Comparing the effects of Acetaminophen, Meperidine, and their combination on postoperative pain management in elective cesarean section

Postoperative pain management is one of the most important challenges in Cesarean Section surgeries. Preventive analgesia is an effective approach in controlling this pain. This study was performed with aim to evaluate the efficacy of preventive analgesia and side effects of using acetaminophen, meperidine, and their combination after elective cesarean section under spinal anesthesia. This double-blind randomized study was conducted on 120 full-term pregnant women with ASA class I undergoing elective Cesarean Section under spinal anesthesia at Shiraz Hafez hospital in 2017. The patients were randomly divided into three groups of each containing 40 patients. After delivery, during the clamping of umbilical cord and before the end of surgery, the drugs were injected to the patients. The patients received 15 mg/kg intravenous acetaminophen, 0.5 mg/kg intravenous meperidine, and a combination of them, respectively. After clamping the umbilical cord, the groups were compared in terms of postoperative pain severity and complications. Data were analyzed by SPSS software (version 22) and ANOVA and Chi-square tests. P<0.05 was considered statistically significant. The mean score of pain severity during the first six hours after the operation was significantly lower in the acetaminophen group compared to the meperidine group (P<0.001). The mean score of pain severity, duration of recovery, and time interval between the initial and the next administration of additional analgesics doses was significantly lower in meperidine plus acetaminophen group compared with other groups (P<0.001). Moreover, incidence of postoperative headache was significantly higher in meperidine group and shivering was significantly higher acetaminophen group (P=0.005). Acetaminophen had a higher efficacy in postoperative pain management compared to meperidine, and their combination had greater analgesic effect and lower side effects.