Microembolism and pulmonary haemodynamics in the early phase of experimental septic shock.

In the early phase of experimental septic shock in dogs the dynamics of the organ distribution of platelets and fibrinogen is characterized by a transient trapping of platelet aggregates in the lungs without concomitant accumulation of fibrinogen or fibrin. Within 5 min disintegrating polymorphonuclear leucocytes can be found in the lung capillaries adjacent to focal endothelial cell damage. The endothelial changes are also found in thrombocytopenic and in defibrinogenated dogs. The initial pulmonary hemodynamic response, characterized by increased pulmonary resistance, is greatly attenuated in thrombocytopenic dogs but no altered in defibrinogenated dogs.