Methods for improving oxygenation in infants mechanically ventilated for severe hyaline membrane disease

Abstract

The effect on arterial blood gas tensions, aortic blood pressure, and intra-oesophageal pressure of altering inspiration: expiration ratio and pressure during expiration was investigated in 9 infants being treated by mechanical ventilation for very severe hyaline membrane disease. The results showed that the use of a long inspiratory phase and a positive expiratory pressure acted synergistically to reduce alveolar-arterial oxygen difference and estimated right-to-left shunt: this reduction was proportional to mean airway pressure. The usefulness of a positive expiratory pressure in raising arterial oxygen tension was limited by its effect in causing alveolar hypoventilation. No adverse effects on the circulation due to the application of high mean airway pressures were detected.