Spinal analgesia in cardiac surgery: a meta-analysis of randomized controlled trials.

OBJECTIVE: Controversial results exist on the effects of spinal analgesia in cardiac surgery. The authors conducted a review of randomized studies to show whether there are any advantages in clinically relevant outcomes using spinal analgesia in patients undergoing cardiac surgery. DESIGN: Meta-analysis. SETTING: Multiple hospitals. PARTICIPANTS: A total of 1,106 patients from 25 randomized trials. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULT: PubMed, BioMedCentral, CENTRAL, EMBASE, Cochrane Central Register of Controlled Trials, and conference proceedings were searched (updated January 2009) for randomized trials that compared general anesthesia with an anesthetic plan including spinal analgesia in cardiac surgery. Four independent reviewers performed data extraction, with divergences resolved by consensus. A total of 1,106 patients from 25 randomized studies were included in the analysis. Overall analysis showed that there were no differences in terms of mortality (2/562 [0.4%] in the spinal group v 2/514 [0.4%] in the control arm [risk difference (RD) = 0.00 [-0.02, +0.02], p = 1.0), perioperative myocardial infarction (9/421 [2.1%] in the spinal group v 11/407 [2.7%] in the control arm [RD = 0.00, -(0.03, +0.02), p = 0.77), and the length of hospital stay (WMD = -0.28 days [-0.68, -0.13], p = 0.18, with 419 included patients). CONCLUSIONS: This analysis indicated that spinal analgesia does not improve clinically relevant outcomes in patients undergoing cardiac surgery, discouraging further randomized controlled trials on this topic even if changes in techniques, devices, and drugs could modify the outlook of the comparison between spinal and standard anesthesia in this setting.