A Comparative Study on the Efficacy of Wound Infiltration of Tramadol versus Bupivacaine for Postcesarean Section Pain Control in a Tertiary Hospital in Manila, Philippines: A Double-blind Randomized Controlled Trial

Abstract

ABSTRACT Background: In developing countries, postcesarean pain control remains a challenge due to the limited supply of medication and medical equipment. Wound infiltration provides a cost-effective, easy-to-administer postoperative analgesia with a high safety of margin. Several studies suggest that tramadol and local anesthetics have similarities in terms of its action. The study aims to compare the efficacy of tramadol and bupivacaine administered through wound infiltration in postcesarean patients aged 18-40 years old at a tertiary hospital in Manila, Philippines. Methods: Using a double-blind randomized controlled trial, study participants for low transverse cesarean section (CS) were allocated to either Group A or Group B. Group A (n = 20) received a local infiltration of 2 mg/kg tramadol diluted to 20 ml of 0.9% saline solution. Group B (n = 20) received a local infiltration of 0.5 ml/kg of 0.25% bupivacaine isobaric diluted to 20 ml of 0.9% saline solution. All wound infiltrations were performed once at the postoperative site to establish cost-effectivity. Pain severity was assessed using the Visual Analogue Scale (VAS) scoring at rest and at movement done by the anesthesiologist at 4, 8, 16 and 24 h post-CS. A significance level of 0.05 was set and P<0.05 was considered statistically significant. Before inclusion in the study, informed consent was secured from the study participants. The research protocol and informed consent were submitted for ethical review and were subsequently approved. Results: There is no significant difference between the VAS scores of patients treated with tramadol and those treated with bupivacaine across all times of recording except for VAS scores at movement during the 16th and 24th hours. Results of the study revealed that the VAS scores in the tramadol group are lower at all times than those of the bupivacaine group. In general, it is also observable that the VAS scores are higher when the patient is moving than when at rest. There were no observed effects in breastfeeding and no allergic, cardiovascular or central nervous system side effects were observed among all study participants. Conclusion: Because of its mechanism similar to that of local anesthetics, tramadol wound infiltration is a suitable, safe and cost-effective alternative to bupivacaine for pain control after CS.