Randomized controlled trial to study the effect of dexamethasone as additive to ropivacaine on duration of ultrasound-guided transversus abdominis plane block in cesarean section

Abstract

Background: Transversus abdominis plane (TAP) block is a regional anesthesia technique whose efficacy has been proven for postoperative pain relief after cesarean section (CS). Dexamethasone, a glucocorticoid, is now emerging as a new adjunct to local anesthetics for prolonging the duration of action and has been studied in different brachial plexus blocks. The primary outcome was to study the effect of dexamethasone as additive to ropivacaine on the duration of TAP block as assessed by time to first analgesic (TFA) . The secondary outcome was total postoperative analgesic consumption, postoperative nausea and vomiting, and patient satisfaction. Method: This RCT was conducted on seventy American Society of Anesthesiology Grade I and II patients undergoing CS under subarachnoid block. Patients were randomly allocated to two groups comprising 35 patients each. Patients in Group I received ultrasound-guided bilateral TAP block at the end of surgery using 40 ml ropivacaine 0.2% and 2 ml saline, and patients in Group II received the block using 40 ml ropivacaine 0.2% and 2 ml (8 mg) dexamethasone. Result: TFA was significantly longer in Group II (5.92 ± 1.02 vs. 3.11 ± 0.82 h, P = 0). Group II also had decreased tramadol requirement postoperatively (100.00 ± 0.00 vs. 140.00 ± 50.26 mg, P = 0.046). The incidence of nausea and vomiting was also lower (82.86% vs. 97.14%, P = 0.02318). The patient satisfaction with regard to pain relief was more (57.14% vs. 25.71%, P = 0.038). Conclusion: Addition of dexamethasone to ropivacaine in TAP block prolonged the duration of the block. There was no complication seen with TAP block in any of the patients.