Comparison of Intravenous Ondansetron and Low Dose Ketamine in Preventing Post Spinal Shivering

This randomized controlled trial assessed whether intravenous ondansetron is more effective than low dose ketamine in preventing shivering after spinal anesthesia in adults undergoing elective surgery. Post spinal shivering is a frequent and uncomfortable complication of spinal anesthesia and may increase oxygen demand and interfere with routine monitoring. Adults aged 20 to 70 years (body weight 50 to 80 kg; American Society of Anesthesiologists class I to II) scheduled for elective procedures under standardized spinal anesthesia were randomly allocated in equal numbers to receive either ondansetron 8 mg intravenously or ketamine 0.25 mg/kg intravenously, administered 5 minutes after the spinal injection. Perioperative temperature management was standardized for all participants. The primary outcome was the occurrence of post spinal shivering during intraoperative monitoring. Among 180 participants, shivering occurred in 30.0% of those receiving ondansetron and 44.4% of those receiving ketamine, showing a statistically significant reduction with ondansetron.