Comparison of subcutaneous hydromorphone with intramuscular meperidine for immediate postoperative analgesia

Intramuscular (i.m.) injection with meperidine is the most common analgesic approach to treat postoperative pain in Taiwan. Hydromorphone (Dilaudid) can provide very potent and rapid analgesic effect through subcutaneous (s.c.) injection. Although hydromorphone is widely used in North America, no study has compared the analgesic efficacy, side effect profiles and patients' satisfaction with the method of injection of hydromorphone s.c. and meperidine i.m. for the immediate post-operative analgesia. In this randomized and double-blind study, 60 female patients scheduled for abdominal total hysterectomy were treated either with 1 mg hydromorphone s.c. (n = 30) or 50 mg meperidine i.m. (n = 30) when they regained consciousness and asked for analgesic treatment in the recovery room. Visual analogue score (VAS) of wound pain was obtained at 0, 10 and 30 min after injection by a blinded observer. The occurrence and severity of nausea, vomiting, dizziness, drowsiness, flatus passage and respiratory depression were recorded. Post-operative analgesia in the ward was maintained by patient-controlled analgesia (PCA) with intravenous morphine. Time to first PCA demand, the number of demands, delivery, delivery/demand ratio and 24 h morphine consumption were documented. We found that VAS was reduced at 10 min and, to a greater extent, at 30 min postinjection in both groups but with no significant difference between the two groups. The occurrence and severity of side effect profiles were similar in both groups except that dizziness was more frequently observed after meperidine injection. Delivery, demand, delivery/demand ratio and 24 hr morphine consumption by PCA were not significantly different between the two groups. Time to first PCA trigger was also similar. Patients receiving hydromorphone s.c. injection exhibited higher satisfactory score than those receiving meperidine i.m. injection. Hydromorphone 1 mg, injected subcutaneously, was as effective as intramuscular meperidine 50 mg while permitting more favorable injection technique and fewer side effects. We suggest that subcutaneous hydromorphone is a good alternative to intramuscular meperidine for postoperative analgesia in the recovery room.