacturers: 3M; Adhezion Biomedical, AngioDynamics; Bard, Baxter; B.Braun; Becton, Dickinson and Company; Centurion Medical Products; Cook Medical; Entrotech, Flomedical; ICU Medical; Medtronic; Smiths Medical, Teleflex. Griffith University has received consultancy payments on Claire M. Rickard’s behalf from product manufacturers: 3M, Bard; BBraun, BD, ResQDevices, Smiths Medical. Dr. Higgins and Dr. Rippey have nothing to disclose. All of the aforementioned have not biased or influenced this review.

All authors have made substantial contributions with this review. Each author has contributed to drafting and editing the manuscript and approves the final version for publishing.

Up to a billion peripheral intravenous catheters (PIVCs) are inserted annually; therefore, the importance of this invasive device in modern medicine cannot be argued.¹ The insertion of a PIVC is a clinical procedure undertaken by a range of clinical staff and in a variety of patient populations and settings. In many clinical environments (for example, the emergency department [ED]), PIVCs are the predominant first-choice vascular access device (VAD).^2,3 Researchers in one study estimated over 25 million PIVCs are used in French EDs each year,³ and intravenous therapy is the leading ED treatment in the United States.⁴

First-time insertion success (FTIS) for PIVCs has been reported at 18% to 98% in adult populations.^5,6 The variability of FTIS likely reflects not just a variety of clinician groups and patient populations but also the absence of uniform approaches to PIVC insertion. Terms frequently used to describe or formalize a pattern of care or a clinical procedure include the following: diagnostic and prognostic tools and/or plans, frameworks, predictive assessment tools, prediction models, rules, decision-making rules, scores, scales, risk factors, risk algorithms, and algorithms.^7-12 In this paper, we use the terms tools, clinical prediction rules, and algorithms (TRAs) to review such frameworks that have been reported in the context of promoting FTIS for PIVCs.

The purpose of this systematic scoping review was to investigate what PIVC decision-making approaches exist to facilitate FTIS of PIVCs in adult hospitalized patients. Our intention was to systematically synthesize the research on TRAs, to review significant associations identified with these TRAs, and to critique TRA validity and reliability.

Scoping Review

We selected a scoping review method that, by definition, maps the evidence to identify gaps,^13,14 set research agendas, and identify implications for decision making. This allowed a targeted approach to answering our 3 research questions:

• What published clinical TRAs exist to facilitate PIVC insertion in adults?
• What clinical, patient and/or product variables have been identified using TRAs as having significant associations with FTIS for PIVCs in adult patients?
• What is the reported reliability, validity, responsiveness, clinical feasibility, and utility of existing TRAs for PIVC insertion in adults?

Our aim was to identify the amount, variety and essential qualities of TRA literature rather than to critically appraise and evaluate the effectiveness of TRAs, a process reserved for systematic review and meta-analysis of interventional studies.^13,14 We followed scoping review guidelines published by members and collaborators of the Joanna Briggs Institute, an internationally recognized leader in research synthesis, evidence use, and implementation. The guidance is based on 5 steps: (i) scoping review objective and question, (ii) background of the topic to support scoping review, (iii) study selection, (iv) charting the results, and (v) collating and summarizing results.¹⁵ Clinicometric assessment of a TRA or any clinical prediction rule requires 4 specific phases: (i) development (identification of predictors from data), (ii) validation (testing the rule in a separate population for reliability), (iii) impact analysis or responsiveness (How clinically useful is the rule in the clinical setting? Is it resource heavy or light? Is it cost effective?), and (iv) implementation and adoption (uptake into clinical practice).¹⁶

Search Strategy

We included studies that described the use or development of any TRA regarding PIVC insertion in the adult hospitalized population.

Inclusion Criteria

Studies were included if they were published in the English Language, included TRAs for PIVC insertion in adult hospital patients, and prospectively assessed a clinical category of patient for PIVC insertion using a traditional approach. We defined a traditional PIVC insertion approach as an assessment and/or insertion with touch and feel, therefore, without vessel-locating technology such as ultrasound and/or near infrared technology.

Exclusion Criteria

Exclusion criteria included pediatric studies, authors’ personal (nonresearch) experience of tools, TRAs focused on postinsertion assessment of the cannula (such as phlebitis, infiltration, and/or dressing failure), and papers with a focus on VADs other than PIVCs. We excluded studies using PIVC ultrasound and/or near infrared technology because these are not standard in all insertions and greatly change the information available for pre-insertion assessment as well as the likelihood of insertion success.

In June 2016, a systematic search of the Cochrane library, Ovid Medline® In-process & Other Non-Indexed Citations and Ovid MEDLINE(R) <1946 to Present>, EBSCO CINAHL databases, and Google Scholar with specific keywords to identify publications that identified or defined TRAs was undertaken. Medical subject headings were created with assistance from a research librarian using tailored functions within individual databases. With key search terms, we limited studies to those related to our inclusion criteria. See Appendix 1 for our search strategy for Medline and CINAHL.

We used Covidence, a web-based application specifically designed for systematic reviews to screen and evaluate eligible publications.¹⁷ Two authors (PJC and NSH) screened the initial retrieved searches based upon the predetermined inclusion and exclusion criteria.

Data Extraction

A paper template was developed and used by 2 reviewers (P.J.C. and N.S.H.). Data included the following: study sample, aim(s), design, setting and country in which the study took place, clinical and patient variables, and how the TRAs were developed and tested. Studies were categorized by TRA type. We also sought to identify if clinical trial registration (where appropriate) was evidenced, in addition to evidence of protocol publication and what standardized reporting guidelines were used (such as those outlined by the EQUATOR Network).¹⁸

Data Synthesis

Formal meta-analysis was beyond the scope and intention of this review. However, we provide the FTIS rate and the ranges of odds ratios (ORs) with 95% confidence intervals (CIs) for certain independent predictors.

Thirty-six references were imported for screening against title and abstract content, with 11 studies excluded and 25 studies assessed for full-text eligibility (see Figure, PRISMA Flowchart). We then excluded a further 12 studies (6 did not meet inclusion criteria, 2 were focused on the prehospital setting, 2 were personal correspondence and focused on another type of VAD, 1 was a protocol to establish a TRA, and 1 was a framework for all device types), leaving 13 studies included in the final review (see Figure). These studies presented data on 4 tools,^19-22 4 predictive models^3,23-25 (of which 3 present receiver operating characteristic/area under the curve scores),^3,23,24 2 framed as risk factor studies,^26,27 and 1 of each of the following: a scale,²⁸ a score,²⁹ and an estimation of the incidence report rate (Table 1).³⁰ Seven studies had “difficult” or “difficulty” in their title as a term to use to describe insertion failure.^{3,19,24-27,30} One study was titled exclusively for the nursing profession,²⁰ 5 studies were reported in medical journals,^{3,24,26,29,30} and 6 were reported in nursing journals,^19-22,25,27 with the remainder published in a vascular access journal.^23,28

General Characteristics of Included Studies

One TRA which was registered as a clinical trial²⁴ involved a standardized reporting tool as is recommended by the EQUATOR Network.¹⁸

Nine of the 13 papers reported that TRA components were chosen based on identified predictors of successful insertion from observational data^{3,19,23-28,30}, with 5 papers using multivariate logistic regression to identify independent predictors.^3,23,24,26,2 At least 4330 insertion attempts on patients were reported. Seven papers reported FTIS, which ranged from 61%-90%.^3,23-27,30

Two clinical settings accounted for 10 of the 13 included studies. We identified 5 papers from the ED setting^{3,23,26,29,30} and 5 studies specific to cancer settings.^19-22,28 Two ED papers identified clinical predictors of insertion difficulty, with 1 identifying an existing medical diagnosis (such as sickle cell disease, diabetes, or intravenous drug abuse) and the other reporting a pragmatic patient self-report of difficulty.^26,30 Three studies focused on patient-exclusive variables (such as vein characteristics)^19,21,28 and some with a combined clinician and patient focus.^{3,23-25,27,30}Relatively few studies reported interobserver measurements to describe the reliability of clinical assessments made.^3,19,21,28 Webster et al. in Australia assessed interrater reliability of a vein assessment tool (VAT) and found high agreement (kappa 0.83 for medical imaging nurses and 0.93 for oncology nurses).²¹ Wells compared reliability with Altman’s K scores obtained from a different VAT when compared with the Deciding on Intravenous Access tool and found good agreement.²² Vein deterioration was proposed as a variable for inclusion when developing an assessment tool within an oncological context.³¹ In Spain, de la Torre and colleagues²⁸ demonstrated good interrater agreement (with kappa, 0.77) for the Venous International Assessment (VIA) tool. The VIA offers a grading system scale to predict the patient’s declining vessel size while undergoing chemotherapy via peripheral veins with PIVCs. Grade I suggests little or no insertion failure, whereas a Grade V should predict insertion failure.

Patient Variables

Vein characteristics were significant independent factors associated with insertion success in a number of studies.^{3,19,23,24,27,28} These included the number of veins, descriptive quality (eg, small, medium, large), size, location, visible veins, and palpable veins. Other factors appear to be patient specific (such as chronic conditions), including diabetes (OR, 2.1 [adjusted to identify demographic risk factors]; 95% CI, 1.3-3.4), sickle cell disease (OR, 3.5; 95% CI, 1.4-4.8), and intravenous drug abuse (OR, 2.4; 95% CI, 1.1-5.3).²⁶ It is unclear if a consistent relationship between weight classification and insertion outcomes exists. Despite a finding that BMI was not independently associated with insertion difficulty,²⁶ one study reports that BMI was independently associated with insertion failure (BMI <18.5 [OR, 2.24; 95% CI, 1.07-4.67], BMI >30 [OR, 1.98; 95% CI, 1.9-3.60])³ and another reports emaciated patients were associated with greater failure when compared to normal weight patients (OR, 0.07; 95% CI, 0.02-0.34).²³ Consequently, extremes of BMI appear to be associated with insertion outcomes despite 1 study reporting no significant association with BMI as an independent factor of insertion failure.²⁶ A history of difficult intravenous access (DIVA) was reported in 1 study and independently associated with insertion failure (OR, 3.86; 95% CI, 2.39-6.25; see Table 2). DIVA appears to be the motivating factor in the title of 7 studies. When defined, the definitions of DIVA are heterogeneous and varied and include the following: >1 minute to insert a PIVC and requiring >1 attempt²⁷; 2 failed attempts³⁰; 3 or more PIVC attempts.²⁶ In the remaining 4 studies, variables associated with difficulty are identified and, therefore, TRAs to target those in future with predicted difficulty prior to any attempts are proposed.^3,19,24,25

Clinician Variables

Specialist nurse certification, years of experience, and self-report skill level (P < 0.001) appear to be significantly associated with successful insertions.²⁵ This is in part validated in another study reporting greater procedural inserting PIVCs as an independent predictor of success (OR, 4.404; 95% CI, 1.61-12-06; see Table 2).²³ Two studies involved simple pragmatic percentage cut offs for PIVCs: likelihood of use²⁹ and likelihood of insertion success.²³ One paper using a cross-sectional design that surveyed ED clinicians suggested if the clinician’s predicted likelihood of the patient needing a PIVC was >80%, this was a reasonable trigger for PIVC insertion.²⁹ The other, in a self-report cohort study, reported that a clinician’s likelihood estimation of PIVC FTIS prior to insertion is independently associated with FTIS (OR, 1.06; 95% CI, 1.04-1.07).²³

Product Variables

In this review, higher failure rates were identified in smaller sizes (22-24 g).²⁶ One study revealed gauge size was significantly associated with a failed first attempt in a univariate analysis (OR, 0.44; 95% CI, 0.34-0.58), but this was not retained in a multivariate model.²⁴ Matching the PIVC size with vein assessment is considered in the VIA tool.²⁸ It suggests a large PIVC (18 g) can be considered in patients with at least 6 vein options; smaller PIVCs of 22 to 24 g are recommended when 3 or fewer veins are found.²⁸ One paper describes a greater proportion of success between PIVC brands.²⁵

The published evidence for TRAs for PIVCs is limited, with few studies using 2 or more reliability, validity, responsiveness, clinical feasibility, or utility measurements in their development. There is a clear need to assess the clinical utility and clinical feasibility of these approaches so they can be externally validated prior to clinical adoption.¹⁶ For this reason, a validated TRA is likely required but must be appropriate for the capability of the healthcare services to use it. We suggest the consistent absence of all of these phases is owing to the variety of healthcare practitioners who are responsible for the insertion, the care and surveillance of peripheral cannulae, and the fragmentation of clinical approaches that exist.³²

Previously, a comprehensive systematic review on the subject of PIVCs found that the presence of a visible and/or palpable vein is usually associated with FTIS.³³ This current review found evidence of simple scores or cutoff percentage estimates in 2 TRA reports to predict either appropriate PIVC insertion or FTIS.^23,29 If such methods are supported by future experimental trials, then such simple approaches could initiate huge clinical return, particularly given that idle or unused PIVCs are of substantial clinical concern.^34-36 PIVCs transcend a variety of clinical environments with excessive use identified in the ED, where it may be performed for blood sampling alone and, hence, are labeled as “just in case” PIVCs and contribute to the term “idle PIVC.”^23,34 Therefore, a clinical indication to perform PIVC insertion in the first instance must be embedded into any TRA; for example, clinical deterioration is likely and the risks are outweighed by benefit, intravenous fluids and/or medicines are required, and/or diagnostic or clinical procedures are requested (such as contrast scans or procedural sedation).

In the majority of papers reviewed, researchers described how to categorize patients into levels of anticipated and predicted difficulty, but none offered corresponding detailed recommendations for strategies to increase insertion success, such as insertion with ultrasound or vascular access expert. Hypothetically, adopting a TRA may assist with the early identification of difficult to cannulate patients who may require a more expert vascular access clinician. However, in this review, we identify that a uniform definition for DIVA is lacking. Both Webster et al.²¹ and Wells²² suggest that an expert inserter is required if difficult access is identified by their tools, but there is no clear description of the qualities of an expert inserter in the literature.³⁷ Recently, consensus recommendations for the definition of vascular access specialist add to discussions about defining vascular access as an interdisciplinary specialist role.³⁸ This is supported by other publications that highlight the association between PIVC procedural experience and increased insertion success.^6,23,39-41With regards to products, PIVC gauge size may or may not be significantly associated with insertion success. For identifying a relationship of PIVC gauge with vein quality, both the vein diameter and description will help with the clinical interpretation of results. For example, it may be the case that bigger veins are easier to insert a PIVC and, thus, larger PIVCs are inserted. The opposite can occur when the veins are small and poorly visualized; hence, one may select a small gauge catheter. This argument is supported by Prottengeier et al.⁴² in a prehospital study that excluded PIVC size in a multivariate analysis because of confounding. However, gauge size is very likely to influence postinsertion complications. Prospective studies are contradictory and suggest 16 to 18 g PIVCs are more likely to contribute to superficial thrombus,⁴³ phlebitis, and, thus, device failure, in contrast to others reporting more frequent dislodgement with smaller 22 g PIVCs.^6,44Finally, the studies included did not assess survival times of the inserted PIVCs, given postinsertion failure in the hospitalized patient is prevalent⁴⁵ and, importantly, modifiable.⁴⁶ A TRA may yield initial insertion success, but if postinsertion the PIVC fails because of a modifiable reason that the TRA has not acknowledged, then it may be of negligible overall benefit. Therefore, TRAs for PIVC insertion need calibration, further development, and ongoing refinement prior to external validation testing.²⁴ Future research should also examine the role of TRAs in settings where ultrasound or other insertion technology is routinely used.

This review identifies a clinically significant gap in vascular access science. The findings of this review support recent work on vessel health and preservation^47-49 and appropriate device insertion.⁵⁰ It also points to the need for further research on the development and testing of an appropriate clinical TRA to improve vascular access outcomes in clinical practice.

Acknowledgments

The authors thank Ms. Kylie Black and Mr. Simon Lewis, who are medical research librarians at The University of Western Australia.

Disclosure

 Mr. Carr has received “speakers bureau” payment form CareFusion in 2013 and Becton Dickinson (BD) in 2014 for lectures on the subject of vascular access. He received a grant from CareFusion (facilitated by his institution at the time) to attend a scientific meeting on vascular access in the USA in 2012. Griffith University has received unrestricted investigator initiated research or educational grants on Marie Cooke’s behalf from product manufacturers: Baxter; Becton, Dickinson and Company; Centurion Medical Products and Entrotech Lifesciences. Griffith University has received unrestricted investigator initiated research or educational grants on Claire M. Rickard’s behalf from product manufacturers: 3M; Adhezion Biomedical, AngioDynamics; Bard, Baxter; B.Braun; Becton, Dickinson and Company; Centurion Medical Products; Cook Medical; Entrotech, Flomedical; ICU Medical; Medtronic; Smiths Medical, Teleflex. Griffith University has received consultancy payments on Claire M. Rickard’s behalf from product manufacturers: 3M, Bard; BBraun, BD, ResQDevices, Smiths Medical. Dr. Higgins and Dr. Rippey have nothing to disclose. All of the aforementioned have not biased or influenced this review.

All authors have made substantial contributions with this review. Each author has contributed to drafting and editing the manuscript and approves the final version for publishing.

Up to a billion peripheral intravenous catheters (PIVCs) are inserted annually; therefore, the importance of this invasive device in modern medicine cannot be argued.¹ The insertion of a PIVC is a clinical procedure undertaken by a range of clinical staff and in a variety of patient populations and settings. In many clinical environments (for example, the emergency department [ED]), PIVCs are the predominant first-choice vascular access device (VAD).^2,3 Researchers in one study estimated over 25 million PIVCs are used in French EDs each year,³ and intravenous therapy is the leading ED treatment in the United States.⁴

First-time insertion success (FTIS) for PIVCs has been reported at 18% to 98% in adult populations.^5,6 The variability of FTIS likely reflects not just a variety of clinician groups and patient populations but also the absence of uniform approaches to PIVC insertion. Terms frequently used to describe or formalize a pattern of care or a clinical procedure include the following: diagnostic and prognostic tools and/or plans, frameworks, predictive assessment tools, prediction models, rules, decision-making rules, scores, scales, risk factors, risk algorithms, and algorithms.^7-12 In this paper, we use the terms tools, clinical prediction rules, and algorithms (TRAs) to review such frameworks that have been reported in the context of promoting FTIS for PIVCs.

The purpose of this systematic scoping review was to investigate what PIVC decision-making approaches exist to facilitate FTIS of PIVCs in adult hospitalized patients. Our intention was to systematically synthesize the research on TRAs, to review significant associations identified with these TRAs, and to critique TRA validity and reliability.

Scoping Review

We selected a scoping review method that, by definition, maps the evidence to identify gaps,^13,14 set research agendas, and identify implications for decision making. This allowed a targeted approach to answering our 3 research questions:

• What published clinical TRAs exist to facilitate PIVC insertion in adults?
• What clinical, patient and/or product variables have been identified using TRAs as having significant associations with FTIS for PIVCs in adult patients?
• What is the reported reliability, validity, responsiveness, clinical feasibility, and utility of existing TRAs for PIVC insertion in adults?

Our aim was to identify the amount, variety and essential qualities of TRA literature rather than to critically appraise and evaluate the effectiveness of TRAs, a process reserved for systematic review and meta-analysis of interventional studies.^13,14 We followed scoping review guidelines published by members and collaborators of the Joanna Briggs Institute, an internationally recognized leader in research synthesis, evidence use, and implementation. The guidance is based on 5 steps: (i) scoping review objective and question, (ii) background of the topic to support scoping review, (iii) study selection, (iv) charting the results, and (v) collating and summarizing results.¹⁵ Clinicometric assessment of a TRA or any clinical prediction rule requires 4 specific phases: (i) development (identification of predictors from data), (ii) validation (testing the rule in a separate population for reliability), (iii) impact analysis or responsiveness (How clinically useful is the rule in the clinical setting? Is it resource heavy or light? Is it cost effective?), and (iv) implementation and adoption (uptake into clinical practice).¹⁶

Search Strategy

We included studies that described the use or development of any TRA regarding PIVC insertion in the adult hospitalized population.

Inclusion Criteria

Studies were included if they were published in the English Language, included TRAs for PIVC insertion in adult hospital patients, and prospectively assessed a clinical category of patient for PIVC insertion using a traditional approach. We defined a traditional PIVC insertion approach as an assessment and/or insertion with touch and feel, therefore, without vessel-locating technology such as ultrasound and/or near infrared technology.

Exclusion Criteria

Exclusion criteria included pediatric studies, authors’ personal (nonresearch) experience of tools, TRAs focused on postinsertion assessment of the cannula (such as phlebitis, infiltration, and/or dressing failure), and papers with a focus on VADs other than PIVCs. We excluded studies using PIVC ultrasound and/or near infrared technology because these are not standard in all insertions and greatly change the information available for pre-insertion assessment as well as the likelihood of insertion success.

In June 2016, a systematic search of the Cochrane library, Ovid Medline® In-process & Other Non-Indexed Citations and Ovid MEDLINE(R) <1946 to Present>, EBSCO CINAHL databases, and Google Scholar with specific keywords to identify publications that identified or defined TRAs was undertaken. Medical subject headings were created with assistance from a research librarian using tailored functions within individual databases. With key search terms, we limited studies to those related to our inclusion criteria. See Appendix 1 for our search strategy for Medline and CINAHL.

We used Covidence, a web-based application specifically designed for systematic reviews to screen and evaluate eligible publications.¹⁷ Two authors (PJC and NSH) screened the initial retrieved searches based upon the predetermined inclusion and exclusion criteria.

Data Extraction

A paper template was developed and used by 2 reviewers (P.J.C. and N.S.H.). Data included the following: study sample, aim(s), design, setting and country in which the study took place, clinical and patient variables, and how the TRAs were developed and tested. Studies were categorized by TRA type. We also sought to identify if clinical trial registration (where appropriate) was evidenced, in addition to evidence of protocol publication and what standardized reporting guidelines were used (such as those outlined by the EQUATOR Network).¹⁸

Data Synthesis

Formal meta-analysis was beyond the scope and intention of this review. However, we provide the FTIS rate and the ranges of odds ratios (ORs) with 95% confidence intervals (CIs) for certain independent predictors.

Thirty-six references were imported for screening against title and abstract content, with 11 studies excluded and 25 studies assessed for full-text eligibility (see Figure, PRISMA Flowchart). We then excluded a further 12 studies (6 did not meet inclusion criteria, 2 were focused on the prehospital setting, 2 were personal correspondence and focused on another type of VAD, 1 was a protocol to establish a TRA, and 1 was a framework for all device types), leaving 13 studies included in the final review (see Figure). These studies presented data on 4 tools,^19-22 4 predictive models^3,23-25 (of which 3 present receiver operating characteristic/area under the curve scores),^3,23,24 2 framed as risk factor studies,^26,27 and 1 of each of the following: a scale,²⁸ a score,²⁹ and an estimation of the incidence report rate (Table 1).³⁰ Seven studies had “difficult” or “difficulty” in their title as a term to use to describe insertion failure.^{3,19,24-27,30} One study was titled exclusively for the nursing profession,²⁰ 5 studies were reported in medical journals,^{3,24,26,29,30} and 6 were reported in nursing journals,^19-22,25,27 with the remainder published in a vascular access journal.^23,28

General Characteristics of Included Studies

One TRA which was registered as a clinical trial²⁴ involved a standardized reporting tool as is recommended by the EQUATOR Network.¹⁸

Nine of the 13 papers reported that TRA components were chosen based on identified predictors of successful insertion from observational data^{3,19,23-28,30}, with 5 papers using multivariate logistic regression to identify independent predictors.^3,23,24,26,2 At least 4330 insertion attempts on patients were reported. Seven papers reported FTIS, which ranged from 61%-90%.^3,23-27,30

Two clinical settings accounted for 10 of the 13 included studies. We identified 5 papers from the ED setting^{3,23,26,29,30} and 5 studies specific to cancer settings.^19-22,28 Two ED papers identified clinical predictors of insertion difficulty, with 1 identifying an existing medical diagnosis (such as sickle cell disease, diabetes, or intravenous drug abuse) and the other reporting a pragmatic patient self-report of difficulty.^26,30 Three studies focused on patient-exclusive variables (such as vein characteristics)^19,21,28 and some with a combined clinician and patient focus.^{3,23-25,27,30}Relatively few studies reported interobserver measurements to describe the reliability of clinical assessments made.^3,19,21,28 Webster et al. in Australia assessed interrater reliability of a vein assessment tool (VAT) and found high agreement (kappa 0.83 for medical imaging nurses and 0.93 for oncology nurses).²¹ Wells compared reliability with Altman’s K scores obtained from a different VAT when compared with the Deciding on Intravenous Access tool and found good agreement.²² Vein deterioration was proposed as a variable for inclusion when developing an assessment tool within an oncological context.³¹ In Spain, de la Torre and colleagues²⁸ demonstrated good interrater agreement (with kappa, 0.77) for the Venous International Assessment (VIA) tool. The VIA offers a grading system scale to predict the patient’s declining vessel size while undergoing chemotherapy via peripheral veins with PIVCs. Grade I suggests little or no insertion failure, whereas a Grade V should predict insertion failure.

Patient Variables

Vein characteristics were significant independent factors associated with insertion success in a number of studies.^{3,19,23,24,27,28} These included the number of veins, descriptive quality (eg, small, medium, large), size, location, visible veins, and palpable veins. Other factors appear to be patient specific (such as chronic conditions), including diabetes (OR, 2.1 [adjusted to identify demographic risk factors]; 95% CI, 1.3-3.4), sickle cell disease (OR, 3.5; 95% CI, 1.4-4.8), and intravenous drug abuse (OR, 2.4; 95% CI, 1.1-5.3).²⁶ It is unclear if a consistent relationship between weight classification and insertion outcomes exists. Despite a finding that BMI was not independently associated with insertion difficulty,²⁶ one study reports that BMI was independently associated with insertion failure (BMI <18.5 [OR, 2.24; 95% CI, 1.07-4.67], BMI >30 [OR, 1.98; 95% CI, 1.9-3.60])³ and another reports emaciated patients were associated with greater failure when compared to normal weight patients (OR, 0.07; 95% CI, 0.02-0.34).²³ Consequently, extremes of BMI appear to be associated with insertion outcomes despite 1 study reporting no significant association with BMI as an independent factor of insertion failure.²⁶ A history of difficult intravenous access (DIVA) was reported in 1 study and independently associated with insertion failure (OR, 3.86; 95% CI, 2.39-6.25; see Table 2). DIVA appears to be the motivating factor in the title of 7 studies. When defined, the definitions of DIVA are heterogeneous and varied and include the following: >1 minute to insert a PIVC and requiring >1 attempt²⁷; 2 failed attempts³⁰; 3 or more PIVC attempts.²⁶ In the remaining 4 studies, variables associated with difficulty are identified and, therefore, TRAs to target those in future with predicted difficulty prior to any attempts are proposed.^3,19,24,25

Clinician Variables

Specialist nurse certification, years of experience, and self-report skill level (P < 0.001) appear to be significantly associated with successful insertions.²⁵ This is in part validated in another study reporting greater procedural inserting PIVCs as an independent predictor of success (OR, 4.404; 95% CI, 1.61-12-06; see Table 2).²³ Two studies involved simple pragmatic percentage cut offs for PIVCs: likelihood of use²⁹ and likelihood of insertion success.²³ One paper using a cross-sectional design that surveyed ED clinicians suggested if the clinician’s predicted likelihood of the patient needing a PIVC was >80%, this was a reasonable trigger for PIVC insertion.²⁹ The other, in a self-report cohort study, reported that a clinician’s likelihood estimation of PIVC FTIS prior to insertion is independently associated with FTIS (OR, 1.06; 95% CI, 1.04-1.07).²³

Product Variables

In this review, higher failure rates were identified in smaller sizes (22-24 g).²⁶ One study revealed gauge size was significantly associated with a failed first attempt in a univariate analysis (OR, 0.44; 95% CI, 0.34-0.58), but this was not retained in a multivariate model.²⁴ Matching the PIVC size with vein assessment is considered in the VIA tool.²⁸ It suggests a large PIVC (18 g) can be considered in patients with at least 6 vein options; smaller PIVCs of 22 to 24 g are recommended when 3 or fewer veins are found.²⁸ One paper describes a greater proportion of success between PIVC brands.²⁵

The published evidence for TRAs for PIVCs is limited, with few studies using 2 or more reliability, validity, responsiveness, clinical feasibility, or utility measurements in their development. There is a clear need to assess the clinical utility and clinical feasibility of these approaches so they can be externally validated prior to clinical adoption.¹⁶ For this reason, a validated TRA is likely required but must be appropriate for the capability of the healthcare services to use it. We suggest the consistent absence of all of these phases is owing to the variety of healthcare practitioners who are responsible for the insertion, the care and surveillance of peripheral cannulae, and the fragmentation of clinical approaches that exist.³²

Previously, a comprehensive systematic review on the subject of PIVCs found that the presence of a visible and/or palpable vein is usually associated with FTIS.³³ This current review found evidence of simple scores or cutoff percentage estimates in 2 TRA reports to predict either appropriate PIVC insertion or FTIS.^23,29 If such methods are supported by future experimental trials, then such simple approaches could initiate huge clinical return, particularly given that idle or unused PIVCs are of substantial clinical concern.^34-36 PIVCs transcend a variety of clinical environments with excessive use identified in the ED, where it may be performed for blood sampling alone and, hence, are labeled as “just in case” PIVCs and contribute to the term “idle PIVC.”^23,34 Therefore, a clinical indication to perform PIVC insertion in the first instance must be embedded into any TRA; for example, clinical deterioration is likely and the risks are outweighed by benefit, intravenous fluids and/or medicines are required, and/or diagnostic or clinical procedures are requested (such as contrast scans or procedural sedation).

In the majority of papers reviewed, researchers described how to categorize patients into levels of anticipated and predicted difficulty, but none offered corresponding detailed recommendations for strategies to increase insertion success, such as insertion with ultrasound or vascular access expert. Hypothetically, adopting a TRA may assist with the early identification of difficult to cannulate patients who may require a more expert vascular access clinician. However, in this review, we identify that a uniform definition for DIVA is lacking. Both Webster et al.²¹ and Wells²² suggest that an expert inserter is required if difficult access is identified by their tools, but there is no clear description of the qualities of an expert inserter in the literature.³⁷ Recently, consensus recommendations for the definition of vascular access specialist add to discussions about defining vascular access as an interdisciplinary specialist role.³⁸ This is supported by other publications that highlight the association between PIVC procedural experience and increased insertion success.^6,23,39-41With regards to products, PIVC gauge size may or may not be significantly associated with insertion success. For identifying a relationship of PIVC gauge with vein quality, both the vein diameter and description will help with the clinical interpretation of results. For example, it may be the case that bigger veins are easier to insert a PIVC and, thus, larger PIVCs are inserted. The opposite can occur when the veins are small and poorly visualized; hence, one may select a small gauge catheter. This argument is supported by Prottengeier et al.⁴² in a prehospital study that excluded PIVC size in a multivariate analysis because of confounding. However, gauge size is very likely to influence postinsertion complications. Prospective studies are contradictory and suggest 16 to 18 g PIVCs are more likely to contribute to superficial thrombus,⁴³ phlebitis, and, thus, device failure, in contrast to others reporting more frequent dislodgement with smaller 22 g PIVCs.^6,44Finally, the studies included did not assess survival times of the inserted PIVCs, given postinsertion failure in the hospitalized patient is prevalent⁴⁵ and, importantly, modifiable.⁴⁶ A TRA may yield initial insertion success, but if postinsertion the PIVC fails because of a modifiable reason that the TRA has not acknowledged, then it may be of negligible overall benefit. Therefore, TRAs for PIVC insertion need calibration, further development, and ongoing refinement prior to external validation testing.²⁴ Future research should also examine the role of TRAs in settings where ultrasound or other insertion technology is routinely used.

This review identifies a clinically significant gap in vascular access science. The findings of this review support recent work on vessel health and preservation^47-49 and appropriate device insertion.⁵⁰ It also points to the need for further research on the development and testing of an appropriate clinical TRA to improve vascular access outcomes in clinical practice.

Acknowledgments

The authors thank Ms. Kylie Black and Mr. Simon Lewis, who are medical research librarians at The University of Western Australia.

Disclosure

 Mr. Carr has received “speakers bureau” payment form CareFusion in 2013 and Becton Dickinson (BD) in 2014 for lectures on the subject of vascular access. He received a grant from CareFusion (facilitated by his institution at the time) to attend a scientific meeting on vascular access in the USA in 2012. Griffith University has received unrestricted investigator initiated research or educational grants on Marie Cooke’s behalf from product manufacturers: Baxter; Becton, Dickinson and Company; Centurion Medical Products and Entrotech Lifesciences. Griffith University has received unrestricted investigator initiated research or educational grants on Claire M. Rickard’s behalf from product manufacturers: 3M; Adhezion Biomedical, AngioDynamics; Bard, Baxter; B.Braun; Becton, Dickinson and Company; Centurion Medical Products; Cook Medical; Entrotech, Flomedical; ICU Medical; Medtronic; Smiths Medical, Teleflex. Griffith University has received consultancy payments on Claire M. Rickard’s behalf from product manufacturers: 3M, Bard; BBraun, BD, ResQDevices, Smiths Medical. Dr. Higgins and Dr. Rippey have nothing to disclose. All of the aforementioned have not biased or influenced this review.

All authors have made substantial contributions with this review. Each author has contributed to drafting and editing the manuscript and approves the final version for publishing.