1 Laboratory for Neonatal Research, Boston Hospital for Women (Lying-in Division), and the Department of Pediatrics, Harvard Medical School, Boston
The arterial-alveolar pressure difference for nitrogen (aADN2) was directly measured during the first 4 hours after birth in nine clinically normal infants. Transient gross elevations of the aADN2 were seen in most babies, indicating early maldistribution of ventilation.
However, by 4 hours of age, the aADN2 had subsided to 6 ± 22 mm Hg, a value characteristic of normal older infants and children. These findings are in conflict with previous indirect assessments of aADN2 by analyses of urinary nitrogen pressure. It is concluded that normal infants achieve excellent uniformity of pulmonary distribution of gas and blood soon after birth.
Submitted on June 12, 1968