Arterial oxygen studies in premature newborns with and without mild respiratory disorders.

Arterial oxygen studies in full-term infants at various ages have been made by numerous authors (Stahlman, 1957; Weisbrot, James, Prince, Holaday, and Apgar, 1958; Graham, Koeff, Tsao, Sloan, and Wilson, 1959; Reardon, Baumann, and Hadded, 1960; Oliver, Demis, and Bates, 1961; Nelson, Prod'hom, Cherry, Lipsitz, and Smith, 1963). Few similar studies have been performed on premature infants (Graham, Reardon, Wilson, Tsao, and Baumann, 1950; Prod'hom, Levison, Cherry, Drorbaugh, Hubbell, and Smith, 1964). In 1965 Moss, Emmanouilides, Rettori, Higashimo, and Adams published data from premature infants in the first 72 hours of life, showing that 'normal' prematures had lower arterial oxygen tensions than adults, and that this difference was accentuated in prematures with 'mild respiratory distress': the criteria for classifying the babies as 'normal' were not explained in detail and the type and the severity of respiratory distress were not defined clearly. Furthermore, no studies were performed in infants of more than 72 hours. The present paper provides data on arterial blood gases in normal premature infants from 3 hours to 40 days of age. The criteria for normality were based on clinical grounds and on chest x-ray findings. In addition, data from premature infants with tachypnoea and with transient mild respiratory distress, but without x-ray changes suggestive of pneumonia or hyaline membrane disease (Iannaccone, Bucci, and Savignoni, 1965), are also presented. Material and Methods