The effect of intravenous ketamine and pethidine on postoperative shivering in surgical patients under general anesthesia in Tikur anbessa specialized hospital, Addis Ababa, Ethiopia: A prospective observational cohort study

Background: Postanesthesia shivering is one of the potential complications of anesthesia which may increase patient morbidity. Various methods have been employed to control postoperative shivering. This study assessed the effectiveness of prophylactic low-dose intravenous ketamine and pethidine for postoperative shivering after general anesthesia.Methods and materials: This prospective cohort study recruited 76 ASA I and II patients aged 18-65 years old and underwent elective surgery under general anesthesia. The patients were grouped based on either ketamine 0.5mg/kg or pethidine 0.5 mg/kg having been administered by the anaesthetist in charge as a prophylaxis for postoperative shivering 20 minutes before completion of the surgery. The incidence and severity of postoperative shivering were compared between the two groups every 10 minutes until one hour postoperatively. The side effects of the study drugs were also compared between the two groups in the recovery room. Categorical data were analyzed with the Chi-Square test. Parametric and nonparametric data between the groups were analyzed using independent samples t-test and Mann-Whitney U test, respectively. A p-value of Results: The incidence of shivering between the ketamine and pethidine groups was 11(28.2%) and 14(35.9%), respectively (p=0.467). The severity of shivering was not significantly different between the two groups (p=0.893). The occurrence of nausea and vomiting and sedation attributed to the drugs was significantly less in the ketamine group (p0.05)Conclusion and Recommendation: This study revealed administering low-dose IV ketamine (0.5mg/kg) 20 minutes before completion of surgery reduced postoperative shivering as nearly equally as pethidine. The study also showed clinically better outcomes in favor of ketamine since it was associated with fewer side effects. Thus, we recommend low-dose IV ketamine 20 minutes before completion of surgery under general anesthesia to prevent postoperative shivering.