A Comparison of Physostigmine, Nefopam, Clonidine and Placebo in Preventing Anaesthetic Shivering

A post anesthetic shivering is a frequent complication following general anaesthesia. The aim of this study was to compare the effectiveness of physostigmine, nefopam, clonidine and placebo in the prevention of post-anaesthetic shivering. We studied 120patients undergoing urological surgery. Patients were allocated to one of four groups: physostigmine group (n=30) received 2mg physostigmine, nefopam group (n =30) received 7mg nefopam, clonidine group (n =30) received 100μ clonidine and placebo group received saline 0.9%. All drugs were given intravenously over 15 min at the start of skin closure, Haemodynamic parameters and temperature were measured at induction of anaesthesia (TO), 5 min. (IT), 15 min. (T2), 30 min. (T3) and 60 min. (T4) after arrival to PACU. Significantly less shivering occurred following administration of physostigmine, nefopam and clonidine (8.8%, 4.9% and 9.8%) compared to placebo 47%. The degree of shivering was also significantly reduced following physostigmine, nefopam and clonidine (p 0.01). Extubation time, haemodynamic parameters and tympanic temperature were similar in all groups except that extubation time (was significantly prolonged in clonidine group. Aldrete score, duration of PACU stay and post operative analgesic requirements did not differ between the groups except that Aldrete score at arrival in clonidine group was significantly lower. PONV occurs significantly only in physostigmine and placebo groups (p 0.05). Physostigmine, nefopam and clonidine significantly reducing the incidence and severity of post anaesthetic shivering but nefopam is the best choice.