"Shock lung" resulting from perfusion of canine lungs with stored bank blood

An in situ lung perfusion model was used to study the impact of stored bank blood, with or without dacron wool filtration, on morphologic and functional derangement in canine lungs. Autologous blood was stored 24 hours or 21 days in ACD solution and then passed through standard recipient set filters before perfusion through the left lower lung lobes of dogs equipped to have pressure and gas tensions monitored from pulmonary artery, vein and bronchus. In an additional group of dogs, 21-day stored blood was additionally filtered through dacron-wool prior to lung perfusion. Pulmonary vascular resistance increased markedly for lungs perfused with stored blood, whether or not dacron-wool filtered, as compared with lungs perfused with fresh blood. Effective compliance decreased in both groups of lungs perfused with stored blood, and arteriovenous oxygen gradients decreased significantly in these groups as compared with fresh blood-perfused lungs. As an index of congestion, wet/dry lung weight ratios increased for both groups perfused with stored blood which also showed gross and microscopic evidence of pulmonary edema. As a measure of microaggregated blood debris, screen filtration pressure determinations were not significantly different in fresh or stored canine blood in ACD. We conclude from observations of these canine lung perfusions that pulmonary anatomic and functional injury can result from the use of stored bank blood which may be modified, but not eliminated, by depth filtration. We infer that microaggregated blood debris is not the primary noxious factor in stored canine blood, and a toxic serum-borne factor may be implicated.