Ultrasound guided abdominal field blocks improve postoperative pain relief in cesarean delivery: a prospective randomized controlled study

Abstract

Background: Abdominal field blocks with local anesthetic solutions have been suggested in postoperative analgesia in patients undergoing abdominal wall incisions. In the present study we assessed the analgesic efficacy of ultrasound guided rectus sheath and transversus abdominis plane blocks over first 24 postoperative hours after cesarean deliveries performed through pfannensteil or midline incisions.

Methodology: Sixty women undergoing elective or emergency cesarean delivery were enrolled in this randomized, controlled, double-blind trial, and then randomized either to undergo ultrasound guided rectus sheath and transversus abdominis plane blocks with bupivacaine (n=30) or no block (n=30). Inj diclofenac and inj. paracetamol 1 G, were given to all patients, and inj tramadol was given on request as a rescue analgesic. All patients received a spinal anesthesia with 0.5% heavy bupivacaine, and at the end of surgery (after the skin sutures) bilateral rectus sheath and transversus abdominis plane blocks were performed using 15 to 20 ml of 0.25% bupivacaine in each block on either side (to maximal dose of 3 mg/kg) and no block in the control patients. Each patient was evaluated postoperatively by a blinded investigator at 2, 4, 6, 12 and 24 h postoperatively.

Results: Ultrasound guided abdominal field blocks with 0.25% bupivacaine reduced the total tramadol requirement in the first 24 postoperative hours (157 ± 50.709 vs 386.67 ± 29.16 mg) and also the visual analogue pain scores at 2 (2 vs 8) ,4 (2 vs 8),6 (2 vs 8),12 (4 vs 7) and 24 (4 vs 7) hours postoperatively. No significant difference was found between groups in the incidence of nausea. Sedation was reduced in the patients who received the blocks. There were no complications attributed to the blocks.

Conclusion: Ultrasound guided abdominal field blocks, as a part of a multimodal analgesic regimen, provided greater analgesia up to 24 h postoperatively after elective or emergency cesarean delivery.

Key words: Abdominal field blocks; Lower segment cesarean delivery; Rectus sheath block; Transversus abdominis plane block.