Tehran University of Medical Sciences Archives of Anesthesiology and Critical Care 2423-5849 0 0 2026 02 04 1386 1386 Masoomeh Nataj Majd Department of Anesthesiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Sajjad Al Nasery Department of Anesthesia, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran. Afzal Shamsi Department of Anesthesia, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran. 2025 08 19 2025 08 21 Background: Nausea and vomiting are distressing symptoms that are commonly experienced during cesarean section and can also occur in the period following the procedure. Shivering is also common with spinal anesthesia. This study aimed to compare the effectiveness of ketamine and tramadol in preventing post-spinal shivering, nausea, and vomiting during cesarean section surgery. Methods: This clinical trial study was conducted in 2025 on 108 pregnant mothers who were candidates for cesarean section under spinal anesthesia. The samples were selected at Arash Hospital using a convenience method and were randomly assigned to two groups: ketamine (53 people) and tramadol (52 people). The dose of ketamine was 0.25 mg/kg, and tramadol was 0.5 mg/kg. We measured the patient's vital signs (such as body temperature, blood pressure, and heart rate), vomiting status, nausea and shivering, and any other changes that may indicate the occurrence of nausea/vomiting or shivering. Results: The mean age of the total cohort was 29.84 years, with no significant difference between the tramadol and ketamine groups. Weight, BMI, and NPO time were comparable between the two groups, confirming that they were well-balanced at baseline. Post-intervention outcomes showed significant differences between the two groups. The heart rate was significantly lower in the ketamine group compared to the tramadol group, and systolic blood pressure was higher in the ketamine group. Fever was slightly higher in the ketamine group. The rates of shivering in the tramadol and ketamine groups were 26.92% and 18.87%, respectively, which were not statistically significant. The rates of vomiting or nausea in the tramadol and ketamine groups were also reported to be 73.1% and 11.32%, respectively, which were significant (P<0.001). The use of rescue medications (pethidine/ephedrine and plasil/ondansetron) mirrored these findings, with significant differences between groups. Conclusion: In conclusion, ketamine demonstrated favorable effects on hemodynamic stability, nausea/vomiting, and temperature regulation compared to tramadol, with significant differences observed in nausea/vomiting incidence. https://aacc.tums.ac.ir/index.php/aacc/article/view/1386