Effects of dexmedetomidine on sevoflurane requirement for 50% excellent tracheal intubation in children: a randomized, double-blind comparison.
OBJECTIVE
We investigated the effects of two dexmedetomidine bolus and infusion combinations on the amount of sevoflurane required to produce 50% excellent tracheal intubation conditions (ED50 TI).


METHODS
In a prospective, double-blinded parallel, randomized manner, 60 children (ASA I or II, age 3-8 years) undergoing elective surgery were allocated to one of three groups: saline only (group D0 ), a bolus dose of 1.0 μg·kg(-1) dexmedetomidine followed by a continuous infusion of 0.5 μg·kg(-1) ·h(-1) (group D1 ), or a bolus dose of 2.0 μg·kg(-1) dexmedetomidine followed by a continuous infusion of 1.0 μg·kg(-1) ·h(-1) (group D2 ). Each bolus dose of dexmedetomidine was infused over 10 min, after which a dexmedetomidine infusion and 5% sevoflurane were immediately begun, with sevoflurane subsequently adjusted to target specific values determined according to Dixon's up-and-down method. After the target concentration of sevoflurane was maintained stable for 15 min, laryngoscopy and tracheal intubation were performed. Intubation was considered excellent only if all subcomponents of the intubation score were rated excellent. Patient enrollment continued until there were six pairs of consecutive patients in which not excellent tracheal intubation conditions were followed by excellent conditions.


RESULTS
The ED50 TI of sevoflurane in group D2 (1.41 ± 0.07%) was significantly lower than in group D1 (2.36 ± 0.16%; P < 0.001), the latter being significantly lower than in group D0 (3.52 ± 0.21%; P < 0.001).


CONCLUSIONS
Dexmedetomidine infusion produced a dose-dependent decrease in the ED50 TI of sevoflurane in children.
Department of Anesthesiology, Children's Hospital of Fudan University, Shanghai, China.
Lin
L
He
Xuan
X
Wang
Shan
S
Zheng
D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D002675:Child, Preschool; D020927:Dexmedetomidine / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage*; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D007442:Intubation, Intratracheal; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage*; D011446:Prospective Studies; D000077149:Sevoflurane
D018685:Anesthetics, Inhalation; D006993:Hypnotics and Sedatives; D008738:Methyl Ethers; D000077149:Sevoflurane; D020927:Dexmedetomidine
ED
50; adrenergic alpha-Agonists; anesthesia; anesthetic; anesthetics volatile; dexmedetomidine; equipment; pediatric; sevoflurane; tracheal; tubes