RIFLE criteria for acute kidney dysfunction following liver transplantation: incidence and risk factors

Introduction

Acute renal dysfunction (ARD) is one of the most common complications of orthotopic liver transplantation (OLT), with an incidence ranging from 12 to 64% [1,2]. These patients are often critically ill in the perioperative period with a number of other co-morbidities, resulting in an increased susceptibility to ARD. The RIFLE criteria were developed to provide a consensus definition for acute renal dysfunction in critically ill patients. Using the RIFLE criteria, we aimed to determine the incidence and risk factors for acute renal dysfunction in the early postoperative period.

Methods

The records of 112 patients who underwent OLT, performed by the same team in the Baskent University Hospital, from January 2000 to February 2009, were retrospectively analyzed. Three levels of renal dysfunction, outlined in the RIFLE criteria, were investigated. Collected data included demographic features; co-morbidities; etiology of the liver failure; perioperative laboratory values; intraoperative hemodynamic parameters; use and volume of crystalloids, colloids, blood products, cell saver system, and albumin; portal vein clamping time; requirement for inotropes, vasopressors, and antihypertensive drugs; duration of anesthesia; and urine output.

Results

ARD occurred in 64 of OLTs (57%). Risk, injury, and failure frequencies were 19%, 11%, and 28%, respectively. Compared with those who did not have ARD postoperatively, those who did had significantly higher MELD scores (19 ± 7 vs 16 ± 8; P = 0.018), more frequently required inotropic agents intraoperatively (54% vs 35%; P = 0.070), received more colloids (300 ± 433 ml vs 105 ± 203 ml; P = 0.007), had a longer portal vein clamping time (88.0 ± 42.0 minutes vs 73.0 ± 20.0 minutes; P = 0.037), and had a higher incidence of intraoperative acidosis (64% vs 44%; P = 0.047). Logistic regression analysis was performed using these data to find the predictors for development of ARD. ARD was found to be associated with MELD score (odds ratio 1.107, 95% CI 1.022 to 1.200, P = 0.013), portal vein clamping time (odds ratio 1.020 95% CI 1.000 to 1.040, P = 0.053) and intraoperative acidosis (odds ratio 3.610, 95% CI 1.212 to 10.753 P = 0.021).

Conclusions

Based on RIFLE criteria, more than one-half of the patients who underwent liver transplantation developed ARD postoperatively. A higher MELD score, longer portal vein clamping time, and occurrence of intraoperative acidosis were identified as the independent risk factors for development of ARD in this group of patients.