Pulmonary dysfunction during paraquat-induced lung injury: a model of acute alveolar injury.

Acute lung injury produced by paraquat causes progressive pulmonary insufficiency. To define the pattern of this injury, the sequence of changes in respiratory mechanics and pulmonary gas exchange was studied in eight mongrel dogs which received repetitive doses of paraquat intraperitoneally. Four other dogs served as controls. All dogs were studied while supine during halothane anesthesia. After baseline measurements, saline (control) or paraquat was administered and the studies repeated at 2, 4, 7, and 9 days. Control dogs showed no significant changes. Dogs receiving paraquat had reduced lung volume, decreased lung compliance with a shift of the static deflation pressure-volume curve downward and to the right, and hypoxemia which could not be entirely accounted for by an increased right-to-left intrapulmonary shunt. This study demonstrated that repeated doses of paraquat given intraperitoneally produced a pattern of acute lung injury in the dog which permitted the study of respiratory mechanics and gas exchange during progressive stages of lung injury.