Does the pattern of ventilation determine the degree of lung damage following intensive care of the newborn?

Lung function tests were performed on 14 infants 22 to 67 wk following mechanical ventilation of 6 h to 51 days and on 5 infants of comparable age who had been treated with continuous positive airway pressure (CPAP). Airway resistance increased (P less than 0.01) and specific airway conductance decreased (P less than 0.001) in the ventilated infants compared with the CPAP-treated group who were normal. The airway resistance and specific airway conductance were normal in two ventilated infants and in one CPAP-treated infant who were studied earlier in the neonatal period. There were no significant differences in thoracic gas volume between groups of ventilated and nonventilated babies studied initially or at follow-up. There was no relationship between lung damage and the following: peak inspiratory pressure, the duration of high pressure ventilation, the level of CPAP or its duration, or the duration of greater than 60% oxygen administration. The degree of lung damage was not related to the maximum ventilatory frequency used, but there was a significant correlation with the duration of rapid frequency ventilation. This study supports the view that barotrauma is a major cause of lung disease following neonatal intensive care.