Comparison of bupivacaine and fentanyl as an adjuvant of epidural morphine for postoperative analgesia.

We conducted a retrospective study to determine whether bupivacaine or fentanyl is a better adjuvant to epidural morphine for postoperative analgesia using 108 patients. Following epidural lidocaine anesthesia with or without light general anesthesia for major gynecological surgeries, 59 patients received epidural morphine (EPM) 2 mg (group M), 21 patients received morphine 2 mg plus 0.25% plain bupivacaine 6-10 ml epidurally (group B), and 28 patients received morphine 2 mg plus fentanyl 100 μg epidurally (group F). The analgesic interval, defined as the duration from EPM injection to the first request of analgesics for incisional pain, was significantly longer in group F than in group M (29±11vs 19±17 h,P<0.05), but similar to group B (22±14 h). Group F patients required the least amount of analgesics for incisional pain of the three groups during the first 24 h postoperatively (P<0.01). The incidence of adverse effects was similar among all three groups. In conclusion, fentanyl appears to be a better adjuvant to epidural morphine than bupivacaine.