Hemorrhagic shock in dogs without major pulmonary changes.

Abstract

Dogs were submitted to one of three hemorrhagic shock procedures: normovolemic shock, oligemic hypotension or posthemorrhagic hypotension. 13 animals fulfilled well-filled criteria of irreversible hemorrhagic shock, based on mortality, take-up volume and metabolic changes. Lung function was measured at regular intervals. Lungs were fixed by infusion fixation. The macroscopial aspect of the lungs was not different from that of six control dogs which were anesthetized for the same period. Minor microscopical changes were found, but the only histological parameter which was significantly different from the controls was accumulation of granulocytes. Gas exchange remained normal, ventilation was increased with an enlarged dead space and veno-arterial shunting was reduced. Pulmonary vascular resistance was not different from the control group.