Risk factors of postoperative delirium after liver transplantation: a systematic review and meta-analysis.

INTRODUCTION The aim of this study was to summarize the incidence and risk factors of postoperative delirium (POD) after liver transplantation (LT) and associations of POD after LT with outcomes. EVIDENCE ACQUISITION A literature search of Pubmed, EMBASE, and the Cochrane Databases was performed to identify studies reporting POD after LT. The Newcastle-Ottawa Scale was used to rate study quality. Effect estimates were extracted and combined using random-effect model. Pooled mean differences and odds ratios for individual risk factors were calculated using inverse-variance method and Mantel-Haenszel method, as appropriate. EVIDENCE SYNTHESIS Eight articles with 1434 patients were included in the meta-analysis. Overall, the pooled estimated incidence rates of POD after LT were 30% (95% confidence interval: 20-39%). Fourteen statistically significant risk factors were identified in the pooled analysis: alcohol excess, preoperative renal replacement therapy (RRT), preoperative hospital length of stay (LOS), depression, hepatic encephalopathy, alcohol etiology of liver failure, Child-Turcotte-Pugh Score, APACHE II Score, MELD Score, preoperative INR, preoperative bilirubin, intraoperative use of fentanyl, intraoperative RBC transfusion, postoperative ammonia. Patients with POD had a significantly increased mechanical ventilation, postoperative RRT, LOS and mortality rate compared with those without POD. CONCLUSIONS POD after LT was common and multifactorial in etiology. There are significant associations of POD after LT with some clinical outcomes. Effective interventions during perioperative period may be promising to reduce the risk of POD after LT.