Prophylactic Intravenous Dexamethasone Versus Low-Dose Ketamine For Prevention Of Post-Spinal Shivering In Elective Cesarean Delivery: A Randomized Double-Blind Controlled Trial

Abstract

Background: Shivering is a frequent complication following spinal anesthesia and is related to elevated oxygen consumption, extensive metabolic requirements, maternal agitation, and disruption of perioperative monitors during cesarean section under spinal anesthesia. Several pharmacological agents have been used for its prevention, including dexamethasone and low-dose ketamine.

Objective: The current study compared the effectiveness and safety of using low-dose ketamine and intravenous dexamethasone immediately before spinal anesthetic for preventing post-spinal anesthetic shivering in women who underwent perioperative spinal anesthetic for elective cesarean section.

Methods: A randomized, double-blind, controlled clinical trial was conducted on 160 pregnant women (ASA I-II) scheduled for elective cesarean section under spinal anesthesia at Arash Hospital, Tehran University of Medical Sciences. Participants were randomly allocated into two equal groups (n=80 each). Low-dose ketamine (0.2 mg/kg) rectally was also administered to the ketamine group before spinal anesthesia, while dexamethasone (4 mg intravenous) was administered to the dexamethasone group. Demographic parameters, hemodynamic parameters, incidence, severity, and shivering, the effects of shivering on the mother, and neonatal outcomes were documented.

Results: The baseline demographic and obstetric parameters were similar across groups (p>0.05). Neonatal outcomes showed no significant differences. Maternal hemodynamics remained stable; however, immediately after spinal anesthesia, heart rate and blood pressure were significantly higher in the ketamine group (p<0.05). The incidence of shivering was lower in the dexamethasone group. A statistically significant difference was observed at 10 minutes after spinal anesthesia, with a greater proportion of patients remaining shivering-free in the dexamethasone group compared with the ketamine group (92.5% vs. 77.5%, p=0.04). No differences were observed for maternal adverse effects or neonatal outcomes.

Conclusion: Both prophylactic intravenous dexamethasone and low-dose ketamine were safe and effective for preventing post-spinal anesthesia shivering. Dexamethasone demonstrated superior control of shivering with a statistically significant advantage at 10 minutes after spinal anesthesia, while maintaining an excellent maternal and neonatal safety profile.