///2019 Abstract Details
2019 Abstract Details2019-07-13T07:45:15-05:00

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

Abstract Number: O2-02
Abstract Type: Original Research

Ashraf S Habib MB, BCh1 ; Srdjan S Nedeljkovic MD2; Attila Kett MD3; Manuel C. Vallejo MD, DMD4; Jean-Louis Horn MD5; Brendan Carvalho MBBCh6

Background: In women receiving intrathecal morphine, transversus abdominis plane (TAP) blocks with standard bupivacaine may not improve analgesia after cesarean delivery.1 However, in a retrospective analysis, use of a TAP block with long-acting liposomal bupivacaine (LB) after cesarean delivery reduced opioid consumption and improved analgesia.2 We present results of a multicenter, randomized, double-blind study (NCT03176459) comparing opioid consumption after TAP blocks with LB plus bupivacaine HCl vs bupivacaine HCl alone as part of a multimodal analgesia protocol including intrathecal morphine postsurgery.

Methods: Adults (N=186) with term pregnancies of 37-42 weeks scheduled to undergo elective cesarean delivery using spinal anesthesia, including intrathecal morphine 150 mcg, were randomized (1:1) to receive TAP with LB 266 mg plus bupivacaine HCl 50 mg or bupivacaine HCl 50 mg alone after surgery. All patients received IV ketorolac 15 mg and IV acetaminophen 1000 mg at the end of surgery, followed by oral acetaminophen 650 mg and ibuprofen 600 mg every 6 h for ≤72 h or until discharge. Efficacy was evaluated in a prespecified modified intent-to-treat (mITT) population who met study protocol criteria. Primary efficacy endpoint was total postsurgical opioid consumption (morphine equivalent dosing [MED]) through 72 h after cesarean delivery. Pain intensity was measured with a 10-cm visual analog scale. Opioid sparing was prespecified as taking ≤10 mg of oxycodone (or equivalent) with no opioid-related side effects through 72 h. Treatment-emergent adverse events (TEAEs) were recorded through day 14.

Results: In the mITT efficacy set (LB, n=71; bupivacaine, n=65), demographics were similar across groups. Total opioid consumption (MED) through 72 h was significantly lower in the LB vs bupivacaine group (least squares mean [LSM] standard error [SE], 15.5 [6.67] vs 32.0 [6.25] mg; P=0.01). Reductions were also observed at 1 week (LSM [SE], 23.3 [9.75] vs 45.8 [9.13] mg; P=0.02) and 2 weeks (LSM [SE], 28.2 [11.20] vs 47.8 [10.49] mg; P=0.05). Area under the curve of imputed pain intensity scores through 72 h was lower in the LB vs bupivacaine group (LSM [SE], 147.9 [21.13] vs 178.5 [19.78]; P=0.002). Percentage of opioid-spared patients was 2.2 times higher in the LB vs bupivacaine group (54 vs 25%; P=0.001). Safety was similar between groups; 64% of patients in the LB group experienced a TEAE vs 56% in the bupivacaine group. The most common TEAEs were pruritus and nausea. Serious TEAEs were rare (~3% in both groups), with no fatal TEAEs.

Conclusions: TAP block using LB plus bupivacaine HCl as part of a multimodal analgesia protocol after cesarean delivery resulted in reduced opioid consumption and pain during and after hospitalization vs bupivacaine HCl alone. Results suggest an opioid-sparing benefit of adding LB to bupivacaine TAP blocks in a cesarean delivery setting.

References

1. Can J Anaesth. 2012;59:766-78.

2. J Pain Res. 2018;11:3109-16.

SOAP 2019