The Effect of Different Intrathecal Doses of Meperidine on Shivering during Delivery Under Spinal Anesthesia

Background: This study was performed to compare the effect of different doses of intrathecal meperidine on the incidence and intensity of shivering and other side-effects after spinal anesthesia for cesarean delivery. Methods: One hundred and fifty-six parturient women scheduled for elective cesarean delivery were enrolled in four groups. Spinal anesthesia consisted of heavy bupivacaine 0.5% (10 mg) in the standard group (Group I), heavy bupivacaine 0.5% (10 mg) plus meperidine (0.2 mg per kg) in Group II, heavy bupivacaine 0.5% (10 mg) plus meperidine (0.3 mg per kg) in Group III, heavy bupivacaine 0.5% (10 mg) plus meperidine (0.4 mg per kg) in Group IV. The signs and symptoms were recorded by an observer unaware of the study groups. Data were analyzed using analysis of variance, Kruskal-Wallis H-test and chi-square. A P value less than 0.05 was considered to be significant. Results: The systolic blood pressure, amount of bleeding, Pulse Rate, O2 saturation, neonatal apgar scores, core temperatures and sensory level revealed no difference between groups (P>0.05). The incidence (47.5%, 37.5%, 27.5% and 15.0%, respectively) and intensity of shivering decreased as the dose of meperidine increased (P=0.002) but the incidence of nausea and vomiting (8.0%, 15.4%, 25.9% and 35.8%, respectively) (P=0.000) and pruritis (25.64, 28.21, 38.46, and 48.72 respectively) increased as the dose of meperidine increased (P=0.000). Conclusion: The high dose of intrathecal meperidine is effective in reducing the incidence and intensity of shivering associated with spinal anesthesia for cesarean delivery but the high incidence of nausea and vomiting is unpleasant for the patient and can be a major problem with a high dose of meperdine.