Pulmonary mechanics in infants surviving severe neonatal respiratory insufficiency.

Pulmonary mechanics was studied in 24 survivors of severe neonatal ventilatory insufficiency, 15 infants had idiopathic respiratory distress syndrome (IRDS), 6 recurrent severe apnoeic spells, and 3 postasphyxia syndrome. Of the infants with IRDS, 5 were treated with intermittent positive pressure ventilation (IPPV), 3 with continuous positive airway pressure (CPAP) via an endotracheal tube and 7 with CPAP applied via a face chamber. The other infants were all treated with IPPV. IPPV-treated infants generally had lower than expected values of dynamic compliance and pulmonary conductance, particularly after prolonged treatment. All infants treated with CPAP via a face chamber had normal mechanics, but a trend towards obstruction of the airways after varying periods of time was observed in most infants, irrespective of diagnosis or treatment. One infant treated with CPAP via an endotracheal tube and given pure oxygen for a long time had gross abnormalities suggesting bronchopulmonary dysplasia. Measurement of pulmonary conductance appears to be a reliable prognostic tool as concerns pulmonary symptoms later in infancy.