Lungs in Crisis: Exploring the Complexity and Management of Pulmonary Hemorrhage in Premature Neonates.

Pulmonary hemorrhage (PH) is a critical and often life-threatening condition that involves the extravasation of blood into the alveolar spaces of the lungs, resulting in impaired gas exchange and acute respiratory compromise. Very low birth weight (<1,500 g) and extremely low birth weight (ELBW; <1,000 g) infants, particularly those with underdeveloped lungs and some degree of pulmonary hypoplasia, are considered at heightened risk for PH. Among ELBW infants, PH carries an estimated mortality rate of up to 50%, underscoring its continued significance as a major contributor to neonatal morbidity and mortality. Other risk factors include a hemodynamically significant patent ductus arteriosus, surfactant administration, mechanical ventilation, and sepsis, which promote pulmonary interstitial edema and compromise alveolar integrity. This article offers neonatal clinicians a timely exploration of the current state of the science of PH, including a review of the physiology of lung and pulmonary vasculature development and treatment modalities.