Caudal bupivacaine supplemented with morphine or clonidine, or supplemented with morphine plus clonidine in children undergoing infra-umbilical urological and genital procedures: a prospective, randomized and double-blind study.

PURPOSE: We aimed to evaluate postoperative analgesia of morphine, or clonidine, or morphine plus clonidine, added to caudal bupivacaine in children undergoing infra-umbilical urological and genital procedures.

METHODS: Eighty patients aged 1-10 years were prospectively enrolled. After the induction of general anesthesia, the patients were randomized to four caudal anesthesia groups: Group B (1.0 mL/kg of bupivacaine 0.166% with epinephrine 1:600,000); Group BM (1.0 mL/kg of bupivacaine 0.166% with epinephrine 1:600,000 plus morphine 20 μg/kg); Group BC (bupivacaine 0.166% with epinephrine 1:600,000 plus clonidine 1.0 μg/kg), and Group BMC (bupivacaine 0.166% with epinephrine 1:600,000 plus morphine 20 μg/kg and clonidine 1.0 μg/kg). Duration of surgery, emergence time, postoperative pain score measured by the face, legs, activity, cry, consolability (FLACC) scale, postoperative analgesia time, and overall use of rescue analgesics were recorded.

RESULTS: The FLACC pain score (6, 12, and 24 h after the surgery) and the number of patients requiring analgesics during the first 24 h of the postoperative period were higher in Groups B and BC than in Groups BM and BMC (p < 0.05). The incidence of pruritus and urinary retention was comparable between the groups (p > 0.05). However, the incidence of postoperative nausea and vomiting (PONV) was higher in Groups BM (35%) and BMC (25%) than in Groups B (5%) and BC (5%) (p < 0.05).

CONCLUSION: To conclude, we showed that 20 μg/kg of morphine added to caudal bupivacaine 0.166% plus epinephrine 1:600,000 decreased the use of analgesics in the postoperative period, although it was associated with an increased incidence of PONV. However, the addition of clonidine (1.0 μg/kg) to caudal bupivacaine provided no additional clinical benefit over bupivacaine alone.