Comparison of different volumes of Bupivacaine for ultrasound guided sacral erector spinae block in pediatric patients undergoing hypospadias repair.

Paediatric male patients aged 8 to 12 yrs with American Society of Anesthesiologists (ASA) physical status I or II scheduled to undergo surgery for hypospadias repair will be included in the study. All children will be evaluated one day prior to surgery. The patients will be instructed on usage of pin prick method for dermatomal spread and a 10mm visual analog scale (VAS) for pain [graded from 0 ( no pain) to 10 ( most severe pain) during preoperative evaluation .From computer generated randomization, patients will be randomly allocated to one of the two groups comprising of thirty patients. Inhalational induction of anaesthesia will be done in a standardized manner to facilitate the placement of supraglottic airway device. Group I (n=30) will be given ultrasound guided sacral erector spinae plane block with 1 mlkg-1 of 0.25% bupivacaine. Group II(n=30) will be given ultrasound guided sacral erector spinae plane block with 0.75 mlkg-1 of 0.25% bupivacaine . Number of blocked dermatomes will be assessed at 30 mins, 45 mins, 60 mins using pin prick method. Pain assessment will be done postoperatively using VAS score at 0 hr, every 15 mins upto 1 hr, every half an hour upto 2 hours, 2 hrly upto 12 hours and then at 18th hour and 24 th hour postoperatively. Rescue analgesic will be given at VAS score 4. Patient will be given 15mgkg-1 paracetamol infusion over 10 min but not more frequently than 6 hours. If pain persists after paracetamol administration, oral ibuprofen 10mgkg-1 will be given but not more frequently than 8 hours.