Effect of continuous positive-pressure ventilation (CPPV) on edema formation in dog lung

Effect of continuous positive-pressure ventilation (CPPV) on edema forma-tion in dog lung. J. Appl. Physiol. 39(4): 672-679. 1975.-The effect of CPPV on edema formation in lungs perfused at constant blood flow was studied in whole dogs and in isolated dog lungs. In intact animals, subjected to an increase in left atria1 pressure relative to pleural pressure of 40 Torr, pulmonary shunts correlate inversely (r =-0.82) with the level of end-expiratory pressure (PEE). CPPV had no significant effect on total extravasation of liquid even though PEE higher than 20 Torr was effective in pre-venting liquid from accumulating in the airways. In isolated lobes, perfused at constant blood flow and at a venous pressure of zero, accumulation of liquid occurred when PEE was increased above 8-10 Torr. At comparable levels of pulmonary arterial pressure, an increase in PEE resulted in lesser accumulation of liquid than when pulmonary venous pressure was elevated