Recent development of sophisticated
intensive care technique for use in newborn infants with the
respiratory distress syndrome (RDS) has resulted in changes in the therapeutic strategies and moved the problem of neonatal survival into the realm of new therapeutic realities. At present, the
mechanical ventilation methods form an integral part of the
intensive care strategy of infants with RDS. They have come to the forefront of infant care because of their successful use in ventilatory support and children survival where other therapeutic modalities have failed. The present prospective observational longitudinal study was designed to assess the real-time convenience, reliability and accuracy of the changes in the oxygenation index (OI), arterial-to-alveolar
oxygen tension ratio (a/A PO2) and alveolar-arterial
oxygen gradient (A-a)DO2 in
ventilator-dependent neonates with RDS, to analyze their feasibility and potential information yield in
oxygen inhalation therapy as well as their prognostic implications and predictive value. Twenty neonates with RDS, heralded by
respiratory failure which necessitated the initiation of
oxygen inhalation therapy and ventilatory support within 24 hours of birth, were enrolled in the study. Ten of the infants survived and the remaining ten died. OI, (a/A PO2) and (A-a)DO2 were followed up sequentially and thoroughly analyzed as the primary outcome measures of the study. The indices were calculated on the basis of the complete monitoring of the ventilatory equipment parameters and
acid-base status carried out on an hourly basis. Our results show that: 1. The combination of three indexes (OI, (a/A)PO2 and (A-a)DO2 we propose is a useful discriminating predictor of neonatal lung maturity reflecting arterial blood gas status in
ventilator-dependent neonates with RDS. 2. The indices detect the efficacy of the modern conventional ventilatory support with real-time convenience and reliable accuracy forming the cornerstone of clinical decision-making in RDS
neonatal intensive care and allowing timely corrections of the ventilatory equipment parameters. 3. The prospective follow-up of these indices improves the predictive value as compared to any single test of neonatal lung maturity and has important prognostic implications in the management of neonates with RDS.