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Combined Transversus Abdominis Plane and Rectus Sheath Blocks in Open Inguinal Hernia Repair: Protocol for a Double-Blind Randomized Controlled Trial (PRO-RSTAP)

Nordström P, Lumme A, Virman J, Kalliomäki ML

Acta anaesthesiologica Scandinavica, 2026

Abstract

Background: Inguinal hernia repair is one of the most common surgical procedures worldwide and is frequently performed as day-case surgery. Postoperative pain may delay recovery and occasionally necessitate unplanned hospital admission. Regional anesthesia techniques, including transversus abdominis plane (TAP) and rectus sheath (RS) blocks, have shown promise in improving analgesia. However, their combined efficacy in open inguinal hernia repair has not been established in randomized trials.

Methods: The PRO-RSTAP trial is a prospective, double-blind, four-arm randomized controlled trial conducted at three hospitals in Finland. The study evaluates the individual and combined effects of TAP and RS blocks in adults undergoing elective open inguinal hernia repair. Two hundred patients are randomized equally into four groups: (1) placebo TAP + placebo RS, (2) active TAP + placebo RS, (3) active RS + placebo TAP, and (4) active TAP + active RS. All patients receive standardized sedation and multimodal analgesia, including paracetamol, nonsteroidal anti-inflammatory drugs (NSAIDs), and rescue opioids. The primary outcome is cumulative perioperative opioid consumption from block administration until hospital discharge, expressed as intravenous morphine equivalents. Secondary outcomes include pain scores, conversion to general anesthesia, postoperative nausea and vomiting, time to discharge, and unplanned admissions or emergency visits within 7 days. The planned sample size…

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Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design.

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