LAUSR

Exhaled Nitric oxide (eNO) is an inflammatory marker. In 2002 Hall et al. [J Appl Physiol. 92:59‐66] established an infant eNO measurement method, fulfilling four criteria of feasibility: simple, non‐invasive, without impact on the natural breathing pattern, and accounting for flow by NO output (V'NO). Although tidal breathing is accepted as an eNO measurement method in uncooperative patients, it is seldom used outside research labs. The variability and lack of validated methods have restrained from exploring the area in preterm and term neonates the last years. This study aimed to validate clinically feasible longitudinal online tidal eNO and V'NO in a real‐life birth cohort of un‐sedated, hospitalized preterm, and term neonates.