Epidemiology of neonatal pneumothorax developed spontaneously and during respiratory supports in neonatal intensive care units.

Background: Information on incidence and risk factors associated with different types of neonatal pneumothorax were lacking globally.

Objectives: To determine incidences of pneumothorax developed spontaneously and during different modes of respiratory support, and risk factors associated with each type of pneumothorax.

Study design: Retrospective observational study of neonates in the Malaysian National Neonatal Registry.

Setting: 44 Malaysian neonatal intensive care units (NICUs).

Participants: All neonates born in 2015-2020 and admitted to NICUs.

Results: Pneumothorax developed in 3265 neonates: 37.5% occurred spontaneously, 62.5% during respiratory support. The incidence of all types of pneumothorax was 1.75 per 1000 livebirths, and of spontaneous pneumothorax was 0.58 per 1000 livebirths. Pneumothorax developed in 0.6% (450/70512) of neonates during continuous positive air way pressure therapy (nCPAPt), 1.8% (990/54994) of neonates during conventional mechanical ventilation (CMV), and 7.0% (599/8557) of neonates during high frequency ventilation (HFV). Term neonates had significantly higher pneumothorax rate than preterms (p<0.001). Multiple logistic regression analyses show that exposure to intermittent positive pressure ventilation and chest compression at birth were significant independent factors associated with increased risk of spontaneous pneumothorax and CMV, and persistent pulmonary hypertension was associated with increased risk of spontaneous pneumothorax and pneumothorax during CMV and HFV.

Conclusions: The most common type of pneumothorax was spontaneous in-onset. Neonates on HFV had the highest and those on nCPAPt the lowest rate of pneumothorax. Improving training of resuscitation techniques at birth and strategies of use of invasive modes of respiratory support may reduce incidences of all types of pneumothorax.