Positive-pressure ventilation at moderately high frequency in newborn infants with respiratory distress syndrome (IRDS).

In 24 seriously ill newborn infants with respiratory distress syndrome (IRDS) and ensuing respiratory failure, high-frequency positive-pressure ventilation was administered. The mean gestational age of the infants was 32 +/- 3 weeks. In the infant ventilator employed, the compressible volume had been reduced in order to give higher flow rates but lower intratracheal pressures. The ventilation frequency was kept constant at 60-66 per min and the insufflation period at 32-35% of the ventilatory cycle. A positive end-expiratory pressure (PEEP) of 0.2-0.6 kPa was used. Arterial PCO2 was maintained at 4.0-5.3 kPa and PO2 at 8.5-10.5 kPa by adjusting the gas flow through the patient circuit, the peak tubing pressure, the PEEP and the oxygen concentration in inspired gas. High-frequency positive-pressure ventilation improved oxygenation and gave adequate alveolar ventilation in all infants, in most cases at a low peak pressure. Only one infant developed pneumothorax during intermittent positive pressure ventilation, and in no infant did bronchopulmonary dysplasia or retrolental fibroplasia occur. One infant died from intracranial hemorrhage during the ventilation period, giving a survival rate of 96%.