Derivation of urine output thresholds that identify a very high risk of AKI in patients with septic shock.
OBJECTIVE
To promote early detection of AKI, recently proposed pretest probability models combine sub-Kidney Disease Improving Global Outcomes (KDIGO) AKI criteria with baseline AKI risk. The primary objective of this study was to determine sub-KDIGO thresholds that identify patients with septic shock at highest risk for AKI.


METHODS
This was a retrospective analysis of 390 adult patients admitted to the medical intensive care unit (ICU) of a tertiary, academic medical center with septic shock between January 2008 and December 2010. Hourly urine output was collected from the time of septic shock recognition (hour 0) to hour 96, urine catheter removal, or ICU discharge (whichever occurred first). All available serum creatinine (SCr) measurements were collected until hour 96. The AKI pretest probability model was assessed during the first 12 hours of resuscitation and included the initial episode of oliguria, increase from baseline to peak SCr level, and Acute Physiology and Chronic Health Evaluation (APACHE) III score in a multivariable receiver-operator characteristic (ROC) analysis. The primary outcome was the incidence of stage II or III (stage II+) AKI defined by KDIGO criteria. Secondary outcomes included the need for RRT and 28-day mortality.


RESULTS
Ninety-eight (25%) patients developed stage II+ AKI after septic shock recognition. APACHE III score and increase in SCr level in the first 12 hours were not statistically associated with stage II+ AKI in multivariable ROC analysis. Consecutive oliguria for 3 hours had fair predictive ability for achieving stage II+ AKI criteria (area under ROC curve, 0.73; 95% confidence interval [95% CI], 0.68 to 0.78), and oliguria for 5 hours demonstrated optimal accuracy (82%; 95% CI, 79% to 86%).


CONCLUSIONS
Three to 5 hours of consecutive oliguria in patients with septic shock may provide a valuable measure of AKI risk. Further validation to support this finding is needed.
Pharmacy Services, Sanford Medical Center, Fargo, North Dakota;
David D
DD
Leedahl
Pharmacy Services, frazee.erin@mayo.edu.
Erin N
EN
Frazee
Pharmacy Services.
Garrett E
GE
Schramm
Division of Biomedical Statistics and Informatics, and.
Ross A
RA
Dierkhising
Division of Biomedical Statistics and Informatics, and.
Eric J
EJ
Bergstralh
Department of Anesthesiology and Critical Care Medicine and Division of Renal Diseases and Hypertension, George Washington University Medical Center, Washington, DC.
Lakhmir S
LS
Chawla
Division of Nephrology and Hypertension and Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, Minnesota; and.
Kianoush B
KB
Kashani
D018806:APACHE; D000046:Academic Medical Centers; D058186:Acute Kidney Injury / Q000097:blood / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D003404:Creatinine / Q000097:blood; D004219:District of Columbia; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009846:Oliguria / Q000097:blood / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D011237:Predictive Value of Tests; D012372:ROC Curve; D017582:Renal Replacement Therapy; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012772:Shock, Septic / Q000097:blood / Q000150:complications* / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D062606:Tertiary Care Centers; D013997:Time Factors; D016896:Treatment Outcome; D014546:Urinary Catheterization; D014554:Urination; D014563:Urodynamics
D015415:Biomarkers; D003404:Creatinine
Acute kidney injury; clinical alarms; early diagnosis; intensive care units; kidney function tests; septic shock