Is unilateral transversus abdominis plane block an analgesic alternative for ureteric shock wave lithotripsy?

BACKGROUND: Various sedative and analgesic techniques have been used during shock wave lithotripsy (SWL). AIM: This study aimed at evaluating the efficacy of ultrasound-guided unilateral transversus abdominis plane (TAP) block as an analgesic technique alternative during ureteric SWL. SETTINGS AND DESIGN: Prospective randomized comparative study. MATERIALS AND METHODS: Fifty patients scheduled for ureteric SWL were randomly allocated into two equal groups: Group (F) received 1.5 mcg/kg fentanyl intravenous and group (T) received unilateral TAP block with injection of 25 ml of bupivacaine 0.25% (62.5 mg). STATISTICAL ANALYSIS: Statistical analysis was performed using SPSS program version 19 and EP16 program. RESULTS: The visual analog scale was significantly less in group (T) than in group (F) both intra-operatively (at 10, 20, 30, and 40 min) and postoperatively (at 10 min intervals in the postanesthesia care unit [PACU]) (P < 0.001). Rescue analgesia with pethidine during the procedure and in the PACU was less (P < 0.001) in the group (T) than group (F) with a median of 20 mg versus 55 mg, respectively. The higher sedation scores observed in group (F) at 15, 25, and 35 min during the procedure, and at 20 min during the PACU time were statistically highly significant (P < 0.001), but only significant at 10 min (P = 0.03) and 30 min (P = 0.007) during the PACU time. There was also highly significant decrease (P < 0.001) in the time of PACU stay in group (T) (38.2 ± 6.6 min) compared with group (F) (89.2 ± 13.39 min). We recorded 6 patients in group (F) (24%) who have developed respiratory depression (respiratory rate < 10 breaths/min) compared to 0% in group (T) (P = 0.022). In addition, in group (F) nausea was noted in 8 patients (32%) and vomiting in 6 patients (24%), which was statistically significant when compared to group (T) (0%) (P = 0.01 and 0.022, respectively). CONCLUSION: Ultrasound-guided unilateral TAP block is an effective alternative analgesic technique during ureteric SWL.