Prospective randomized trial of high thoracic epidural analgesia for coronary artery bypass surgery.

BACKGROUND: Postoperative pain may be severe after coronary artery bypass surgery. High thoracic epidural analgesia (HTEA) provides intense analgesia.

METHODS: Eighty patients were randomized to HTEA or intravenous morphine analgesia (control). Patients received coronary artery bypass surgery (CABG) with cardiopulmonary bypass. Pain was measured by visual analogue scale 0 to 10. Psychologic morbidity, intraoperative hemodynamics, ventricular function, lung function, and physiotherapy cooperation were also assessed. On the third postoperative day HTEA and morphine were ceased and only oral medications were used. Acetaminophen, indomethacin, and tramadol were allowed as supplemental analgesics in both groups.

RESULTS: The primary endpoint of pain scores was significantly less with HTEA on postoperative days 1 and 2 at rest, 0.02 +/- 0.2 versus 0.8 +/- 1.8 (p = 0.008) and 0.1 +/- 0.4 versus 1.2 +/- 2.7 (p = 0.022), respectively, and with coughing 1.2 +/- 1.7 versus 4.4 +/- 3.1 (p < 0.001) and 1.5 +/- 2.0 versus 3.6 +/- 3.1 (p = 0.001), respectively. When HTEA and morphine were ceased on day 3, there were no significant differences. The secondary endpoints of postoperative depression (p = 0.033) and posttraumatic stress subscales (p = 0.021) of the Minnesota Multiphasic Personality Inventory were lower with HTEA. Extubation occurred earlier with HTEA, 2.6 versus 5.4 hours (p < 0.001). HTEA showed improved physiotherapy cooperation (p < 0.001), arterial oxygen tension (p = 0.041), and peak expiratory flow rate (p = 0.001). Mean arterial pressure was lower with HTEA (p = 0.036), otherwise there were no differences in intraoperative hemodynamics or ventricular function.

CONCLUSIONS: Epidural analgesia reduces pain after coronary operation and is associated with improved physiotherapy cooperation, earlier extubation, and reduced risk of depression and posttraumatic stress.