BACKGROUND: Hypoxaemia occurs frequently in infants during anaesthetic induction.
OBJECTIVE: We evaluated the effect of positive end-expiratory pressure during anaesthesia induction on nonhypoxic apnoea time in infants.
DESIGN: Randomised controlled trial.
SETTING: Tertiary care children’s hospital, single centre, from November 2018 to October 2019.
PATIENTS: We included patients under 1 year of age receiving general anaesthesia.
INTERVENTION: We assigned infants to a 7 cmH2O or 0 cmH2O positive end-expiratory pressure group. Anaesthesia was induced with 0.02 mg·kg-1 atropine, 5 mg·kg-1 thiopental sodium and 3 to 5% sevoflurane, and neuromuscular blockade with 0.6 mg·kg-1 rocuronium. Thereafter, 100% oxygen was provided via face mask with volumecontrolled ventilation of 6 ml·kg-1 tidal volume, and either 7 cmH2O or no positive end-expiratory pressure. After 3 min of ventilation, the infants’ trachea was intubated but disconnected from the breathing circuit, and ventilation resumed when pulse oximetry reached 95%.
MAIN OUTCOME MEASURE: The primary outcome was nonhypoxic apnoea time defined as the time from cessation of ventilation to a pulse oximeter reading of 95%, whereas the secondary outcome was the incidence of significant atelectasis (consolidation score≥2) assessed by lung ultrasound.
RESULTS: Sixty patients were included in the final analysis. Apnoea time in the 7 cmH2O positive end-expiratory pressure group (105.2 s) increased compared with that in the control group (92.1 s) (P=0.011, mean difference 13.0 s, 95% CI, 3.1 to 22.9 s). Significant atelectasis was observed in all patients without positive end-expiratory pressure and 66.7% of those with 7 cmH2O positive end-expiratory pressure (P=0.019, 95% CI, 1.7 to 563.1, odds ratio 31.2).
CONCLUSION: Positive end-expiratory pressure during anaesthesia induction with face mask ventilation increased nonhypoxic apnoea time in infants.