Oxygen Equilibrium Measurements of Human Red Blood Cells

From a medical viewpoint, the aim of blood oxygen affinity measurement is to determine whether the oxygen binding properties of red blood cells (RBCs) are normal or not. If abnormal, there may be several reasons. One is an abnormality of the hemoglobin (Hb) itself. A second, more frequent reason, is a metabolic defect (or status) leading to change in the intraerythrocytic concentration of 2,3-diphosphoglycerate (DPG). Some toxic mechanisms may also lead to compounds with modified oxygen-binding properties such as methemoglobin (MetHb) or carbonmonoxyhemoglobin. Interpretation of the results therefore requires one to measure the DPG content of the RBCs at the time of the test, as well as the MetHb percentage in a fresh lysate. It is also important to have information concerning the smoking habits of the patient.