Disturbances of hemostasis during declamping shock.

The aorta, above or below renal arteries was clamped for 60 minutes, in a canine model. The blood was taken for testing from above the aorta bifurcation before clamping, after 30 minutes of its duration, directly after declamping and every 30 minute during next 4 hours. Irrespective of clamping level, the platelet count, clot retraction and prothrombin consumption do not undergo significant changes. However, the activity of platelet factor 4 is increased. Prothrombin time, recalcination time, kaolin-kephalin time and the activities of factors V, VII, XI and XII do not differ as well. Thrombin time is prolonged and antithrombin III activity is reduced. Euglobulin fibrinolysis time undergoes prolongation and antiplasmin content is increased. The observed changes show a variable tendency, regardless of clamping level and increase with the passage of experiment time. An increase in the coagulation activity and a decrease in the fibrinolytic activity of the blood plasma may be a resultant of the changes. Finally it may promote thrombus formation and indicates the preventive use of heparin.