Effect of dexamethasone on analgesic efficacy of transverse abdominis plane block in laparoscopic gynecological procedures: A prospective randomized clinical study

Background and Aims: Dexamethasone has been increasingly used as an adjuvant to local anesthetics in peripheral nerve blocks with various studies showing an opioid sparing the effect of intravenous (IV) dexamethasone as well in a multimodal analgesia technique. It is not clear whether this effect of dexamethasone is because of its peripheral action or because of its systemic absorption. In our study, we compared the effectiveness of dexamethasone on duration of analgesia when used as an adjuvant with local anesthetic in transverse abdominis plane block (TAP) versus when given systemically by IV route along with block only, in patients undergoing laparoscopic gynecological procedures under general anesthesia (GA). Material and Methods: This is a prospective, randomized, parallel treatment, double-blinded study. The primary outcome of our study was the time to administration of first rescue analgesia. Forty patients were randomly assigned to perineural (PN) and IV Group using a computer-generated random numbers table and allocated using sealed opaque envelopes technique. After induction of GA, PN group received ultrasound guided TAP block with 15 ml of 0.25% levobupivacaine plus 4 mg (1 ml) dexamethasone on each side. Patients in IV group received TAP block on both sides with 15 ml of 0.25% levobupivacaine and 8 mg IV dexamethasone. Results: Time to request for first rescue analgesia was 6.63 +/- 1.5 h in PN group and 5.04 +/- 1.7 h in IV group. Pain scores were comparable in both the groups. Conclusion: Dexamethasone administered in either of the routes has comparative effect on quality of analgesia of TAP block with 0.25% levobupivacaine.