Effect of positive end expiratory pressure on non‐hypoxic apnea time and atelectasis during induction of anesthesia in infant: A randomized controlled trial

Abstract 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 cmH 2 O 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.