Stress--a significant factor in venous thrombosis?

The changes in blood coagulation, fibrinolysis and sympatho–adrenal activity have been studied in 30 patients before, during and after elective surgery. The significance of adrenaline in the causation of the changes in coagulation and fibrinolysis has been investigated in three experimental models, using in man the adrenergic stimulus produced by exercise and in sheep the adrenergic stimulus produced by haemorrhage. During exercise in man the coagulation change closely correlated with the adrenaline response but fibrinolysis did not. Furthermore, the coagulation response was modified by beta adrenergic blockade with propranolol, oxprenolol, pindolol and butoxamine but not practolol, suggesting that this response was mediated by the beta−2 adrenergic receptor. Fibrinolysis was not inhibited by these drugs. Substantiation and development of these findings could lead to a new approach to the problem of venous thrombosis by inhibiting the coagulation changes that occur with surgery, without altering the fibrinolytic response.