ABSTRACT
The extensive popularity of the isolated perfused lung preparation stems from the ease with which the preparation can be established, as also to the variety of data that can be obtained. Among the experimental preparations used to investigate the pathophysiology of pulmonary edema, one of the most popular is the isolated, perfused lung. The unique advantages of this preparation are that blood flow, vascular pressures, and the extent of fluid accumulation can all be accurately determined. In general, the isolated dog lung responds sluggishly to vasoconstrictors. For instance, hypoxic vasoconstriction cannot be elicited in the isolated dog lung. The circuit resembles that for constant flow perfusion, except that the blood is pumped into an arterial reservoir proximal to the bubble trap. The isolated perfused lung is particularly useful for the determination of the lung microvascular filtration rate. For micropuncture, the isolated lobe is held at a constant inflation pressure. Therefore, an exact quantitation of lung microvascular liquid exchange is possible.
