Evaluation of acute kidney injury as defined by the risk, injury, failure, loss, and end-stage criteria in critically ill patients undergoing abdominal aortic aneurysm repair.

BACKGROUND: Acute kidney injury (AKI) is considered as a common and significant complication following abdominal aortic aneurysm (AAA) repair. This study aimed to assess the associated risk factors of AKI in the critically ill patients undergoing AAA repair and to evaluate the appropriate AKI management in the specific population.
METHODS: We retrospectively examined data from all critically ill patients undergoing AAA repairs at our institution from April 2007 to March 2012. Multivariable analysis was used to identify factors associated with postoperative AKI, which was defined by risk, injury, failure, loss and end-stage (RIFLE) kidney disease criteria. The goal-directed hemodynamic optimization (maintenance of optimal hemodynamics and neutral or negative fluid balance) and renal outcomes were also reviewed.
RESULTS: Of the 71 patients enrolled, 32 (45.1%) developed AKI, with 30 (93.8%) cases diagnosed on admission to surgical intensive care unit (SICU). Risk factors for AKI were ruptured AAA (odds ratio (OR) = 5.846, 95% confidence interval (CI): 1.346 - 25.390), intraoperative hypotension (OR = 6.008, 95%CI: 1.176 to 30.683), and perioperative blood transfusion (OR = 4.611, 95%CI: 1.307 - 16.276). Goal-directed hemodynamic optimization resulted in 75.0% complete and 18.8% partial renal recovery. Overall in-hospital mortality was 2.8%. AKI was associated with significantly increased length of stay ((136.9 ± 24.5) hours vs. (70.4 ± 11.3) hours) in Surgical Intensive Care Unit.
CONCLUSIONS: Critically ill patients undergoing AAA repair have a high incidence of AKI, which can be early recognized by RIFLE criteria. Rupture, hypotension, and blood transfusion are the significant associated risk factors. Application of goal-directed hemodynamic optimization in this cohort appeared to be effective in improving renal outcome.