Comparing Bi-level and Single-level ESP Block for Open Inguinal Hernia Repair

"ESP block is a paraspinal fascial plane block that involves injection of local anesthetic underneath the anterior fascia of the erector spinae muscles.~Local anaesthetic mixture (lignocaine 2% with adrenaline, bupivacaine 0.25%) will be delivered with insulated needle in bolus(es) to above-mentioned levels (L1 in 1ESP group, T12 \& L1 in 2ESP group)"