Advantages of infant ventilators over adapted adult ventilators in pediatrics.

A lung simulator with variable compliance and resistance components was used to evaluate the dynamic compliance of the Bournes, Babybird, and Pediatric Emerson postoperative ventilators. With increase in airway pressure from combined changes in compliance and resistance, the internal compliance of the Bournes was lowest and the internal compliance of the Emerson was highest. With low constant airway resistance (50 cm/L/sec), the Babybird exhibited tidal volume losses similar to those of the Bournes in the face of decreased lung compliance. With constant lung compliance (10 ml/cm H2O) and increasing airway resistance, the Babybird had marked volume losses at higher volumes. Under all simulated conditions, internal compliance of the Emerson, although large, was relatively constant and the Bournes had the smallest internal compliance.