Intraoperative Normal Saline Administration and Acute Kidney Injury in Patients Undergoing Liver Transplantation

Background Normal saline is still used in patients undergoing living donor liver transplantation (LDLT) with normonatremia. We investigated whether the normal saline administered during LDLT is associated with the increased risk of acute kidney injury (AKI) compared with the balanced crystalloids. Methods We reviewed 1011 cases undergoing LDLT. The primary exposure variable was normal saline administered intraoperatively compared with the balanced crystalloid. To compare the risk of AKI after adjusting for potential confounders of baseline characteristics and surgical parameters, a propensity score matching analysis was performed. As a sensitivity analysis, ordinal logistic regression analysis was performed for AKI using inverse probability of treatment weighting (IPTW). Results The incidence of AKI was significantly higher in the saline group (n = 88/174, 50.6%) than in the balanced group (n = 67/174, 38.5%) after matching (P = .010). The incidence of stage 2 or 3 AKI was also significantly higher in the saline group (n = 26/174, 14.9%) than in the balanced group (n = 43/174, 24.7%) after matching (P = .022). The length of hospital stay was significantly longer in the saline group than in the balanced group after matching. Ordinal logistic regression analysis using IPTW showed that the saline group showed a significant association of saline administration with the risk of AKI (odds ratio 1.23, 95% CI 1.05-1.28, P = .013). Conclusion Our propensity score analysis using propensity score matching and IPTW showed that normal saline administration during LDLT is associated with a high risk of postoperative AKI and longer hospital stays. However, our results should be interpreted carefully due to the relatively long period of data collection.