Hyaline Membrane Disease

Abstract
• Sixty-nine neonates with severe hyaline membrane disease (HMD) were mechanically ventilated using either a 1:2 or a 2:1 inspiratory to expiratory (I/E) ratio. Survivors in the 2:1 group required a lower fraction of oxygen in the inspired air (FiO2) and lower end-expiratory pressure to achieve satisfactory oxygenation. During the first week of life, time of exposure to FiO2 > 0.60 while being mechanically ventilated was 29.7 ± 7.5 hours for the 1:2 group and 6.9 ± 2.7 hours for the 2:1 group, while time of exposure to endexpiratory pressure > 3 cm H2O was 49.4 ± 7.9 hours for the 1:2 group and 13.4 ± 7.4 hours for the 2:1 group. Mortality and the incidence of air leak, patent ductus arteriosus, intraventricular hemorrhage, necrotizing enterocolitis, bronchopulmonary dysplasia, and pulmonary hemorrhage were not different for the two groups. Using an increased I/E ratio during the acute phase of HMD improved oxygenation but did not alter morbidity or mortality. (Am J Dis Child 134:373-376, 1980)