Journal of critical care

Epidemiology and outcomes of acute kidney injury in critically ill surgical patients.

PMID 25171816


Acute kidney injury (AKI) is common in critically ill patients but is poorly defined in surgical patients. We studied AKI in a representative cohort of critically ill surgical patients. This was a retrospective 1-year cohort study of general surgical intensive care unit patients. Patients were identified from a prospective database, and clinical data were reviewed. Acute kidney injury events were defined by risk, injury, failure, loss, and end-stage renal classification criteria. Outcomes were inpatient and 1-year mortality, inpatient lengths of stay, and discharge renal function. Risk factors for AKI and outcomes were compared by univariate and multivariate analyses. Of 624 patients, 296 (47%) developed AKI. Forty-two percent of events were present upon admission, whereas 36% occurred postoperatively. Risk, injury, failure, loss, and end-stage renal classification distributions by grade were as follows: risk, 152 (51%); injury, 69 (23%); and failure, 75 (25%). Comorbid diabetes, emergency admission, major surgery, sepsis, and illness severity were independently associated with renal dysfunction. Patients with AKI had significantly worse outcomes, including increased inpatient and 1-year mortality. Acute kidney injury starting before admission was associated with worse renal dysfunction and greater renal morbidity than de novo inpatient events. Acute kidney injury is common in critically ill surgical patients and is associated with increased mortality, persisting renal impairment and greater resource use.