Abstract
Haemostasis has been studied by several authors during exposure to altitude hypoxia.
On acute induction to hypoxia, platelet count, platelet aggregability and bleeding
time are normal; an increase of thromboxane released from platelets and of prostacyclin,
released from endothelial cells is observed; coagulation factors are unchanged except
of F. VIII which is increased; modified antithrombin III (ATm) are normal; fibrinopeptide
A is increased in subjects with pulmonary edema and fibrinolytic activity after venous
occlusion is normal.
In chronic hypoxia, during a stay at 6542 m (Mt. Sajama), we found in 7 subjects an
important increase in D. Dimer (p < 0.001) that seems to correspond to an activation
of coagulation and a decrease of F. VIII R. Cof/F. VIII R. Ag ratio which suggests
an endothelial cell damage.
Key words
Hypoxia - haemostasis - factor VIII - D. Dimer - fibrinopeptide A
