Propofol for tracheal intubation in children anesthetized with sevoflurane: a dose-response study.
BACKGROUND
Tracheal intubation during sevoflurane induction is frequently facilitated with i.v. propofol. We designed a dose-response study to evaluate the intubating conditions, and the incidence and duration of apnea after i.v. propofol in children.


METHODS
Sixty healthy children were randomly assigned to 0, 0.5, 1, 2 or 3 mg x kg(-1) i.v. propofol during sevoflurane/nitrous oxide anesthesia. Tracheal intubation was performed approximately 30 s after propofol by an anesthesiologist who was blind to the treatment. The anesthesiologist assessed the responses to laryngoscopy and intubation using a standardized scale. Incidence and duration of apnea after propofol as well as heart rate, and systolic blood pressure before and after laryngoscopy were recorded. Data were analyzed using one-way and repeated measures ANOVA, the Jonckheere-Terpstra test, and logistic regression, with P < 0.05 accepted.


RESULTS
The laryngoscopy score after 3 mg x kg(-1) propofol was less than that after 0 mg x kg(-1) (P < 0.01) and 0.5 mg x kg(-1) (P < 0.05). Incidence of apnea after propofol 3 mg x kg(-1), 8/10, was greater than after 0 mg x kg(-1), 3/14 (P < 0.011) and 0.5 mg x kg(-1), 3/12 (P < 0.03). Duration of apnea after 3 mg x kg(-1) was greater than after 0 and 0.5 mg x kg(-1) (P < 0.01). The risk of apnea increased 1.83 fold for each 1 mg x kg(-1) dose increase in propofol (P < 0.01). Mean heart rate and systolic pressure decreased with the main effect, time.


CONCLUSIONS
During sevoflurane/nitrous oxide anesthesia, propofol 3 mg x kg(-1) provides superior intubating conditions with an increased incidence of and prolonged apnea compared with 0 and 0.5 mg x kg(-1).
Lerman
Jerrold
J
Department of Anesthesia, Women and Children's Hospital of Buffalo, SUNY @ Buffalo and University of Rochester, Rochester, NY, USA. jerrold.lerman@gmail.com
Houle
Timothy T
TT
Matthews
Benjamin T
BT
Houck
James
J
Burrows
Frederick A
FA
D000233:Adenoidectomy; D000768:Anesthesia, General; D000771:Anesthesia, Intravenous; D018685:Anesthetics, Inhalation; D001049:Apnea / Q000628:therapy; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods*; D007828:Laryngoscopy; D008297:Male; D008738:Methyl Ethers; D009609:Nitrous Oxide; D015742:Propofol; D018401:Sample Size; D000077149:Sevoflurane; D014068:Tonsillectomy
D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane; D009609:Nitrous Oxide; D015742:Propofol