Patient-controlled analgesia (PCA) is effectively used for postoperative pain control. Fentanyl has a strong analgesic effect but has some side effects. The purpose of this study was to compare the side effects and analgesic effects of fentanyl alone and combination with nalbuphine in patients using intravenous PCA.

Forty six ASA class 1 or 2 patients were randomly divided into two groups. Group F (n = 23) received fentanyl 1,200microgram in 100 ml of normal saline. Group NF (n = 23) received nalbupine 60 mg and fentanyl 600microgram in 100 ml of normal saline. All patients used the same background infusion rate (2 ml/hr), bolus dose (2 ml) and lockout interval (15 min) just after emergence from general anesthesia. The analgesic effect was evaluated by using a visual analogue scale (VAS) at 1 hr, 6 hr, 12 hr, 24 hr and 48 hr postoperatively. Side effects and satisfaction degree were also checked.

No significant differences were observed between the two groups in terms of pain scores and satisfaction degrees. The side effects were similar in both groups except that sedation was significantly (P<0.05) lower in group NF.

We conclude that nalbuphine with fentanyl in combination is a useful method for intravenous PCA. On comparing the incidence of side effects in the two groups, sedation was found to be lower for the combined regimen.