The efficacy of a single dose of pethidine, fentanyl and morphine in treating postanesthesia shivering.

Postanesthesia shivering is an undesirable event that may induce a variety of adverse consequences including patient discomfort, increased oxygen consumption and wound pain. Thus, its pharmacological treatment should be regarded. The purpose of this study was to compare the efficacy of morphine, fentanyl and pethidine for the treatment of postanesthesia shivering. Fifty patients who developed shivering were treated in a randomized double blinded manner with an intravenous bolus dose of 2 or 4 mg morphine, 25 or 50 mg pethidine, and 50 μg fentanyl. Then, they were monitored for 30 minutes and the shivering suppression grade, the time taken to stop shivering, the shivering cessation time, recurrence of shivering and opioid side effects were evaluated. Core body temperature was measured immediately before, and at 15 and 30 minute after administering the drug. The groups did not differ significantly regarding shivering suppression grade, shivering cessation time, and recurrence of shivering. There was a significant difference in the time taken to stop shivering between groups. Following injection of the drugs, the core temperatures increased in the five groups with statistical difference. All opioids were effective in treating postanesthesia shivering in a similar extent.