Dexmedetomidine in TAP Block for Inguinal Hernia Repair (TAP-dex)

The Effect of Adding Dexmedetomidine to the Local Anesthetic Solution for Ultrasonography-guided TAP Block in Inguinal Hernia Repair

This prospective double-blind randomized study will aim at evaluating the short- and long-term postoperative analgesic efficacy of the ultrasound-guided transversus abdominis plane (TAP) block with a combination of local anesthetic and dexmedetomidine in inguinal hernia repair under general anesthesia

Inguinal hernia repair is one of the most commonly performed surgical procedures worldwide, especially in the day-case setting. It can be accompanied by moderate to severe postoperative pain, which can delay return to normal daily activities or lead to the development of chronic pain. Chronic pain after hernia repair has a reported prevalence ranging between 0% and 43% with both nociceptive and neuropathic features. The transversus abdominis plane (TAP) block is an effective regional anesthetic technique to reduce postoperative pain intensity, time to first rescue anesthetic administration and opioid demand after upper and lower abdominal surgery. Dexmedetomidine is a selective α2-adrenergic agonist with analgesic properties that has been shown to prolong local anesthetic action when used as an adjunct to local anesthetic solutions in neuraxial anesthesia. The aim of this prospective, double-blind placebo controlled randomized study will be to evaluate the analgesic efficacy of ultrasound-guided TAP block where local anesthetic is supplemented by dexmedetomidine in patients undergoing unilateral elective inguinal hernia repair with the Lichtenstein technique under general anesthesia.

ultrasound-guided transversus abdominis plane block with 25 mL ropivacaine 0.5% and 2 mL dexmedetomidine

ultrasound-guided transversus abdominis plane block with 25 mL ropivacaine 0.5% and 2 mL normal saline

in patients allocated to the dexmedetomidine group, ultrasound-guided transversus abdominis plane block will be performed with the combination of local anesthetic and dexmedetomidine

in patients allocated to the dexmedetomidine group, ultrasound-guided transversus abdominis plane block will be performed with the combination of local anesthetic and normal saline

pain score by the use of Numeric Rating Scale (NRS) 3 hours postoperatively, ranging from 0 to 10, where 0 means "no pain" and 10 means "worst pain imaginable"

pain score by the use of Numeric Rating Scale (NRS) 6 hours postoperatively, ranging from 0 to 10, where 0 means "no pain" and 10 means "worst pain imaginable"

pain score by the use of Numeric Rating Scale (NRS) 24 hours postoperatively, ranging from 0 to 10, where 0 means "no pain" and 10 means "worst pain imaginable"

occurrence of chronic pain at the site of the operation, with the use of the NRS, at rest and during movement

satisfaction from postoperative analgesia on a four-point Likert scale with 1 marked as minimal satisfaction and 4 as maximal satisfaction

Inclusion Criteria: American Society of Anesthesiologists (ASA) patients I-III undergoing inguinal hernia repair with a mesh open hernia repair elective surgery Exclusion Criteria: inability to consent to the study due to language barriers or cognitive dysfunction - bilateral inguinal hernia repair, body mass index over 40 kg m-2, skin infection at the puncture site contraindication to paracetamol or non-steroidal anti-inflammatory drug (NSAIDs) administration known previous hepatic or renal impairment as assessed by the patients' history and routine biochemical markers coagulation abnormalities history of gastroesophageal reflux and preoperative use of opioids or NSAIDs for chronic pain conditions reoperation of recurrent inguinal hernia after previous mesh repair

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