Comparing the Effects of Low Dose of Ketamine, Tramadol, and Ondansetron in Prevention of Post Spinal Anesthesia Shivering in Cesarean Section

Background: Shivering frequently occurs in cesarean section (CS) under spinal anesthesia (SA), resulting in several complications. To date, pethidine has been considered as the gold standard for post-SA shivering control, but it is contraindicated in breastfeeding women. Methods: This randomized, double-blind study was conducted at Alzahra hospital in Guilan, Iran, From January 2019 to November 2020. A total of 508 eligible term parturient women were enrolled and randomly divided into four groups of low dose ketamine (K), tramadol (T), ondansetron (O), and placebo (P). The incidence and severity of shivering and patients’ complications were recorded and compared among the groups. Results: The patients were homogenous in terms of demographic variables. Shivering was witnessed in 68 (53.5%), 26 (20.5%), 75 (59.1%), and 82 (64.6%) patients in K, T, O, and P groups, respectively (P = 0.0001). Regarding shivering severity, there was a significant difference among the four groups (P = 0.0001). In addition, a significant difference was seen regarding Apgar scores at the first minute, but not at the fifth minute (P = 0.168). Conclusions: Considering the high incidence of shivering in placebo group, prophylactic intervention in CS under SA seems to be necessary. Among the studied drugs, tramadol was the most effective one, followed by a low dose of ketamine and ondansetron.