Pneumothorax in Newborns

Pneumothorax in newborns is the accumulation of air in the pleural space when an overdistended alveolus ruptures and air escapes around the lung. It is the most clinically important of the neonatal air-leak syndromes and can range from an incidental, asymptomatic finding to a tension pneumothorax that compresses the lung and great vessels and causes sudden deterioration.

Definition

Neonatal pneumothorax is the presence of air in the pleural space of a newborn, arising from rupture of overdistended alveoli with dissection of air into the pleura, and ranging from asymptomatic to a life-threatening tension pneumothorax.

Scope

The entry covers how air escapes from the alveolus into the pleural space in the newborn, the conditions and interventions that raise the risk, and the spectrum from asymptomatic air leak to tension pneumothorax. It is a reference description of the disorder and does not provide instructions for emergency drainage or other treatment.

Core questions

• How does air escape from the alveolus into the pleural space in the newborn?
• Which underlying lung conditions and interventions increase the risk of pneumothorax?
• What distinguishes a simple pneumothorax from a tension pneumothorax?
• How does pneumothorax fit within the broader family of neonatal air-leak syndromes?

Key concepts

• Pleural space and air leak
• Alveolar overdistension and rupture
• Tension pneumothorax
• Positive-pressure ventilation as a risk factor
• Underlying lung disease (RDS, meconium aspiration)
• Air-leak syndromes (pneumomediastinum, pulmonary interstitial emphysema)

Mechanisms

When alveolar pressure rises sharply or unevenly, overdistended alveoli can rupture and air dissects along tissue planes; if it reaches the pleural space, a pneumothorax forms. Uneven inflation occurs in lungs with non-uniform compliance, such as those affected by respiratory distress syndrome or meconium aspiration, and positive-pressure ventilation raises the risk. If air continues to enter the pleural space under pressure without escape, it accumulates as a tension pneumothorax that compresses the lung, shifts the mediastinum, and impairs venous return and cardiac output, producing rapid clinical deterioration. Pneumothorax is one of several related air-leak syndromes that share this mechanism of alveolar rupture.

Clinical relevance

Pneumothorax is an important and potentially sudden complication in newborns with lung disease or on respiratory support, and recognizing it as part of the air-leak spectrum is central to neonatal respiratory care. This entry is reference material describing the disorder and is not guidance for managing or draining a pneumothorax in any individual infant.

Epidemiology

Asymptomatic pneumothorax can occur even after uncomplicated births, while symptomatic pneumothorax is more frequent in infants with underlying lung disease such as respiratory distress syndrome or meconium aspiration and in those receiving positive-pressure ventilation. Lung-protective ventilation strategies aim to reduce air leak (Sweet et al., 2023).

Evidence & guidelines

Neonatal respiratory guidelines emphasize ventilation strategies that limit overdistension and thereby the risk of air leak, including pneumothorax (Sweet et al., 2023). Such guidance is summarized for orientation only and does not constitute clinical direction for any individual infant.

History

Air-leak syndromes, including pneumothorax, were recognized early in the era of mechanical ventilation of newborns, when aggressive positive-pressure ventilation of stiff lungs frequently caused alveolar rupture; the same era's ventilator-related lung injury was described by Northway and colleagues (1967). The later move toward gentler, lung-protective ventilation reflects efforts to reduce these complications.

Key figures

• William Northway
• David Sweet

Seminal works

• northway-1967
• sweet-2023

Frequently asked questions

What causes a pneumothorax in a newborn?

It is caused by rupture of overdistended alveoli, which lets air escape into the pleural space around the lung. Risk is higher with underlying lung disease such as respiratory distress syndrome or meconium aspiration and with positive-pressure ventilation.

What is a tension pneumothorax?

A tension pneumothorax is a severe form in which air continues to accumulate in the pleural space under pressure, compressing the lung and shifting the mediastinum so that venous return and cardiac output fall, leading to sudden, life-threatening deterioration.