Abstract:
<h4>Background</h4>Pediatric preoxygenation and inhalation induction of anesthesia can include a mixture of gases. In children, the clinical impact on oxygenation while using other gases with oxygen during an inhalation induction is unknown.<h4>Aim</h4>We aimed to determine the impact of oxygen, nitrous oxide, and air concentrations added to the volatile agent by recording the incidence of hypoxemia following an inhalation gaseous induction in children.<h4>Method</h4>Records from an Automated Information Management System were used to find the incidence of hypoxemia following an inhalation induction of anesthesia. Episodes of hypoxemia (SaO<sub>2</sub> < 90% sustained for at least 120 s) were recorded in the 10 min after the 3-min induction period. Nitrous oxide and oxygen concentrations were recorded and nitrogen concentration was deduced. We also considered patient sex, age, and ASA status as covariates.<h4>Results</h4>A total of 27 258 cases were included in the analysis. The overall incidence of hypoxemia following an inhalation induction of anesthesia was 5.08% (95% CI 4.83 5.35). Hypoxemia was more common in younger patients and those with higher ASA scores. Controlling for those factors and sex, the incidence of hypoxemia increased 1.2-fold when inspired oxygen concentration was less than 60% and hypoxemia was 2.37 times greater than the overall incidence when the inspired oxygen concentration was less than 40%. There was no clear effect of different concentrations of nitrous oxide or nitrogen when those were factored into the model.<h4>Conclusion</h4>The risk of hypoxemia following an inhalation induction of anesthesia in children is minimized when the inspired concentration of oxygen is greater than 60%.
