Nephrology

INDIANAPOLIS – Contrary to conventional wisdom, endovascular aneurysm repair (EVAR) provides outcomes superior to those achieved with open surgical repair of abdominal aortic aneurysm in patients with chronic renal insufficiency, a large study indicates.

"EVAR should be the first-line therapy in the patient with chronic renal insufficiency when the patient has the appropriate anatomy. However, in patients with severe renal impairment, a higher threshold should be applied for repair because the risks of both open repair and EVAR are significantly higher," Dr. Bao-Ngoc H. Nguyen declared at the annual meeting of the American Surgical Association.

"Chronic renal failure is quite prevalent in patients with abdominal aortic aneurysm: up to 30%. It is quite worrisome because any further decline in renal function in these patients could push them toward dialysis. More than that, postoperative renal failure is a predictor for early and late mortality," noted Dr. Nguyen of George Washington University, Washington.

She presented a retrospective study in patients with abdominal aortic aneurysm and chronic kidney disease. The aim, she explained, was to answer a key question: "Which one of these two treatment modalities is the lesser of two evils?"

For answers, Dr. Nguyen and coinvestigators turned to the American College of Surgeons National Quality Improvement Program (NSQIP) database for 2005-2010. They identified 3,523 patients with moderate chronic renal insufficiency, defined as an estimated glomerular filtration rate (eGFR) of 30-60 mL/minute, who underwent EVAR for abdominal aortic aneurysm and 1,117 treated via open surgical repair. Another 363 EVAR patients had severe chronic renal insufficiency, with an eGFR of less than 30 mL/minute, as did 139 patients who underwent open repair. Vascular surgeons performed all procedures in this study.

Patients with moderate renal insufficiency who underwent EVAR had markedly lower 30-day rates of mortality, pulmonary complications, cardiovascular events, and postoperative renal dysfunction, including acute kidney injury, than did those who had open surgical repair. One or more adverse events occurred in 6% of the EVAR group, compared with 24.1% of open repair patients. In a multivariate analysis controlled for preoperative differences in the patient groups, those undergoing open repair had an adjusted 4.1-fold greater risk of mortality as well as a 2.2-fold increased risk of cardiovascular events, a 4.2-fold increased risk of renal deterioration including a 5.2-fold greater risk of dialysis, and additional hazards.

In contrast, among the much smaller population of patients with baseline severe chronic renal insufficiency, there was no significant difference between the two treatment groups in terms of 30-day mortality, postoperative renal deterioration, or cardiovascular complications, although pulmonary complications were an adjusted fivefold more likely in the open surgery than among EVAR patients. Of note, rates of all adverse outcomes were markedly higher in both groups than in those with moderate chronic renal insufficiency, such that one or more adverse events occurred in 16.9% of EVAR patients and 42.5% of the open repair patients with severe chronic renal insufficiency.

Discussant Dr. Michael Watkins commented that this study has one glaring shortcoming resulting from a limitation of the NSQIP database.

While NSQIP contains only validated data entered by unbiased, well-trained professionals and NSQIP is "far superior" to the various administrative databases commonly used in evaluating outcomes, it doesn’t include key details about patients’ presenting anatomy, observed Dr. Watkins, director of the vascular research laboratory at Massachusetts General Hospital, Boston.

"Was the anatomy really similar in the two groups, or were patients who underwent open repair not candidates for EVAR?" he asked.

Dr. Nguyen conceded that this constitutes a major study limitation, adding that she agrees with Dr. Watkins that anatomy should be the first and foremost factor considered in deciding upon the surgical approach in abdominal aortic aneurysm repair.

She reported having no financial conflicts.

[email protected]

INDIANAPOLIS – Contrary to conventional wisdom, endovascular aneurysm repair (EVAR) provides outcomes superior to those achieved with open surgical repair of abdominal aortic aneurysm in patients with chronic renal insufficiency, a large study indicates.

"EVAR should be the first-line therapy in the patient with chronic renal insufficiency when the patient has the appropriate anatomy. However, in patients with severe renal impairment, a higher threshold should be applied for repair because the risks of both open repair and EVAR are significantly higher," Dr. Bao-Ngoc H. Nguyen declared at the annual meeting of the American Surgical Association.

"Chronic renal failure is quite prevalent in patients with abdominal aortic aneurysm: up to 30%. It is quite worrisome because any further decline in renal function in these patients could push them toward dialysis. More than that, postoperative renal failure is a predictor for early and late mortality," noted Dr. Nguyen of George Washington University, Washington.

She presented a retrospective study in patients with abdominal aortic aneurysm and chronic kidney disease. The aim, she explained, was to answer a key question: "Which one of these two treatment modalities is the lesser of two evils?"

For answers, Dr. Nguyen and coinvestigators turned to the American College of Surgeons National Quality Improvement Program (NSQIP) database for 2005-2010. They identified 3,523 patients with moderate chronic renal insufficiency, defined as an estimated glomerular filtration rate (eGFR) of 30-60 mL/minute, who underwent EVAR for abdominal aortic aneurysm and 1,117 treated via open surgical repair. Another 363 EVAR patients had severe chronic renal insufficiency, with an eGFR of less than 30 mL/minute, as did 139 patients who underwent open repair. Vascular surgeons performed all procedures in this study.

Patients with moderate renal insufficiency who underwent EVAR had markedly lower 30-day rates of mortality, pulmonary complications, cardiovascular events, and postoperative renal dysfunction, including acute kidney injury, than did those who had open surgical repair. One or more adverse events occurred in 6% of the EVAR group, compared with 24.1% of open repair patients. In a multivariate analysis controlled for preoperative differences in the patient groups, those undergoing open repair had an adjusted 4.1-fold greater risk of mortality as well as a 2.2-fold increased risk of cardiovascular events, a 4.2-fold increased risk of renal deterioration including a 5.2-fold greater risk of dialysis, and additional hazards.

In contrast, among the much smaller population of patients with baseline severe chronic renal insufficiency, there was no significant difference between the two treatment groups in terms of 30-day mortality, postoperative renal deterioration, or cardiovascular complications, although pulmonary complications were an adjusted fivefold more likely in the open surgery than among EVAR patients. Of note, rates of all adverse outcomes were markedly higher in both groups than in those with moderate chronic renal insufficiency, such that one or more adverse events occurred in 16.9% of EVAR patients and 42.5% of the open repair patients with severe chronic renal insufficiency.

Discussant Dr. Michael Watkins commented that this study has one glaring shortcoming resulting from a limitation of the NSQIP database.

While NSQIP contains only validated data entered by unbiased, well-trained professionals and NSQIP is "far superior" to the various administrative databases commonly used in evaluating outcomes, it doesn’t include key details about patients’ presenting anatomy, observed Dr. Watkins, director of the vascular research laboratory at Massachusetts General Hospital, Boston.

"Was the anatomy really similar in the two groups, or were patients who underwent open repair not candidates for EVAR?" he asked.

Dr. Nguyen conceded that this constitutes a major study limitation, adding that she agrees with Dr. Watkins that anatomy should be the first and foremost factor considered in deciding upon the surgical approach in abdominal aortic aneurysm repair.

She reported having no financial conflicts.

[email protected]

INDIANAPOLIS – Contrary to conventional wisdom, endovascular aneurysm repair (EVAR) provides outcomes superior to those achieved with open surgical repair of abdominal aortic aneurysm in patients with chronic renal insufficiency, a large study indicates.

"EVAR should be the first-line therapy in the patient with chronic renal insufficiency when the patient has the appropriate anatomy. However, in patients with severe renal impairment, a higher threshold should be applied for repair because the risks of both open repair and EVAR are significantly higher," Dr. Bao-Ngoc H. Nguyen declared at the annual meeting of the American Surgical Association.

"Chronic renal failure is quite prevalent in patients with abdominal aortic aneurysm: up to 30%. It is quite worrisome because any further decline in renal function in these patients could push them toward dialysis. More than that, postoperative renal failure is a predictor for early and late mortality," noted Dr. Nguyen of George Washington University, Washington.

She presented a retrospective study in patients with abdominal aortic aneurysm and chronic kidney disease. The aim, she explained, was to answer a key question: "Which one of these two treatment modalities is the lesser of two evils?"

For answers, Dr. Nguyen and coinvestigators turned to the American College of Surgeons National Quality Improvement Program (NSQIP) database for 2005-2010. They identified 3,523 patients with moderate chronic renal insufficiency, defined as an estimated glomerular filtration rate (eGFR) of 30-60 mL/minute, who underwent EVAR for abdominal aortic aneurysm and 1,117 treated via open surgical repair. Another 363 EVAR patients had severe chronic renal insufficiency, with an eGFR of less than 30 mL/minute, as did 139 patients who underwent open repair. Vascular surgeons performed all procedures in this study.

Patients with moderate renal insufficiency who underwent EVAR had markedly lower 30-day rates of mortality, pulmonary complications, cardiovascular events, and postoperative renal dysfunction, including acute kidney injury, than did those who had open surgical repair. One or more adverse events occurred in 6% of the EVAR group, compared with 24.1% of open repair patients. In a multivariate analysis controlled for preoperative differences in the patient groups, those undergoing open repair had an adjusted 4.1-fold greater risk of mortality as well as a 2.2-fold increased risk of cardiovascular events, a 4.2-fold increased risk of renal deterioration including a 5.2-fold greater risk of dialysis, and additional hazards.

In contrast, among the much smaller population of patients with baseline severe chronic renal insufficiency, there was no significant difference between the two treatment groups in terms of 30-day mortality, postoperative renal deterioration, or cardiovascular complications, although pulmonary complications were an adjusted fivefold more likely in the open surgery than among EVAR patients. Of note, rates of all adverse outcomes were markedly higher in both groups than in those with moderate chronic renal insufficiency, such that one or more adverse events occurred in 16.9% of EVAR patients and 42.5% of the open repair patients with severe chronic renal insufficiency.

Discussant Dr. Michael Watkins commented that this study has one glaring shortcoming resulting from a limitation of the NSQIP database.

While NSQIP contains only validated data entered by unbiased, well-trained professionals and NSQIP is "far superior" to the various administrative databases commonly used in evaluating outcomes, it doesn’t include key details about patients’ presenting anatomy, observed Dr. Watkins, director of the vascular research laboratory at Massachusetts General Hospital, Boston.

"Was the anatomy really similar in the two groups, or were patients who underwent open repair not candidates for EVAR?" he asked.

Dr. Nguyen conceded that this constitutes a major study limitation, adding that she agrees with Dr. Watkins that anatomy should be the first and foremost factor considered in deciding upon the surgical approach in abdominal aortic aneurysm repair.

She reported having no financial conflicts.

[email protected]

Americans should lower sodium consumption to optimize their health – but not below levels of 2,300 mg per day, according to a new report from the Institute of Medicine.

People aged 51 years and older, African-Americans, and those with hypertension, diabetes, or chronic kidney disease can follow the same advice, according to authors of the report, released during a webinar May 14.

© Georges Lievre / Fotolia.com

That recommendation is a departure from the current Dietary Guidelines for Americans from the U.S. Department of Health and Human Services, which recommends that these higher-risk groups limit sodium intake to 1,500 mg daily. The HHS guidelines recommend that most other people aged 14-50 years limit sodium intake to 2,300 mg per day.

On average, Americans consume 3,400 mg or more of sodium a day (equivalent to 1.5 teaspoons of salt), despite efforts over the past few decades to reduce sodium consumption, according to the IOM report, which was sponsored by the Centers for Disease Control and Prevention.

"We found no consistent evidence to support an association between sodium intake and either a beneficial or adverse effect on most direct health outcomes," said Dr. Brian L. Strom, George S. Pepper Professor of Public Health and Preventive Medicine at the University of Pennsylvania, Philadelphia, who chaired the committee that released the report.

The committee did not suggest an optimal target range for sodium consumption.

Dr. Strom and his colleagues reviewed medical studies from 2003 to 2012 that evaluated the direct impact of sodium intake on outcomes such as heart disease and death. Although the studies varied widely in the quality of their methodology and data collection, the report’s authors came to the following conclusions:

• There was a positive relationship between higher levels of sodium and risk of heart disease, consistent with previous research looking at sodium’s effects on blood pressure.

• There were insufficient data to determine if lowering sodium intake below 2,300 mg/day conferred any increase or decrease in the risk of heart disease, stroke, or death.

• Sodium intake of 1,840 mg/day or less may increase the risk of adverse health effects such as cardiovascular events or death among people with mid- to late-stage heart failure receiving aggressive treatment.

• Health outcomes studies provide little evidence about the effects of low sodium intake among those with diabetes, kidney disease, and heart disease, suggesting that people affected by these conditions could follow recommendations for the general public.

But the recommendations prompted calls for caution by some health experts.

The IOM report included "weak studies with numerous problems" and did not include evidence on the effects of sodium reduction on blood pressure, "a key determinant of health and the largest determinant of preventable mortality worldwide," Dr. Lawrence Appel, director of the Welch Center for Prevention, Epidemiology, and Clinical Research at Johns Hopkins University, Baltimore, said in an interview.

Dr. Appel said he still supports the recommendations of the Dietary Guidelines, which he helped create. "Middle- and older-aged adults, African Americans, and patients with hypertension, diabetes, and chronic kidney disease are those at greatest risk for blood pressure–related heart disease and stroke," he said, and they stand to benefit from keeping sodium levels to 1,500 mg/day or less.

Americans should lower sodium consumption to optimize their health – but not below levels of 2,300 mg per day, according to a new report from the Institute of Medicine.

People aged 51 years and older, African-Americans, and those with hypertension, diabetes, or chronic kidney disease can follow the same advice, according to authors of the report, released during a webinar May 14.

© Georges Lievre / Fotolia.com

That recommendation is a departure from the current Dietary Guidelines for Americans from the U.S. Department of Health and Human Services, which recommends that these higher-risk groups limit sodium intake to 1,500 mg daily. The HHS guidelines recommend that most other people aged 14-50 years limit sodium intake to 2,300 mg per day.

On average, Americans consume 3,400 mg or more of sodium a day (equivalent to 1.5 teaspoons of salt), despite efforts over the past few decades to reduce sodium consumption, according to the IOM report, which was sponsored by the Centers for Disease Control and Prevention.

"We found no consistent evidence to support an association between sodium intake and either a beneficial or adverse effect on most direct health outcomes," said Dr. Brian L. Strom, George S. Pepper Professor of Public Health and Preventive Medicine at the University of Pennsylvania, Philadelphia, who chaired the committee that released the report.

The committee did not suggest an optimal target range for sodium consumption.

Dr. Strom and his colleagues reviewed medical studies from 2003 to 2012 that evaluated the direct impact of sodium intake on outcomes such as heart disease and death. Although the studies varied widely in the quality of their methodology and data collection, the report’s authors came to the following conclusions:

• There was a positive relationship between higher levels of sodium and risk of heart disease, consistent with previous research looking at sodium’s effects on blood pressure.

• There were insufficient data to determine if lowering sodium intake below 2,300 mg/day conferred any increase or decrease in the risk of heart disease, stroke, or death.

• Sodium intake of 1,840 mg/day or less may increase the risk of adverse health effects such as cardiovascular events or death among people with mid- to late-stage heart failure receiving aggressive treatment.

• Health outcomes studies provide little evidence about the effects of low sodium intake among those with diabetes, kidney disease, and heart disease, suggesting that people affected by these conditions could follow recommendations for the general public.

But the recommendations prompted calls for caution by some health experts.

The IOM report included "weak studies with numerous problems" and did not include evidence on the effects of sodium reduction on blood pressure, "a key determinant of health and the largest determinant of preventable mortality worldwide," Dr. Lawrence Appel, director of the Welch Center for Prevention, Epidemiology, and Clinical Research at Johns Hopkins University, Baltimore, said in an interview.

Dr. Appel said he still supports the recommendations of the Dietary Guidelines, which he helped create. "Middle- and older-aged adults, African Americans, and patients with hypertension, diabetes, and chronic kidney disease are those at greatest risk for blood pressure–related heart disease and stroke," he said, and they stand to benefit from keeping sodium levels to 1,500 mg/day or less.

Americans should lower sodium consumption to optimize their health – but not below levels of 2,300 mg per day, according to a new report from the Institute of Medicine.

People aged 51 years and older, African-Americans, and those with hypertension, diabetes, or chronic kidney disease can follow the same advice, according to authors of the report, released during a webinar May 14.

© Georges Lievre / Fotolia.com

That recommendation is a departure from the current Dietary Guidelines for Americans from the U.S. Department of Health and Human Services, which recommends that these higher-risk groups limit sodium intake to 1,500 mg daily. The HHS guidelines recommend that most other people aged 14-50 years limit sodium intake to 2,300 mg per day.

On average, Americans consume 3,400 mg or more of sodium a day (equivalent to 1.5 teaspoons of salt), despite efforts over the past few decades to reduce sodium consumption, according to the IOM report, which was sponsored by the Centers for Disease Control and Prevention.

"We found no consistent evidence to support an association between sodium intake and either a beneficial or adverse effect on most direct health outcomes," said Dr. Brian L. Strom, George S. Pepper Professor of Public Health and Preventive Medicine at the University of Pennsylvania, Philadelphia, who chaired the committee that released the report.

The committee did not suggest an optimal target range for sodium consumption.

Dr. Strom and his colleagues reviewed medical studies from 2003 to 2012 that evaluated the direct impact of sodium intake on outcomes such as heart disease and death. Although the studies varied widely in the quality of their methodology and data collection, the report’s authors came to the following conclusions:

• There was a positive relationship between higher levels of sodium and risk of heart disease, consistent with previous research looking at sodium’s effects on blood pressure.

• There were insufficient data to determine if lowering sodium intake below 2,300 mg/day conferred any increase or decrease in the risk of heart disease, stroke, or death.

• Sodium intake of 1,840 mg/day or less may increase the risk of adverse health effects such as cardiovascular events or death among people with mid- to late-stage heart failure receiving aggressive treatment.

• Health outcomes studies provide little evidence about the effects of low sodium intake among those with diabetes, kidney disease, and heart disease, suggesting that people affected by these conditions could follow recommendations for the general public.

But the recommendations prompted calls for caution by some health experts.

The IOM report included "weak studies with numerous problems" and did not include evidence on the effects of sodium reduction on blood pressure, "a key determinant of health and the largest determinant of preventable mortality worldwide," Dr. Lawrence Appel, director of the Welch Center for Prevention, Epidemiology, and Clinical Research at Johns Hopkins University, Baltimore, said in an interview.

Dr. Appel said he still supports the recommendations of the Dietary Guidelines, which he helped create. "Middle- and older-aged adults, African Americans, and patients with hypertension, diabetes, and chronic kidney disease are those at greatest risk for blood pressure–related heart disease and stroke," he said, and they stand to benefit from keeping sodium levels to 1,500 mg/day or less.

SAN DIEGO – Of men given an ICD-9 diagnosis of erectile dysfunction, 25% receive any treatment for the condition.

Treatment frequency was higher in men who had low levels of testosterone (51% treated) and lower in those who had prostate cancer (15% treated). Treatment frequency did not vary significantly with other associated comorbidities, Dr. Brian T. Helfand said in a press briefing at the annual meeting of the American Urological Association.

Dr. Helfand of the department of urology at NorthShore University Health System in Evanston, Ill., and his associates used an IMS data set to identify 6,228,509 men over the age of 30 years who received an ICD-9 diagnosis of erectile dysfunction (ED) during a 12-month period that ended in July 2011. IMS is a large insurance claims data set that encompasses more than 80% of prescription data in the United States.

Men were classified as treated if they filled a prescription for a phosphodiesterase type-5 (PDE5) inhibitor, injection or urethral prostaglandins, or androgen replacement therapy. They were classified as untreated if they received an ED diagnosis but did not fill a prescription in the study period. The researchers monitored the therapies by prescription frequency, age, comorbidities, and physician specialty.

Among the 25% of men who filled prescriptions, PDE5 was the most commonly prescribed medication (75%), followed by androgen replacement therapy (31%). Fewer than 2% of patients used any prostaglandin therapy. "The men who were in the oldest age groups were the least likely to fill a prescription," Dr. Helfand said.

The greatest proportion of prescriptions overall were ordered by primary care physicians (28%), followed by endocrinologists (27%), and urologists (21%). The remaining 24% were ordered by various other clinicians.

Dr. Helfand said limitations of the study include the exclusion of Medicare data plus lack of information about the severity of ED, efficacy of treatments, and adherence to long-term therapy.

Dr. Ajay Nangia, who is an associate professor of urology at the University of Kansas Medical Center and the moderator of the press briefing, noted that ED is a medical disease that is often a portent of other disorders. Recognizing that men with ED go untreated may mean that they’re also possibly underinvestigated for associated condition such as diabetes, lipid disorders, and risk factors such as smoking.

Dr. Helfand said that he had no relevant financial conflicts to disclose. One of the study authors, Dr. Kevin McVary, disclosed consultant, advisory, or other roles with several companies, including Allergan, Lilly, NxThera, Watson, NeoTract, and GSK.

[email protected]

SAN DIEGO – Of men given an ICD-9 diagnosis of erectile dysfunction, 25% receive any treatment for the condition.

Treatment frequency was higher in men who had low levels of testosterone (51% treated) and lower in those who had prostate cancer (15% treated). Treatment frequency did not vary significantly with other associated comorbidities, Dr. Brian T. Helfand said in a press briefing at the annual meeting of the American Urological Association.

Dr. Helfand of the department of urology at NorthShore University Health System in Evanston, Ill., and his associates used an IMS data set to identify 6,228,509 men over the age of 30 years who received an ICD-9 diagnosis of erectile dysfunction (ED) during a 12-month period that ended in July 2011. IMS is a large insurance claims data set that encompasses more than 80% of prescription data in the United States.

Men were classified as treated if they filled a prescription for a phosphodiesterase type-5 (PDE5) inhibitor, injection or urethral prostaglandins, or androgen replacement therapy. They were classified as untreated if they received an ED diagnosis but did not fill a prescription in the study period. The researchers monitored the therapies by prescription frequency, age, comorbidities, and physician specialty.

Among the 25% of men who filled prescriptions, PDE5 was the most commonly prescribed medication (75%), followed by androgen replacement therapy (31%). Fewer than 2% of patients used any prostaglandin therapy. "The men who were in the oldest age groups were the least likely to fill a prescription," Dr. Helfand said.

The greatest proportion of prescriptions overall were ordered by primary care physicians (28%), followed by endocrinologists (27%), and urologists (21%). The remaining 24% were ordered by various other clinicians.

Dr. Helfand said limitations of the study include the exclusion of Medicare data plus lack of information about the severity of ED, efficacy of treatments, and adherence to long-term therapy.

Dr. Ajay Nangia, who is an associate professor of urology at the University of Kansas Medical Center and the moderator of the press briefing, noted that ED is a medical disease that is often a portent of other disorders. Recognizing that men with ED go untreated may mean that they’re also possibly underinvestigated for associated condition such as diabetes, lipid disorders, and risk factors such as smoking.

Dr. Helfand said that he had no relevant financial conflicts to disclose. One of the study authors, Dr. Kevin McVary, disclosed consultant, advisory, or other roles with several companies, including Allergan, Lilly, NxThera, Watson, NeoTract, and GSK.

[email protected]

SAN DIEGO – Of men given an ICD-9 diagnosis of erectile dysfunction, 25% receive any treatment for the condition.

Treatment frequency was higher in men who had low levels of testosterone (51% treated) and lower in those who had prostate cancer (15% treated). Treatment frequency did not vary significantly with other associated comorbidities, Dr. Brian T. Helfand said in a press briefing at the annual meeting of the American Urological Association.

Dr. Helfand of the department of urology at NorthShore University Health System in Evanston, Ill., and his associates used an IMS data set to identify 6,228,509 men over the age of 30 years who received an ICD-9 diagnosis of erectile dysfunction (ED) during a 12-month period that ended in July 2011. IMS is a large insurance claims data set that encompasses more than 80% of prescription data in the United States.

Men were classified as treated if they filled a prescription for a phosphodiesterase type-5 (PDE5) inhibitor, injection or urethral prostaglandins, or androgen replacement therapy. They were classified as untreated if they received an ED diagnosis but did not fill a prescription in the study period. The researchers monitored the therapies by prescription frequency, age, comorbidities, and physician specialty.

Among the 25% of men who filled prescriptions, PDE5 was the most commonly prescribed medication (75%), followed by androgen replacement therapy (31%). Fewer than 2% of patients used any prostaglandin therapy. "The men who were in the oldest age groups were the least likely to fill a prescription," Dr. Helfand said.

The greatest proportion of prescriptions overall were ordered by primary care physicians (28%), followed by endocrinologists (27%), and urologists (21%). The remaining 24% were ordered by various other clinicians.

Dr. Helfand said limitations of the study include the exclusion of Medicare data plus lack of information about the severity of ED, efficacy of treatments, and adherence to long-term therapy.

Dr. Ajay Nangia, who is an associate professor of urology at the University of Kansas Medical Center and the moderator of the press briefing, noted that ED is a medical disease that is often a portent of other disorders. Recognizing that men with ED go untreated may mean that they’re also possibly underinvestigated for associated condition such as diabetes, lipid disorders, and risk factors such as smoking.

Dr. Helfand said that he had no relevant financial conflicts to disclose. One of the study authors, Dr. Kevin McVary, disclosed consultant, advisory, or other roles with several companies, including Allergan, Lilly, NxThera, Watson, NeoTract, and GSK.

[email protected]

SAN DIEGO – The number of urologists practicing in the United States is expected to decrease by 29% between 2009 and 2025, according to a new analysis.

"It’s one thing if the demand for urologists is going up and the supply is stable, but to have the demand go up and the supply almost falling off of a cliff is worrisome," Dr. Raj S. Pruthi said in an interview at the annual meeting of the American Urological Association. "The people who will be hardest hit by this are ones who already struggle with access: those who live in rural communities."

Dr. Pruthi and his colleagues used stock and flow models, starting with the supply of urologists in 2009. They added new entrants from the graduate medical education (GME) pipeline and subtracted attrition from training and from the workforce due to retirement or breaks from practice. The forecast model estimates a 29% head count reduction and a 25% decrease in the full-time equivalent (FTE) supply of urologists between 2009 and 2025. The projected decrease is more than four times greater than the Health Resources and Services Administration’s Physician Supply Model, which estimated a 7% decrease over the same time period.

Dr. Pruthi warned that none of the proposed changes to GME (recommendations from the Council of Graduate Medical Education’s 16th report or a recent proposal to Congress) will increase GME enough to offset the projected decline in head count. "GME funding has been capped since 1996," he said. "We’re setting forth a recipe for a very big problem that we’re going to have for future generations in terms of who’s going to take care of" a rapidly aging population.

As the Affordable Health Care Act takes shape, "one thing that’s not been considered adequately is physician supply," added Dr. Pruthi, chief of urologic surgery at the University of North Carolina at Chapel Hill. "Are there enough of us to help care for the population? That needs to be part of the calculus. We need to do efficient, appropriate care. We need to cut health care costs, but we have to remember our physician supply."

The shrinking number of urologists could affect mortality rates, as research has demonstrated an association between a higher density of urologists in a defined area and lower mortality from prostate, bladder, and kidney cancer. "As supply contracts, rural areas are likely to have an even greater loss of urologic surgeons since these areas have a higher percentage of surgeons closer to retirement age than urban areas," the researchers noted in their abstract. "The result may decrease access to screening, medical and surgical treatment for urologic conditions."

Dr. Pruthi acknowledged that the ability to predict physician demand is an imprecise science. However, "there is indirect data to suggest that our demand isn’t going to go away. It’s only going to go up with that rising incidence and with the rising number of aging baby boomers. Second, we don’t know the appropriate ratio of supply and demand. If you have limited supply, you have limited access. Is our culture accepting of that? Some of these limitations to access may have health consequences."

He and his associates plan to conduct more detailed work on the projection model, including the impact of increasing numbers of women entering the urology field. "About 5% of urologists are female, but in current residency matching the numbers are about 25% female," he said. "What impact will that have? We don’t know yet."

Dr. Pruthi said that he had no relevant financial conflicts to disclose.

[email protected]

SAN DIEGO – The number of urologists practicing in the United States is expected to decrease by 29% between 2009 and 2025, according to a new analysis.

"It’s one thing if the demand for urologists is going up and the supply is stable, but to have the demand go up and the supply almost falling off of a cliff is worrisome," Dr. Raj S. Pruthi said in an interview at the annual meeting of the American Urological Association. "The people who will be hardest hit by this are ones who already struggle with access: those who live in rural communities."

Dr. Pruthi and his colleagues used stock and flow models, starting with the supply of urologists in 2009. They added new entrants from the graduate medical education (GME) pipeline and subtracted attrition from training and from the workforce due to retirement or breaks from practice. The forecast model estimates a 29% head count reduction and a 25% decrease in the full-time equivalent (FTE) supply of urologists between 2009 and 2025. The projected decrease is more than four times greater than the Health Resources and Services Administration’s Physician Supply Model, which estimated a 7% decrease over the same time period.

Dr. Pruthi warned that none of the proposed changes to GME (recommendations from the Council of Graduate Medical Education’s 16th report or a recent proposal to Congress) will increase GME enough to offset the projected decline in head count. "GME funding has been capped since 1996," he said. "We’re setting forth a recipe for a very big problem that we’re going to have for future generations in terms of who’s going to take care of" a rapidly aging population.

As the Affordable Health Care Act takes shape, "one thing that’s not been considered adequately is physician supply," added Dr. Pruthi, chief of urologic surgery at the University of North Carolina at Chapel Hill. "Are there enough of us to help care for the population? That needs to be part of the calculus. We need to do efficient, appropriate care. We need to cut health care costs, but we have to remember our physician supply."

The shrinking number of urologists could affect mortality rates, as research has demonstrated an association between a higher density of urologists in a defined area and lower mortality from prostate, bladder, and kidney cancer. "As supply contracts, rural areas are likely to have an even greater loss of urologic surgeons since these areas have a higher percentage of surgeons closer to retirement age than urban areas," the researchers noted in their abstract. "The result may decrease access to screening, medical and surgical treatment for urologic conditions."

Dr. Pruthi acknowledged that the ability to predict physician demand is an imprecise science. However, "there is indirect data to suggest that our demand isn’t going to go away. It’s only going to go up with that rising incidence and with the rising number of aging baby boomers. Second, we don’t know the appropriate ratio of supply and demand. If you have limited supply, you have limited access. Is our culture accepting of that? Some of these limitations to access may have health consequences."

He and his associates plan to conduct more detailed work on the projection model, including the impact of increasing numbers of women entering the urology field. "About 5% of urologists are female, but in current residency matching the numbers are about 25% female," he said. "What impact will that have? We don’t know yet."

Dr. Pruthi said that he had no relevant financial conflicts to disclose.

[email protected]

SAN DIEGO – The number of urologists practicing in the United States is expected to decrease by 29% between 2009 and 2025, according to a new analysis.

"It’s one thing if the demand for urologists is going up and the supply is stable, but to have the demand go up and the supply almost falling off of a cliff is worrisome," Dr. Raj S. Pruthi said in an interview at the annual meeting of the American Urological Association. "The people who will be hardest hit by this are ones who already struggle with access: those who live in rural communities."

Dr. Pruthi and his colleagues used stock and flow models, starting with the supply of urologists in 2009. They added new entrants from the graduate medical education (GME) pipeline and subtracted attrition from training and from the workforce due to retirement or breaks from practice. The forecast model estimates a 29% head count reduction and a 25% decrease in the full-time equivalent (FTE) supply of urologists between 2009 and 2025. The projected decrease is more than four times greater than the Health Resources and Services Administration’s Physician Supply Model, which estimated a 7% decrease over the same time period.

Dr. Pruthi warned that none of the proposed changes to GME (recommendations from the Council of Graduate Medical Education’s 16th report or a recent proposal to Congress) will increase GME enough to offset the projected decline in head count. "GME funding has been capped since 1996," he said. "We’re setting forth a recipe for a very big problem that we’re going to have for future generations in terms of who’s going to take care of" a rapidly aging population.

As the Affordable Health Care Act takes shape, "one thing that’s not been considered adequately is physician supply," added Dr. Pruthi, chief of urologic surgery at the University of North Carolina at Chapel Hill. "Are there enough of us to help care for the population? That needs to be part of the calculus. We need to do efficient, appropriate care. We need to cut health care costs, but we have to remember our physician supply."

The shrinking number of urologists could affect mortality rates, as research has demonstrated an association between a higher density of urologists in a defined area and lower mortality from prostate, bladder, and kidney cancer. "As supply contracts, rural areas are likely to have an even greater loss of urologic surgeons since these areas have a higher percentage of surgeons closer to retirement age than urban areas," the researchers noted in their abstract. "The result may decrease access to screening, medical and surgical treatment for urologic conditions."

Dr. Pruthi acknowledged that the ability to predict physician demand is an imprecise science. However, "there is indirect data to suggest that our demand isn’t going to go away. It’s only going to go up with that rising incidence and with the rising number of aging baby boomers. Second, we don’t know the appropriate ratio of supply and demand. If you have limited supply, you have limited access. Is our culture accepting of that? Some of these limitations to access may have health consequences."

He and his associates plan to conduct more detailed work on the projection model, including the impact of increasing numbers of women entering the urology field. "About 5% of urologists are female, but in current residency matching the numbers are about 25% female," he said. "What impact will that have? We don’t know yet."

Dr. Pruthi said that he had no relevant financial conflicts to disclose.

[email protected]

CHARLESTON, S.C. – Most women who undergo an isolated midurethral sling procedure pass active bladder testing on the first attempt, but the likelihood of being discharged with an indwelling catheter increases as bladder capacity increases, maximum flow rate decreases, or detrusor overactivity occurs, findings from a retrospective cross-sectional study have shown.

Of 112 patients who underwent an isolated midurethral sling procedure at a single site, 90 (80.4%) passed active bladder testing (ABT) on the first attempt prior to discharge home, and 22 (19.6%) failed, Dr. Meadow M. Good reported at the annual meeting of the Society of Gynecologic Surgeons.

Bladder testing involved filling the bladder with sterile fluid to 300 mL or to patient discomfort, whichever came first. Passing the test required that two-thirds of the instilled volume was voided.

Average bladder capacity among those who failed ABT was 415 cc, compared with 381 cc in those who passed; average maximum flow rate in those who failed ABT was 15.6 cc/second, compared with 21.6 cc/second in those who passed; and detrusor overactivity was observed in 41% of those who failed ABT, compared with 20% of those who passed, said Dr. Good of the University of Texas Southwestern Medical Center, Dallas.

Furthermore, the capacity-to-infused volume ratio was 1:5 for those who failed ABT and 1:3 for those who passed. Most (81.8%) of those who failed had bladder capacity greater than the infused amount, but no significant difference in the capacity-to-infused volume ratios was seen in the group who passed ABT.

On multivariate analysis, every 50-cc increase in bladder capacity significantly increased the odds of failing ABT (odds ratio, 1.25); every unit increase in the maximum flow rate significantly decreased the odds of ABT failure (OR, 0.91); and the presence of detrusor overactivity was associated with a fivefold increase in the odds of failure (OR, 5.0).

Age, race, body mass index, maximum urethral closure pressure, and maximum detrusor pressure during pressure-flow studies were not found to be associated with ABT outcomes.

Patients included in this study were all those who underwent an isolated midurethral sling procedure at the medical center between January 2011 and August 2012, excluding those who had intraoperative complications requiring discharge with a Foley catheter.

The findings are important because the rates of postoperative urinary retention following midurethral sling procedures are highly variable, and the identification of factors associated with ABT failure could help improve outcomes.

"Patients with postoperative retention are generally discharged home with an indwelling catheter or intermittent self-catheterization; catheter-associated bacteria lead to increased urinary tract infections and health care costs, and to decreased quality of life," Dr. Good said, adding that reducing the rates of postoperative catheter use should be a priority.

"While further research is needed, filling patients to cystometric capacity may improve the success of postoperative bladder testing," she said.

Dr. Good reported having no relevant financial disclosures.

CHARLESTON, S.C. – Most women who undergo an isolated midurethral sling procedure pass active bladder testing on the first attempt, but the likelihood of being discharged with an indwelling catheter increases as bladder capacity increases, maximum flow rate decreases, or detrusor overactivity occurs, findings from a retrospective cross-sectional study have shown.

Of 112 patients who underwent an isolated midurethral sling procedure at a single site, 90 (80.4%) passed active bladder testing (ABT) on the first attempt prior to discharge home, and 22 (19.6%) failed, Dr. Meadow M. Good reported at the annual meeting of the Society of Gynecologic Surgeons.

Bladder testing involved filling the bladder with sterile fluid to 300 mL or to patient discomfort, whichever came first. Passing the test required that two-thirds of the instilled volume was voided.

Average bladder capacity among those who failed ABT was 415 cc, compared with 381 cc in those who passed; average maximum flow rate in those who failed ABT was 15.6 cc/second, compared with 21.6 cc/second in those who passed; and detrusor overactivity was observed in 41% of those who failed ABT, compared with 20% of those who passed, said Dr. Good of the University of Texas Southwestern Medical Center, Dallas.

Furthermore, the capacity-to-infused volume ratio was 1:5 for those who failed ABT and 1:3 for those who passed. Most (81.8%) of those who failed had bladder capacity greater than the infused amount, but no significant difference in the capacity-to-infused volume ratios was seen in the group who passed ABT.

On multivariate analysis, every 50-cc increase in bladder capacity significantly increased the odds of failing ABT (odds ratio, 1.25); every unit increase in the maximum flow rate significantly decreased the odds of ABT failure (OR, 0.91); and the presence of detrusor overactivity was associated with a fivefold increase in the odds of failure (OR, 5.0).

Age, race, body mass index, maximum urethral closure pressure, and maximum detrusor pressure during pressure-flow studies were not found to be associated with ABT outcomes.

Patients included in this study were all those who underwent an isolated midurethral sling procedure at the medical center between January 2011 and August 2012, excluding those who had intraoperative complications requiring discharge with a Foley catheter.

The findings are important because the rates of postoperative urinary retention following midurethral sling procedures are highly variable, and the identification of factors associated with ABT failure could help improve outcomes.

"Patients with postoperative retention are generally discharged home with an indwelling catheter or intermittent self-catheterization; catheter-associated bacteria lead to increased urinary tract infections and health care costs, and to decreased quality of life," Dr. Good said, adding that reducing the rates of postoperative catheter use should be a priority.

"While further research is needed, filling patients to cystometric capacity may improve the success of postoperative bladder testing," she said.

Dr. Good reported having no relevant financial disclosures.

CHARLESTON, S.C. – Most women who undergo an isolated midurethral sling procedure pass active bladder testing on the first attempt, but the likelihood of being discharged with an indwelling catheter increases as bladder capacity increases, maximum flow rate decreases, or detrusor overactivity occurs, findings from a retrospective cross-sectional study have shown.

Of 112 patients who underwent an isolated midurethral sling procedure at a single site, 90 (80.4%) passed active bladder testing (ABT) on the first attempt prior to discharge home, and 22 (19.6%) failed, Dr. Meadow M. Good reported at the annual meeting of the Society of Gynecologic Surgeons.

Bladder testing involved filling the bladder with sterile fluid to 300 mL or to patient discomfort, whichever came first. Passing the test required that two-thirds of the instilled volume was voided.

Average bladder capacity among those who failed ABT was 415 cc, compared with 381 cc in those who passed; average maximum flow rate in those who failed ABT was 15.6 cc/second, compared with 21.6 cc/second in those who passed; and detrusor overactivity was observed in 41% of those who failed ABT, compared with 20% of those who passed, said Dr. Good of the University of Texas Southwestern Medical Center, Dallas.

Furthermore, the capacity-to-infused volume ratio was 1:5 for those who failed ABT and 1:3 for those who passed. Most (81.8%) of those who failed had bladder capacity greater than the infused amount, but no significant difference in the capacity-to-infused volume ratios was seen in the group who passed ABT.

On multivariate analysis, every 50-cc increase in bladder capacity significantly increased the odds of failing ABT (odds ratio, 1.25); every unit increase in the maximum flow rate significantly decreased the odds of ABT failure (OR, 0.91); and the presence of detrusor overactivity was associated with a fivefold increase in the odds of failure (OR, 5.0).

Age, race, body mass index, maximum urethral closure pressure, and maximum detrusor pressure during pressure-flow studies were not found to be associated with ABT outcomes.

Patients included in this study were all those who underwent an isolated midurethral sling procedure at the medical center between January 2011 and August 2012, excluding those who had intraoperative complications requiring discharge with a Foley catheter.

The findings are important because the rates of postoperative urinary retention following midurethral sling procedures are highly variable, and the identification of factors associated with ABT failure could help improve outcomes.

"Patients with postoperative retention are generally discharged home with an indwelling catheter or intermittent self-catheterization; catheter-associated bacteria lead to increased urinary tract infections and health care costs, and to decreased quality of life," Dr. Good said, adding that reducing the rates of postoperative catheter use should be a priority.

"While further research is needed, filling patients to cystometric capacity may improve the success of postoperative bladder testing," she said.

Dr. Good reported having no relevant financial disclosures.

Increased exposure to selenium was associated with a significantly reduced risk of advanced prostate cancer, according to the results of a large, prospective cohort study of men in the Netherlands.

The results of the study, conducted in men with low to moderate selenium levels, "suggest that selenium may prevent advanced, clinically relevant, prostate cancer," noted Milan Geybels, M.Sc., at the annual meeting of the American Association for Cancer Research. And since there is little evidence on risk factors that can modify prostate cancer risk, "any compound that would prevent the incidence of advanced, clinically relevant prostate cancer would have a substantial impact on public health," Mr. Geybels said in an interview.

The men were enrolled in the Netherlands Cohort Study, a study of diet and cancer in 58,279 men between the ages of 55 and 69 years at entry. Over 17 years, 898 men were diagnosed with advanced prostate cancer and were compared with 1,203 men also in the study. Using the concentration of selenium in the men’s toenails, an indication of long-term exposure, the investigators determined that the risk of advanced prostate cancer was significantly reduced as selenium levels increased. The risk for advanced prostate cancer was more than 60% lower in men with the highest levels of toenail selenium, when compared with those with the lowest levels, and the association was "more pronounced" among the men diagnosed later in the follow-up period, noted Mr. Geybels, a doctoral candidate in cancer epidemiology at Maastricht University, the Netherlands.

Previous prospective studies on the possible link between selenium and prostate cancer risk have produced conflicting results. Many of the studies included men with moderate to high selenium levels. Also, they did not exclusively study advanced prostate cancer, and "almost exclusively" used blood levels of selenium, which reflect recent exposure, he noted.

SELECT (Selenium and Vitamin E Cancer Prevention Trial) found no relationship between selenium supplementation and prostate cancer risk. However, "a possible explanation for the null finding is that selenium intake among SELECT participants was adequate ... [so], further selenium supplementation had no effect on prostate cancer incidence," he said.

The intake of selenium varies worldwide as a result of variations in soil content and the related variability in the selenium content in foods; in the Netherlands, low selenium is common.

The results need to be replicated in more prospective studies, and if confirmed, "A prevention trial of selenium and advanced prostate cancer in a low selenium population may be justified," said Mr. Geybels. Whether levels higher than those detected in the men in the study are associated with a further reduction in risk is unknown.

He and his coauthors had no disclosures to report.

[email protected]

Increased exposure to selenium was associated with a significantly reduced risk of advanced prostate cancer, according to the results of a large, prospective cohort study of men in the Netherlands.

The results of the study, conducted in men with low to moderate selenium levels, "suggest that selenium may prevent advanced, clinically relevant, prostate cancer," noted Milan Geybels, M.Sc., at the annual meeting of the American Association for Cancer Research. And since there is little evidence on risk factors that can modify prostate cancer risk, "any compound that would prevent the incidence of advanced, clinically relevant prostate cancer would have a substantial impact on public health," Mr. Geybels said in an interview.

The men were enrolled in the Netherlands Cohort Study, a study of diet and cancer in 58,279 men between the ages of 55 and 69 years at entry. Over 17 years, 898 men were diagnosed with advanced prostate cancer and were compared with 1,203 men also in the study. Using the concentration of selenium in the men’s toenails, an indication of long-term exposure, the investigators determined that the risk of advanced prostate cancer was significantly reduced as selenium levels increased. The risk for advanced prostate cancer was more than 60% lower in men with the highest levels of toenail selenium, when compared with those with the lowest levels, and the association was "more pronounced" among the men diagnosed later in the follow-up period, noted Mr. Geybels, a doctoral candidate in cancer epidemiology at Maastricht University, the Netherlands.

Previous prospective studies on the possible link between selenium and prostate cancer risk have produced conflicting results. Many of the studies included men with moderate to high selenium levels. Also, they did not exclusively study advanced prostate cancer, and "almost exclusively" used blood levels of selenium, which reflect recent exposure, he noted.

SELECT (Selenium and Vitamin E Cancer Prevention Trial) found no relationship between selenium supplementation and prostate cancer risk. However, "a possible explanation for the null finding is that selenium intake among SELECT participants was adequate ... [so], further selenium supplementation had no effect on prostate cancer incidence," he said.

The intake of selenium varies worldwide as a result of variations in soil content and the related variability in the selenium content in foods; in the Netherlands, low selenium is common.

The results need to be replicated in more prospective studies, and if confirmed, "A prevention trial of selenium and advanced prostate cancer in a low selenium population may be justified," said Mr. Geybels. Whether levels higher than those detected in the men in the study are associated with a further reduction in risk is unknown.

He and his coauthors had no disclosures to report.

[email protected]

Increased exposure to selenium was associated with a significantly reduced risk of advanced prostate cancer, according to the results of a large, prospective cohort study of men in the Netherlands.

The results of the study, conducted in men with low to moderate selenium levels, "suggest that selenium may prevent advanced, clinically relevant, prostate cancer," noted Milan Geybels, M.Sc., at the annual meeting of the American Association for Cancer Research. And since there is little evidence on risk factors that can modify prostate cancer risk, "any compound that would prevent the incidence of advanced, clinically relevant prostate cancer would have a substantial impact on public health," Mr. Geybels said in an interview.

The men were enrolled in the Netherlands Cohort Study, a study of diet and cancer in 58,279 men between the ages of 55 and 69 years at entry. Over 17 years, 898 men were diagnosed with advanced prostate cancer and were compared with 1,203 men also in the study. Using the concentration of selenium in the men’s toenails, an indication of long-term exposure, the investigators determined that the risk of advanced prostate cancer was significantly reduced as selenium levels increased. The risk for advanced prostate cancer was more than 60% lower in men with the highest levels of toenail selenium, when compared with those with the lowest levels, and the association was "more pronounced" among the men diagnosed later in the follow-up period, noted Mr. Geybels, a doctoral candidate in cancer epidemiology at Maastricht University, the Netherlands.

Previous prospective studies on the possible link between selenium and prostate cancer risk have produced conflicting results. Many of the studies included men with moderate to high selenium levels. Also, they did not exclusively study advanced prostate cancer, and "almost exclusively" used blood levels of selenium, which reflect recent exposure, he noted.

SELECT (Selenium and Vitamin E Cancer Prevention Trial) found no relationship between selenium supplementation and prostate cancer risk. However, "a possible explanation for the null finding is that selenium intake among SELECT participants was adequate ... [so], further selenium supplementation had no effect on prostate cancer incidence," he said.

The intake of selenium varies worldwide as a result of variations in soil content and the related variability in the selenium content in foods; in the Netherlands, low selenium is common.

The results need to be replicated in more prospective studies, and if confirmed, "A prevention trial of selenium and advanced prostate cancer in a low selenium population may be justified," said Mr. Geybels. Whether levels higher than those detected in the men in the study are associated with a further reduction in risk is unknown.

He and his coauthors had no disclosures to report.

[email protected]

Q:  As a hospitalist, I often see patients in our ICU develop AKI. Our pharmacist helps us with medication dosing, but sometimes I feel as if we're pulling a dose out of the air. Are there any studies or guidelines we can refer to?
Standard medication dosing adjustments for patients with impaired renal function are generally based on estimated glomerular filtration rate (eGFR). Because SCr is a lagging indicator of AKI, all methods of deriving eGFR from SCr are valid only when the patient is in a steady state.¹⁰

SCr has yet to be replaced by a real-time biomarker for AKI; this has left clinicians in the ICU setting with no simple or concise method for real-time assessment of renal function. In response to this common clinical conundrum, the RIFLE criteria,⁸ mentioned above, incorporates urinary output and relative increase in SCr as assessment criteria (see table for definitions).

This revised classification system may help the clinician define the severity of AKI in the acute setting. However, no medication dosing guidelines currently correspond with RIFLE staging. To further complicate the picture, there is evidence to suggest that AKI may affect drug metabolism through nonrenal pathways, such as hepatic clearance and transport functions.¹¹ Add to this the potential for impaired drug absorption, distribution, and/or clearance due to variance in intravascular volume status, hepatic hypoperfusion, hypoxia, decreased protein synthesis, and competitive inhibition from concomitant medications—in short, the variables become too complex for calculating therapeutic drug dosing to be possible.

In the absence of definitive guidelines, the clinician plays a critical role in medication dosing adjustment for the ICU patient with AKI. The clinician must use astute clinical judgment to assess and prioritize the unique constellation of factors in any given case. Some of the factors that should be carefully considered when estimating medication dose adjustments in this context include RIFLE staging, trend in SCr, baseline SCr, nephrotoxicity of the medication to be administered, the drug's volume of distribution, the metabolic pathways of drug excretion, and the patient's weight.

A serum drug level, when available, is generally the best guide for dosing adjustment.¹⁰ The RIFLE staging does offer some clinical pearls that may be helpful. Though not evidence-based recommendations, these guides are commonly used in the clinical environment.

When patients are in the Failure stage, for example (see specifics in the table), they are generally considered to have an eGFR of less than 15 mL/min for purposes of drug dose adjustment (personal communication, Gideon Kayanan, PharmD, February 2013). However, patients in this category are much more likely than others to be undergoing dialysis, in which case the pharmacokinetics and pharmacodynamics are further complicated. In some cases, it may be appropriate to order creatinine clearance studies with a 6- or 12-hour urine collection and extrapolate a 24-hour creatinine clearance from this value.

The dearth of literature addressing this topic (despite the prevalence of AKI in the acute care setting) is a clear indication of the complexity of creating guidelines to address such a dynamic, multivariate pharmacokinetic process. Review of the literature clearly demonstrates that medical science in this area is not yet sufficiently developed to produce a standardized, data-driven guideline for dose adjustment calculation in patients with AKI.¹⁰ Until biomarkers are detected that offer real-time assessment of renal function and that can be used in the clinical setting, there will continue to be a component of estimation, analysis of trends, and reliance on clinical judgment in adjusting medication doses for inpatients with AKI. —AC

References
1. National Institute of Diabetes and Digestive and Kidney Diseases, NIH. US Renal Data System, 2010 Annual Data Report. www.usrds.org/2010/view/default.asp. Accessed March 5, 2013.

2. National Institute of Diabetes and Digestive and Kidney Diseases, NIH. US Renal Data System, 2011 Annual Data Report. www.usrds.org/2011/view/v2_00_appx.asp. Accessed March 5, 2013.

3. Waikar SS, Liu KD, Chertow GM. Diagnosis, epidemiology and outcomes of acute kidney injury. Clin J Am Soc Nephrol. 2008;3:844-861.

4. Chertow GM, Burdick E, Honour M, et al. Acute kidney injury, mortality, length of stay, and costs in hospitalized patients. J Am Soc Nephrol. 2005;16:3365-3370.

5. Hsu RK, McCulloch CE, Dudley RA, et al. Temporal changes in incidence of dialysis-requiring AKI. J Am Soc Nephrol. 2012;24:37-42.

6. Wang HE, Muntner P, Chertow GM, Warnock DG. Acute kidney injury and mortality in hospitalized patients. Am J Nephrol. 2012;35:349-355.

7. Nisula S, Kaukonen KM, Vaara ST, et al. Incidence, risk factors and 90-day mortality of patients with acute kidney injury in Finnish intensive care units: the FINNAKI study. Intensive Care Med. 2013;39:420-428.

8. Hoste EA, Clermont G, Kersten A, et al. RIFLE criteria for acute kidney injury are associated with hospital mortality in critically ill patients: a cohort analysis. Crit Care. 2006;10:R73.

9. Coca SG, Yusuf B, Shlipak MG, et al. Long-term risk of mortality and other adverse outcomes after acute kidney injury: a systematic review and meta-analysis. Am J Kidney Dis. 2009;53:961-973.

10. Matzke GR, Aronoff GR, Atkinson AJ Jr, et al. Drug dosing consideration in patients with acute and chronic kidney disease: a clinical update from Kidney Disease: Improving Global Outcomes (KDIGO). Kidney Int. 2011;80:1122-1137.

11. Vilay AM, Churchwell MD, Mueller BA. Clinical review: drug metabolism and nonrenal clearance in acute kidney injury. Crit Care. 2008;12:235.

Q:  As a hospitalist, I often see patients in our ICU develop AKI. Our pharmacist helps us with medication dosing, but sometimes I feel as if we're pulling a dose out of the air. Are there any studies or guidelines we can refer to?
Standard medication dosing adjustments for patients with impaired renal function are generally based on estimated glomerular filtration rate (eGFR). Because SCr is a lagging indicator of AKI, all methods of deriving eGFR from SCr are valid only when the patient is in a steady state.¹⁰

SCr has yet to be replaced by a real-time biomarker for AKI; this has left clinicians in the ICU setting with no simple or concise method for real-time assessment of renal function. In response to this common clinical conundrum, the RIFLE criteria,⁸ mentioned above, incorporates urinary output and relative increase in SCr as assessment criteria (see table for definitions).

This revised classification system may help the clinician define the severity of AKI in the acute setting. However, no medication dosing guidelines currently correspond with RIFLE staging. To further complicate the picture, there is evidence to suggest that AKI may affect drug metabolism through nonrenal pathways, such as hepatic clearance and transport functions.¹¹ Add to this the potential for impaired drug absorption, distribution, and/or clearance due to variance in intravascular volume status, hepatic hypoperfusion, hypoxia, decreased protein synthesis, and competitive inhibition from concomitant medications—in short, the variables become too complex for calculating therapeutic drug dosing to be possible.

In the absence of definitive guidelines, the clinician plays a critical role in medication dosing adjustment for the ICU patient with AKI. The clinician must use astute clinical judgment to assess and prioritize the unique constellation of factors in any given case. Some of the factors that should be carefully considered when estimating medication dose adjustments in this context include RIFLE staging, trend in SCr, baseline SCr, nephrotoxicity of the medication to be administered, the drug's volume of distribution, the metabolic pathways of drug excretion, and the patient's weight.

A serum drug level, when available, is generally the best guide for dosing adjustment.¹⁰ The RIFLE staging does offer some clinical pearls that may be helpful. Though not evidence-based recommendations, these guides are commonly used in the clinical environment.

When patients are in the Failure stage, for example (see specifics in the table), they are generally considered to have an eGFR of less than 15 mL/min for purposes of drug dose adjustment (personal communication, Gideon Kayanan, PharmD, February 2013). However, patients in this category are much more likely than others to be undergoing dialysis, in which case the pharmacokinetics and pharmacodynamics are further complicated. In some cases, it may be appropriate to order creatinine clearance studies with a 6- or 12-hour urine collection and extrapolate a 24-hour creatinine clearance from this value.

The dearth of literature addressing this topic (despite the prevalence of AKI in the acute care setting) is a clear indication of the complexity of creating guidelines to address such a dynamic, multivariate pharmacokinetic process. Review of the literature clearly demonstrates that medical science in this area is not yet sufficiently developed to produce a standardized, data-driven guideline for dose adjustment calculation in patients with AKI.¹⁰ Until biomarkers are detected that offer real-time assessment of renal function and that can be used in the clinical setting, there will continue to be a component of estimation, analysis of trends, and reliance on clinical judgment in adjusting medication doses for inpatients with AKI. —AC

References
1. National Institute of Diabetes and Digestive and Kidney Diseases, NIH. US Renal Data System, 2010 Annual Data Report. www.usrds.org/2010/view/default.asp. Accessed March 5, 2013.

2. National Institute of Diabetes and Digestive and Kidney Diseases, NIH. US Renal Data System, 2011 Annual Data Report. www.usrds.org/2011/view/v2_00_appx.asp. Accessed March 5, 2013.

3. Waikar SS, Liu KD, Chertow GM. Diagnosis, epidemiology and outcomes of acute kidney injury. Clin J Am Soc Nephrol. 2008;3:844-861.

4. Chertow GM, Burdick E, Honour M, et al. Acute kidney injury, mortality, length of stay, and costs in hospitalized patients. J Am Soc Nephrol. 2005;16:3365-3370.

5. Hsu RK, McCulloch CE, Dudley RA, et al. Temporal changes in incidence of dialysis-requiring AKI. J Am Soc Nephrol. 2012;24:37-42.

6. Wang HE, Muntner P, Chertow GM, Warnock DG. Acute kidney injury and mortality in hospitalized patients. Am J Nephrol. 2012;35:349-355.

7. Nisula S, Kaukonen KM, Vaara ST, et al. Incidence, risk factors and 90-day mortality of patients with acute kidney injury in Finnish intensive care units: the FINNAKI study. Intensive Care Med. 2013;39:420-428.

8. Hoste EA, Clermont G, Kersten A, et al. RIFLE criteria for acute kidney injury are associated with hospital mortality in critically ill patients: a cohort analysis. Crit Care. 2006;10:R73.

9. Coca SG, Yusuf B, Shlipak MG, et al. Long-term risk of mortality and other adverse outcomes after acute kidney injury: a systematic review and meta-analysis. Am J Kidney Dis. 2009;53:961-973.

10. Matzke GR, Aronoff GR, Atkinson AJ Jr, et al. Drug dosing consideration in patients with acute and chronic kidney disease: a clinical update from Kidney Disease: Improving Global Outcomes (KDIGO). Kidney Int. 2011;80:1122-1137.

11. Vilay AM, Churchwell MD, Mueller BA. Clinical review: drug metabolism and nonrenal clearance in acute kidney injury. Crit Care. 2008;12:235.

Q:  As a hospitalist, I often see patients in our ICU develop AKI. Our pharmacist helps us with medication dosing, but sometimes I feel as if we're pulling a dose out of the air. Are there any studies or guidelines we can refer to?
Standard medication dosing adjustments for patients with impaired renal function are generally based on estimated glomerular filtration rate (eGFR). Because SCr is a lagging indicator of AKI, all methods of deriving eGFR from SCr are valid only when the patient is in a steady state.¹⁰

SCr has yet to be replaced by a real-time biomarker for AKI; this has left clinicians in the ICU setting with no simple or concise method for real-time assessment of renal function. In response to this common clinical conundrum, the RIFLE criteria,⁸ mentioned above, incorporates urinary output and relative increase in SCr as assessment criteria (see table for definitions).

This revised classification system may help the clinician define the severity of AKI in the acute setting. However, no medication dosing guidelines currently correspond with RIFLE staging. To further complicate the picture, there is evidence to suggest that AKI may affect drug metabolism through nonrenal pathways, such as hepatic clearance and transport functions.¹¹ Add to this the potential for impaired drug absorption, distribution, and/or clearance due to variance in intravascular volume status, hepatic hypoperfusion, hypoxia, decreased protein synthesis, and competitive inhibition from concomitant medications—in short, the variables become too complex for calculating therapeutic drug dosing to be possible.

In the absence of definitive guidelines, the clinician plays a critical role in medication dosing adjustment for the ICU patient with AKI. The clinician must use astute clinical judgment to assess and prioritize the unique constellation of factors in any given case. Some of the factors that should be carefully considered when estimating medication dose adjustments in this context include RIFLE staging, trend in SCr, baseline SCr, nephrotoxicity of the medication to be administered, the drug's volume of distribution, the metabolic pathways of drug excretion, and the patient's weight.

A serum drug level, when available, is generally the best guide for dosing adjustment.¹⁰ The RIFLE staging does offer some clinical pearls that may be helpful. Though not evidence-based recommendations, these guides are commonly used in the clinical environment.

When patients are in the Failure stage, for example (see specifics in the table), they are generally considered to have an eGFR of less than 15 mL/min for purposes of drug dose adjustment (personal communication, Gideon Kayanan, PharmD, February 2013). However, patients in this category are much more likely than others to be undergoing dialysis, in which case the pharmacokinetics and pharmacodynamics are further complicated. In some cases, it may be appropriate to order creatinine clearance studies with a 6- or 12-hour urine collection and extrapolate a 24-hour creatinine clearance from this value.

The dearth of literature addressing this topic (despite the prevalence of AKI in the acute care setting) is a clear indication of the complexity of creating guidelines to address such a dynamic, multivariate pharmacokinetic process. Review of the literature clearly demonstrates that medical science in this area is not yet sufficiently developed to produce a standardized, data-driven guideline for dose adjustment calculation in patients with AKI.¹⁰ Until biomarkers are detected that offer real-time assessment of renal function and that can be used in the clinical setting, there will continue to be a component of estimation, analysis of trends, and reliance on clinical judgment in adjusting medication doses for inpatients with AKI. —AC

References
1. National Institute of Diabetes and Digestive and Kidney Diseases, NIH. US Renal Data System, 2010 Annual Data Report. www.usrds.org/2010/view/default.asp. Accessed March 5, 2013.

2. National Institute of Diabetes and Digestive and Kidney Diseases, NIH. US Renal Data System, 2011 Annual Data Report. www.usrds.org/2011/view/v2_00_appx.asp. Accessed March 5, 2013.

3. Waikar SS, Liu KD, Chertow GM. Diagnosis, epidemiology and outcomes of acute kidney injury. Clin J Am Soc Nephrol. 2008;3:844-861.

4. Chertow GM, Burdick E, Honour M, et al. Acute kidney injury, mortality, length of stay, and costs in hospitalized patients. J Am Soc Nephrol. 2005;16:3365-3370.

5. Hsu RK, McCulloch CE, Dudley RA, et al. Temporal changes in incidence of dialysis-requiring AKI. J Am Soc Nephrol. 2012;24:37-42.

6. Wang HE, Muntner P, Chertow GM, Warnock DG. Acute kidney injury and mortality in hospitalized patients. Am J Nephrol. 2012;35:349-355.

7. Nisula S, Kaukonen KM, Vaara ST, et al. Incidence, risk factors and 90-day mortality of patients with acute kidney injury in Finnish intensive care units: the FINNAKI study. Intensive Care Med. 2013;39:420-428.

8. Hoste EA, Clermont G, Kersten A, et al. RIFLE criteria for acute kidney injury are associated with hospital mortality in critically ill patients: a cohort analysis. Crit Care. 2006;10:R73.

9. Coca SG, Yusuf B, Shlipak MG, et al. Long-term risk of mortality and other adverse outcomes after acute kidney injury: a systematic review and meta-analysis. Am J Kidney Dis. 2009;53:961-973.

10. Matzke GR, Aronoff GR, Atkinson AJ Jr, et al. Drug dosing consideration in patients with acute and chronic kidney disease: a clinical update from Kidney Disease: Improving Global Outcomes (KDIGO). Kidney Int. 2011;80:1122-1137.

11. Vilay AM, Churchwell MD, Mueller BA. Clinical review: drug metabolism and nonrenal clearance in acute kidney injury. Crit Care. 2008;12:235.

Q: In 10 years as a hospitalist advanced practitioner, I've been seeing more and more AKI in our ICU. Is this true everywhere, or are we doing something wrong?
AKI is on the rise nationwide (see hospitalization data in figure), and it carries grim implications for patient outcomes.^1-3 AKI with a rise in serum creatinine (SCr) as modest as 0.3 mg/dL is associated with a 70% increase in mortality risk. A rise in SCr exceeding 0.5 mg/dL has been associated with a 6.5-fold rise in the risk for death, even when adjusted for age and gender.⁴ This is higher than the mortality rate for inpatients admitted with cardiovascular disease or cancer, and just slightly more favorable than the mortality risk associated with sepsis (odds ratios, 6.6 and 7.5, respectively). AKI management in the non-ICU setting incurs the third highest median direct hospital cost, after acute MI and stroke.³

A recent retrospective analysis of hospital admissions nationwide from 2000 to 2009 shows a 10% annual increase in the incidence of AKI requiring dialysis, with at least doubling of the incidence and the number of deaths during that 10-year time period.⁵ Analyzing the incidence of AKI not requiring dialysis over time is more challenging because the criteria to define AKI have not been static; however, the rise in AKI requiring dialysis has mirrored the rise in AKI not requiring dialysis—suggesting that there is in fact an increased incidence of AKI, independent of variability in the defining criteria.³

Researchers reported in 2012 that during the previous year, the incidence of AKI among all hospitalized patients was 1 in 5.⁶ In the ICU, incidence of AKI has been reported at 39%, with a mortality rate of 25%.⁷ Based on the RIFLE criteria (a recently revised classification system whose name refers to Risk, Injury, Failure; Loss and End-stage kidney disease),⁸ as many as two-thirds of patients admitted to the ICU meet criteria for a diagnosis of AKI.

Predictors for AKI include advancing age, baseline SCr below 1.2 mg/dL, the presence of diabetes, use of IV contrast, acute coronary syndromes, sepsis, liver or heart failure, and use of nephrotoxic medications.³

It is important for clinicians to recognize the implications of AKI, even when it manifests as a relatively minor rise in SCr. In addition to its association with poor outcomes in hospitalized patients, AKI increases the risk for chronic kidney disease and for readmissions within six months after hospital discharge.⁹ Unfortunately, our increased awareness of the implications of AKI in the inpatient setting has yet to translate into significant improvement in outcomes.

The evolution and availability of epidemiologic and outcome data, we can only hope, will serve to direct more resources and further study toward this issue. Clinicians' efforts to prevent and treat AKI can have profound implications for many of our nation's most chronically and critically ill patients. —AC

REFERENCES
1. National Institute of Diabetes and Digestive and Kidney Diseases, NIH. US Renal Data System, 2010 Annual Data Report. www.usrds.org/2010/view/default.asp. Accessed March 5, 2013.

2. National Institute of Diabetes and Digestive and Kidney Diseases, NIH. US Renal Data System, 2011 Annual Data Report. www.usrds.org/2011/view/v2_00_appx.asp. Accessed March 5, 2013.

3. Waikar SS, Liu KD, Chertow GM. Diagnosis, epidemiology and outcomes of acute kidney injury. Clin J Am Soc Nephrol. 2008;3:844-861.

4. Chertow GM, Burdick E, Honour M, et al. Acute kidney injury, mortality, length of stay, and costs in hospitalized patients. J Am Soc Nephrol. 2005;16:3365-3370.

5. Hsu RK, McCulloch CE, Dudley RA, et al. Temporal changes in incidence of dialysis-requiring AKI. J Am Soc Nephrol. 2012;24:37-42.

6. Wang HE, Muntner P, Chertow GM, Warnock DG. Acute kidney injury and mortality in hospitalized patients. Am J Nephrol. 2012;35:349-355.

7. Nisula S, Kaukonen KM, Vaara ST, et al. Incidence, risk factors and 90-day mortality of patients with acute kidney injury in Finnish intensive care units: the FINNAKI study. Intensive Care Med. 2013;39:420-428.

8. Hoste EA, Clermont G, Kersten A, et al. RIFLE criteria for acute kidney injury are associated with hospital mortality in critically ill patients: a cohort analysis. Crit Care. 2006;10:R73.

9. Coca SG, Yusuf B, Shlipak MG, et al. Long-term risk of mortality and other adverse outcomes after acute kidney injury: a systematic review and meta-analysis. Am J Kidney Dis. 2009;53:961-973.

10. Matzke GR, Aronoff GR, Atkinson AJ Jr, et al. Drug dosing consideration in patients with acute and chronic kidney disease: a clinical update from Kidney Disease: Improving Global Outcomes (KDIGO). Kidney Int. 2011;80:1122-1137.

11. Vilay AM, Churchwell MD, Mueller BA. Clinical review: drug metabolism and nonrenal clearance in acute kidney injury. Crit Care. 2008;12:235.

Q: In 10 years as a hospitalist advanced practitioner, I've been seeing more and more AKI in our ICU. Is this true everywhere, or are we doing something wrong?
AKI is on the rise nationwide (see hospitalization data in figure), and it carries grim implications for patient outcomes.^1-3 AKI with a rise in serum creatinine (SCr) as modest as 0.3 mg/dL is associated with a 70% increase in mortality risk. A rise in SCr exceeding 0.5 mg/dL has been associated with a 6.5-fold rise in the risk for death, even when adjusted for age and gender.⁴ This is higher than the mortality rate for inpatients admitted with cardiovascular disease or cancer, and just slightly more favorable than the mortality risk associated with sepsis (odds ratios, 6.6 and 7.5, respectively). AKI management in the non-ICU setting incurs the third highest median direct hospital cost, after acute MI and stroke.³

A recent retrospective analysis of hospital admissions nationwide from 2000 to 2009 shows a 10% annual increase in the incidence of AKI requiring dialysis, with at least doubling of the incidence and the number of deaths during that 10-year time period.⁵ Analyzing the incidence of AKI not requiring dialysis over time is more challenging because the criteria to define AKI have not been static; however, the rise in AKI requiring dialysis has mirrored the rise in AKI not requiring dialysis—suggesting that there is in fact an increased incidence of AKI, independent of variability in the defining criteria.³

Researchers reported in 2012 that during the previous year, the incidence of AKI among all hospitalized patients was 1 in 5.⁶ In the ICU, incidence of AKI has been reported at 39%, with a mortality rate of 25%.⁷ Based on the RIFLE criteria (a recently revised classification system whose name refers to Risk, Injury, Failure; Loss and End-stage kidney disease),⁸ as many as two-thirds of patients admitted to the ICU meet criteria for a diagnosis of AKI.

Predictors for AKI include advancing age, baseline SCr below 1.2 mg/dL, the presence of diabetes, use of IV contrast, acute coronary syndromes, sepsis, liver or heart failure, and use of nephrotoxic medications.³

It is important for clinicians to recognize the implications of AKI, even when it manifests as a relatively minor rise in SCr. In addition to its association with poor outcomes in hospitalized patients, AKI increases the risk for chronic kidney disease and for readmissions within six months after hospital discharge.⁹ Unfortunately, our increased awareness of the implications of AKI in the inpatient setting has yet to translate into significant improvement in outcomes.

The evolution and availability of epidemiologic and outcome data, we can only hope, will serve to direct more resources and further study toward this issue. Clinicians' efforts to prevent and treat AKI can have profound implications for many of our nation's most chronically and critically ill patients. —AC

REFERENCES
1. National Institute of Diabetes and Digestive and Kidney Diseases, NIH. US Renal Data System, 2010 Annual Data Report. www.usrds.org/2010/view/default.asp. Accessed March 5, 2013.

2. National Institute of Diabetes and Digestive and Kidney Diseases, NIH. US Renal Data System, 2011 Annual Data Report. www.usrds.org/2011/view/v2_00_appx.asp. Accessed March 5, 2013.

3. Waikar SS, Liu KD, Chertow GM. Diagnosis, epidemiology and outcomes of acute kidney injury. Clin J Am Soc Nephrol. 2008;3:844-861.

4. Chertow GM, Burdick E, Honour M, et al. Acute kidney injury, mortality, length of stay, and costs in hospitalized patients. J Am Soc Nephrol. 2005;16:3365-3370.

5. Hsu RK, McCulloch CE, Dudley RA, et al. Temporal changes in incidence of dialysis-requiring AKI. J Am Soc Nephrol. 2012;24:37-42.

6. Wang HE, Muntner P, Chertow GM, Warnock DG. Acute kidney injury and mortality in hospitalized patients. Am J Nephrol. 2012;35:349-355.

7. Nisula S, Kaukonen KM, Vaara ST, et al. Incidence, risk factors and 90-day mortality of patients with acute kidney injury in Finnish intensive care units: the FINNAKI study. Intensive Care Med. 2013;39:420-428.

8. Hoste EA, Clermont G, Kersten A, et al. RIFLE criteria for acute kidney injury are associated with hospital mortality in critically ill patients: a cohort analysis. Crit Care. 2006;10:R73.

9. Coca SG, Yusuf B, Shlipak MG, et al. Long-term risk of mortality and other adverse outcomes after acute kidney injury: a systematic review and meta-analysis. Am J Kidney Dis. 2009;53:961-973.

10. Matzke GR, Aronoff GR, Atkinson AJ Jr, et al. Drug dosing consideration in patients with acute and chronic kidney disease: a clinical update from Kidney Disease: Improving Global Outcomes (KDIGO). Kidney Int. 2011;80:1122-1137.

11. Vilay AM, Churchwell MD, Mueller BA. Clinical review: drug metabolism and nonrenal clearance in acute kidney injury. Crit Care. 2008;12:235.

Q: In 10 years as a hospitalist advanced practitioner, I've been seeing more and more AKI in our ICU. Is this true everywhere, or are we doing something wrong?
AKI is on the rise nationwide (see hospitalization data in figure), and it carries grim implications for patient outcomes.^1-3 AKI with a rise in serum creatinine (SCr) as modest as 0.3 mg/dL is associated with a 70% increase in mortality risk. A rise in SCr exceeding 0.5 mg/dL has been associated with a 6.5-fold rise in the risk for death, even when adjusted for age and gender.⁴ This is higher than the mortality rate for inpatients admitted with cardiovascular disease or cancer, and just slightly more favorable than the mortality risk associated with sepsis (odds ratios, 6.6 and 7.5, respectively). AKI management in the non-ICU setting incurs the third highest median direct hospital cost, after acute MI and stroke.³

A recent retrospective analysis of hospital admissions nationwide from 2000 to 2009 shows a 10% annual increase in the incidence of AKI requiring dialysis, with at least doubling of the incidence and the number of deaths during that 10-year time period.⁵ Analyzing the incidence of AKI not requiring dialysis over time is more challenging because the criteria to define AKI have not been static; however, the rise in AKI requiring dialysis has mirrored the rise in AKI not requiring dialysis—suggesting that there is in fact an increased incidence of AKI, independent of variability in the defining criteria.³

Researchers reported in 2012 that during the previous year, the incidence of AKI among all hospitalized patients was 1 in 5.⁶ In the ICU, incidence of AKI has been reported at 39%, with a mortality rate of 25%.⁷ Based on the RIFLE criteria (a recently revised classification system whose name refers to Risk, Injury, Failure; Loss and End-stage kidney disease),⁸ as many as two-thirds of patients admitted to the ICU meet criteria for a diagnosis of AKI.

Predictors for AKI include advancing age, baseline SCr below 1.2 mg/dL, the presence of diabetes, use of IV contrast, acute coronary syndromes, sepsis, liver or heart failure, and use of nephrotoxic medications.³

It is important for clinicians to recognize the implications of AKI, even when it manifests as a relatively minor rise in SCr. In addition to its association with poor outcomes in hospitalized patients, AKI increases the risk for chronic kidney disease and for readmissions within six months after hospital discharge.⁹ Unfortunately, our increased awareness of the implications of AKI in the inpatient setting has yet to translate into significant improvement in outcomes.

The evolution and availability of epidemiologic and outcome data, we can only hope, will serve to direct more resources and further study toward this issue. Clinicians' efforts to prevent and treat AKI can have profound implications for many of our nation's most chronically and critically ill patients. —AC

REFERENCES
1. National Institute of Diabetes and Digestive and Kidney Diseases, NIH. US Renal Data System, 2010 Annual Data Report. www.usrds.org/2010/view/default.asp. Accessed March 5, 2013.

2. National Institute of Diabetes and Digestive and Kidney Diseases, NIH. US Renal Data System, 2011 Annual Data Report. www.usrds.org/2011/view/v2_00_appx.asp. Accessed March 5, 2013.

3. Waikar SS, Liu KD, Chertow GM. Diagnosis, epidemiology and outcomes of acute kidney injury. Clin J Am Soc Nephrol. 2008;3:844-861.

4. Chertow GM, Burdick E, Honour M, et al. Acute kidney injury, mortality, length of stay, and costs in hospitalized patients. J Am Soc Nephrol. 2005;16:3365-3370.

5. Hsu RK, McCulloch CE, Dudley RA, et al. Temporal changes in incidence of dialysis-requiring AKI. J Am Soc Nephrol. 2012;24:37-42.

6. Wang HE, Muntner P, Chertow GM, Warnock DG. Acute kidney injury and mortality in hospitalized patients. Am J Nephrol. 2012;35:349-355.

7. Nisula S, Kaukonen KM, Vaara ST, et al. Incidence, risk factors and 90-day mortality of patients with acute kidney injury in Finnish intensive care units: the FINNAKI study. Intensive Care Med. 2013;39:420-428.

8. Hoste EA, Clermont G, Kersten A, et al. RIFLE criteria for acute kidney injury are associated with hospital mortality in critically ill patients: a cohort analysis. Crit Care. 2006;10:R73.

9. Coca SG, Yusuf B, Shlipak MG, et al. Long-term risk of mortality and other adverse outcomes after acute kidney injury: a systematic review and meta-analysis. Am J Kidney Dis. 2009;53:961-973.

10. Matzke GR, Aronoff GR, Atkinson AJ Jr, et al. Drug dosing consideration in patients with acute and chronic kidney disease: a clinical update from Kidney Disease: Improving Global Outcomes (KDIGO). Kidney Int. 2011;80:1122-1137.

11. Vilay AM, Churchwell MD, Mueller BA. Clinical review: drug metabolism and nonrenal clearance in acute kidney injury. Crit Care. 2008;12:235.