[A comparison of three drugs (pethidine, magnesium sulfate and droperidol) in patients with post-anesthesia shivering].

Shivering is one of the common complications after general anesthesia. It increases metabolic rate markedly and may cause myocardial ischemia in patients with decreased cardiopulmonary function. We investigated, therefore, the effects of three drugs (pethidine, magnesium sulfate and droperidol) on shivering in 30 patients under enflurane anesthesia. The patients were of ASA class I or II physical status and had no cardiovascular or respiratory disease. For post-anesthesia shivering, every patient was administered with pethidine 0.5 mg.kg-1, MgSO4 30 mg.kg-1 or droperidol 0.15 mg.kg-1. Their VO2 and VCO2 were measured for 5 minutes during shivering and 15 minutes after drug administration. We also evaluated the therapeutic efficacy of each drug for the treatment of shivering by examining VO2 and VCO2 before and after drug administration. With pethidine and MgSO4, both VO2 and VCO2 decreased significantly after each drug administration. With pethidine, VO2 and VCO2 decreased significantly more than that in MgSO4 (P less than 0.01 vs P less than 0.05). But with droperidol, there was no significant change. These results suggest that pethidine is most effective followed by MgSO4.