Comparing Alfentanil, Sufentanil, Ketamine And Pethidine for Prevention of Postanesthetic Shivering: A Randomized Placebo-Controlled Clinical Trial

Recent studies have shown that anesthetic drugs can cause postoperative shivering. The incidence of postanesthetic shivering varies between 5 and 65% and patients report it as one of the leading causes of discomfort after operation. It may also induce a variety of physiological consequences such as increased O2 consumption and cardiac output. The effect of alfentanil, sufentanil and ketamine on prevention or decrease of postanesthetic shivering is not still clear. This study was performed to find out a suitable alternative for pethidine in prevention of postanesthetic shivering. In this randomized double-blind prospective study, 160 patients were classified into five equal groups according to drugs used for prevention of postoperative shivering after general anesthesia. Alfentanil, sufentanil, ketamine and pethidine groups received the drugs 30 minutes before the end of surgery and were compared with placebo (control group). The primary outcome measures were the incidence and severity of postoperative shivering. The five groups were were not different regarding age, gender, height, weight and the physical status class based on the American Society of Anesthesiologists score. In recovery room, postoperative shivering was seen in 18 patients, 2 in ketamine, 2 in pethidine, 4 in alfentanil, 3 in sufentanil and 7 in placebo group. Fisher’s exact test showed no statistically difference between the groups (P = 0.34). Intravenous infusion of alfentanil, sufentanil and ketamine 30 minutes before the end of surgery effectively reduced the occurrence and severity of postoperative shivering after the general anesthesia, without significant side effects but not as well as pethidine.