EFFECTS OF INTERMITTENT POSITIVE PRESSURE VENTILATION ON LUNG FUNCTION IN HYALINE MEMBRANE DISEASE

Summary: Fifty-eight infants with hyaline membrane disease were admitted to an intensive care unit. Twenty of these developed respiratory failure despite bicarbonate and oxygen therapy. They were then treated by intermittent positive pressure ventilation and 13 of the 20 survived. The mechanism of IPPV was determined in 12 of these by the measurement of lung function and blood-gas tensions. Results indicated that a normal alveolar ventilation could be produced in these infants by a 50 per cent increase in their original minute volume. An adequate tidal volume (20 ml) could only be obtained by a high peak transpulmonary pressure (35 cm H2O) and this volume had to be delivered at a mean rate of 56 cycles per minute. A reduction in either transpulmonary pressure or the rate of cycling resulted in an inadequate alveolar ventilation and a precipitious fall in Pao2. Assisted breathing appeared to be more effective than passive ventilation over a short period of time. Measurements were made within 4 minutes of paralyzing the respiratory muscles, and must therefore be accepted with reserve. © 1969 John Sherratt and Son Ltd.