[Haemodynamics and shock prevention in acute haemorrhage from the upper intestinal tract (author's transl)].

Acute haemorrhages in the upper intestinal tract derive mainly from smaller low-pressure vessels. Bleeding is generally protracted and is often clinically occult. The clinical signs are a more reliable indicator of the severity of the haemorrhage than are measurements of the central venous pressure, shock index and cardiac output. The considerable tolerance of man to blood loss is probably attributable to the erect standing position. It has the advantage that it provides a large measure of counter-regulatory possibilities; but has the disadvantage that there is only a very narrow margin of safety as regards the development of irreversible shock. Close and consistent co-ordination of diagnosis and therapy is essential in all cases of gastro-intestinal haemorrhage.