Effect of the Modified Surgeon Assisted Bilateral Transversus Abdominis Plane Block on Time Required for First Analgesic Dose after Cesarean Section under Spinal Anesthesia: Randomized placebo-control

Background: The transverses abdominis plane block (TAP block) is one of the widely used regional analgesic techniques in cesarean section. There are different variations of the procedure. The aim of the present study was to evaluate the analgesic effect of the modified surgeon assisted bilateral TAP block in patients undergoing cesarean section Patients&Methods: Sixty patients undergoing cesarean section under spinal anesthesia were randomized into two groups to receive either TAP block with 40 ml of bupivacaine 0.25%(study group) or 40 ml normal saline as placebo after obtaining informed consent. All patients will receive intravenous diclofencac75mg every 12 hrs postoperatively. Postoperatively, there was an assessment every 2hrs during the first 24hrs by the visual analogue pain scale (VAPS). Time to the first analgesic request will be measured as primary outcome and all patients will receive opioid on demand or VAPS > 4 with 25mg pethidine intramuscularly. Moreover, total opioid requirement in 24hrs will be measured as secondary outcome along with postoperative complications as nausea, vomiting and abdominal distention. Complications related to the TAP procedure will be also assessed. Results: The median (interquartile range) time to the first analgesic request in the first 24hrs postoperatively was significantly shorter in the placebo group compared to the study group; 4h (4, 6) and 24h (10, 24) with p value < 0.001. Postoperative opioid requirement was significantly higher in the control group (30/30{100%}) than the study group (13/30{43.3%}). The median (interquartile range) number of opioid doses was significantly higher in the placebo group compared with the study group; 2(2, 2) and 0(0, 1) respectively. At all points in the study, pain scores both were lower in the study group (p < 0.0001). Conclusion: The modified surgeon assisted bilateral TAP block is relatively new, safe and cost effective technique which provides adequate postoperative analgesia allowing for better maternal ambulation and better postoperative recovery. Trial registration: Clinicaltrial.gov registration number: NCT04623632