A Multi-Center Evaluation of Early Acute Kidney Injury in Critically Ill Trauma Patients

RATIONALE: Few studies have evaluated the epidemiology of acute kidney injury (AKI) in trauma. OBJECTIVE: To evaluate the incidence, risk factors, and outcomes associated with early AKI (evident within 24 hours of admission) in critically ill trauma patients. METHODS: A retrospective interrogation of prospectively collected data from the Australian New Zealand Intensive Care Society Adult Patient Database. A total of 9,449 trauma patients were admitted for >or=24 hours to 57 intensive care units across Australia from January 1(st), 2000, to December 31(st), 2005. MAIN FINDINGS: The crude incidence of AKI was 18.1% (n = 1,711). Older age, female sex (OR 1.60, 95% CI, 1.43-1.78, p < 0.0001), and the presence of co-morbid illness (OR 2.70, 95% CI 2.3-3.2, p < 0.0001) were associated with higher odds of AKI. Those with trauma not associated with brain injury (OR 2.40, 95% CI, 2.1-2.7, p < 0.0001) and a higher illness severity (OR 1.12, 95% CI, 1.11-1.12, p < 0.001) also had higher likelihood of AKI. Overall, AKI was associated with a higher crude mortality (16.7% vs. 7.8%, OR 2.36, 95% CI, 2.0-2.7, p < 0.001). Each RIFLE category of AKI was independently associated with hospital mortality in multi-variable analysis (risk: OR 1.69; injury OR 1.88; failure 2.29). CONCLUSIONS: Trauma admissions to ICU are frequently complicated by early AKI. Those at high risk for AKI appear to be older, female, with co-morbid illnesses, and present with greater illness severity. Early AKI in trauma is also independently associated with higher mortality. These data indicate a higher burden of AKI than previously described.