Lower abdominal surgeries are commonly done in pediatric group of patients and are associated with severe postoperative pain. Adequate analgesia during the perioperative period is vital to reduce the stress response to surgery and perioperative morbidity and to hasten the recovery.

For effective perioperative analgesia, regional anesthetic methods can be used along with other analgesics. One of the most often used methods of regional anesthesia in children is caudal epidural block, which provides efficient postoperative analgesia for sub-umbilical interventions. 

Regional anesthesia in pediatrics has undergone a radical change as a result of the use of ultrasonography (US)-guided nerve blocks. Both upper and lower abdominal procedures using many truncal blocks have a good success rate. For infra-umbilical procedures, nerve blockade has been demonstrated to be just as successful as caudal block.

A recently discovered block called the quadratus lumborum block (QLB) uses ultrasound to successfully deliver secure and long-lasting analgesia. It is a fascial plane block that is becoming more and more common for pain control after lower abdominal surgeries. By using ultrasonography (US) to image the abdominal muscles as a guide, it is carried out with a local anesthetic injection between the Quadratus lumborum muscle and Psoas major muscle, and it is anticipated that analgesia will be provided from the level of the T7-L1 dermatome segment.

Justification: 

Caudal block provides adequate analgesia during the intraoperative and early post-operative stages with more effective and consistent results. However it is associated with adverse effects and complications.

For somatic analgesia of both the upper and lower abdomen, the QL block is a novel abdominal truncal block. The QL block provides an excellent analgesic effect, with patients reporting a reduction in pain of 1-2/10 on the pain scale.

According to observations, QL block led to shorter hospital stays and lower postoperative pain scores.

Very few studies have been done comparing Quadratus lumborum block and caudal block for lower abdominal surgeries in pediatric patients, hence we propose to carry out a Prospective Randomised Controlled Trial to compare the effectiveness of caudal epidural block against ultrasound-guided quadratus lumborum block as a postoperative analgesic in pediatric lower abdominal procedures.