Bilateral Ultrasound Guided ESP Block Versus TAP Block on Post-operative Analgesia After Total Abdominal Hysterectomy

Sample size: Assuming that Mean±SD of reduced pain scores in erector spinae plane block is 4.7±3.7 versus 2.5±1 in transversus abdominis plane block.So, the total sample size is 48 cases (24 in each group) using Open Source Statistics for Public Health (open Epi) with confidence interval 95% and power of test is 80%. d) Method of sample collection: Forty eight female patients will be divided into two groups by a computer‐generated randomization table: Group (ES) (n=24): will receive bilateral ultrasound guided erector spinae plane block with each block 20 ml of bupivacaine 0.375% plus 5ug/ml adrenaline (1:200000) at the level of T9. Group (TA) (n=24): will receive bilateral ultrasound guided transversus abdominis plane block with each block 20 ml of bupivacaine 0.375% plus 5ug/ml adrenaline (1:200000).