Nalbuphine Plus Caudal Bupivacaine in Hypospadius Repair
Condition: Post Operative Pain
MeSH terms: Pain, Postoperative
Study type: Interventional

Summary: 
      Caudal aneasthesia for pediatric surgery was first reported in 1933. Since then, studies have
      described the indications for pediatric caudal block, the level of analgesia, doses,
      advantages and disadvantages of this technique.

      In children, caudal anesthesia is most effectively used as adjunct to general aneasthesia and
      has an opioid-sparing effect, permitting faster and smoother emergence from aneasthesia.

      A single shot caudal anesthesia provides relatively brief analgesia for 4 to 8 hours
      depending on the agent used. Prolongation of anesthesia can be achieved by adding various
      adjuvants, such as opioids and nonopioids such as clonidine, ketamine, midazolam, and
      neostigmine,with varying degrees of success.
    

Detailed description: 
      The somatic innervation of the lower urogenital system arises principally from the spinal
      nerves sacral 2 to sacral 4 by way of the pudendal nerve. After passing under the
      sacrospinous ligament and over the sacrotuberous ligament through Alcock's canal, the
      pudendal nerve passes through the transverse perineal muscle to course on the dorsum of the
      penis as the dorsal nerve of the penis. The dorsal nerve of the penis is thought to be a
      sensory nerve. The autonomic innervation of the penis arises from the vesical and prostatic
      plexus, which is composed of sympathetic nerves from lumbar 1 and lumbar 2, and
      parasympathetic nerves from sacral 2 to sacral 4. The cavernosal nerve leaves the pelvis
      between the transverse perineal muscles and the membranous urethra before passing beneath the
      arch of pubis to supply each corporal body.

      After the pudendal nerve leaves the pudendal canal, two main terminal branches arise, the
      inferior rectal and the perineal nerves. The function of the inferior rectal nerve is motor
      innervation of external anal sphincter and is thought to be devoid of urogenital function.
      Sensory portions of the inferior rectal nerve are important for perianal skin sensation. The
      perineal nerve has both a motor and sensory component. The motor efferents are known to
      innervate the pelvic musculature, mainly the bulbospongiosus muscle. To achieve complete
      anesthesia (analgesia) for hypospadius repair, afferent blockade must be complete at lumbar 1
      through sacral 4.

      Nalbuphine is a mixed k-agonist and µ-antagonist opioid of the phenanthrene group; it is
      related chemically to naloxone and oxymorphone. Nalbuphine leads to activation of spinal and
      supraspinal opioid receptors which leads to good analgesia with minimal sedation, minimal
      nausea and vomiting, less respiratory depression and stable cardiovascular functions. Safety
      and efficacy of nalbuphine have been established in the clinical field and its safety and
      efficacy also established via the epidural route. Nalbuphine was also added in epidural
      analgesia for adults and provided an increase in the efficacy and the duration of
      postoperative analgesia. The effect of nalbuphine addition in caudal anesthesia in pediatrics
      is not well established.
    

Intervention name(s): Nalbuphine
Intervention type(s): Drug
Intervention description(s): Children will be randomly assigned into 2 groups of 30 patients each. They will receive caudal anesthesia using bupivacaine 0.25% 1ml/kg plus 2 ml normal saline in the control group, bupivacaine 0.25% 1ml/kg plus nalbuphine 0.1 mg/kg in 2 ml solution in the nalbuphine group.
Intervention MeSH terms: Nalbuphine
Allocation: Randomized
Intervention model: Single Group Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment