COMPARISON OF EXTRAVASCULAR LUNG WATER VOLUME WITH RADIOGRAPHIC FINDINGS IN DOGS WITH EXPERIMENTALLY INCREASED PERMEABILITY PULMONARY-EDEMA

The relationship between extravascular lung water volume (ELWV) and ch est radiographical findings was studied in general-anesthetized beagle s. The dogs were experimentally injected with oleic acid to increase p ulmonary vascular permeability. When the ELWV value in the dogs increa sed more than approximately 37% from the control value, their chest ra diographs began to show signs of pulmonary edema. At this time, the ch est X-ray density increased to 10% above the control level. PaO2 decre ased, and PaCO2 increased after the administration of oleic acid. This clearly showed that the pulmonary gas exchange function was reduced f ollowing increasing ELWV. This comparison showed that probably the the rmal-sodium double indicator dilution measurement of ELWV can detect s light hyperpermeability pulmonary edema that does not show on chest ra diographs. The chest radiograph was therefore not suitable for the det ection of slight pulmonary edema, because it did not show any changes in the early stages in hyperpermeability pulmonary edema.