The use of isotopes in blood investigations

Summary

The red cell survival test is simple and may be of help in the elucidation of anaemias. Excessive accumulation of radio-activity in the spleen is an indication for splenectomy. It is possible to measure bleeding from the bowel more accurately with radio-chromium than by any of the chemical tests.

As regards blood volume, our work is still in a preliminary stage. Radio-active chromium should in theory give the correct answer; up to the present radio-active albumen is more popular in surgical quarters as it is technically a simple method. We hope that by preparing small bottles containing about 20 c.c. of tagged, washed Group O cells we shall have a convenient and accurate method. It would involve sending to the surgeons the blood and two syringes, one for injecting the highly radio-active chromated cells and for taking the less active venous samples. The counting of these samples should take about a quarter of an hour.

Radio-active Vitamin B₁₂ must certainly be of use in the diagnosis of pernicious anaemia and of subacute combined degeneration of the cord.