Chintabanyat O.Sanmuk P.Kiatchai T.Aroonpruksakul N.Mahidol University2025-11-082025-11-082025-09-30Translational Pediatrics Vol.14 No.9 (2025) , 2201-221022244336https://repository.li.mahidol.ac.th/handle/123456789/112967Background: Effective preoxygenation is critical for preventing hypoxemia during airway management, particularly in infants and young children who are physiologically more vulnerable. Although the standard practice of administering 100% oxygen via face mask for at least 3 minutes is adapted from adult protocols, supporting evidence in young children remains limited. This study aimed to evaluate the efficacy of standard 3-minute tidal volume breathing preoxygenation in achieving a fractional expired oxygen concentration (FeO2) of 0.9 in children aged 0–6 years. Methods: This prospective observational study included children aged 0–6 years undergoing elective surgery under general anesthesia. Exclusion criteria included baseline oxygen saturation <95%, preoperative oxygen supplementation, pulmonary disease, and overweight status. Sedation was administered using with intravenous fentanyl and midazolam. The primary outcomes were the proportion of patients achieving FeO<inf>2</inf> ≥0.9 within 3 minutes of preoxygenation. Secondary outcomes included the proportion of participants achieving FeO<inf>2</inf> ≥0.9 at other time points, and the median FeO<inf>2</inf> values at 1, 2, and 3 minutes. Subgroup analyses were conducted based on age group (0–2 vs. 3–6 years) and face mask compliance. Results: A total of 126 patients were included in the analysis. The FeO2 of 0.9 was reached by 31.0%, 80.2%, and 91.3% of participants at 1, 2, and 3 minutes of preoxygenation, respectively. The median time to achieve FeO2 ≥0.9 was 80.0 seconds (95% confidence interval: 74.3–85.7). There was no statistically significant difference in time to reach the target FeO<inf>2</inf> between age groups (P=0.10). However, children with good face mask compliance achieved the target significantly faster than those with fair compliance (median time: 80.0 vs. 100.0 seconds, P=0.009). Conclusions: Standard preoxygenation with 100% oxygen for 3 minutes is effective in achieving an FeO<inf>2</inf> ≥0.9 in 91.3% of children under six years of age. Although age did not significantly influence the time to reach the target FeO<inf>2</inf>, better face mask compliance was associated with more rapid oxygenation.MedicineArticleSCOPUS10.21037/tp-2025-2772-s2.0-10502064963522244344