THE MINIMUM EFFECTIVE DOSES OF PETHIDINE AND DOXAPRAM IN THE TREATMENT OF POST-ANESTHETIC SHIVERING

This study was designed to find the minimum effective doses of doxapra m and pethidine to stop post-anaesthetic shivering. Two hundred and tw enty healthy patients who shivered following routine surgery were allo cated randomly to receive one of 10 doses of doxapram (0.18, 0.23, 0.2 9, 0.35, 0.41, 0.47, 0.7, 0.93, 1.17 and 1.4 mg.kg(-1)), one of five d oses of pethidine (0.12, 0.18, 0.23, 0.29 and 0.35 mg.kg(-1)) or salin e. Probit analysis demonstrated that the number of patients who stoppe d shivering with doxapram was independent of the amount of drug given in this dose range. The lowest dose of doxapram (0.18 mg.kg(-1)) was s ignificantly more effective than placebo (p < 0.01). For pethidine the re was a dose-dependent effect on shivering to a maximum of 95% of pat ients successfully treated with 0.35 mg.kg(-1). We conclude that 0.35 mg.kg(-1) of pethidine is the minimum dose required to treat post-anae sthetic shivering effectively. We also conclude that 0.18 mg.kg(-1) of doxapram is as effective as 1.4 mg.kg(-1) in the treatment of post-an aesthetic shivering. Further study is required to find the minimum eff ective dose of doxapram.