Effect of Haemorrhage upon Red Cell Size and Red Cell Distribution

In 1940 Brennan reported that " as a result of haemorrhage individual red corpuscles increase very appreciably in size, often by 30 to 50%." From his observations, which Con- sisted in making red cell counts and in haematocrit deter- minations, he concluded that "following haemorrhage many patients' red cells become side-tracked-probably in the muscle capillaries; often more than 20%." Brennan also claimed that transfusion of 500 to 1,000 c.cm. of