///2012 Abstract Details
2012 Abstract Details2019-08-02T19:38:42-06:00

The effect of transversus abdominis plane (TAP) block with and without clonidine on post-Cesarean delivery pain and wound hyperalgesia.

Abstract Number: TW-6
Abstract Type: Original Research

Laurent Bollag MD1 ; Philippe Richebe MD, PhD2; Monica Siaulys MD, PhD3; Clemens Ortner MD, MSc4; Ruth Landau MD5

Background and Objectives

The ultrasound-guided transversus abdominis plane (TAP) block may be offered for post-Cesarean analgesia, particularly when standard regimens with intrathecal opioid or non-steroidal anti-inflammatory drugs are contraindicated or insufficient. TAP solutions with local anesthetics offer no benefits compared with intrathecal morphine(1). Intrathecal clonidine has been shown to have antihyperalgesic properties(2). Adjuvants to extend TAP block duration and possibly reduce wound hyperalgesia (WHA), known to be a risk factor for chronic pain, have not been studied. We hypothesized that a TAP block with clonidine will improve short and long term post-surgical outcomes.

Methods

In a placebo-controlled trial, 3 TAP solutions were compared in 90 women undergoing a Cesarean delivery under spinal anesthesia: Placebo group=NaCl 0.9% 20.5ml per side, BupTAP Group=bupivacaine 0.375% 20ml + 0.5ml NaCl 0.9% per side, CloTAP Group=bupivacaine 0.375% 20ml + clonidine 75mcg (=0.5ml) per side. Wound hyperalgesia index at 48h (WHI48h; WHA extent divided by incision length), pain scores, analgesic consumption, and pain descriptors up to 12 months were compared between groups.

Results

WHI48h [median (25th-75th percentiles)] was 1.07 (0.48-3.26) in the Placebo group, 1.27 (0.59-2.95) in the BupTAP group and 0.74 (0.09-2.25) in the CloTAP group (p=0.48) (Figure). PACU iv morphine request was significantly higher in the Placebo group compared to TAP groups (p=0.01). Post-operative pain scores did not differ significantly between groups (Figure), nor did the requests for breakthrough medication at 48h (30% in Placebo, 24% in BupTAP and 12% in CloTAP; p=0.25) or chronic pain indicators reported at 3, 6 and 12 months.

Conclusions

This is the 1st study comparing two TAP solutions with a mapping of wound hyperalgesia after Cesarean delivery. TAP blocks with or without clonidine did not affect wound hyperalgesia, nor did they improve short or long term pain scores in healthy women undergoing an elective Cesarean delivery.

The lack of apparent effect could be due to a dose-effect or to the lack of effect of peripheral clonidine; dose-response studies for the use of clonidine via TAP may be needed to identify the optimal dose (if any). Further studies are warranted to determine the benefits of anti-hyperalgesic adjuvants in TAP solutions for individuals at risk for chronic pain.

1. Reg Anesth Pain Med 2010;35:324-5

2. Anesth Analg 2008;107:948-55



SOAP 2012