Effect of dexmedetomidine on the characteristics of bupivacaine in a caudal block in pediatrics

Acta Anaesthesiol Scand. 2009 Feb;53(2):251-6. doi: 10.1111/j.1399-6576.2008.01818.x. Epub 2008 Dec 6.


Background: Dexmedetomidine (DEX) is a highly selective alpha(2)-adrenoceptor agonist that has been used increasingly in children. However, the effect of caudal DEX has not been evaluated before in children. This prospective randomized double-blinded study was designed to evaluate the analgesic efficacy of caudal DEX with bupivacaine in providing pain relief over a 24-h period.

Methods: Sixty children (ASA status I) aged 1-6 years undergoing unilateral inguinal hernia repair/orchidopexy were allocated randomly to two groups (n = 30 each). Group B received a caudal injection of bupivacaine 2.5 mg/ml, 1 ml/kg; Group BD received the same dose of bupivacaine mixed with DEX 1 microg/kg during sevoflurane anesthesia. Processed electroencephalogram (bispectral index score), heart rate, blood pressure, pulse oximetry and end-tidal sevoflurane were recorded every 5 min. The characteristics of emergence, objective pain score, sedation score and quality of sleep were recorded post-operatively. Duration of analgesia and requirement for additional analgesics were noted.

Results: The end-tidal sevoflurane concentration and the incidence of agitation were significantly lower in the BD group (P < 0.05). The duration of analgesia was significantly longer (P < 0.001) and the total consumption of rescue analgesic was significantly lower in Group BD compared with Group B (P < 0.01). There was no statistically significant difference in hemodynamics between both groups. However, group BD had better quality of sleep and a prolonged duration of sedation (P < 0.05).

Conclusion: Caudal DEX seems to be a promising adjunct to provide excellent analgesia without side effects over a 24-h period. It has the advantage of keeping the patients calm for a prolonged time. Implications statement: Caudally administered DEX (1 microg/kg), combined with bupivacaine, was associated with an extended duration of post-operative pain relief.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adjuvants, Anesthesia / administration & dosage
  • Adjuvants, Anesthesia / pharmacology*
  • Adrenergic alpha-Agonists / pharmacokinetics
  • Adrenergic alpha-Agonists / therapeutic use*
  • Analgesics, Non-Narcotic / therapeutic use*
  • Anesthesia, Caudal / methods*
  • Anesthetics, Local / administration & dosage
  • Anesthetics, Local / pharmacology*
  • Bupivacaine / administration & dosage
  • Bupivacaine / pharmacology*
  • Child
  • Child, Preschool
  • Dexmedetomidine / administration & dosage
  • Dexmedetomidine / pharmacology*
  • Double-Blind Method
  • Drug Synergism
  • Hernia, Inguinal / surgery*
  • Humans
  • Hypnotics and Sedatives / administration & dosage
  • Hypnotics and Sedatives / pharmacology*
  • Infant
  • Male
  • Pain, Postoperative / drug therapy*
  • Prospective Studies
  • Psychomotor Agitation / prevention & control
  • Receptors, Adrenergic, alpha-2 / drug effects
  • Sleep / drug effects


  • Adjuvants, Anesthesia
  • Adrenergic alpha-Agonists
  • Analgesics, Non-Narcotic
  • Anesthetics, Local
  • Hypnotics and Sedatives
  • Receptors, Adrenergic, alpha-2
  • Dexmedetomidine
  • Bupivacaine