Effects of Dexmedetomidine as Adjunct to Pudendal Block for Pediatric Penile Surgery

Caudal block is often performed to relieve postoperative pain in pediatric urological surgery. Recently, pudendal block is also used in penile surgery and it has advantage because of less side effects such as transient weakness of low extremities, but limited to use in penile surgery. Local anesthesia is a single shot injection, so additional analgesic drugs is required when the effect of local anesthetics are disappeared. Dexmedetomidine, an alpha adrenergic agonist, is commonly used in pediatric sedation. It has analgesic effect and potentiates the effect of local anesthetics. There are many studies about the potentiation of the effect of local anesthetics when added to dexmedetomidine in adults, it has been limited in pediatrics. Recent study said that local anesthetics with dexmedetomidine had prolonged duration of analgesia in caudal block, also in ilioinguinal block. Thus it is expected to have a prolonged effect when investigators use dexmedetomidine in pediatrics as well as adults.

Inclusion Criteria:

1. The patients aged between 6 months and 6 years in elective penile surgeries (hypospadias, urethral fistula or stricture after hypospadias repair, penile curvature)
2. American Society of Anesthesiologists (ASA) class I, II

Exclusion Criteria:

1. Coagulopathy
2. allergy to local anesthetics
3. meatal island onlay proximal transverse island flap (MIOPTI) (more than 4 h for the surgery)
4. illiteracy, foreigner