Abstract
Pulmonary function tests (PFTs) in the Neonatal Intensive Care Unit (NICU) have played a pivotal role in neonatal care. They have helped quantify the effects of therapeutic interventions, guide ventilator management, and serve as endpoints in clinical trials. Preterm delivery, the most common cause of altered lung development, establishes early lung function trajectories that persist into later life. Early PFTs in preterm infants can enhance our understanding of factors influencing these trajectories. This review summarizes techniques performed in the NICU and early infancy and the evolution of continuous lung function monitoring through the bedside ventilator. It provides examples incorporating PFTs in the NICU and early infancy to improve outcomes and identifies evolving technology in this area. This review does not include studies of control of breathing in newborn infants. Looking ahead, the field would greatly benefit from developing a sustainable, non-invasive PFT technique that can be applied across the lifespan.