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Background: High‐flow nasal oxygenation is reported to prolong duration of apnea while maintaining adequate oxygen saturation with the mouth closed. Also, buccal oxygenation is known to have similar effects in obese adults. We compared the effect of these two methods on prolongation of acceptable apnea time in pediatric patients with their mouth open. Methods: Thirty‐eight patients, aged 0–10 years were randomly allocated to either the high‐flow nasal oxygenation group (n = 17) or the buccal oxygenation group (n = 21). After induction of anesthesia including neuromuscular blockade, manual ventilation was initiated until the expiratory oxygen concentration reached 90%. Subsequently, ventilation was paused, and the patient's head was extended, and mouth was opened. The HFNO group received 2 L·min−1·kg−1 of oxygen, and the BO group received 0.5 L·min−1·kg−1 of oxygen. We set a target apnea time according to previous literature. When the apnea time reached the target, we defined the case as "success" in prolongation of safe apnea time and resumed ventilation. When the pulse oximetry decreased to 92% before the target apnea time, it was recorded as "failure" and rescue ventilation was given. Results: The success rate of safe apnea prolongation was 100% in the high‐flow nasal oxygenation group compared to 76% in the buccal oxygenation group (p =.04). Oxygen reserve index, end‐tidal or transcutaneous carbon dioxide partial pressure, and pulse oximetry did not differ between groups. Conclusion: High‐flow nasal oxygenation is effective in maintaining appropriate arterial oxygen saturation during apnea even in children with their mouth open and is superior to buccal oxygenation. Buccal oxygenation may be a good alternative when high‐flow nasal oxygenation is not available. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to assess the impact of positive‐end‐expiratory pressure (PEEP) on the non‐hypoxic apnea time in infants during anesthesia induction with an inspired oxygen fraction of 0.8. Methods: This age stratified randomized controlled trial included patients under 1 year of age. Preoxygenation was performed using an inspired oxygen fraction of 0.8 for 2 min. Inspired oxygen fraction of 0.8 was administered via a face mask with volume‐controlled ventilation at a tidal volume of 6 mL.kg−1, with or without 7 cmH2O of PEEP. Tracheal intubation was performed after 3 min of ventilation; however, it was disconnected from the breathing circuit. Ventilation was resumed once the pulse oximetry readings reached 95%. The primary outcome was the non‐hypoxic apnea time, defined as the time from the cessation of ventilation to achieving a pulse oximeter reading of 95%. The secondary outcome measures included the degree of atelectasis assessed by ultrasonography and the presence of gastric air insufflation. Results: Eighty‐four patients were included in the final analysis. In the positive end‐expiratory pressure group, the atelectasis score decreased (17.0 vs. 31.5, p <.001; mean difference and 95% CI of 11.6, 7.5–15.6), while the non‐hypoxic apnea time increased (80.1 s vs. 70.6 s, p =.005; mean difference and 95% CI of −9.4, −16.0 to −2.9), compared to the zero end‐expiratory pressure group, among infants who are 6 months old or younger, not in those aged older than 6 months. Discussion: The application of positive end‐expiratory pressure reduced the incidence of atelectasis and extended the non‐hypoxic apnea time in infants who are 6 months old or younger. However, it did not affect the incidence of atelectasis nor the non‐hypoxic apnea time in patients aged older than 6 months. [ABSTRACT FROM AUTHOR]

Aims: This study determined the optimal positive end‐expiratory pressure levels in infants in supine and prone positions under general anesthesia using electrical impedance tomography (EIT). Methods: This prospective observational single‐centre study included infants scheduled for surgery in the prone position. An electrical impedance tomography sensor was applied after inducing general anesthesia. The optimal positive end‐expiratory pressure in the supine position was determined in a decremental trial based on EIT and compliance. Subsequently, the patient's position was changed to prone. Electrical impedance tomography parameters, including global inhomogeneity index, regional ventilation delay, opening pressure, the centre of ventilation, and pendelluft volume, were continuously obtained up to 1 h after prone positioning. The optimal positive end‐expiratory pressure in the prone position was similarly determined. Results: Data from 30 infants were analyzed. The mean value of electrical impedance tomography‐based optimal positive end‐expiratory pressure in the prone position was significantly higher than that in the supine position [10.9 (1.6) cmH2O and 6.1 (0.9) cmH2O, respectively (p <.001)]. Significant differences were observed between electrical impedance tomography‐ and compliance‐based optimal positive end‐expiratory pressure. Peak and mean airway, plateau, and driving pressures increased 1 h after prone positioning compared with those in the supine position. In addition, the centre of ventilation for balance in ventilation between the ventral and dorsal regions improved. Conclusion: The prone position required higher positive end‐expiratory pressure than the supine position in mechanically ventilated infants under general anesthesia. EIT is a promising tool to find the optimal positive end‐expiratory pressure, which needs to be individualized. [ABSTRACT FROM AUTHOR]