Mortality and morbidity associated with pressure- and volume-limited infant ventilators

S. J. Boros and A. A. Orgill

The effect of pressure-limited (PL) and volume-limited (VL) ventilation on mortality and morbidity in infants with severe hyaline membrane disease (HMD) was examined in a prospective controlled study. Criteria for mechanical ventilation were PaO2 value of 50 mm Hg or less or a Paco2 value of 70 mm Hg or greater, while the infant was receiving nasal continuous positive airway pressure (CPAP) at oxygen concentrations (FIO2) of 0.8 or greater and CPAP of 8 cm H2O or greater; HMD associated with severe perinatal asphyxia requiring mechanical ventilation in the delivery room. Consecutive patients were alternately assigned to receive either PL or VL ventilation. Twenty infants were ventilated with PL machines using low peak inspiratory pressures (mean maximum inspiratory pressure of 28 cm H2O) and prolonged inspiratory times. Twenty other infants were ventilated with VL machines, using essentially unlimited peak inspiratory pressures (mean maximum inspiratory pressure of 62 mm H2O) and prolonged expiratory times. There were no significant differences in survival, incidence of pneumothorax or pulmonary interstitial emphysema, or noteworthy bronchopulmonary dysplasia.