The optimum time for intravenous cannulation after induction with sevoflurane in children premedicated with dexmedetomidine.

BACKGROUND: Inhalation anesthesia is a frequently used method for anesthesia induction, especially in young children. No information is available on the optimum time for safe intravenous cannulation after inhalational induction in children with dexmedetomidine premedication. The purpose of the present study was to determine the optimal time for intravenous cannulation after induction of anesthesia with sevoflurane and nitrous oxide in children premedicated with intranasal dexmedetomidine.

METHODS: This prospective and observational study was conducted by using the up-down sequential method. Children, who were aged 2-6 years with ASA physical status I, and who underwent inhalation induction for elective surgery were included in the study. Anesthesia was induced with sevoflurane and nitrous oxide after the premedication with intranasal dexmedetomidine (2 mcg/kg). Intravenous cannulation was attempted on the dorsum of the hand by an experienced anesthesiologist 4 min after the loss of the eyelash reflex in the first patient. The procedure was considered successful in patients without any movement, cough, or laryngospasm. The waiting time for cannulation was increased by 15 s if the procedure was not successful in the previous patient, and on the contrary, it was reduced by 15 s if the procedure was successful in the previous patient. The probit test was used in the analysis of up-down sequences.

RESULTS: In the present study in which a total of 40 patients were included, the effective cannulation time was found to be 14.40 s (95% confidence limits, 1.30-27.82 s) in 50% of the patients, and the effective cannulation time was found as 84.64 s (95% confidence limits, 69.61-218.26 s) in 95% of the patients.

CONCLUSIONS: In conclusion, we suggest that the appropriate time for cannulation is 85 s (1.45 min) after the loss of eyelash reflex in children sedated with dexmedetomidine and induction with sevoflurane and nitrous oxide-oxygen mixture.