Preemptive analgesic efficacy of ultrasound-guided transversus abdominis plane block in patients undergoing gynecologic surgery via a transverse lower abdominal skin incision

Abstract

Background: The transversus abdominis plane block is recently described peripheral block to providing analgesia to the anterior abdominal wall. The goal of this study is to evaluate the analgesic efficacy of the ultrasound-guided transversus abdominis plane block (US-TAP block) in patients undergoing gynecologic surgery via a transverse lower abdominal skin incision.

Methods: Thirty-two patients undergoing gynecologic surgery were randomized to undergo standard care such as PCA, or to receive additional US-TAP block with standard care. After general anesthesia induction, a bilateral US-TAP block was performed using 0.375% ropivacaine 20 ml on each side. Postoperative demand of rescue analgesics in PACU and ward were recorded. Each patient was assessed postoperatively by a blinded investigator in the postanesthesia care unit (PACU) and at 2, 6, 10, 24, 48 hr postoperatively to investigate pain, drowsiness, nausea and itch.

Results: The US-TAP block reduced pain intensity compared to standard care in the PACU (5.2 ± 3.1 vs 8.4 ± 1.3) and at 2, 24 postoperative hours (3.0 ± 2.4 vs 5.2 ± 2.4, 0.9 ± 1.5 vs 2.2 ± 1.9). Fentanyl requirements in PACU was reduced (20.3 ± 20.9 vs 62.5 ± 35.4 µg, P < 0.05). In ward, pethidine requirements was reduced (21.9 ± 28.7 vs 56.3 ± 34.8 mg, P < 0.05).

Conclusions: The US-TAP block with standard care provide more effective analgesia after gynecologic surgery via a transverse lower abdominal skin incision.

Keywords: Anesthesia; Nerve block; Ultrasonograpy.

Fig. 1

Sonographic anatomy of the US-guided TAP block. Images show the lateral abdominal wall using a probe held in the mid-axillary line in the axial plane. The right of image is anterior. (A) Narrow arrow: needle, SQ: subcutaneous tissue, EO: external oblique muscle, IO: internal oblique muscle, TA: transversus abdominis muscle, P: peritoneal cavity. Broad arrow, transversus abdominis plane. (B) Narrow arrow: needle, LA: local anesthetic.