Background: Single-breath vital capacity technique is currently administered for inhalation induction of anesthesia with sevoflurane in adults. Because sevoflurane is used in children, the aim of this open nonrandomized trial was to explore the feasibility and acceptance of this technique in midazolam premedicated patients aged from 4 to 15 years old.
Methods: A pediatric population (n = 118) was instructed in the vital capacity technique after their arrival in the induction room in a standardized and playful manner. Induction was performed with a circle-absorber breathing circuit, primed with sevoflurane 7% in 100% O2. Success of the single-breath vital capacity, delay of induction, hemodynamic and airway tolerance, acceptance by the children and side effects were analyzed. A multivariate logistic regression model was used to identify independent risk factors associated with the failure of the vital capacity technique.
Results: Single-breath vital capacity technique was achieved by 57% of the children. The success rate highly correlated with age and ranged from 10% in 4-5 years old to 75% at 11 years and 95% by 14 years. Other factors for success were cooperation and understanding. The need for more than two explanations of the technique was predictive of failure. Delays in the loss of the eyelash reflex and central pupil myosis were obtained in 34 s (18-50) and 242 s (145-278), respectively [median (interquartile ranges)]. Hemodynamic tolerance was good with few airway complications.
Conclusion: Rapid anesthesia induction using a single-breath technique with 7% sevoflurane is effective and well tolerated in children, particularly in those above 9 years of age, and in fact, success rate was markedly lower in the young age groups.