Comparison of Prophylactic Intravenous Pethidine versus Intravenous Ondansetron in Prevention Post Spinal Shivering in Hysterectomy

Abstract
Background: Spinal anesthesia is known to significantly impair thermoregulation; shivering associated with spinal anesthesia is reported up to 55%. Pethidine probably acts directly on the thermoregulatory center or via opioid receptors. Mechanism of action of 5HT antagonist as anti-shivering is thought to be related to inhibition of serotonin reuptake on the preoptic anterior hypothalamic region.
Aim of Study: This study was designed to compare the effectiveness of intravenous Pethidine versus intravenous Ondansetron for prevention of post-spinal shivering (primary outcome), hemodynamic changes, side effects of both groups were also evaluated (secondary outcome).
Material and Methods: Patients were randomly assigned allocated into two groups (Group P n=30 patients) received pethidine 0.4mg/kg and (Group O n=30 patients) received Ondansetron 4mg as premedication (each drug was mixed into 10ml isotonic saline and given to the patient, slowly IV).
Results: Non-significant differences between two groups as regards episodes of shivering, grading of shivering and tympanic temperature, but there is delayed onset of shivering episodes in pethdine group. There was statistically significant decrease in patients had nausea and vomiting in O group. While there was no statistically significant difference as regard sedation in both groups.
Conclusion: The use of Prophylactic 4mg Ondansetron (5HT3 antagonist) is equally effective as 0.4mg/kg pethidine in the prevention of perioperative shivering following spinal anesthesia, maintains core temperature and Prophylactic Ondansetron also reduces the need of antiemetics.