Ninety-three patients were scheduled for off-pump coronary artery bypass (OPCAB) under propofol/fentanyl anesthesia. Day before surgery patients were asked for informed consent and randomized into three postoperative analgesia regimens aiming at a visual analog scale (VAS) score <30 mm at rest. The control group (n=31) received intravenous fentanyl 10 µg/ml postoperatively 3-8 mL/h. After placement of an epidural catheter at the level of Th2-Th4 before OPCAB, a thoracic epidural infusion (EI) group (n=31) received epidural anesthesia (EA) intraoperatively with ropivacaine 0.75% 1 mg/kg and fentanyl 1 µg/kg followed by continuous EI of ropivacaine 0.2% 3-8 mL/h and fentanyl 2 µg/mL postoperatively. The patient-controlled epidural analgesia (PCEA) group (n=31), in addition to EA and EI, received PCEA (ropivacaine/fentanyl bolus 1 mL, lock-out interval 12 min) postoperatively. Hemodynamics and blood gases were measured throughout 24 h after OPCAB.