Alterations in pulmonary function of premature lambs due to positive end-expiratory pressure.

These studies compare lung mechanics and volumes of premature lambs delivered at 139 days of gestation by cesarean section and ventilated by either intermittent positive pressure (IPP) or positive end-expiratory pressure (PEEP). During the first few hours of life, sequential determinations of lung compliance, specific lung compliance; lung resistance, specific lung conductance and functional residual capacity were made at half-hour intervals. Measurements in 5 lambs ventilated with PEEP demonstrated that lung compliance (p less than 0.005), specific lung compliance (p less than 0.001) and specific lung conductance (p less than 0.005) decreased; while lung resistance (p less than 0.10) and functional residual capacity (p less than 0.02) increased as compared to 7 lambs ventilated with IPP.