The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Feb 1978
Prevention of pulmonary insufficiency through prophylactic use of PEEP and rapid respiratory rates.
This study evaluated the effectiveness of prophylactic positive end-expiratory pressure (PEEP) rapid respiratory rates (RRR), and high tidal volume (HTV) in prevention of congestive atelectasis. Measurements of pulmonary hemodynamics, mechanics, gas exchange, functional residual capacity (FRC), pathology, and cinemicroscopy were performed in 45 anesthetized dogs subjected to hemorrhagic hypotension. Randomly, the animals received control ventilation, HTV (20 ml. per kilogram), RRR (32 breaths per minute), or PEEP (5 cm. of water). ⋯ RRR did not affect FRC but minimized the SPV-LA gradient. This effect on the pulmonary venules theoretically could be mediated by stimulating lymphatic flow, thereby decreasing interstitial edema. Thus PEEP and RRR are beneficial when used prophylactically but may work by widely differing mechanisms.