Nefopam and clonidine in the prevention of postanaesthetic shivering

Postanaesthetic shivering affects up to 70% of patients after general anaes thesia, and may be very distressing. Various drugs have been used to treat or prevent postanaesthetic shivering, but the ideal one has not yet been fo und. Sixty patients undergoing elective abdominal or orthopaedic surgery un der general anaesthesia were included in a randomised, double-blind study. Patients received clonidine (3 mu g.kg(-1)), nefopam (0.15 mg.kg(-1)) or sa line 0.9% as a placebo at the end of surgery, prior to extubation. Nefopam and clonidine significantly reduced the incidence and severity of shivering in comparison with the placebo. The recovery time, between the end of anae sthesia and extubation, was significantly longer in the clonidine-treated p atients [13.6 (5.2) min] than in either the nefopam [9.6 (2.8) min] or the placebo [10.0 (5.4) min] groups. Mean arterial blood pressure and heart rat e were significantly lower in the clonidine group compared with both other groups. Our results suggest that nefopam and clonidine are effective in the prevention of postanaesthetic shivering. However, following clonidine admi nistration the recovery time was prolonged and hypotension was significantl y greater than after nefopam.