Caudal epidural block is a well-established and commonly performed regional neuraxial technique for providing intraoperative and postoperative analgesia in children scheduled for lower abdomen/perineal surgical interventions. Although the efficacy and safety of Caudal epidural block are fairly high, the associated complications, such as inadvertent dural puncture, unwarranted motor blockade of the lower limbs, and disturbance of bladder function, limit its use. Furthermore, a major limitation of an uncomplicated Caudal epidural block when administered as a "single-shot" technique is its brief duration of action (up to 6 hours), which makes administration of additional analgesics necessary .

Ultrasonography guidance, by virtue of real-time visualization of the muscle layers and fascial planes, has significantly facilitated practice of regional nerve blockade for it offers confirmation of the spread of the local anesthetic drug in the correct space. Interestingly, there has been a reinvigoration of interest in ultrasonography-guided transversus abdominis plane block in children since its emergence as a valid postoperative analgesia alternative in adults undergoing abdominal surgery. transversus abdominis plane block involves blockade of spinal afferent nerves in the neurofascial plane between the internal oblique and transversus abdominis muscle. Whereas the advantages (reduction in pain intensity/analgesic requirements) of ultrasonography-guided transversus abdominis plane block have been well documented in adults in the first 48 hours post surgery, in children, its use as a primary postoperative analgesia technique remains limited. Caudal anesthesia is easy to perform in younger children; however, its main disadvantage is the short duration of action. Even bupivacaine, along-acting local anesthetic drug, can provide only4-8 h of analgesia. Dexmedetomidine is a highly selective alfa2 agonist with sedative and analgesic properties. It has an alfa1/2 selectivity ratio of 1600 : 1, which is eight times more potent than clonidine (200 : 1)[16]. DEX has been used effectively in intensive care to aid weaning from mechanical ventilation and is being used increasingly in children

Inclusion Criteria:

• patients 2-8 years

Exclusion Criteria: