Background: Patients undergoing total abdominal hysterectomy suffer significant postoperative pain. The transversus abdominis plane (TAP) block is a recently described approach to providing analgesia to the anterior abdominal wall. We evaluated the analgesic efficacy of the TAP block in patients undergoing total abdominal hysterectomy via a transverse lower abdominal wall incision, in a randomized, controlled, double-blind clinical trial.
Methods: Fifty females undergoing elective total abdominal hysterectomy were randomized to undergo TAP block with ropivacaine (n = 24) versus placebo (n = 26) in addition to standard postoperative analgesia comprising patient-controlled IV morphine analgesia and regular diclofenac and acetaminophen. All patients received a general anesthetic and, before surgical incision, a bilateral TAP block was performed using 1.5 mg/kg ropivacaine (to a maximal dose of 150 mg) or saline on each side. Each patient was assessed postoperatively by a blinded investigator in the postanesthesia care unit and at 2, 4, 6, 12, 24, 36, 48 h postoperatively.
Results: The TAP block with ropivacaine reduced postoperative visual analog scale pain scores compared to placebo block. Mean (+/-SD) total morphine requirements in the first 48 postoperative hours were also reduced (55 +/- 17 mg vs 27 +/- 20 mg, P < 0.001). The incidence of sedation was reduced in patients undergoing TAP blockade. There were no complications attributable to the TAP block.
Conclusions: The TAP block, as a component of a multimodal analgesic regimen, provided superior analgesia when compared to placebo block up to 48 postoperative hours after elective total abdominal hysterectomy.