Minimal effective dose of ultrasound-guided rectus sheath block to reduce oral analgesic requirement after ambulatory laparoscopic tubal resection: a randomized controlled superiority trial

Abstract

Background The effective dose during ultrasound-guided rectus sheath block (URSB) for reducing pain after laparoscopic tubal ligation is reported to be 100 mg of 0.25% bupivacaine. We examined the minimal effective dose of 0.25% bupivacaine for URSB on oral analgesic requirement after ambulatory single-port laparoscopic tubal resection. Methods A prospective, randomized controlled, superiority trial was conducted among patients who had been scheduled for ambulatory laparoscopic tubal resection between September 2015 and January 2019 at a tertiary care hospital in southern Thailand. Anesthesia was induced following protocol. The intervention group was allocated to receive a bilateral URSB using 10 ml of 0.25% bupivacaine on either side after intubation (total 50 mg) while the control group did not receive the sham block. Patients and assessors were blinded to the study intervention. All patients received a multimodal analgesia regimen as follows: fentanyl and ketorolac intraoperatively and fentanyl and oral acetaminophen at the post-anesthetic care unit. Postoperative oral analgesic requirement (acetaminophen and/or ibuprofen) at home was the primary outcome. Postoperative time to first analgesic requirement, oral analgesia (acetaminophen/ibuprofen), and pain score at 6 and 24 h were accessed via telephone interviews. Percentage, effect size (ES), and 95% confidence interval (CI) were presented. Results A total of 66 out of 79 eligible patients were analyzed (32 intervention, 34 control). Intraoperative fentanyl consumption was significantly lower in the intervention group (ES [95% CI]: 0.58 [0.08, 1.07] mcg, p = 0.022). Time to first oral analgesia in the intervention group was significantly longer than that of the control group (ES [95% CI]: 0.66 [0.14, 1.16] h, p = 0.012). The proportion of oral analgesia requirement at 24 h after surgery in the control group was significantly higher than that in the intervention group (97% vs 75%, p = 0.012). Pain scores at 6 and 24 h were similar in both groups although slightly lower in the intervention group (ES [95% CI]: 0.22 [−0.26, 0.71], p = 0.368 and 0.33 [−0.16, 0.81], p = 0.184, respectively). Conclusion A dose of 0.25% bupivacaine 50 mg for URSB reduced the oral analgesic requirement at 24 h and prolonged the time to first analgesic requirement after ambulatory laparoscopic tubal resection. Trial registration Thaiclinicaltrials.orgTCTR20150921002. Registered on 18 September 2015

Investigation into the clinical performance of rectus sheath block in reducing postoperative pain following surgical intervention: A systematic review and meta-analysis of randomised controlled trials

“…Five studies reported 24-h IV morphine equivalent consumption for nine RSB trial comparisons. [ 30 32 34 36 37 40 41 42 ] Overall, RSB was found to provide superior postoperative consumption of analgesics in contrast to controls after 24 h (SMD = -1.55, 95% CI [-2.35, -0.74], P < 0.001). Heterogeneity was considered considerable (I 2 = 95%, Cochrane Q statistic P < 0.001).…”

“…A final total of 20 RCTs satisfied our inclusion criteria and were included in this analysis [ Table 1 ]. [ 5 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 ] The risk-of-bias analysis for all included studies is summarised in Figure 2 . Details on the evidence review for the primary and secondary outcomes can be found in Table 2 .…”

“…Analysis of the continuous outcomes suggests that the RSB provides a clinically superior analgesic efficacy during the 0-2 h postoperative period when compared to control (SMD = -1.46, 95% CI [-2.04, -0.88], P < 0.001). [ 5 25 26 27 28 29 30 31 32 33 34 35 36 39 40 41 43 ] Heterogeneity was found to be considerable (I 2 = 94%, Cochrane Q statistic P < 0.001). At the 10-12 h endpoint, RSB was again deemed effective in minimising postoperative pain scores (SMD -1.02, 95% CI [-1.51, -0.52], P <0.001),[ 25 26 30 31 32 33 34 36 37 38 41 42 ] with heterogeneity again being considerable (I 2 = 95%, Cochrane Q statistic P < 0.001).…”

“…Finally, in the 12-24 h postoperative period, RSB was found insignificant compared to control at reducing postoperative pain scores (SMD -0.25, 95% CI [-0.55, 0.06], P = 0.11, I 2 = 83%). [ 5 26 29 31 32 34 36 38 39 40 41 42 ] Heterogeneity was again considerable (I 2 = 83%, Cochrane Q statistic P <0.001). Details for each primary endpoint are outlined in Figure 3 .…”

Regional anaesthesia: what surgical procedures, what blocks and availability of a “block room”?

“…A recent RCT showed improved postoperative pain management in an outpatient laparoscopic tubal resection, with the use of bupivacaine in a rectus sheath block (RSB) [141]. Although less is known so far and further investigation is needed to establish the role of a RSB in the outpatient setting.…”