EFFECTS OF ENDOTOXIN ON PULMONARY CAPILLARY PERMEABILITY, ULTRASTRUCTURE AND SURFACTANT
OKLAHOMA UNIV MEDICAL CENTER OKLAHOMA CITY
Pagination or Media Count:
A method is described for measuring pulmonary capillary permeability by isogravimetric perfusion of excised dog lungs. The isogravimetric capillary pressures were determined in 1 normal canine lungs perfused with blood to which endotoxin has been added 2 excised lungs of endotoxin-shocked dogs 3 perfused lungs of normal control dogs. No increase in pulmonary capillary permeability was noted but a statistically significant decrease in permeability was found in lungs of survivors of endotoxin shock Pulmonary surfactant was observed to decrease only when endotoxin was added to the perfusate of normal lungs. Surfactant was preserved in survivors of endotoxin shock. Light and electron microscopy revealed granular inclusions with polymorphonuclear neutrophils in the lungs of dogs after endotoxin shock or lungs perfused ex vivo with endotoxin and was compatible with phagocytized glycogen. The endothelial cell thinning observed in endotoxin survivors may have been responsible for the decrease in pulmonary capillary permeability. Both pre- and postcapillary vascular resistances were increased at low blood flows but returned to control levels at normal blood flows. The relative increase in postcapillary pulmonary vascular resistance at low blood flows may play a role in the clinical wet lung type of respiratory insufficiency seen frequently in bacteremic shock, although no increase in capillary permeability was observed.