Effects of perioperative central neuraxial analgesia on outcome after coronary artery bypass surgery: A meta-analysis

Background: Perioperative central neuraxial analgesia may improve outcome after coronary artery bypass surgery due to attenuation of stress response and superior analgesia. Methods: MEDLINE and other databases were searched for randomized controlled trials in patients undergoing coronary artery bypass surgery with cardiopulmonary bypass who were randomized to either general anesthesia (GA) versus general anesthesia-thoracic epidural analgesia (TEA) or general anesthesia-intrathecal analgesia (IT). Results: Fifteen trials enrolling 1,178 patients were included for TEA analysis. TEA did not affect incidences of mortality (0.7% TEA vs. 0.3% GA) or myocardial infarction (2.3% TEA vs. 3.4% GA). TEA significantly reduced the risk of dysrhythmias with an odds ratio of 0.52, pulmonary complications with an odds ratio of 0.41, and time to tracheal extubation by 4.5 h and reduced analog pain scores at rest by 7.8 mm and with activity by 11.6 mm. Seventeen trials enrolling 668 patients were included for IT analysis. IT had no significant effect on incidences of mortality (0.3% IT vs. 0.6% GA), myocardial infarction (3.9% IT vs. 5.7% GA), dysrhythmias (24.8% vs. 29.1%), nausea/vomiting (31.3% vs. 28.5%), or time to tracheal extubation (10.4 h IT vs. 10.9 h GA). IT modestly decreased systemic morphine use by 11 mg and decreased pain scores by 16 mm. IT significantly increased the incidence of pruritus (10% vs. 2.5%). Conclusions: There were no differences in the rates of mortality or myocardial infarction after coronary artery bypass grafting with central neuraxial analgesia. There were associated improvements in faster time until tracheal extubation, decreased pulmonary complications and cardiac dysrhythmias, and reduced pain scores.