Transversus Abdominis Plane Block With Liposomal Bupivacaine for Pain After Cesarean Delivery in a Multicenter, Randomized, Double-Blind, Controlled Trial

Abstract

BACKGROUND: In women undergoing cesarean delivery under spinal anesthesia with intrathecal morphine, transversus abdominis plane (TAP) block with bupivacaine hydrochloride (HCl) may not improve postsurgical analgesia. This lack of benefit could be related to the short duration of action of bupivacaine HCl. A retrospective study reported that TAP block with long-acting liposomal bupivacaine (LB) reduced opioid consumption and improved analgesia following cesarean delivery. Therefore, we performed a prospective multicenter, randomized, double-blind trial examining efficacy and safety of TAP block with LB plus bupivacaine HCl versus bupivacaine HCl alone. METHODS: Women (n = 186) with term pregnancies undergoing elective cesarean delivery under spinal anesthesia were randomized (1:1) to TAP block with LB 266 mg plus bupivacaine HCl 50 mg or bupivacaine HCl 50 mg alone. Efficacy was evaluated in a protocol-compliant analysis (PCA) set that was defined a priori. The primary end point was total postsurgical opioid consumption (oral morphine equivalent dosing [MED]) through 72 hours. Pain intensity was measured using a visual analog scale. Adverse events (AEs) after treatment were recorded through day 14. RESULTS: Total opioid consumption through 72 hours was reduced with LB plus bupivacaine HCl versus bupivacaine HCl alone (least squares mean [LSM] [standard error (SE)] MED, 15.5 mg [6.67 mg] vs 32.0 mg [6.25 mg]). This corresponded to an LSM treatment difference of −16.5 mg (95% confidence interval [CI], −30.8 to −2.2 mg; P = .012). The area under the curve of imputed pain intensity scores through 72 hours supported noninferiority of LB plus bupivacaine HCl versus bupivacaine HCl alone (LSM [SE], 147.9 [21.13] vs 178.5 [19.78]; LSM treatment difference, −30.6; 95% CI, −75.9 to 14.7), with a prespecified noninferiority margin of 36 ( P = .002). In an analysis of all treated patients, including those not meeting criteria for inclusion in the PCA, there was no difference in postsurgical opioid consumption between groups. In the LB plus bupivacaine HCl group, 63.6% of patients experienced an AE after treatment versus 56.2% in the bupivacaine HCl–alone group. Serious AEs after treatment were rare (≈3% in both groups). CONCLUSIONS: TAP block using LB plus bupivacaine HCl as part of a multimodal analgesia protocol incorporating intrathecal morphine resulted in reduced opioid consumption after cesarean delivery in the PCA set. Results suggest that with correct TAP block placement and adherence to a multimodal postsurgical analgesic regimen, there is an opioid-reducing benefit of adding LB to bupivacaine TAP blocks after cesarean delivery ( ClinicalTrials.gov identifier: NCT03176459).

Transversus Abdominis Plane Block With Liposomal Bupivacaine vs. Regular Anesthetics for Pain Control After Surgery: A Systematic Review and Meta-Analysis

“…Our results indicated statistically significant reduction of pain with the use of LB for TAP block at 12 h (MD: −0.89, 95% CI: −1.44, −0.34 I 2 = 0% p = 0.01), 24 h (MD: −0.64, 95% CI: −1.21, −0.06 I 2 = 0% p = 0.03), 48 h (MD: −0.40, 95% CI: −0.77, −0.04 I 2 = 0% p = 0.03) but not at 72 h (MD: −0.37, 95% CI: −1.31, 0.56 I 2 = 57% p = 0.43) ( Figure 2). Nedeljkovic et al (30) in their study reported a statistically significant difference in pain scores between LB and RB at all time intervals up to 72 h. Hutchins et al (34) reported significantly lower maximal pain scores in the LB group at 24-, 48-, and 72-h time points compared to the RB group.…”

“…For the first primary outcome of our study i.e., total analgesic consumption, a meta-analysis could not be performed owing to significant differences in data collection and presentation among the included studies. Examining the results by specific periods, out of three studies (30,31,36) evaluating analgesic consumption for 0-48 h, only Nedeljkovic et al (30) reported statistically significant results. Hutchins et al (33,34) in their two trials reported analgesic consumption for 24-48 and 48-72 h but with opposite results.…”

“…Ten were excluded as per the reasons mentioned in Table 1 (20)(21)(22)(23)(24)(25)(26)(27)(28)(29). A total of seven studies were included in this systematic review and meta-analysis (30)(31)(32)(33)(34)(35)(36). Details of the included studies are presented in Table 2.…”

“…Five studies were RCTs (30)(31)(32)(33)(34), one was a prospective (35), while another was a retrospective study of a prospectively collected database (36). Ultrasound (US) guidance was used for the TAP blocks in four studies (30,33,34,36). The amount of LB and RB varied across studies along with variations in the analgesic regimen.…”

“…Except for the study of Guerra et al (35), all studies included pain scores as one of their outcomes. Hutchins et al (34) did not report the numerical or graphical data on pain scores in their article, while Nedeljkovic et al (30) did not report data as mean and SD. Data from the remaining four studies were pooled for a meta-analysis.…”