Comparison between alfentanil, pethidine and placebo in the treatment of post-anaesthetic shivering

We have compared the effects of pethidine, alfentanil and placebo in the treatment of post-anaesthetic shivering. Ninety patients who shivered after routine surgery were allocated randomly to receive normal saline (n=30), alfentanil 250 mu g (n=30) or pethidine 25 mg (n=30). After 10 min, 26 patients had stopped shivering in the pethidine group which was significantly more than the incidence in the two other groups (placebo=7; alfentanil=12) (P<0.0002). Alfentanil was not significantly different from normal saline in affecting shivering. We conclude that alfentanil 250 mu g was not effective in the treatment of post-anaesthetic shivering.