Effect of initial and subsequent mask applications on breathing and heart rate in preterm infants at birth.

Objective: Application of a face mask may provoke the trigeminocardiac reflex, leading to apnoea and bradycardia. This study investigates whether re-application of a face mask in preterm infants at birth alters the risk of apnoea compared with the initial application, and identify factors that influence this risk.

Methods: Resuscitation videos and respiratory function monitor data collected from preterm infants <30 weeks gestation between 2018 and 2020 were reviewed. Breathing and heart rate before and after the initial and subsequent mask applications were analysed.

Results: In total, 111 infants were included with 404 mask applications (102 initial and 302 subsequent mask applications). In 254/404 (63%) applications, infants were breathing prior to mask application, followed by apnoea after 67/254 (26%) mask applications. Apnoea and bradycardia occurred significantly more often after the initial mask application compared with subsequent applications (apnoea initial: 32/67 (48%) and subsequent: 44/187 (24%), p<0.001; bradycardia initial: 61% and subsequent 21%, p<0.001). Apnoea was followed by bradycardia in 73% and 71% of the initial and subsequent mask applications, respectively (p=0.607).In a logistic regression model, a lower breathing rate (OR 0.908 (95% CI 0.847 to 0.974), p=0.007) and heart rate (OR 0.935 (95% CI 0.901 to 0.970), p<0.001) prior to mask application were associated with an increased likelihood of becoming apnoeic following subsequent mask applications.

Conclusion: In preterm infants at birth, apnoea and bradycardia occurs more often after an initial mask application than subsequent applications, with lower heart and breathing rates increasing the risk of apnoea in subsequent applications.