Comparison of meperidine, tramadol and fentanyl for post-spinal shivering prevention during cesarean delivery: A double-blind randomized controlled trial.

Aim To assess the effects of intravenously administered meperidine, fentanyl and tramadol in reducing the incidence, onset time and severity of the shivering response in parturients during cesarean delivery under spinal anesthesia. Secondary outcomes included patient satisfaction and sedation scores. Methods After Ethics board approval and informed written consent, 350 parturients (ASA physical status I or II), between 20 and 40 years of age, undergoing emergency or elective cesarean delivery under spinal anesthesia were recruited. Parturients were then randomly allocated to seven study groups: normal saline (control), low-dose meperidine (0.5 mg/kg), high-dose meperidine (0.75 mg/kg), low-dose fentanyl (0.5 mcg/kg), high-dose fentanyl (0.75 mcg/kg), low-dose tramadol (0.5 mg/kg) and high-dose tramadol (0.75 mg/kg). The incidence, onset time and severity of shivering, along with patient satisfaction and sedation scores were measured. Results All study drugs showed significant reduction in incidence, onset time and severity of shivering and greater satisfaction scores compared to the control group (P < 0.01). Within each drug class, no significant differences in shivering were found between the high-dose and low-dose groups. Among study drugs, low-dose tramadol was superior due to shivering prevention and significantly reduced sedation. Conclusion Intravenously administered meperidine, fentanyl and tramadol reduce shivering incidence, onset time and severity in parturients undergoing cesarean delivery following spinal anesthesia. Importantly, low-dose intravenous tramadol (0.5 mg/kg) allowed shivering prevention and low sedation scores, thereby offering greater parturient satisfaction and better maternal-newborn bonding.