Effect of Adding Dexamethasone as a Ropivacaine Adjuvant in Ultrasound-Guided Transversus Abdominis Plane Block for Inguinal Hernia Repair

Background: The transverses abdominals plane block (TAP) is a regional anesthesia technique that provided analgesia to the parietal peritoneum, skin and muscles of the anterior abdominal wall. The aim of this randomized double-blind study was to evaluate postoperative analgesia on patients undergoing open inguinal hernia repair under general anesthesia (GA), (GA + TAP) block preformed with ropivacaine and (GA + TAP-D) block preformed with ropivacaine and 4 mg dexamethasone.

Methods: 90 (ASA I-II) adult patients for unilateral open inguinal hernia repair were included in this study. In group I (n = 30) patents received only general anesthesia (GA). Patients in group II (n = 30) received GA and unilateral TAP block with 25 ml of 0.5% ropivacaine and the patients in group III (n = 30) received GA and unilateral TAP-D block with 25 ml of 0.5% ropivacaine + 4 mg Dexamethadsone. In this study we assessed the pain score - VAS at rest at 2, 4, 6, 12 and 24 hours after the operation and the total analgesic consumption of morphine over 24 hours.

Results: There were statistically significant differences in the VAS scores between group I, group II and group III at all postoperative time points - 2^hr, 4^hr, 6^hr, 12^hr and 24^hr. (p < 0.00001). The cumulative 24 hours morphine consumption after the operation was significantly lower in group III (5.53 1.21 mg) than in group II (6.16 2.41 mg) and group I (9.26 2.41 mg). This difference is statistically significant (p < 0.00001).

Conclusion: Concerning the inguinal hernia repair we found better postoperative pain scores and 24 hours reduction of the morphine consumption in group III (GA and TAP-D block) compared with group I (GA) and group II (GA + TAP block).