Comparative Study between Dexmedetomidine and Fentanyl as Adjuvants to Bupivacaine for Prevention of Post Spinal Shivering in Caesarean Sections

Abstract Background Shivering is a common complication in regional anesthesia during cesarean sections. It can impair monitoring and increase oxygen demand, CO2 production, and wound pain, healing, and discharge. Spinal anesthesia can increase vulnerability to hypothermia, leading to shivering. Dexmedetomidine and fentanyl have been shown to prevent post-spinal shivering. Aim of the Work This study aimed to compare the efficacy and safety of fentanyl and dexmedetomidine in preventing perioperative shivering and their effects on block intensity, hemodynamics, sedation, postoperative pain, and analgesic requirement. Patients and Methods 150 obstetric patients were included and randomized into three equal groups: control, fentanyl, and dexmedetomidine group. Each group received 12.5 mg hyperbaric bupivacaine 0.5% intrathecally with different adjuvants. Results Both fentanyl and dexmedetomidine groups showed a decreased incidence and intensity of shivering compared to the control group. There was no statistically significant difference between the two groups in this regard (p-value >0.05). The onset and duration of sensory and motor block were faster and prolonged in both fentanyl and dexmedetomidine groups compared to the control group, but dexmedetomidine showed faster onset and more prolonged duration than fentanyl. Dexmedetomidine also showed a statistically significant difference regarding hypotension (p-value <0.05) but non-significant regarding bradycardia (p-value >0.05) compared to other groups. There were no statistically significant differences in sedation intensity between the groups (p-value >0.05). Fentanyl showed a higher incidence of nausea, vomiting, and pruritis compared to other study groups. Conclusion Both fentanyl and dexmedetomidine are safe to use with bupivacaine for prevention of perioperative shivering in cesarean sections. Both drugs decreased the incidence and intensity of shivering, and dexmedetomidine was more effective in terms of prolongation of sensory and motor block duration and reducing opioid requirements. Dexmedetomidine showed fewer side effects during the intra and postoperative period compared to fentanyl.