Comparison of Spinal Morphine and Transversus Abdominis Plane Block for Postoperative Pain Management in Patients Undergone Cesarean Section Under Spinal Anesthesia at Hawassa University Comphrensive and Specialized Hospital Ethiopia 2019: Randomized

Abstract Background: Pain after cesarean section is common and associated with long hospital stay, infections, less infant care and it may leads to chronic pain. Caesarean Section (CS) has been one of the most frequently performed major surgical interventions, and causes severe postoperative pain and subsequent manipulation performed through Pfannenstiel incision is associated commonly with significant degree of pain in the postoperative period, up to 79% of women experience pain at the incision site that can last for up to 2 months. Spinal opioid & abdominal field block has been investigated as effective analgesia for postoperative pain and reduce the need of systemic medications and their associated side effect. The aim of this study is to compare spinal morphine and transversus abdominis plane block for postoperative pain management. Method: In this prospective, randomized controlled trial 108 pregnant mothers scheduled for Cesarean section under spinal anesthesia was allocated randomly to receive either spinal morphine 0.1mg (group SM; n 56) or transversus abdominis plane block 20ml of 0.25% (group TAP;n 52). Patients were followed postoperatively to assess time to first analgesic request, analgesic consumption and pain intensity through numerical rating scale for the first 24 hours, at 2, 4, 6, 12, and 24 hours. Comparison of numerical variables between study groups was done using unpaired student t- test and Manny Whitney U test for symmetric and asymmetric data respectively. Time to event variable was analyzed by using Kaplan Meir survival function. P value less than 0.05 were considered as statistically significant. Result: One hundred twenty patients were screened for this prospective, randomized, doubled blind, controlled study. Of these, One hundred and fourteen patients were recruited and randomly assigned and received interventions. Among them, One hundred and eight patients completed this study. Time to first analgesic request was significantly shorter in TAP with a median (IQR) of 240 (180-390) minute vs 360 (270-480) minute in SM. Twenty four hour median morphine consumption was reduced in spinal morphine group 0 (0-4) mg compared to TAP block group 4 (0-6) mg (p<0.001). Median postoperative NRS score during movement and rest at 2nd hour, 6th hour, 12th hour and 24th hour were statistically significant different between groups (p <0.001). Conclusion: In conclusion preservative free 100µg spinal morphine for cesarean section provides prolonged postoperative analgesia time, better postoperative analgesia, and less postoperative analgesic consumption than TAP block.