Structured abstractQuestionWhat are the effects of neuraxial blockade with epidural or spinal anesthesia on postoperative morbidity and mortality?Data sourcesStudies were identified by computerized searches of Current Contents (1995–6), EMBASE (1980–96), MEDLINE (1966–96), and the Cochrane Library (1988) using the keywords “regional anesthesia”, “regional anaesthesia”, “spinal”, or “epidural” and the Cochrane Collaboration search terms for randomized trials. Citation review of reference lists and hand search of conference proceedings were also performed.Study selectionStudies were selected if they were trials of patients randomized to intraoperative neuraxial blockade (epidural or spinal anesthesia) or general anesthesia. The neuraxial anesthesia group could also receive general anesthesia concurrently; the general anesthesia group could also receive postoperative neuraxial blockade.Data extractionData were extracted on trial design, interventions, patient characteristics, and events. The main outcomes were all cause mortality, deep vein thrombosis (DVT), pulmonary embolism (PE), myocardial infarction (MI), transfusion requirements, pneumonia, other infections, respiratory depression, and renal failure.Main resultsOne hundred forty-one trials with a total of 9559 patients met the inclusion criteria. Neuraxial blockade significantly reduced 30-day all cause mortality, DVT, PE, transfusion requirements, and respiratory depression (Table I). Reductions were noted in MI, stroke, wound infections, and renal failure, but these were not statistically significant. There were no differences in the number of deaths between 30 days and six months after surgery.ConclusionsIntraoperative neuraxial blockade reduces 30-day all cause mortality, thromboembolic events, transfusion requirements, and respiratory depression.FundingHealth Research Council of New Zealand, Astra Zeneca.