Continuous renal replacement therapy and survival in acute liver failure: A systematic review and meta-analysis

Acute liver failure (ALF) is a rare syndrome leading to significant morbidity and mortality. An important cause of mortality is cerebral edema due to hyperammonemia. Different therapies for hyperammonemia have been assessed including continuous renal replacement therapy (CRRT). We conducted a systematic review and meta-analysis to determine the efficacy of CRRT in ALF patients. We searched MEDLINE, EMBASE, Cochrane Library, and Web of Science. Inclusion criteria included adult patients admitted to an ICU with ALF. Intervention was the use of CRRT for one or more indications with the comparator being standard care without the use of CRRT. Outcomes of interest were overall survival, transplant-free survival (TFS), mortality and changes in serum ammonia levels. In total, 305 patients underwent CRRT while 1137 patients did not receive CRRT. CRRT was associated with improved overall survival [risk ratio (RR) 0.83, 95% confidence interval (CI) 0.70–0.99, p-value 0.04, I2 = 50%] and improved TFS (RR 0.65, 95% CI 0.49–0.85, p-value 0.002, I2 = 25%). There was a trend towards higher mortality with no CRRT (RR 1.24, 95% CI 0.84–1.81, p-value 0.28, I2 = 37%). Ammonia clearance data was unable to be pooled and was not analyzable. Use of CRRT in ALF patients is associated with improved overall and transplant-free survival compared to no CRRT. •Ammonia is a key driver of cerebral edema in acute liver failure.•Cerebral edema is a big contributor to mortality in acute liver failure.•Continuous renal replacement therapy has been shown to reduce ammonia levels.•This study found continuous renal replacement therapy improves overall survival.•This study found continuous renal replacement therapy improves transplant-free survival.