Transversalis Fascia Plane Block Versus Low-Dose Intrathecal Morphine for Open Inguinal Hernia Repair

Open inguinal hernia repair is commonly associated with early postoperative pain, which may delay mobilization, reduce patient satisfaction, and increase opioid consumption. Low-dose intrathecal morphine may provide prolonged postoperative analgesia after spinal anesthesia; however, it may also be associated with opioid-related adverse effects such as nausea, vomiting, pruritus, urinary retention, sedation, and respiratory depression. The transversalis fascia plane block is an ultrasound-guided fascial plane block that targets the sensory innervation of the lower abdominal wall, particularly the T12-L1 dermatomal region and the ilioinguinal and iliohypogastric nerve distribution. Although TFP block has been evaluated in lower abdominal procedures, direct comparison with low-dose intrathecal morphine in open inguinal hernia repair is limited. This prospective, randomized, controlled, assessor-blinded trial aims to compare ultrasound-guided TFP block with low-dose intrathecal morphine in adult patients undergoing elective unilateral open inguinal hernia repair under spinal anesthesia. The primary outcome is total rescue opioid consumption during the first 24 postoperative hours. Secondary outcomes include pain scores at rest and with movement, time to first rescue analgesia, opioid-related adverse effects, quality of recovery, patient satisfaction, mobilization time, readiness for discharge, block success, sensory block distribution, and block-related complications.