Objective: Forces transmitted to the neonate as a consequence of accelerations during transport have been associated with adverse neonatal outcomes including broncho-pulmonary dysplasia. In this study, we sought to determine the relationship between the duration of transport and respiratory performance in the rat model.Methods: Four groups of Sprague-Dawley rat pups (10–12 pups/groups) were exposed to simulated medical transport on postnatal day of life 11 or 12. Each group was exposed to an average impulse of 27.4 m/s2/min for 0, 30, 60 or 90 min. During the exposure periods, impulse was monitored by computerized sampling using a digital accelerometer. Post-exposure, animals were immediately prepared, placed on mechanical ventilation and analyzed for elastance, tissue damping, airway resistance, ratio of damping to elastance (eta), hysteresivity, and inertance at positive end expiratory pressures (PEEPs) of 0, 3 and 6 cm3 of H2O. Total phospholipid content and surfactant proteins A, B, and C mRNA levels in broncho-alveolar lavage fluid and lung tissue were obtained.Results: Increased transport time resulted in a significant step-wise increase in airway resistance at all levels of PEEP (P2O (P2O (P2O (PConclusion: Rat pups experienced significant deterioration of respiratory function with increasing duration of simulated transport.