The
analgesic profile of epidural
nalbuphine for
postoperative pain relief and the impact of local anaesthetic choice upon this profile was investigated in 58 patients undergoing elective Caesarean delivery under epidural anaesthesia. Patients were randomized to receive either
lidocaine 2% with 1:200,000
epinephrine or
2-chloroprocaine 3% for perioperative anaesthesia, followed by either 10, 20, or 30 mg of epidural
nalbuphine administered at the first complaint of postoperative discomfort. Postoperative
analgesia was quantitated on a visual analogue (VAS) scale, and by the time from the epidural
opioid injection until the first request for supplemental
pain medication. The duration of
analgesia after
lidocaine anaesthesia followed by 10, 20 or 30 mg
nalbuphine was 77 (53-127) min, 205 (110-269) min, and 185 (116-241), respectively (median, 95% confidence interval, P less than 0.01, 20 and 30 mg vs 10 mg). Following
2-chloroprocaine anaesthesia, VAS remained consistently elevated: the median duration of
analgesia was only 30-40 min and did not differ among the three doses of
nalbuphine. Side-effects consisted only of
somnolence, and were noted only following
lidocaine anaesthesia.
Somnolence was observed in 0, 20% and 50% of those receiving 10 mg, 20 mg and 30 mg of
nalbuphine respectively (NS). No evidence of
respiratory depression was noted in any patient. It is concluded that 20 or 30 mg of epidural
nalbuphine provides
analgesia for only two to four hours following Caesarean delivery with
lidocaine anaesthesia, but anaesthesia with
2-chloroprocaine resulted in minimal or no
analgesia from this
opioid.
Nalbuphine appears to be a disappointing agent for epidural use after Caesarean delivery.