Reduction of postoperative mortality and morbidity with epidural or spinalanaesthesia: results from overview of randomised trials

Objectives To obtain reliable estimates of the effects of neuraxial blockad e with epidural or spinal anaesthesia on postoperative morbidity and mortal ity. Design Systematic review of all trials with randomisation to intraoperative neuraxial blockade or not Studies 141 trials including 9599 patients for which data were available be fore 1 January 1997. Trials were eligible irrespective of their primary aim s, concomitant use of general anaesthesia, publication status, or language. Trials were identified by extensive search methods, and substantial amount s of data were obtained or confirmed by correspondence with trialists. Main outcome measures. All cause mortality. deep vein thrombosis, pulmonary embolism, myocardial infarction, transfusion requirements, pneumonia, othe r infections, respiratory depression, and renal failure. Results Overall mortality was reduced by about a third in patients allocate d to neuraxial blockade (103 deaths/4871 patients versus 144/4688 patients, odds ratio = 0.70, 95% confidence interval 0.54 to 0.90. P = 0.006). Neura xial blockade reduced the odds of deep vein thrombosis by 44%, pulmonary em bolism by 55%, transfusion requirements by 50%, pneumonia by 39%, and respi ratory depression by 59% (all P < 0.001). There were also reductions in myo cardial infarction and renal failure. Although there was limited power to a ssess subgroup effects, the proportional reductions in mortality did not cl early differ by surgical group, type of blockade (epidural or spinal), or i n those trials in which neuraxial blockade was combined with general anaest hesia compared with trials in which neuraxial blockade was used alone. Conclusions Neuraxial blockade reduces postoperative mortality and other se rious complications. The size of some of these benefits remains uncertain, and further research is required to determine whether these effects are due solely to benefits of neuraxial blockade or partly to avoidance of general anaesthesia. Nevertheless, these findings support more widespread use of n euraxial blockade.