| Abstract | The applicability of a computerized, on-line, breath-by-breath nitrogen washout technique to respiratory studies in newborn infants is described. Reproducibility and accuracy of the system are entirely comparable to standards previously established in adult studies. Methodology allows simple, rapid, and direct assessment of a newborn infant's functional residual capacity, the uniformity of inspired gas distribution, and longitudinal time changes in these parameters. Studies in 40 normal infants < 2 to 128 hours of age have confirmed some previously published findings, but do not support the concept of very early establishment of optimal ventilatory distribution. Coupled with hemodynamic and blood gas studies, results obtained by this technique can provide a thorough evaluation of an infant's cardiopulmonary status. It is anticipated that such studies will provide valuable help in guiding and assessing results of ventilatory assistance and pharmacologic interventions in the respiratory distress syndrome. |