Ultrasound-guided TAP Block with or without Dexmedetomidine vs. Local Infiltration of the Wound after Open Herniorrhaphy: A Randomized Prospective Controlled Study

Abstract

Objectives: Transversus abdominis plane (TAP) block and local anesthetic wound infiltration (LAI) can provide a variable effective pain relief at the wound site after surgery. This prospective study was designed to evaluate the postoperative analgesic efficacy of TAP with or without dexmedetomidine compared with LAI of the wound after herniorrhaphy.Materials and methods: Sixty adult patients were divided into 3 groups of 20 patients each. Group1 (TAPD): Patients received single shot ultrasound-guided (US) TAP block using 15 mL of levobupivacaine 0.5% mixed with 0.9 μg/kg of dexmedetomidine. Group 2 (TAP): Patients received single shot US guided TAP block using 15 mL of levobupivacaine 0.5%. Group 3 (LAI): Patients received local anesthetic infiltration (LAI) patients received local infiltration using 15 mL of levobupivacaine 0.5%. The following parameters were assessed at, 2, 10, 18 and 24 h postoperatively: postoperative duration of analgesia, analgesic pain scores using the visual analogue scale (VAS) for pain, amount of supplemental intravenous morphine, postoperative nausea and vomiting during 24 h.Results: We found that a lower significant difference (P<0.05) of VAS pain scores at rest and on movement between group TAPD and group TAP at time 24 h postoperatively. Also, there was a lower significant difference (P<0.05) of VAS pain scores at rest and on movement between group TAPD and group LAI at 10, 18 and 24 h. Moreover, there was a lower significant difference (P<0.05) between group TAP and group LAI at times 10 and 18 h. Also, supplemental morphine consumption within 24 h was a statistically higher (P<0.05) in group LAI compared to groups TAPD and TAP.Conclusion: Using dexmedetomidine as an additive to levobupivacaine in ultrasound-guided TAP block for herniorrhaphy provides prolonged duration of postoperative analgesia, and lowered VAS pain scores. Also local anesthetic infiltration can give accepted postoperative analgesia but with shorter duration than TAP block