Abstract

Title of the article:
Study of dose related effects of dexmedetomidine on laryngeal mask airway removal in children undergoing herniotomy-adouble blind randomized study.

Abstract:
Background and objective: Respiratory complications during removal of airway device and postoperative agitation are commonly experienced problems in pediatric anaesthesia. Dexmedetomidine being a potent α2 adrenergic receptor agonist has the capability to circumvent this problem. This study was designed to evaluate efficacy of two doses of dexmedetomidine on laryngeal mask airway removal.
Material and method: Ninety children of 1 to 8 years were recruited for this randomized double blind study. The patients were randomly allocated into three groups and received either normal saline (Group S), dexmedetomidine 0.5µg/kg (Group D0.5) or dexmedetomidine 1 µg/kg (Group D1) with 30 patients in each group. Anaesthesia was induced with Sevoflurane in oxygen. All patients received intravenous fentanyl 1μg/kg followed by caudal block. LMA of appropriate size was inserted when jaw relaxation was adequate and then 5ml of the study drug was administered over 10 minute. LMA removal was assessed according to preset criteria. Assessment of emergence agitation was done using Aonos four point scale.
Result: Incidence of smooth LMA removal was significantly more in D1 compared to S (p=0.0001*) and in D1 compared to D0.5 (p=0.0020*) but difference was not significant between D0.5 and S (p=0.1142).Patients who did not have emergence agitation was significantly more in D0.5 (p=0.05*) and D1 (p=0.0001*) compared to S and also in D1 compared to D0.5 (p=0.0102*).
Conclusion:A single dose of dexmedetomidine 1µg/kg provides better conditions for smooth removal of laryngeal mask airway in children. Dexmedetomidine 0.5µg/kg is inadequate for smooth LMA removal, hence higher dose should be used. However higher dose of dexmedetomidine is associated with delayed recovery from anaesthesia. Both dexmedetomidine 0.5µg/kg and 1µg/kg are useful in preventing emergence agitation. Increasing the dose of dexmedetomidine has positive effect in decreasing incidence of emergence agitation.

Key words: Dexmedetomidine, emergence agitation, laryngeal mask airway