IRCT2015110318091N6 IRCT 2016-01-23 Hormozgan University of Medical Sciences Comparing the effect of three local anesthesia drug regimes Bupivacaine, Bupivacaine-dexmedetomidine and Bupivacaine – fentanyl through an injection through the tail portion of the spinal column for providing postoperative analgesia in children one to five years old in a children's hospital. The Comparison of Bupivacaine, Bupivacaine-dexmedetomidine and Bupivacaine – fentanyl by caudal technique for postoperative analgesia in children 1-5 years old in pediatric hospital. 2015-10-23 anticipated 60 Complete https://irct.ir/trial/16504 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment. 2-3 Postoperative pain in children. Intervention 1: First group (bupivacaine) which included 1 milliliter/kilogram from a solution of 0.25% buupivacaine which was prepared by adding distilled water to 0.5% bupivacaine with equal volumes. Intervention 2: Second group (bupivacaine-dexmedetomidine) which included 1 milliliter/kilogram from a solution of 0.25% bupivacaine which was prepared by adding distilled water to 0.5% bupivacaine and 2 microgram/kilogram dexmedetomidine with equal volumes. Intervention 3: Third group (bupivacaine-fentanyl) which included 1 milliliter/kilogram from a solution of 0.25% bupivacaine which was prepared by adding distilled water to 0.5% bupivacaine and 2 microgram/kilogram fentanyl with equal volumes.