Networks

Airway Disorders Network

Bronchiectasis Section

Bronchiectasis is a condition of dilated, inflamed airways and mucous production caused by a myriad of diseases. Bronchiectasis entails chronic productive cough and an increased risk of infections leading to exacerbations. Chronic bacterial infections are often a hallmark of severe disease, especially with Pseudomonas aeruginosa (O’Donnell AE. N Engl J Med. 2022;387[6]:533). Prophylactic inhaled antibiotics have been used as off-label therapies with mixed evidence, particularly in non-cystic fibrosis bronchiectasis (Rubin BK, et al. Respiration. 2014;88[3]:177). As the incidence of bronchiectasis increases worldwide, the need for evidence-based therapies to reduce symptom burden is increasing.

In a recent publication, Guan and colleagues evaluated the efficacy and safety of tobramycin inhaled solution (TIS) for bronchiectasis with chronic P. aeruginosa in a phase 3, 16-week, multicenter, double-blind randomized, controlled trial (Guan W-J, et al. Chest. 2023;163[1]:64). A regimen of twice-daily TIS, compared with nebulized normal saline, demonstrated a more significant reduction in P. aeruginosa sputum density after two cycles of 28 days on-treatment and 28 days off-treatment (adjusted mean difference, 1.74 log10 colony-forming units/g; 95% CI, 1.12-2.35; (P < .001), and more patients became culture-negative for P. aeruginosa in the TIS group than in the placebo group on day 29 (29.3% vs 10.6%). Adverse events were similar in both groups. Importantly, there was an improvement in quality-of-life bronchiectasis respiratory symptom score by 7.91 points at day 29 and 6.72 points at day 85; all three were statistically significant but just below the minimal clinically important difference of 8 points.

Dr. Conroy Wong and Dr. Miguel Angel Martinez-Garcia (Chest. 2023 Jan;163[1]:3) highlighted in their accompanying editorial that use of health-related quality of life score was a “distinguishing feature” of the trial as “most studies have used the change in microbial density as the primary outcome measure alone.”

Future studies evaluating cyclical vs continuous antibiotic administration, treatment duration, and impact on exacerbations continue to be needed.

Alicia Mirza, MD
Section Member-at-Large

Airway Disorders Network

Bronchiectasis Section

Bronchiectasis is a condition of dilated, inflamed airways and mucous production caused by a myriad of diseases. Bronchiectasis entails chronic productive cough and an increased risk of infections leading to exacerbations. Chronic bacterial infections are often a hallmark of severe disease, especially with Pseudomonas aeruginosa (O’Donnell AE. N Engl J Med. 2022;387[6]:533). Prophylactic inhaled antibiotics have been used as off-label therapies with mixed evidence, particularly in non-cystic fibrosis bronchiectasis (Rubin BK, et al. Respiration. 2014;88[3]:177). As the incidence of bronchiectasis increases worldwide, the need for evidence-based therapies to reduce symptom burden is increasing.

In a recent publication, Guan and colleagues evaluated the efficacy and safety of tobramycin inhaled solution (TIS) for bronchiectasis with chronic P. aeruginosa in a phase 3, 16-week, multicenter, double-blind randomized, controlled trial (Guan W-J, et al. Chest. 2023;163[1]:64). A regimen of twice-daily TIS, compared with nebulized normal saline, demonstrated a more significant reduction in P. aeruginosa sputum density after two cycles of 28 days on-treatment and 28 days off-treatment (adjusted mean difference, 1.74 log10 colony-forming units/g; 95% CI, 1.12-2.35; (P < .001), and more patients became culture-negative for P. aeruginosa in the TIS group than in the placebo group on day 29 (29.3% vs 10.6%). Adverse events were similar in both groups. Importantly, there was an improvement in quality-of-life bronchiectasis respiratory symptom score by 7.91 points at day 29 and 6.72 points at day 85; all three were statistically significant but just below the minimal clinically important difference of 8 points.

Dr. Conroy Wong and Dr. Miguel Angel Martinez-Garcia (Chest. 2023 Jan;163[1]:3) highlighted in their accompanying editorial that use of health-related quality of life score was a “distinguishing feature” of the trial as “most studies have used the change in microbial density as the primary outcome measure alone.”

Future studies evaluating cyclical vs continuous antibiotic administration, treatment duration, and impact on exacerbations continue to be needed.

Alicia Mirza, MD
Section Member-at-Large

Airway Disorders Network

Bronchiectasis Section

Bronchiectasis is a condition of dilated, inflamed airways and mucous production caused by a myriad of diseases. Bronchiectasis entails chronic productive cough and an increased risk of infections leading to exacerbations. Chronic bacterial infections are often a hallmark of severe disease, especially with Pseudomonas aeruginosa (O’Donnell AE. N Engl J Med. 2022;387[6]:533). Prophylactic inhaled antibiotics have been used as off-label therapies with mixed evidence, particularly in non-cystic fibrosis bronchiectasis (Rubin BK, et al. Respiration. 2014;88[3]:177). As the incidence of bronchiectasis increases worldwide, the need for evidence-based therapies to reduce symptom burden is increasing.

In a recent publication, Guan and colleagues evaluated the efficacy and safety of tobramycin inhaled solution (TIS) for bronchiectasis with chronic P. aeruginosa in a phase 3, 16-week, multicenter, double-blind randomized, controlled trial (Guan W-J, et al. Chest. 2023;163[1]:64). A regimen of twice-daily TIS, compared with nebulized normal saline, demonstrated a more significant reduction in P. aeruginosa sputum density after two cycles of 28 days on-treatment and 28 days off-treatment (adjusted mean difference, 1.74 log10 colony-forming units/g; 95% CI, 1.12-2.35; (P < .001), and more patients became culture-negative for P. aeruginosa in the TIS group than in the placebo group on day 29 (29.3% vs 10.6%). Adverse events were similar in both groups. Importantly, there was an improvement in quality-of-life bronchiectasis respiratory symptom score by 7.91 points at day 29 and 6.72 points at day 85; all three were statistically significant but just below the minimal clinically important difference of 8 points.

Dr. Conroy Wong and Dr. Miguel Angel Martinez-Garcia (Chest. 2023 Jan;163[1]:3) highlighted in their accompanying editorial that use of health-related quality of life score was a “distinguishing feature” of the trial as “most studies have used the change in microbial density as the primary outcome measure alone.”

Future studies evaluating cyclical vs continuous antibiotic administration, treatment duration, and impact on exacerbations continue to be needed.

Alicia Mirza, MD
Section Member-at-Large

Mechanical Ventilation and Airways Section

Noninvasive ventilation

Noninvasive ventilation (NIV) is a ventilation modality that supports breathing by using mechanically assisted breaths without the need for intubation or a surgical airway. NIV is divided into two main types, negative-pressure ventilation (NPV) and noninvasive positive-pressure ventilation (NIPPV).

NPV

NPV periodically generates a negative (subatmospheric) pressure on the thorax wall, reflecting the natural breathing mechanism. As this negative pressure is transmitted into the thorax, normal atmospheric pressure air outside the thorax is pulled in for inhalation. Initiated by the negative pressure generator switching off, exhalation is passive due to elastic recoil of the lung and chest wall. The iron lung was a neck-to-toe horizontal cylinder used for NPV during the polio epidemic. New NPV devices are designed to fit the thorax only, using a cuirass (a torso-covering body armor molded shell).

For years, NPV use declined as NIPPV use increased. However, during the shortage of NIPPV devices during COVID and a recent recall of certain CPAP devices, NPV use has increased. NPV is an excellent alternative for those who cannot tolerate a facial mask due to facial deformity, claustrophobia, or excessive airway secretion (Corrado A et al. European Resp J. 2002;20[1]:187).
 

NIPPV

NIPPV is divided into several subtypes, including continuous positive airway pressure (CPAP), bilevel positive airway pressure (BPAP or BiPAP), and average volume-assured pressure support (AVAPS or VAPS). CPAP is defined as a single pressure delivered in inhalation (Pi) and exhalation (Pe). The increased mean airway pressure provides improved oxygenation (O₂) but not ventilation (CO₂). BPAP uses dual pressures with Pi higher than Pe. The increased mean airway pressure provides improved O₂ while the difference between Pi minus Pe increases ventilation and decreases CO₂.

AVAPS is a form of BPAP where Pi varies in an automated range to achieve the ordered tidal volume. In AVAPS, the generator adjusts Pi based on the average delivered tidal volume. If the average delivered tidal volume is less than the set tidal volume, Pi gradually increases while not exceeding Pi Max. Patients notice improved comfort of AVAPS with a variable Pi vs. BPAP with a fixed Pi (Frank A et al. Chest. 2018;154[4]:1060A).

Samantha Tauscher, DO, Resident-in-Training

Herbert Patrick, MD, MSEE, FCCP , Member-at-Large

Mechanical Ventilation and Airways Section

Noninvasive ventilation

Noninvasive ventilation (NIV) is a ventilation modality that supports breathing by using mechanically assisted breaths without the need for intubation or a surgical airway. NIV is divided into two main types, negative-pressure ventilation (NPV) and noninvasive positive-pressure ventilation (NIPPV).

NPV

NPV periodically generates a negative (subatmospheric) pressure on the thorax wall, reflecting the natural breathing mechanism. As this negative pressure is transmitted into the thorax, normal atmospheric pressure air outside the thorax is pulled in for inhalation. Initiated by the negative pressure generator switching off, exhalation is passive due to elastic recoil of the lung and chest wall. The iron lung was a neck-to-toe horizontal cylinder used for NPV during the polio epidemic. New NPV devices are designed to fit the thorax only, using a cuirass (a torso-covering body armor molded shell).

For years, NPV use declined as NIPPV use increased. However, during the shortage of NIPPV devices during COVID and a recent recall of certain CPAP devices, NPV use has increased. NPV is an excellent alternative for those who cannot tolerate a facial mask due to facial deformity, claustrophobia, or excessive airway secretion (Corrado A et al. European Resp J. 2002;20[1]:187).
 

NIPPV

NIPPV is divided into several subtypes, including continuous positive airway pressure (CPAP), bilevel positive airway pressure (BPAP or BiPAP), and average volume-assured pressure support (AVAPS or VAPS). CPAP is defined as a single pressure delivered in inhalation (Pi) and exhalation (Pe). The increased mean airway pressure provides improved oxygenation (O₂) but not ventilation (CO₂). BPAP uses dual pressures with Pi higher than Pe. The increased mean airway pressure provides improved O₂ while the difference between Pi minus Pe increases ventilation and decreases CO₂.

AVAPS is a form of BPAP where Pi varies in an automated range to achieve the ordered tidal volume. In AVAPS, the generator adjusts Pi based on the average delivered tidal volume. If the average delivered tidal volume is less than the set tidal volume, Pi gradually increases while not exceeding Pi Max. Patients notice improved comfort of AVAPS with a variable Pi vs. BPAP with a fixed Pi (Frank A et al. Chest. 2018;154[4]:1060A).

Samantha Tauscher, DO, Resident-in-Training

Herbert Patrick, MD, MSEE, FCCP , Member-at-Large

Mechanical Ventilation and Airways Section

Noninvasive ventilation

Noninvasive ventilation (NIV) is a ventilation modality that supports breathing by using mechanically assisted breaths without the need for intubation or a surgical airway. NIV is divided into two main types, negative-pressure ventilation (NPV) and noninvasive positive-pressure ventilation (NIPPV).

NPV

NPV periodically generates a negative (subatmospheric) pressure on the thorax wall, reflecting the natural breathing mechanism. As this negative pressure is transmitted into the thorax, normal atmospheric pressure air outside the thorax is pulled in for inhalation. Initiated by the negative pressure generator switching off, exhalation is passive due to elastic recoil of the lung and chest wall. The iron lung was a neck-to-toe horizontal cylinder used for NPV during the polio epidemic. New NPV devices are designed to fit the thorax only, using a cuirass (a torso-covering body armor molded shell).

For years, NPV use declined as NIPPV use increased. However, during the shortage of NIPPV devices during COVID and a recent recall of certain CPAP devices, NPV use has increased. NPV is an excellent alternative for those who cannot tolerate a facial mask due to facial deformity, claustrophobia, or excessive airway secretion (Corrado A et al. European Resp J. 2002;20[1]:187).
 

NIPPV

NIPPV is divided into several subtypes, including continuous positive airway pressure (CPAP), bilevel positive airway pressure (BPAP or BiPAP), and average volume-assured pressure support (AVAPS or VAPS). CPAP is defined as a single pressure delivered in inhalation (Pi) and exhalation (Pe). The increased mean airway pressure provides improved oxygenation (O₂) but not ventilation (CO₂). BPAP uses dual pressures with Pi higher than Pe. The increased mean airway pressure provides improved O₂ while the difference between Pi minus Pe increases ventilation and decreases CO₂.

AVAPS is a form of BPAP where Pi varies in an automated range to achieve the ordered tidal volume. In AVAPS, the generator adjusts Pi based on the average delivered tidal volume. If the average delivered tidal volume is less than the set tidal volume, Pi gradually increases while not exceeding Pi Max. Patients notice improved comfort of AVAPS with a variable Pi vs. BPAP with a fixed Pi (Frank A et al. Chest. 2018;154[4]:1060A).

Samantha Tauscher, DO, Resident-in-Training

Herbert Patrick, MD, MSEE, FCCP , Member-at-Large

Diffuse Lung Disease & Transplant Network

Interstitial Lung Disease Section

Delay in diagnosis of IPF: How bad is the problem?

Idiopathic pulmonary fibrosis (IPF) is a devastating disease with a poor prognosis. Antifibrotic therapies for IPF are only capable of slowing disease progression without reversing established fibrosis. As such, the therapeutic efficacy of antifibrotic therapy may be reduced in patients whose diagnosis is delayed.

Unfortunately, diagnostic delay is common in IPF. Studies demonstrate that IPF diagnosis is delayed by more than a year after symptom onset in 43% of subjects, and more than 3 years in 19% of subjects (Cosgrove GP et al. BMC Pulm Med. 2018;18[9]). Approximately one-third of patients with IPF have undergone chest CT imaging more than 3 years prior to diagnosis, and around the same proportion has seen a pulmonologist within the same time span (Mooney J, et al. Ann Am Thorac Soc. 2019;16[3]:393). A median delay to IPF diagnosis of 2.2 years was noted in patients presenting to a tertiary academic medical center and was associated with an increased risk of death independent of age, sex, and forced vital capacity (adjusted hazard ratio per doubling of delay was 1.3) (Lamas DJ et al. Am J Respir Crit Care Med. 2011;184:842).

Robust improvements are clearly required for identifying patients with IPF earlier in their disease course. The Bridging Specialties Initiative from CHEST and the Three Lakes Foundation is one resource designed to improve the timely diagnosis of ILD (ILD Clinician Toolkit available at https://www.chestnet.org/Guidelines-and-Topic-Collections/Bridging-Specialties/Timely-Diagnosis-for-ILD-Patients/Clinician-Toolkit). This, and other initiatives will hopefully reduce delays in diagnosing IPF, allowing for optimal patient care.

Adrian Shifren, MBBCh, FCCP, Member-at-Large

Saniya Khan, MD, MBBS, Member-at-Large

Robert Case Jr., MD, Pulmonary & Critical Care Fellow
 

Critical Care Network

Mechanical Ventilation and Airways Section

Noninvasive ventilation

Noninvasive ventilation (NIV) is a ventilation modality that supports breathing by using mechanically assisted breaths without the need for intubation or a surgical airway. NIV is divided into two main types, negative-pressure ventilation (NPV) and noninvasive positive-pressure ventilation (NIPPV).

NPV

NPV periodically generates a negative (subatmospheric) pressure on the thorax wall, reflecting the natural breathing mechanism. As this negative pressure is transmitted into the thorax, normal atmospheric pressure air outside the thorax is pulled in for inhalation. Initiated by the negative pressure generator switching off, exhalation is passive due to elastic recoil of the lung and chest wall. The iron lung was a neck-to-toe horizontal cylinder used for NPV during the polio epidemic. New NPV devices are designed to fit the thorax only, using a cuirass (a torso-covering body armor molded shell).

For years, NPV use declined as NIPPV use increased. However, during the shortage of NIPPV devices during COVID and a recent recall of certain CPAP devices, NPV use has increased. NPV is an excellent alternative for those who cannot tolerate a facial mask due to facial deformity, claustrophobia, or excessive airway secretion (Corrado A et al. European Resp J. 2002;20[1]:187).
 

NIPPV

NIPPV is divided into several subtypes, including continuous positive airway pressure (CPAP), bilevel positive airway pressure (BPAP or BiPAP), and average volume-assured pressure support (AVAPS or VAPS). CPAP is defined as a single pressure delivered in inhalation (Pi) and exhalation (Pe). The increased mean airway pressure provides improved oxygenation (O₂) but not ventilation (CO₂). BPAP uses dual pressures with Pi higher than Pe. The increased mean airway pressure provides improved O₂ while the difference between Pi minus Pe increases ventilation and decreases CO₂.

AVAPS is a form of BPAP where Pi varies in an automated range to achieve the ordered tidal volume. In AVAPS, the generator adjusts Pi based on the average delivered tidal volume. If the average delivered tidal volume is less than the set tidal volume, Pi gradually increases while not exceeding Pi Max. Patients notice improved comfort of AVAPS with a variable Pi vs. BPAP with a fixed Pi (Frank A et al. Chest. 2018;154[4]:1060A).

Samantha Tauscher, DO, Resident-in-Training

Herbert Patrick, MD, MSEE, FCCP , Member-at-Large
 

Pulmonary Vascular & Cardiovascular Disease Network

Pulmonary Vascular Disease Section

A RACE to the finish: Revisiting the role of BPA in the management of CTEPH

Pulmonary thromboendarterectomy (PTE) is the treatment of choice for patients with CTEPH (Kim NH et al. Eur Respir J. 2019;53:1801915). However, this leaves about 40% of CTEPH patients who are not operative candidates due to inaccessible distal clot burden or significant comorbidities (Pepke-Zaba J et al. Circulation 2011;124:1973). For these inoperable situations, riociguat is the only FDA-approved medical therapy (Delcroix M et al. Eur Respir J. 2021;57:2002828). Balloon pulmonary angioplasty (BPA) became a treatment option for these patients in the last 2 decades. As technique refined, BPA demonstrated improved safety data along with improved hemodynamics and increased exercise capacity (Kataoka M et al. Circ Cardiovasc Interv. 2012;5:756).

A recently published crossover study, the RACE trial, compared riociguat with BPA in treating inoperable CTEPH (Jaïs X et al. Lancet Respir Med. 2022;10[10]:961). Patients were randomly assigned to either riociguat or BPA for 26 weeks. At 26 weeks, patients with pulmonary vascular resistance (PVR) more than 4 Woods Units (WU) were crossed over to receive either BPA or riociguat therapy. At 26 weeks, the BPA arm showed a greater reduction in PVR but more complications, including lung injury and hemoptysis. After a 26-week crossover period, the reduction in PVR was similar in both arms. The complication rate in the BPA arm was lower when preceded by riociguat.

In patients with inoperable CTEPH, BPA has emerged as an attractive management option in addition to the medical therapy with riociguat. However, BPA should be performed at expert centers with experience. Further studies are needed to strengthen the role and optimal timing of BPA in management of post PTE patients with residual PH.

Samantha Pettigrew, MD, Fellow-in-Training

Janine Vintich, MD, FCCP, Member-at-Large

Diffuse Lung Disease & Transplant Network

Interstitial Lung Disease Section

Delay in diagnosis of IPF: How bad is the problem?

Idiopathic pulmonary fibrosis (IPF) is a devastating disease with a poor prognosis. Antifibrotic therapies for IPF are only capable of slowing disease progression without reversing established fibrosis. As such, the therapeutic efficacy of antifibrotic therapy may be reduced in patients whose diagnosis is delayed.

Unfortunately, diagnostic delay is common in IPF. Studies demonstrate that IPF diagnosis is delayed by more than a year after symptom onset in 43% of subjects, and more than 3 years in 19% of subjects (Cosgrove GP et al. BMC Pulm Med. 2018;18[9]). Approximately one-third of patients with IPF have undergone chest CT imaging more than 3 years prior to diagnosis, and around the same proportion has seen a pulmonologist within the same time span (Mooney J, et al. Ann Am Thorac Soc. 2019;16[3]:393). A median delay to IPF diagnosis of 2.2 years was noted in patients presenting to a tertiary academic medical center and was associated with an increased risk of death independent of age, sex, and forced vital capacity (adjusted hazard ratio per doubling of delay was 1.3) (Lamas DJ et al. Am J Respir Crit Care Med. 2011;184:842).

Robust improvements are clearly required for identifying patients with IPF earlier in their disease course. The Bridging Specialties Initiative from CHEST and the Three Lakes Foundation is one resource designed to improve the timely diagnosis of ILD (ILD Clinician Toolkit available at https://www.chestnet.org/Guidelines-and-Topic-Collections/Bridging-Specialties/Timely-Diagnosis-for-ILD-Patients/Clinician-Toolkit). This, and other initiatives will hopefully reduce delays in diagnosing IPF, allowing for optimal patient care.

Adrian Shifren, MBBCh, FCCP, Member-at-Large

Saniya Khan, MD, MBBS, Member-at-Large

Robert Case Jr., MD, Pulmonary & Critical Care Fellow
 

Critical Care Network

Mechanical Ventilation and Airways Section

Noninvasive ventilation

Noninvasive ventilation (NIV) is a ventilation modality that supports breathing by using mechanically assisted breaths without the need for intubation or a surgical airway. NIV is divided into two main types, negative-pressure ventilation (NPV) and noninvasive positive-pressure ventilation (NIPPV).

NPV

NPV periodically generates a negative (subatmospheric) pressure on the thorax wall, reflecting the natural breathing mechanism. As this negative pressure is transmitted into the thorax, normal atmospheric pressure air outside the thorax is pulled in for inhalation. Initiated by the negative pressure generator switching off, exhalation is passive due to elastic recoil of the lung and chest wall. The iron lung was a neck-to-toe horizontal cylinder used for NPV during the polio epidemic. New NPV devices are designed to fit the thorax only, using a cuirass (a torso-covering body armor molded shell).

For years, NPV use declined as NIPPV use increased. However, during the shortage of NIPPV devices during COVID and a recent recall of certain CPAP devices, NPV use has increased. NPV is an excellent alternative for those who cannot tolerate a facial mask due to facial deformity, claustrophobia, or excessive airway secretion (Corrado A et al. European Resp J. 2002;20[1]:187).
 

NIPPV

NIPPV is divided into several subtypes, including continuous positive airway pressure (CPAP), bilevel positive airway pressure (BPAP or BiPAP), and average volume-assured pressure support (AVAPS or VAPS). CPAP is defined as a single pressure delivered in inhalation (Pi) and exhalation (Pe). The increased mean airway pressure provides improved oxygenation (O₂) but not ventilation (CO₂). BPAP uses dual pressures with Pi higher than Pe. The increased mean airway pressure provides improved O₂ while the difference between Pi minus Pe increases ventilation and decreases CO₂.

AVAPS is a form of BPAP where Pi varies in an automated range to achieve the ordered tidal volume. In AVAPS, the generator adjusts Pi based on the average delivered tidal volume. If the average delivered tidal volume is less than the set tidal volume, Pi gradually increases while not exceeding Pi Max. Patients notice improved comfort of AVAPS with a variable Pi vs. BPAP with a fixed Pi (Frank A et al. Chest. 2018;154[4]:1060A).

Samantha Tauscher, DO, Resident-in-Training

Herbert Patrick, MD, MSEE, FCCP , Member-at-Large
 

Pulmonary Vascular & Cardiovascular Disease Network

Pulmonary Vascular Disease Section

A RACE to the finish: Revisiting the role of BPA in the management of CTEPH

Pulmonary thromboendarterectomy (PTE) is the treatment of choice for patients with CTEPH (Kim NH et al. Eur Respir J. 2019;53:1801915). However, this leaves about 40% of CTEPH patients who are not operative candidates due to inaccessible distal clot burden or significant comorbidities (Pepke-Zaba J et al. Circulation 2011;124:1973). For these inoperable situations, riociguat is the only FDA-approved medical therapy (Delcroix M et al. Eur Respir J. 2021;57:2002828). Balloon pulmonary angioplasty (BPA) became a treatment option for these patients in the last 2 decades. As technique refined, BPA demonstrated improved safety data along with improved hemodynamics and increased exercise capacity (Kataoka M et al. Circ Cardiovasc Interv. 2012;5:756).

A recently published crossover study, the RACE trial, compared riociguat with BPA in treating inoperable CTEPH (Jaïs X et al. Lancet Respir Med. 2022;10[10]:961). Patients were randomly assigned to either riociguat or BPA for 26 weeks. At 26 weeks, patients with pulmonary vascular resistance (PVR) more than 4 Woods Units (WU) were crossed over to receive either BPA or riociguat therapy. At 26 weeks, the BPA arm showed a greater reduction in PVR but more complications, including lung injury and hemoptysis. After a 26-week crossover period, the reduction in PVR was similar in both arms. The complication rate in the BPA arm was lower when preceded by riociguat.

In patients with inoperable CTEPH, BPA has emerged as an attractive management option in addition to the medical therapy with riociguat. However, BPA should be performed at expert centers with experience. Further studies are needed to strengthen the role and optimal timing of BPA in management of post PTE patients with residual PH.

Samantha Pettigrew, MD, Fellow-in-Training

Janine Vintich, MD, FCCP, Member-at-Large

Diffuse Lung Disease & Transplant Network

Interstitial Lung Disease Section

Delay in diagnosis of IPF: How bad is the problem?

Idiopathic pulmonary fibrosis (IPF) is a devastating disease with a poor prognosis. Antifibrotic therapies for IPF are only capable of slowing disease progression without reversing established fibrosis. As such, the therapeutic efficacy of antifibrotic therapy may be reduced in patients whose diagnosis is delayed.

Unfortunately, diagnostic delay is common in IPF. Studies demonstrate that IPF diagnosis is delayed by more than a year after symptom onset in 43% of subjects, and more than 3 years in 19% of subjects (Cosgrove GP et al. BMC Pulm Med. 2018;18[9]). Approximately one-third of patients with IPF have undergone chest CT imaging more than 3 years prior to diagnosis, and around the same proportion has seen a pulmonologist within the same time span (Mooney J, et al. Ann Am Thorac Soc. 2019;16[3]:393). A median delay to IPF diagnosis of 2.2 years was noted in patients presenting to a tertiary academic medical center and was associated with an increased risk of death independent of age, sex, and forced vital capacity (adjusted hazard ratio per doubling of delay was 1.3) (Lamas DJ et al. Am J Respir Crit Care Med. 2011;184:842).

Robust improvements are clearly required for identifying patients with IPF earlier in their disease course. The Bridging Specialties Initiative from CHEST and the Three Lakes Foundation is one resource designed to improve the timely diagnosis of ILD (ILD Clinician Toolkit available at https://www.chestnet.org/Guidelines-and-Topic-Collections/Bridging-Specialties/Timely-Diagnosis-for-ILD-Patients/Clinician-Toolkit). This, and other initiatives will hopefully reduce delays in diagnosing IPF, allowing for optimal patient care.

Adrian Shifren, MBBCh, FCCP, Member-at-Large

Saniya Khan, MD, MBBS, Member-at-Large

Robert Case Jr., MD, Pulmonary & Critical Care Fellow
 

Critical Care Network

Mechanical Ventilation and Airways Section

Noninvasive ventilation

Noninvasive ventilation (NIV) is a ventilation modality that supports breathing by using mechanically assisted breaths without the need for intubation or a surgical airway. NIV is divided into two main types, negative-pressure ventilation (NPV) and noninvasive positive-pressure ventilation (NIPPV).

NPV

NPV periodically generates a negative (subatmospheric) pressure on the thorax wall, reflecting the natural breathing mechanism. As this negative pressure is transmitted into the thorax, normal atmospheric pressure air outside the thorax is pulled in for inhalation. Initiated by the negative pressure generator switching off, exhalation is passive due to elastic recoil of the lung and chest wall. The iron lung was a neck-to-toe horizontal cylinder used for NPV during the polio epidemic. New NPV devices are designed to fit the thorax only, using a cuirass (a torso-covering body armor molded shell).

For years, NPV use declined as NIPPV use increased. However, during the shortage of NIPPV devices during COVID and a recent recall of certain CPAP devices, NPV use has increased. NPV is an excellent alternative for those who cannot tolerate a facial mask due to facial deformity, claustrophobia, or excessive airway secretion (Corrado A et al. European Resp J. 2002;20[1]:187).
 

NIPPV

NIPPV is divided into several subtypes, including continuous positive airway pressure (CPAP), bilevel positive airway pressure (BPAP or BiPAP), and average volume-assured pressure support (AVAPS or VAPS). CPAP is defined as a single pressure delivered in inhalation (Pi) and exhalation (Pe). The increased mean airway pressure provides improved oxygenation (O₂) but not ventilation (CO₂). BPAP uses dual pressures with Pi higher than Pe. The increased mean airway pressure provides improved O₂ while the difference between Pi minus Pe increases ventilation and decreases CO₂.

AVAPS is a form of BPAP where Pi varies in an automated range to achieve the ordered tidal volume. In AVAPS, the generator adjusts Pi based on the average delivered tidal volume. If the average delivered tidal volume is less than the set tidal volume, Pi gradually increases while not exceeding Pi Max. Patients notice improved comfort of AVAPS with a variable Pi vs. BPAP with a fixed Pi (Frank A et al. Chest. 2018;154[4]:1060A).

Samantha Tauscher, DO, Resident-in-Training

Herbert Patrick, MD, MSEE, FCCP , Member-at-Large
 

Pulmonary Vascular & Cardiovascular Disease Network

Pulmonary Vascular Disease Section

A RACE to the finish: Revisiting the role of BPA in the management of CTEPH

Pulmonary thromboendarterectomy (PTE) is the treatment of choice for patients with CTEPH (Kim NH et al. Eur Respir J. 2019;53:1801915). However, this leaves about 40% of CTEPH patients who are not operative candidates due to inaccessible distal clot burden or significant comorbidities (Pepke-Zaba J et al. Circulation 2011;124:1973). For these inoperable situations, riociguat is the only FDA-approved medical therapy (Delcroix M et al. Eur Respir J. 2021;57:2002828). Balloon pulmonary angioplasty (BPA) became a treatment option for these patients in the last 2 decades. As technique refined, BPA demonstrated improved safety data along with improved hemodynamics and increased exercise capacity (Kataoka M et al. Circ Cardiovasc Interv. 2012;5:756).

A recently published crossover study, the RACE trial, compared riociguat with BPA in treating inoperable CTEPH (Jaïs X et al. Lancet Respir Med. 2022;10[10]:961). Patients were randomly assigned to either riociguat or BPA for 26 weeks. At 26 weeks, patients with pulmonary vascular resistance (PVR) more than 4 Woods Units (WU) were crossed over to receive either BPA or riociguat therapy. At 26 weeks, the BPA arm showed a greater reduction in PVR but more complications, including lung injury and hemoptysis. After a 26-week crossover period, the reduction in PVR was similar in both arms. The complication rate in the BPA arm was lower when preceded by riociguat.

In patients with inoperable CTEPH, BPA has emerged as an attractive management option in addition to the medical therapy with riociguat. However, BPA should be performed at expert centers with experience. Further studies are needed to strengthen the role and optimal timing of BPA in management of post PTE patients with residual PH.

Samantha Pettigrew, MD, Fellow-in-Training

Janine Vintich, MD, FCCP, Member-at-Large

Ultrasound & Chest Imaging Section

VExUS scan: The missing piece of hemodynamic puzzle?

Volume status and tailoring the correct level of fluid resuscitation is challenging for the intensivist. Determining “fluid overload,” especially in the setting of acute kidney injury, can be difficult. While a Swan-Ganz catheter, central venous pressure, or inferior vena cava (IVC) ultrasound measurement can suggest elevated right atrial pressure, the effect on organ level hemodynamics is unknown.

Abdominal venous Doppler is a method to view the effects of venous pressure on abdominal organ venous flow. An application of this is the Venous Excess Ultrasound Score (VExUS) (Rola, et al. Ultrasound J. 2021;13[1]:32). VExUS uses IVC diameter and pulse wave doppler waveforms from the hepatic, portal, and renal veins to grade venous congestion from none to severe. Studies demonstrate an association between venous congestion and renal dysfunction in cardiac surgery (Beaubien-Souligny, et al. Ultrasound J. 2020;12[1]:16) and general ICU patients (Spiegel, et al. Crit Care. 2020;24[1]:615).

This practice of identifying venous congestion and avoiding over-resuscitation could improve patient care. However, acquiring quality images and waveforms may prove to be difficult, and interpretation may be confounded by other disease states such as cirrhosis. Though it is postulated that removing fluid could be beneficial to patients with high VExUS scores, this has yet to be proven and may be difficult to prove. While the score estimates volume status well, the source of venous congestion is not identified such that it should be used as a clinical supplement to other data.

VExUS has a strong physiologic basis, and early clinical experience indicates a strong role in improving assessment of venous congestion, an important aspect of volume status. This is an area of ongoing research to ensure appropriate and effective use.

Kyle Swartz, DO
Fellow-in-Training

Steven Fox, MD
Fellow-in-Training

John Levasseur, DO

Ultrasound & Chest Imaging Section

VExUS scan: The missing piece of hemodynamic puzzle?

Volume status and tailoring the correct level of fluid resuscitation is challenging for the intensivist. Determining “fluid overload,” especially in the setting of acute kidney injury, can be difficult. While a Swan-Ganz catheter, central venous pressure, or inferior vena cava (IVC) ultrasound measurement can suggest elevated right atrial pressure, the effect on organ level hemodynamics is unknown.

Abdominal venous Doppler is a method to view the effects of venous pressure on abdominal organ venous flow. An application of this is the Venous Excess Ultrasound Score (VExUS) (Rola, et al. Ultrasound J. 2021;13[1]:32). VExUS uses IVC diameter and pulse wave doppler waveforms from the hepatic, portal, and renal veins to grade venous congestion from none to severe. Studies demonstrate an association between venous congestion and renal dysfunction in cardiac surgery (Beaubien-Souligny, et al. Ultrasound J. 2020;12[1]:16) and general ICU patients (Spiegel, et al. Crit Care. 2020;24[1]:615).

This practice of identifying venous congestion and avoiding over-resuscitation could improve patient care. However, acquiring quality images and waveforms may prove to be difficult, and interpretation may be confounded by other disease states such as cirrhosis. Though it is postulated that removing fluid could be beneficial to patients with high VExUS scores, this has yet to be proven and may be difficult to prove. While the score estimates volume status well, the source of venous congestion is not identified such that it should be used as a clinical supplement to other data.

VExUS has a strong physiologic basis, and early clinical experience indicates a strong role in improving assessment of venous congestion, an important aspect of volume status. This is an area of ongoing research to ensure appropriate and effective use.

Kyle Swartz, DO
Fellow-in-Training

Steven Fox, MD
Fellow-in-Training

John Levasseur, DO

Ultrasound & Chest Imaging Section

VExUS scan: The missing piece of hemodynamic puzzle?

Volume status and tailoring the correct level of fluid resuscitation is challenging for the intensivist. Determining “fluid overload,” especially in the setting of acute kidney injury, can be difficult. While a Swan-Ganz catheter, central venous pressure, or inferior vena cava (IVC) ultrasound measurement can suggest elevated right atrial pressure, the effect on organ level hemodynamics is unknown.

Abdominal venous Doppler is a method to view the effects of venous pressure on abdominal organ venous flow. An application of this is the Venous Excess Ultrasound Score (VExUS) (Rola, et al. Ultrasound J. 2021;13[1]:32). VExUS uses IVC diameter and pulse wave doppler waveforms from the hepatic, portal, and renal veins to grade venous congestion from none to severe. Studies demonstrate an association between venous congestion and renal dysfunction in cardiac surgery (Beaubien-Souligny, et al. Ultrasound J. 2020;12[1]:16) and general ICU patients (Spiegel, et al. Crit Care. 2020;24[1]:615).

This practice of identifying venous congestion and avoiding over-resuscitation could improve patient care. However, acquiring quality images and waveforms may prove to be difficult, and interpretation may be confounded by other disease states such as cirrhosis. Though it is postulated that removing fluid could be beneficial to patients with high VExUS scores, this has yet to be proven and may be difficult to prove. While the score estimates volume status well, the source of venous congestion is not identified such that it should be used as a clinical supplement to other data.

VExUS has a strong physiologic basis, and early clinical experience indicates a strong role in improving assessment of venous congestion, an important aspect of volume status. This is an area of ongoing research to ensure appropriate and effective use.

Kyle Swartz, DO
Fellow-in-Training

Steven Fox, MD
Fellow-in-Training

John Levasseur, DO

Sepsis/Shock Section

Fluid Resuscitation – Back to BaSICS

The age-old debate regarding the appropriate timing, volume, and type of fluid resuscitation for patients in septic shock rages on – or does it? In October 2021, the Surviving Sepsis Campaign published updated guidelines for the management of sepsis. One of the biggest changes from prior versions was downgrading the recommendation for an initial 30mL/kg bolus of IV crystalloid for the initial resuscitation of a patient in septic shock to a suggestion, based on dynamic measures to assess individual patients’ fluid balance (Evans, et al. Crit Care Med. 2021;49[11]:e1063-e1143).

Courtesy CHEST

Traditionally, 0.9% saline had been the resuscitative fluid of choice in sepsis. But it has a propensity to cause physiologic derangements such as hyperchloremic metabolic acidosis, renal afferent vasoconstriction, and reduced glomerular filtration rate – not to mention, can be a signal for possibly increased mortality, as seen in the SMART trial (Semler, et al. N Engl J Med. 2018;378[9]:829-839). Normal saline had subsequently fallen from grace in favor of balanced crystalloids such as Lactated Ringer’s and Plasma-Lyte. However, the recent PLUS and BaSICS trials showed no significant difference in 90-day mortality or secondary outcomes of acute kidney injury, need for renal replacement therapy, or ICU mortality (Finfer, et al. N Engl J Med. 2022;386[9]:815-826; Zampieri, et al. JAMA. 2021;326[9]:818-829). While these are large randomized controlled trials, a major weakness is the administration of uncontrolled resuscitative fluids prior to randomization and even postenrollment, which may have biased results.

Ultimately, does the choice between salt water or balanced crystalloids matter? Despite the limitations in the newest trials, probably less than the timely administration of antibiotics and pressors, unless your patient also has a traumatic TBI – then go with the saline. But, in the everlasting quest for medical excellence, choosing the balanced fluid that causes the least physiologic derangement seems to make the most sense.

LCDR Meredith Olsen, MD, USN
Fellow-in-Training

Ankita Agarwal, MD
Fellow-in-Training

The views expressed are those of the authors and do not reflect the official policy or position of the U.S. Navy, Department of Defense, or the U.S. Government.

Sepsis/Shock Section

Fluid Resuscitation – Back to BaSICS

The age-old debate regarding the appropriate timing, volume, and type of fluid resuscitation for patients in septic shock rages on – or does it? In October 2021, the Surviving Sepsis Campaign published updated guidelines for the management of sepsis. One of the biggest changes from prior versions was downgrading the recommendation for an initial 30mL/kg bolus of IV crystalloid for the initial resuscitation of a patient in septic shock to a suggestion, based on dynamic measures to assess individual patients’ fluid balance (Evans, et al. Crit Care Med. 2021;49[11]:e1063-e1143).

Courtesy CHEST

Traditionally, 0.9% saline had been the resuscitative fluid of choice in sepsis. But it has a propensity to cause physiologic derangements such as hyperchloremic metabolic acidosis, renal afferent vasoconstriction, and reduced glomerular filtration rate – not to mention, can be a signal for possibly increased mortality, as seen in the SMART trial (Semler, et al. N Engl J Med. 2018;378[9]:829-839). Normal saline had subsequently fallen from grace in favor of balanced crystalloids such as Lactated Ringer’s and Plasma-Lyte. However, the recent PLUS and BaSICS trials showed no significant difference in 90-day mortality or secondary outcomes of acute kidney injury, need for renal replacement therapy, or ICU mortality (Finfer, et al. N Engl J Med. 2022;386[9]:815-826; Zampieri, et al. JAMA. 2021;326[9]:818-829). While these are large randomized controlled trials, a major weakness is the administration of uncontrolled resuscitative fluids prior to randomization and even postenrollment, which may have biased results.

Ultimately, does the choice between salt water or balanced crystalloids matter? Despite the limitations in the newest trials, probably less than the timely administration of antibiotics and pressors, unless your patient also has a traumatic TBI – then go with the saline. But, in the everlasting quest for medical excellence, choosing the balanced fluid that causes the least physiologic derangement seems to make the most sense.

LCDR Meredith Olsen, MD, USN
Fellow-in-Training

Ankita Agarwal, MD
Fellow-in-Training

The views expressed are those of the authors and do not reflect the official policy or position of the U.S. Navy, Department of Defense, or the U.S. Government.

Sepsis/Shock Section

Fluid Resuscitation – Back to BaSICS

The age-old debate regarding the appropriate timing, volume, and type of fluid resuscitation for patients in septic shock rages on – or does it? In October 2021, the Surviving Sepsis Campaign published updated guidelines for the management of sepsis. One of the biggest changes from prior versions was downgrading the recommendation for an initial 30mL/kg bolus of IV crystalloid for the initial resuscitation of a patient in septic shock to a suggestion, based on dynamic measures to assess individual patients’ fluid balance (Evans, et al. Crit Care Med. 2021;49[11]:e1063-e1143).

Courtesy CHEST

Traditionally, 0.9% saline had been the resuscitative fluid of choice in sepsis. But it has a propensity to cause physiologic derangements such as hyperchloremic metabolic acidosis, renal afferent vasoconstriction, and reduced glomerular filtration rate – not to mention, can be a signal for possibly increased mortality, as seen in the SMART trial (Semler, et al. N Engl J Med. 2018;378[9]:829-839). Normal saline had subsequently fallen from grace in favor of balanced crystalloids such as Lactated Ringer’s and Plasma-Lyte. However, the recent PLUS and BaSICS trials showed no significant difference in 90-day mortality or secondary outcomes of acute kidney injury, need for renal replacement therapy, or ICU mortality (Finfer, et al. N Engl J Med. 2022;386[9]:815-826; Zampieri, et al. JAMA. 2021;326[9]:818-829). While these are large randomized controlled trials, a major weakness is the administration of uncontrolled resuscitative fluids prior to randomization and even postenrollment, which may have biased results.

Ultimately, does the choice between salt water or balanced crystalloids matter? Despite the limitations in the newest trials, probably less than the timely administration of antibiotics and pressors, unless your patient also has a traumatic TBI – then go with the saline. But, in the everlasting quest for medical excellence, choosing the balanced fluid that causes the least physiologic derangement seems to make the most sense.

LCDR Meredith Olsen, MD, USN
Fellow-in-Training

Ankita Agarwal, MD
Fellow-in-Training

The views expressed are those of the authors and do not reflect the official policy or position of the U.S. Navy, Department of Defense, or the U.S. Government.

Pulmonary Vascular Disease Section

Key messages from the 2022 ESC/ERS Guidelines for the Diagnosis and Treatment of Pulmonary Hypertension

1. Per coverage by the American College of Cardiology, “Pulmonary hypertension (PH) is now defined by a mean pulmonary arterial pressure >20 mm Hg at rest. The definition of pulmonary arterial hypertension (PAH) also implies a pulmonary vascular resistance (PVR) >2 Wood units and pulmonary arterial wedge pressure ≤15 mm Hg.”¹ These cut-off values do not translate into new therapeutic recommendations.

2. The diagnostic algorithm for PH now follows a simplified three-step approach, involving first suspicion by first-line physicians, then detection by echocardiography, and confirmation with right heart catheterization, preferably in a PH center.

3. Pulmonary vasoreactivity testing is only recommended in patients with idiopathic PAH, heritable PAH, or drug/toxin associated PAH to identify potential candidates for calcium channel blocker therapy. Inhaled nitric oxide or inhaled iloprost are the recommended agents.

*Mary Jo S. Farmer, MD, PhD
 Member-at-Large

Vijay Balasubramanian, MD, MRCP (UK)
Chair
 

*  The authors for this article were listed in the incorrect order in the print edition of CHEST Physician. The order has been corrected here.

References

1. Mukherjee, D. 2022 ESC/ERS guidelines for pulmonary hypertension: key points. American College of Cardiology. August 30, 2022.

2. Humbert M, Kovacs G, Hoeper MM, et al. 2022 ESC/ERS guidelines for the diagnosis and treatment of pulmonary hypertension. Eur Heart J. 2022;43(38):3618-3731.
 

Pulmonary Vascular Disease Section

Key messages from the 2022 ESC/ERS Guidelines for the Diagnosis and Treatment of Pulmonary Hypertension

1. Per coverage by the American College of Cardiology, “Pulmonary hypertension (PH) is now defined by a mean pulmonary arterial pressure >20 mm Hg at rest. The definition of pulmonary arterial hypertension (PAH) also implies a pulmonary vascular resistance (PVR) >2 Wood units and pulmonary arterial wedge pressure ≤15 mm Hg.”¹ These cut-off values do not translate into new therapeutic recommendations.

2. The diagnostic algorithm for PH now follows a simplified three-step approach, involving first suspicion by first-line physicians, then detection by echocardiography, and confirmation with right heart catheterization, preferably in a PH center.

3. Pulmonary vasoreactivity testing is only recommended in patients with idiopathic PAH, heritable PAH, or drug/toxin associated PAH to identify potential candidates for calcium channel blocker therapy. Inhaled nitric oxide or inhaled iloprost are the recommended agents.

*Mary Jo S. Farmer, MD, PhD
 Member-at-Large

Vijay Balasubramanian, MD, MRCP (UK)
Chair
 

*  The authors for this article were listed in the incorrect order in the print edition of CHEST Physician. The order has been corrected here.

References

1. Mukherjee, D. 2022 ESC/ERS guidelines for pulmonary hypertension: key points. American College of Cardiology. August 30, 2022.

2. Humbert M, Kovacs G, Hoeper MM, et al. 2022 ESC/ERS guidelines for the diagnosis and treatment of pulmonary hypertension. Eur Heart J. 2022;43(38):3618-3731.
 

Pulmonary Vascular Disease Section

Key messages from the 2022 ESC/ERS Guidelines for the Diagnosis and Treatment of Pulmonary Hypertension

1. Per coverage by the American College of Cardiology, “Pulmonary hypertension (PH) is now defined by a mean pulmonary arterial pressure >20 mm Hg at rest. The definition of pulmonary arterial hypertension (PAH) also implies a pulmonary vascular resistance (PVR) >2 Wood units and pulmonary arterial wedge pressure ≤15 mm Hg.”¹ These cut-off values do not translate into new therapeutic recommendations.

2. The diagnostic algorithm for PH now follows a simplified three-step approach, involving first suspicion by first-line physicians, then detection by echocardiography, and confirmation with right heart catheterization, preferably in a PH center.

3. Pulmonary vasoreactivity testing is only recommended in patients with idiopathic PAH, heritable PAH, or drug/toxin associated PAH to identify potential candidates for calcium channel blocker therapy. Inhaled nitric oxide or inhaled iloprost are the recommended agents.

*Mary Jo S. Farmer, MD, PhD
 Member-at-Large

Vijay Balasubramanian, MD, MRCP (UK)
Chair
 

*  The authors for this article were listed in the incorrect order in the print edition of CHEST Physician. The order has been corrected here.

References

1. Mukherjee, D. 2022 ESC/ERS guidelines for pulmonary hypertension: key points. American College of Cardiology. August 30, 2022.

2. Humbert M, Kovacs G, Hoeper MM, et al. 2022 ESC/ERS guidelines for the diagnosis and treatment of pulmonary hypertension. Eur Heart J. 2022;43(38):3618-3731.
 

Pulmonary Physiology & Rehabilitation Section

Exercise tolerance in untreated sleep apnea

Numerous cardiovascular, respiratory, neuromuscular, and perceptual factors determine exercise tolerance. This makes designing a study to isolate the contribution of one factor difficult.

A recently published study (Elbehairy, et al. Chest. 2022; published online September 29, 2022) explores exercise tolerance in patients with untreated OSA compared with age- and weight-matched controls. The authors found that at an equivalent work rate, patients with OSA had greater minute ventilation, principally due to higher breathing frequency. Dead space volume, dead space ventilation, and dead space to tidal volume ratio (VD/VT) were higher in patients with OSA, likely due to a reduction in pulmonary vessel recruitment relative to ventilation. VD/VT decreased more from rest to peak in controls than in patients with OSA, an adaptation that is expected with exercise. Patients with OSA had greater arterial stiffness measured by pulse wave velocity and higher blood pressures, which may have affected cardiac output augmentation. Patients with OSA also had higher resting mean pulmonary artery pressures and exercise dyspnea scores. Regression models predicting peak oxygen uptake and peak work rate were statistically significant, with predictors being age, pulse wave velocity, and resting mean pulmonary artery pressure. The role of diastolic dysfunction remains to be determined.

Prior studies have shown that some effects of OSA on exercise may be reversed with CPAP treatment (Arias, et al. Eur Heart J. 2006;27[9]:1106-1113; Chalegre, et al. Sleep Breath. 2021;25[3]:1195-1202). Understanding the mechanisms of exercise limitation in OSA will help physicians address symptoms, reinforce CPAP adherence, and design tailored pulmonary rehabilitation programs.

Fatima Zeba, MD

Fellow-in-Training

Pulmonary Physiology & Rehabilitation Section

Exercise tolerance in untreated sleep apnea

Numerous cardiovascular, respiratory, neuromuscular, and perceptual factors determine exercise tolerance. This makes designing a study to isolate the contribution of one factor difficult.

A recently published study (Elbehairy, et al. Chest. 2022; published online September 29, 2022) explores exercise tolerance in patients with untreated OSA compared with age- and weight-matched controls. The authors found that at an equivalent work rate, patients with OSA had greater minute ventilation, principally due to higher breathing frequency. Dead space volume, dead space ventilation, and dead space to tidal volume ratio (VD/VT) were higher in patients with OSA, likely due to a reduction in pulmonary vessel recruitment relative to ventilation. VD/VT decreased more from rest to peak in controls than in patients with OSA, an adaptation that is expected with exercise. Patients with OSA had greater arterial stiffness measured by pulse wave velocity and higher blood pressures, which may have affected cardiac output augmentation. Patients with OSA also had higher resting mean pulmonary artery pressures and exercise dyspnea scores. Regression models predicting peak oxygen uptake and peak work rate were statistically significant, with predictors being age, pulse wave velocity, and resting mean pulmonary artery pressure. The role of diastolic dysfunction remains to be determined.

Prior studies have shown that some effects of OSA on exercise may be reversed with CPAP treatment (Arias, et al. Eur Heart J. 2006;27[9]:1106-1113; Chalegre, et al. Sleep Breath. 2021;25[3]:1195-1202). Understanding the mechanisms of exercise limitation in OSA will help physicians address symptoms, reinforce CPAP adherence, and design tailored pulmonary rehabilitation programs.

Fatima Zeba, MD

Fellow-in-Training

Pulmonary Physiology & Rehabilitation Section

Exercise tolerance in untreated sleep apnea

Numerous cardiovascular, respiratory, neuromuscular, and perceptual factors determine exercise tolerance. This makes designing a study to isolate the contribution of one factor difficult.

A recently published study (Elbehairy, et al. Chest. 2022; published online September 29, 2022) explores exercise tolerance in patients with untreated OSA compared with age- and weight-matched controls. The authors found that at an equivalent work rate, patients with OSA had greater minute ventilation, principally due to higher breathing frequency. Dead space volume, dead space ventilation, and dead space to tidal volume ratio (VD/VT) were higher in patients with OSA, likely due to a reduction in pulmonary vessel recruitment relative to ventilation. VD/VT decreased more from rest to peak in controls than in patients with OSA, an adaptation that is expected with exercise. Patients with OSA had greater arterial stiffness measured by pulse wave velocity and higher blood pressures, which may have affected cardiac output augmentation. Patients with OSA also had higher resting mean pulmonary artery pressures and exercise dyspnea scores. Regression models predicting peak oxygen uptake and peak work rate were statistically significant, with predictors being age, pulse wave velocity, and resting mean pulmonary artery pressure. The role of diastolic dysfunction remains to be determined.

Prior studies have shown that some effects of OSA on exercise may be reversed with CPAP treatment (Arias, et al. Eur Heart J. 2006;27[9]:1106-1113; Chalegre, et al. Sleep Breath. 2021;25[3]:1195-1202). Understanding the mechanisms of exercise limitation in OSA will help physicians address symptoms, reinforce CPAP adherence, and design tailored pulmonary rehabilitation programs.

Fatima Zeba, MD

Fellow-in-Training

Pediatric Chest Medicine Section

CPAP for pediatric OSA: “Off-label” use

Pediatric providers are well aware of the “off-label” uses of medications/devices. While it’s not a stretch to apply “adult” diagnostic and therapeutic criteria to older adolescents, more careful consideration is needed for our younger patients. Typically, adenotonsillectomy is first-line treatment for pediatric OSA, but CPAP can be essential for those for whom surgical intervention is not an option, not an option yet, or has been insufficient (residual OSA). Unfortunately, standard CPAP devices are not approved for use in children, and often have a minimum weight requirement of 30 kg. There are respiratory assist devices and home mechanical ventilators that are approved for use in pediatric patients (minimum weight 13 kg or 5 kg) and designed for more complex ventilatory support, and that also are capable of providing continuous pressure. Alternatively, pediatric providers may proceed with the “off-label” use of simpler CPAP-only medical devices and face obstacles in attaining insurance approval. The recent American Academy of Sleep Medicine position statement (Amos, et al. J Clin Sleep Med. 2022;18[8]:2041-3) acknowledges that CPAP therapy can be safe and effective when management is guided by a pediatric specialist and is typically initiated in a monitored setting (inpatient or polysomnogram). The authors bring up excellent points regarding unique considerations for pediatric CPAP therapy, including the need for desensitization and facial development monitoring, lack of technical/software designed for younger/smaller patients, and limited published data (small and diverse cohorts). Ultimately, evaluation of effectiveness and safety, while distinct, must both be seriously considered in this risk-benefit analysis of care.

Pallavi P. Patwari, MD, FAAP, FAASM

Member-at-Large

Pediatric Chest Medicine Section

CPAP for pediatric OSA: “Off-label” use

Pediatric providers are well aware of the “off-label” uses of medications/devices. While it’s not a stretch to apply “adult” diagnostic and therapeutic criteria to older adolescents, more careful consideration is needed for our younger patients. Typically, adenotonsillectomy is first-line treatment for pediatric OSA, but CPAP can be essential for those for whom surgical intervention is not an option, not an option yet, or has been insufficient (residual OSA). Unfortunately, standard CPAP devices are not approved for use in children, and often have a minimum weight requirement of 30 kg. There are respiratory assist devices and home mechanical ventilators that are approved for use in pediatric patients (minimum weight 13 kg or 5 kg) and designed for more complex ventilatory support, and that also are capable of providing continuous pressure. Alternatively, pediatric providers may proceed with the “off-label” use of simpler CPAP-only medical devices and face obstacles in attaining insurance approval. The recent American Academy of Sleep Medicine position statement (Amos, et al. J Clin Sleep Med. 2022;18[8]:2041-3) acknowledges that CPAP therapy can be safe and effective when management is guided by a pediatric specialist and is typically initiated in a monitored setting (inpatient or polysomnogram). The authors bring up excellent points regarding unique considerations for pediatric CPAP therapy, including the need for desensitization and facial development monitoring, lack of technical/software designed for younger/smaller patients, and limited published data (small and diverse cohorts). Ultimately, evaluation of effectiveness and safety, while distinct, must both be seriously considered in this risk-benefit analysis of care.

Pallavi P. Patwari, MD, FAAP, FAASM

Member-at-Large

Pediatric Chest Medicine Section

CPAP for pediatric OSA: “Off-label” use

Pediatric providers are well aware of the “off-label” uses of medications/devices. While it’s not a stretch to apply “adult” diagnostic and therapeutic criteria to older adolescents, more careful consideration is needed for our younger patients. Typically, adenotonsillectomy is first-line treatment for pediatric OSA, but CPAP can be essential for those for whom surgical intervention is not an option, not an option yet, or has been insufficient (residual OSA). Unfortunately, standard CPAP devices are not approved for use in children, and often have a minimum weight requirement of 30 kg. There are respiratory assist devices and home mechanical ventilators that are approved for use in pediatric patients (minimum weight 13 kg or 5 kg) and designed for more complex ventilatory support, and that also are capable of providing continuous pressure. Alternatively, pediatric providers may proceed with the “off-label” use of simpler CPAP-only medical devices and face obstacles in attaining insurance approval. The recent American Academy of Sleep Medicine position statement (Amos, et al. J Clin Sleep Med. 2022;18[8]:2041-3) acknowledges that CPAP therapy can be safe and effective when management is guided by a pediatric specialist and is typically initiated in a monitored setting (inpatient or polysomnogram). The authors bring up excellent points regarding unique considerations for pediatric CPAP therapy, including the need for desensitization and facial development monitoring, lack of technical/software designed for younger/smaller patients, and limited published data (small and diverse cohorts). Ultimately, evaluation of effectiveness and safety, while distinct, must both be seriously considered in this risk-benefit analysis of care.

Pallavi P. Patwari, MD, FAAP, FAASM

Member-at-Large

Disaster Response & Global Health Section

Responding to firearm violence in America

We think of disasters as sudden, calamitous events, but it does not take much imagination to recognize the loss of lives in America from firearm violence as a type of disaster. In 2020, 45,222 people died from gun-related injuries, an increase of 5,155 (14%) since 2019 (Kegler, et al. MMWR Morb Mortal Wkly Rep. 2022;71[19]:656). This is the highest death rate since 1994, and includes increases in both homicides and suicides. Mass shootings constitute a fraction of this total, but there have already been 530 deaths from mass shooting incidents in 2022.

Opinions about the appropriate degree of firearm regulations remain divided, but the need to improve our response as clinicians is clear. The National Center for Disaster Medicine and Public Health recently published consensus recommendations for healthcare response in mass shootings (Goolsby, et al. J Am Coll Surg. 2022; published online July 18, 2022). These recommendations address readiness training, triage, communications, public education, patient tracking, family reunification, and mental health services.

Stop the Bleed is a program originally based on the military’s Tactical Combat Casualty Care standards. It offers training on hemorrhage control for both the public and clinicians, similar to basic life support programs. It encourages bystanders to become trained and empowered to help in a bleeding emergency before professional help arrives. Opportunities for training are a frequent offering at the CHEST Annual Meeting, and additional information can be found at https://www.stopthebleed.org.

Stella Ogake, MD
Member-at-Large

Disaster Response & Global Health Section

Responding to firearm violence in America

We think of disasters as sudden, calamitous events, but it does not take much imagination to recognize the loss of lives in America from firearm violence as a type of disaster. In 2020, 45,222 people died from gun-related injuries, an increase of 5,155 (14%) since 2019 (Kegler, et al. MMWR Morb Mortal Wkly Rep. 2022;71[19]:656). This is the highest death rate since 1994, and includes increases in both homicides and suicides. Mass shootings constitute a fraction of this total, but there have already been 530 deaths from mass shooting incidents in 2022.

Opinions about the appropriate degree of firearm regulations remain divided, but the need to improve our response as clinicians is clear. The National Center for Disaster Medicine and Public Health recently published consensus recommendations for healthcare response in mass shootings (Goolsby, et al. J Am Coll Surg. 2022; published online July 18, 2022). These recommendations address readiness training, triage, communications, public education, patient tracking, family reunification, and mental health services.

Stop the Bleed is a program originally based on the military’s Tactical Combat Casualty Care standards. It offers training on hemorrhage control for both the public and clinicians, similar to basic life support programs. It encourages bystanders to become trained and empowered to help in a bleeding emergency before professional help arrives. Opportunities for training are a frequent offering at the CHEST Annual Meeting, and additional information can be found at https://www.stopthebleed.org.

Stella Ogake, MD
Member-at-Large

Disaster Response & Global Health Section

Responding to firearm violence in America

We think of disasters as sudden, calamitous events, but it does not take much imagination to recognize the loss of lives in America from firearm violence as a type of disaster. In 2020, 45,222 people died from gun-related injuries, an increase of 5,155 (14%) since 2019 (Kegler, et al. MMWR Morb Mortal Wkly Rep. 2022;71[19]:656). This is the highest death rate since 1994, and includes increases in both homicides and suicides. Mass shootings constitute a fraction of this total, but there have already been 530 deaths from mass shooting incidents in 2022.

Opinions about the appropriate degree of firearm regulations remain divided, but the need to improve our response as clinicians is clear. The National Center for Disaster Medicine and Public Health recently published consensus recommendations for healthcare response in mass shootings (Goolsby, et al. J Am Coll Surg. 2022; published online July 18, 2022). These recommendations address readiness training, triage, communications, public education, patient tracking, family reunification, and mental health services.

Stop the Bleed is a program originally based on the military’s Tactical Combat Casualty Care standards. It offers training on hemorrhage control for both the public and clinicians, similar to basic life support programs. It encourages bystanders to become trained and empowered to help in a bleeding emergency before professional help arrives. Opportunities for training are a frequent offering at the CHEST Annual Meeting, and additional information can be found at https://www.stopthebleed.org.

Stella Ogake, MD
Member-at-Large

Bronchiectasis Section

Antibiotics in non–cystic fibrosis bronchiectasis: new perspectives

The clearest benefit of antibiotics in managing non-cystic fibrosis bronchiectasis is for treatment of exacerbations and for chronic azithromycin use. There is a paucity of high-quality evidence for prophylactic antibiotics, though guidelines support this practice, particularly for adults with three or more exacerbations a year. A recent Cochrane database review (Spencer, et al. Cochrane Database Syst Rev. 2022;1[1]:CD013254) examined eight RCTs, with interventions ranging from 16 to 48 weeks, involving 2,180 adults and found little net benefit for prophylactic cycled antibiotics (fluoroquinolones, beta-lactams, and aminoglycosides) in terms of outcomes viz time-to-first-exacerbation and duration of exacerbations, but more than doubled the risk of emerging resistance.

Clinical equipoise exists regarding the duration of antibiotics during exacerbations. Guidelines favor 14 days. A recent RCT (Pallavi, et al. Eur Respir J. 2021;58:2004388) examined the feasibility of bacterial load-guided therapy in 47 participants with bronchiectasis requiring IV antibiotics.

Patients were randomized to either 14 days of antibiotics or treatment guided by bacterial load (BLGG). The 88% of participants in the BLGG group were able to stop antibiotics by day 8, and potentially 81% of participants in the 14-day group could have stopped antibiotics at day 8. Median time to next exacerbation was much longer – 60 days (18-110 days) in the in BLGG group vs 27.5 days (12.5-60 days) in the 14-day group vs (P = .0034). A larger multicenter RCT may clarify the benefits of this approach to shortening duration of antibiotic therapy in patients with bronchiectasis exacerbations.

O’Neil Green, MBBS, FCCP
Member-at-Large

Bronchiectasis Section

Antibiotics in non–cystic fibrosis bronchiectasis: new perspectives

The clearest benefit of antibiotics in managing non-cystic fibrosis bronchiectasis is for treatment of exacerbations and for chronic azithromycin use. There is a paucity of high-quality evidence for prophylactic antibiotics, though guidelines support this practice, particularly for adults with three or more exacerbations a year. A recent Cochrane database review (Spencer, et al. Cochrane Database Syst Rev. 2022;1[1]:CD013254) examined eight RCTs, with interventions ranging from 16 to 48 weeks, involving 2,180 adults and found little net benefit for prophylactic cycled antibiotics (fluoroquinolones, beta-lactams, and aminoglycosides) in terms of outcomes viz time-to-first-exacerbation and duration of exacerbations, but more than doubled the risk of emerging resistance.

Clinical equipoise exists regarding the duration of antibiotics during exacerbations. Guidelines favor 14 days. A recent RCT (Pallavi, et al. Eur Respir J. 2021;58:2004388) examined the feasibility of bacterial load-guided therapy in 47 participants with bronchiectasis requiring IV antibiotics.

Patients were randomized to either 14 days of antibiotics or treatment guided by bacterial load (BLGG). The 88% of participants in the BLGG group were able to stop antibiotics by day 8, and potentially 81% of participants in the 14-day group could have stopped antibiotics at day 8. Median time to next exacerbation was much longer – 60 days (18-110 days) in the in BLGG group vs 27.5 days (12.5-60 days) in the 14-day group vs (P = .0034). A larger multicenter RCT may clarify the benefits of this approach to shortening duration of antibiotic therapy in patients with bronchiectasis exacerbations.

O’Neil Green, MBBS, FCCP
Member-at-Large

Bronchiectasis Section

Antibiotics in non–cystic fibrosis bronchiectasis: new perspectives

The clearest benefit of antibiotics in managing non-cystic fibrosis bronchiectasis is for treatment of exacerbations and for chronic azithromycin use. There is a paucity of high-quality evidence for prophylactic antibiotics, though guidelines support this practice, particularly for adults with three or more exacerbations a year. A recent Cochrane database review (Spencer, et al. Cochrane Database Syst Rev. 2022;1[1]:CD013254) examined eight RCTs, with interventions ranging from 16 to 48 weeks, involving 2,180 adults and found little net benefit for prophylactic cycled antibiotics (fluoroquinolones, beta-lactams, and aminoglycosides) in terms of outcomes viz time-to-first-exacerbation and duration of exacerbations, but more than doubled the risk of emerging resistance.

Clinical equipoise exists regarding the duration of antibiotics during exacerbations. Guidelines favor 14 days. A recent RCT (Pallavi, et al. Eur Respir J. 2021;58:2004388) examined the feasibility of bacterial load-guided therapy in 47 participants with bronchiectasis requiring IV antibiotics.

Patients were randomized to either 14 days of antibiotics or treatment guided by bacterial load (BLGG). The 88% of participants in the BLGG group were able to stop antibiotics by day 8, and potentially 81% of participants in the 14-day group could have stopped antibiotics at day 8. Median time to next exacerbation was much longer – 60 days (18-110 days) in the in BLGG group vs 27.5 days (12.5-60 days) in the 14-day group vs (P = .0034). A larger multicenter RCT may clarify the benefits of this approach to shortening duration of antibiotic therapy in patients with bronchiectasis exacerbations.

O’Neil Green, MBBS, FCCP
Member-at-Large