Background: Dexmedetomidine and Midazolam were utilized as adjuvants for extending the duration of analgesia; the most common local anesthetic used globally for Caudal anesthesia (CA) is a single dose of plain bupivacaine. To achieve adequate post-operative analgesia, we aimed to compare bupivacaine-dexmedetomidine and bupivacaine-midazolam in caudal anesthesia in pediatric hypospadias surgeries.

Methods: We conducted a prospective randomized double-blind controlled clinical study on 51 patients who were scheduled for hypospadias surgery aged from 3 to 8 years; they were allocated randomly into three equal groups (17 patients in each group): Group C (Control): received bupivacaine 0.25% total volume 1ml/kg only, Group D: who received bupivacaine 0.25% in addition to dexmedetomidine 1μg/kg total volume 1ml/kg, Group M: received bupivacaine 0.25% in addition to midazolam 50μg/kg total volume 1ml/kg. The postoperative vital signs, adverse events and duration of the caudal analgesia were assessed utilizing the pediatrics observational Face, Legs, Activity, Cry, Consolability scale (FLACC) pain scale.

Results: Group D had the lowest significant FLACC pain score, followed by Group M, then Group C (P=0.00), Duration of Caudal block was the highest in Group D [14 hours, 95% CI(13.26-14.7)] followed by Group M [10 hours, 95% CI(9.6-10.36)] then Group C [4 hours, 95% CI(3.5-4.49)]

Conclusion: Combining bupivacaine with dexmedetomidine or midazolam dramatically extends the time of postoperative analgesia, which in turn increases the time until the patient requires another analgesic.