CPT® Code 78130

A red cell survival study, identified by CPT® Code 78130, is a specialized laboratory test designed to assess the lifespan of red blood cells (RBCs) within the circulatory system. This test is particularly valuable in the evaluation of patients presenting with anemia, especially when there is a suspicion of hemolytic causes. Under normal physiological conditions, red blood cells typically have a lifespan of approximately 110 to 120 days, after which they undergo senescence, or natural aging, leading to their eventual removal from circulation. A lifespan of less than 100 days, as determined by this study, may indicate the presence of hemolysis, a condition where red blood cells are destroyed prematurely. The procedure begins with the collection of a blood sample from the patient, during which a baseline microhematocrit measurement is obtained to assess the proportion of blood volume that is occupied by red blood cells. Following this, the RBCs are tagged with a radioactive isotope tracer, specifically Chromium-51 (Cr-51) Sodium Chromate. This tagged blood is then incubated and subsequently reintroduced into the patient's bloodstream via intravenous injection. To monitor the lifespan of the tagged RBCs, the patient is required to return for a series of venipunctures, typically ranging from 10 to 21 days, with the first blood sample being drawn 24 hours post-injection. Each sample is analyzed for microhematocrit levels, and the results are plotted over time using a quantitative-semilogarithmic graphing technique. This method allows for a precise determination of the RBC lifespan, providing critical information for diagnosing and managing conditions related to anemia and hemolysis.