Venous occlusion measurement of pulmonary capillary pressure: effects of embolization.

The effects of pulmonary arterial embolization on calculated pulmonary capillary pressure as determined by the venous occlusion technique are examined using a simple pressure-flow model for the lung. It is predicted that pulmonary, arterial embolization can induce significant underestimation of pulmonary capillary pressure in flowing vessels. This underestimation is related to the percent of vessels embolized and the caliber of pulmonary arteries that are embolized (i.e., the size of the emboli). Experimental verification of these theoretical findings is necessary before the conclusions can be extended to the interpretation of venous occlusion experiments in the lung.