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

Comparison of Quadratus Lumborum Block versus Transversus Abdominis Plane Block for Postoperative Pain after Cesarean Delivery - A Randomized Controlled Trial

Abstract Number: BP-04
Abstract Type: Original Research

Caijuan Li MD1 ; Yunping Li MD2; Mao Mao MD3; Shiqin Xu MD4; Xiaofeng Shen MD5; Philip Hess MD6

The transversus abdominus block (TAP) improves post-cesarean pain when neuraxial morphine is unavailable or ineffective (1). The quadratus lumborum block (QL) has been reported to be more effective (2) and potentially to provide visceral analgesia due to spread to the paravertebral space. A large sample study is needed to prove its efficacy compared to both TAP block and placebo.

Methods: ASA 2 women presenting for term singleton primary cesarean under spinal anesthesia (0.5% Ropivacaine 3ml) were randomized to receive a TAP, QL, or placebo block. Ultrasound guided TAP, QL and sham (no injection) were performed at the end of surgery with 0.25% Ropivacaine 30 ml each side which was blinded to the participants and blinded observers. Patients received a low-dose Butorphanol PCA with a 0.15mg/hr background infusion (PCA hourly maximal dose 0.87mg). Blinded observers (other than block operators) measured pain at rest and with movement, number of PCA requests (hits) and PCA doses received, sedation, nausea, vomiting and bowel sounds for 48 hr. The primary outcome was Butorphanol consumption. Comparisons made using repeated measures ANOVA among groups and Log rank analysis for time to first PCA request.

Results: 180 patients were enrolled, 177 completed the study. Groups were similar in patient and obstetric characteristics. Over the first 18 hours, patients in QL group made fewer PCA requests (p=0.02) and received fewer doses (p=0.006) (FIGURE 1) than the Control; but were not statistically different than the TAP group. Time to first PCA request was significantly longer in the QL and TAP groups than the Control group (QL 9h 52m vs. TAP 9h 16m vs. Control 5h 16m; p<0.001). Over the first 12 hours, pain scores at rest (p=0.01) and with movement (p=0.02) were lower in the QL and TAP groups than the Control (FIGURE 1). There were no differences among groups after 18 hours. No differences in side effects (sedation, nausea, vomiting, pruritus, respiratory rate, bowel sounds) or patient satisfaction among groups at any point (p=NS for all).

Conclusion: Both QL and TAP blocks were more effective at controlling pain at rest and with movement for the first 12 hours compared to a placebo control using PCA opioids with a low dose background. The QL block group had fewer PCA requests and doses than the control group for 18 hours and was lower but was not statistically different than the TAP block.

1. J Anesth Perioper Med 2019;6:15-22

2. Reg Anesth Pain Med 2016;41:757-762

SOAP 2019