National surgical quality improvement program underestimates the risk associated with mild and moderate postoperative acute kidney injury.
OBJECTIVE
In a single-center cohort of surgical patients, we assessed the association between postoperative change in serum creatinine and adverse outcomes and compared the American College of Surgeons National Surgical Quality Improvement Program's definition for acute kidney injury with consensus risk, injury, failure, loss, and end-stage kidney and Kidney Disease: Improving Global Outcomes definitions.


METHODS
Retrospective single-center cohort.


METHODS
Academic tertiary medical center.


METHODS
Twenty-seven thousand eight hundred forty-one adult patients with no previous history of chronic kidney disease undergoing major surgery.


METHODS
Risk, injury, failure, loss, and end-stage kidney defines acute kidney injury as change in serum creatinine greater than or equal to 50% while Kidney Disease: Improving Global Outcomes uses 0.3 mg/dL change from the reference serum creatinine. Since National Surgical Quality Improvement Program defines acute kidney injury as serum creatinine change greater than 2 mg/dL, it may underestimate the risk associated with less severe acute kidney injury.


RESULTS
The optimal discrimination limits for both percent and absolute serum creatinine changes were calculated by maximizing sensitivity and specificity along the receiver operating characteristic curves for postoperative complications and mortality. Although prevalence of risk, injury, failure, loss, and end-stage kidney-acute kidney injury was 37%, only 7% of risk, injury, failure, loss, and end-stage kidney-acute kidney injury patients would be diagnosed with acute kidney injury using the National Surgical Quality Improvement Program definition. In multivariable logistic models, patients with risk, injury, failure, loss, and end-stage kidney or Kidney Disease: Improving Global Outcomes-acute kidney injury had a 10 times higher odds of dying compared to patients without acute kidney injury. The optimal discrimination limits for change in serum creatinine associated with adverse postoperative outcomes were as low as 0.2 mg/dL while the National Surgical Quality Improvement Program discrimination limit of 2.0 mg/dL had low sensitivity (0.05-0.28).


CONCLUSIONS
Current American College of Surgeons National Surgical Quality Improvement Program definition underestimates the risk associated with mild and moderate acute kidney injury otherwise captured by the consensus risk, injury, failure, loss, and end-stage kidney and Kidney Disease: Improving Global Outcomes criteria.
1Department of Anesthesiology, University of Florida, Gainesville, FL. 2Department of Surgery, University of Florida, Gainesville, FL. 3Department of Medicine, University of Florida, Gainesville, FL. 4Department of Surgery, North Florida South Georgia Veterans Affairs Medical Center, Gainesville, FL.
Azra
A
Bihorac
Meghan
M
Brennan
Tezcan
T
Ozrazgat-Baslanti
Shahab
S
Bozorgmehri
Philip A
PA
Efron
Frederick A
FA
Moore
Mark S
MS
Segal
Charles E
CE
Hobson
D000046:Academic Medical Centers; D058186:Acute Kidney Injury / Q000097:blood* / Q000209:etiology* / Q000401:mortality; D000328:Adult; D000368:Aged; D003404:Creatinine / Q000097:blood*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000097:blood* / Q000453:epidemiology*; D011184:Postoperative Period; D015995:Prevalence; D051437:Renal Insufficiency / Q000097:blood / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D012959:Socioeconomic Factors
D003404:Creatinine