Background: –    Postoperative shivering is a known complication following exposure to anesthesia. It is seen in approximately 5–65% patients after general anesthesia and 33% patients after regional anesthesia.

Methods: – Evaluate the effects of a single dose of IV Ketamine (0.3 mg/kg) and IV Pethidine (0.3mg/kg) in treating post–operative shivering by studying the following: (a) effect on grade of shivering (b) time taken for resolution of shivering (c) the hemodynamic , percentage saturation of oxygen and temperature changes (d) occurrence of adverse effects, if any.

Results:– (a) Effect on grade of shivering – The percentage of shivering with grade of shivering = 0 at T₁ was 93.3% in group K in comparison to 0% in group P.

(b) Time taken for resolution of shivering –In group K , the mean time taken for resolution of shivering was 47.80 sec while in group P it was 102.50 sec.

(c) Hemodynamic changes– Heart Rate  – The variation in the heart rate prior to beginning of the surgery (baseline) ,  intra operative and post–operative period after drug administration for a period 10 min every minute was not found to be statically significant.

MAP – The MAP variation was insignificant till T₅.After that MAP was higher in group K than group P. The difference was statically significant but not clinically significant.

Pulse Oximetry– None of the patients in both groups had any episode of desaturation.

Temperature– Comparison of core temperature measured preoperatively, interaoperatively, postoperatively at T₀, T₅, T₁₀, in both groups was statistically insignificant (p>0.005) All patients had temperature > 36⁰C

(d)    Adverse effects– In group P no adverse effects were seen. In group K ,05 out of 30

(16.7%) had adverse effects.