Central venous pressure and liver resection: a systematic review and meta analysis

BackgroundA liver resection under low central venous pressure (CVP) has become standard practice; however, the benefits beyond a reduction in blood loss are not well reported. Moreover, the precise method to achieve CVP reduction has not been established. A systematic review and meta analysis of randomized controlled trials (RTCs) was performed to assess the effects of CVP on clinical outcome and to identify the optimum method of CVP reduction.MethodsEMBASE, Medline, PubMed and the Cochrane database were searched for trials comparing low CVP surgery with controls. The primary outcome was post operative complications within 30 days. Secondary outcomes included estimated blood loss (EBL), blood transfusion rates and length of stay (LOS). Sub group analysis was performed to assess the CVP reduction method on the outcome.ResultsEight trials were identified. No difference was observed in the morbidity rate between the high CVP and control groups [odds ratio (OR) = 0.96 (95% confidence interval (CI) 0.66, 1.40) P = 0.84, I2 = 0%]. EBL [weighted mean difference (WMD) = −308.63 ml (95% CI −474.67, −142.58) P = < 0.001, I2 = 73%] and blood transfusion rates [OR 0.65 (95% CI 0.44, 0.97) P = 0.040, I2 = 37%] were significantly lower in the low CVP groups. Neither anaesthetic nor surgical methods of CVP reduction were associated with a reduced post operative morbidity.ConclusionLow CVP surgery is associated with a reduction in EBL; however, this does not translate into an improvement in post operative morbidity. The optimum method of CVP reduction has not been identified.