Caudal vs Local Anesthesia in Hypospadias

Overview

Hypospadias is one of the most common congenital malformations of the genitalia in boys, and is typically managed by surgical intervention. During pediatric urological surgery, caudal anesthesia is one of the most common regional anesthetic techniques used. Also known as caudal block, it has been shown to be a safe and effective anesthetic technique in children with a low incidence of anesthesia-related complications.While the reported incidence of complications directly associated with caudal block is low, there is scarce and inconclusive evidence on the impact of caudal anesthesia on the incidence of surgical complications. As a result, the objective of this superiority, randomized controlled trial is to assess whether the use of caudal anesthesia, when compared to dorsal penile block, is associated with a higher rate of urethrocutaneous fistulas and glans dehiscence post hypospadias repair.

The rationale to conduct a definitive study comes as a result of the limitations inherent in the pre-existing literature due to selection bias, and the primarily retrospective nature of the current evidence, which is unclear whether caudal blocks result in higher complication rates following hypospadias repair. The only way to close this knowledge gap and disturb the current state of clinical equipoise surrounding this topic is to randomly assign the two interventions (caudal or penile block) to patients undergoing hypospadias repair. The rationale to conduct this pilot study is to determine whether the definitive study is feasible and to ensure that any methodological issues are identified and addressed prior to investing significant resources in a definitive trial. This study will be a pilot study to determine the feasibility of conducting a large definitive superiority, parallel, randomized controlled trial (RCT) to assess whether dorsal penile block results in fewer postoperative complications than caudal block in boys (6-48 mos.) undergoing hypospadias repair. Hypospadias repair will be carried out under standardized analgesic administration.. Participants may be given fentanyl (1-3 mcg/kg) at the discretion of the anesthesiologist. Anesthesia will be delivered to all participants via inhalation induction with air/nitrous oxide and sevoflurane. In addition either caudal anesthetic block (0.25% bupivacaine 1 ml/kg to a maximum of 10 ml) or dorsal penile block (bupivacaine without epinephrine 10-20 ml/kg) will be administered based on our randomization scheme. Each patient will also receive antiemetic prophylaxis with dexamethasone 150 mcg/kg ondansetron 50 mcg/kg Acetaminophen suppository 40 mg/kg, and intravenous morphine (0.02-0.1 mg/kg). At Home At home, Oral Morphine (0.2 mg/kg) q4h prn, Ditropan (0.2 mg/kg) q12h prn, Tylenol (15 mg/kg/dose) q4h or Ibuprofen (10 mg/kg/dose) q6h will be prescribed at discharge to be administered at the parents' discretion. Trimethoprim (2 mg/kg) will also be prescribed for administration until catheter removal.