Analgesic Sparing Effect of Dexamethasone with Levobupivacaine in Quadratus Lumborum Block in Patients Undergoing Unilateral Inguinal Hernia Repair

Abstract

The QLB is an effective analgesic technique for various abdominal wall incisions. The QLB covers T7 to L2 dermatomes by the spread of LA drugs either into the paravertebral space or in the thoracolumbar plane, through iliohypogastric and ilioinguinal nerves, A and C fiber nociceptors, mechanoreceptors and high-density network of lumbar sympathetic fibers. The QLB provides somatic and visceral analgesia, hence, we studied the effect of dexamethasone with levobupivacaine in QLB for patients undergoing open inguinal hernia repair surgery Levobupivacaine is a long-acting LA agent, commonly used for peripheral nerve block due to its better safety profile than that of bupivacaine. Despite long duration of action of levobupivacaine, it cannot provide analgesia for adequate period, hence there is need of adjuvants with LA in block or use of alternative analgesic administration for breakthrough surgical site pain, when effect of block wears off. Various adjuvants have been used and studied to improve the duration of LA action in different peripheral nerves and regional block techniques. Dexamethasone as an adjuvant to LA has been shown to prolong the duration of pain-free period, less requirement for rescue opioids consumption, more patient satisfaction and lesser incidence of nausea and vomiting. A similar finding was observed in our study.