Effect of addition of dexamethasone to ropivacaine on post-operative analgesia in ultrasonography-guided transversus abdominis plane block for inguinal hernia repair: A prospective, double-blind, randomised controlled trial

Background and Aims: Ultrasonography (USG)-guided transversus abdominis plane (TAP) block is an abdominal field block with high efficacy. This study was undertaken with the aim of determining the effect of the addition of dexamethasone to 0.5% ropivacaine on post-operative analgesia in USG-guided TAP block for inguinal hernia repair. Methods: A double-blind randomised control study was conducted on sixty patients posted for inguinal hernia repair with the American Society of Anesthesiologists physical Status I or II, who were allocated two groups of 30 each. Patients in Group RS received 0.5% ropivacaine (20 ml) and normal saline (2 ml) whereas patients in Group RD received 0.5% ropivacaine (20 ml) and dexamethasone (2 ml, i.e., 8 mg), in USG-guided TAP Block on the same side, after repair of inguinal hernia under spinal anaesthesia. Visual analogue scale (VAS) scores, time for request of first analgesia and total tramadol consumption in first 24 h were compared. Unpaired Student's t-test and Mann-Whitney U-test were performed using SPSS 23 Software. Results: Patients in Group RD had significantly lower VAS scores as compared to Group RS from 4th to 12th h, postoperatively. Duration of analgesia was significantly more in Group RD (547.50 [530,530] min) when compared with Group RS (387.50 [370,400] min) (P< 0.001). The demand for intravenous tramadol was significantly low in Group RD (223.33 +/- 56.83 mg) as compared to Group RS (293.33 +/- 25.71 mg) (P < 0.001). Conclusion: Addition of dexamethasone to ropivacaine in USG-guided TAP block significantly reduces post-operative pain and prolongs the duration of post-operative analgesia, thereby reducing analgesic consumption.