Comparison of Palonosetron with Ondansetron in Prevention of Postspinal Shivering: A Randomised Controlled Trial

Introduction: Postspinal shivering is a frequent and distressing complication following spinal anaesthesia due to impaired thermoregulation that leads to redistribution of body heat, resulting in hypothermia, increased metabolic demand, and patient discomfort. Uncontrolled shivering can contribute to haemodynamic instability and increased oxygen consumption, which can be detrimental in vulnerable patients. Along with shivering, Postoperative Nausea and Vomiting (PONV) are common postoperative concerns that affect patient recovery and satisfaction. Therefore, effective prophylactic strategies targeting both shivering and PONV are crucial in improving perioperative outcomes. Aim: The present study aimed to compare the efficacy of prophylactic palonosetron versus ondansetron in preventing postspinal shivering and PONV among patients posted for lower limb orthopaedic surgeries under spinal anaesthesia. Materials and Methods: The present double-blinded, randomised controlled trial was conducted at SRM Medical College and Hospital Research Centre, Chennai, Tamil Nadu, India, involving 138 adult patients scheduled for elective lower limb orthopaedic surgeries. Patients were randomly allocated into three groups, each comprising 46 participants. Group P received 0.075 mg of intravenous palonosetron, Group O received 8 mg of intravenous ondansetron, and Group C received 5 mL of intravenous normal saline. All study drugs were administered 30 minutes before spinal anaesthesia. The study assessed haemodynamic parameters, the incidence and severity of shivering, and the incidence and severity of PONV at specified intraoperative and postoperative time intervals. Statistical analysis was performed using One-way Analysis of Variance (ANOVA) for continuous variables and the Chi-square test for categorical data. Results: Baseline demographics and haemodynamic data were comparable among the groups. Palonosetron was significantly more effective in reducing both the incidence and severity of shivering compared to ondansetron. At 15 minutes, Grade 2 shivering was recorded in 43.48% of Group C, 15.22% of group O, and 6.52% of group P (p<0.0001). A similar trend persisted at 45 minutes. By 60 minutes, shivering incidence declined across all groups without significant differences. Palonosetron also outperformed in reducing intraoperative nausea, particularly between 45-60 minutes, while vomiting rates were low and comparable. The overall incidence of PONV was significantly lower in the palonosetron group (p<0.0480). Conclusion: Prophylactic i.v. palonosetron is superior to ondansetron in preventing postspinal shivering and PONV, enhancing perioperative patient comfort and safety