///2016 Abstract Details
2016 Abstract Details2019-07-15T10:10:51-05:00

A Randomized Controlled Trial of the Impact of Ropivacaine Concentration Used for Transversus Abdominis Plane (TAP) Blockade on Post-Cesarean Analgesia

Abstract Number: T-57
Abstract Type: Original Research

Joseph B Bavaro MD1 ; Edward A Yaghmour MD2; Christopher Cambic MD3; Nicole Higgins MD4; John T Sullivan MD, MBA5; Robert J McCarthy PharmD6

Introduction: A multimodal approach to post-cesarean analgesia may include transversus abdominus plane (TAP) blockade (1), particularly in parturients with contraindication to neuraxial morphine such as those at risk for sleep-disordered breathing. The optimal technique for administering post-cesarean TAP blockade has not been defined. The aim of this study was to compare the effect of TAP blockade ropivacaine concentration on 24-hour post-cesarean delivery opioid consumption.

Methods: Obese parturients (BMI > 40 kg/m2) undergoing scheduled cesarean delivery were recruited and received spinal or combined spinal-epidural anesthesia (IT bupivacaine 12mg, fentanyl 15mcg). Patients were randomized to post-operative, ultrasound-guided, bilateral TAP blockade with 15mL per side of either saline, or ropivacaine 0.2, 0.5, or 0.75% by one of 5 investigators. Patients received hydromorphone by PCA and scheduled IV ketorolac (30 mg q 6 hours) for 24h, followed by oral hydrocodone-acetaminophen and ibuprofen. The primary outcome was 24-hour morphine-equivalent opioid consumption. Secondary outcomes included total opioid consumption, NSAID consumption, and VAS pain scores at 2, 6, 24, and 72 hours post-TAP blockade.

Results: 274 patients were approached and 120 enrolled and randomized. Data from 5 patients were excluded from analysis due to exclusion criteria discovered after randomization. There were no differences among groups in BMI, EGA, number of previous CDs, race, or investigator. Compared to saline, median 24h morphine-equivalent consumption was lower in patients who received TAP blockade with ropivacaine 0.2 or 0.5% (table). However, there was no significant difference in 24h morphine-equivalent consumption between the saline and 0.75% ropivacaine groups.

Discussion: Post-cesarean TAP blockade using ropivacaine 0.2% or 0.5% reduced opioid consumption in morbidly obese parturients who received spinal anesthesia for cesarean delivery without intrathecal morphine. However, our observation that ropivacaine 0.75% is no more efficacious than saline was unexpected and may represent the unreliability of TAP blockade in morbidly obese parturients. There were no clear differences in patient characteristics, or a bias toward a particular provider performing the blockade, suggesting that the wide confidence intervals in our data support the lack of reliability of TAP analgesia in this population.

1) McDonnell JG: Anesth Analg 2007;104:193

SOAP 2016