CPT® Code 82820

The CPT® Code 82820 refers to a specific blood test that measures hemoglobin-oxygen affinity, specifically the partial pressure of oxygen (pO2) required for 50% hemoglobin saturation with oxygen. This test evaluates how effectively hemoglobin, the protein in red blood cells responsible for transporting oxygen, binds to oxygen molecules and subsequently releases them into body tissues. The affinity of hemoglobin for oxygen is crucial for ensuring that adequate oxygen is delivered to the body's peripheral tissues. Variations in hemoglobin function, often due to mutations in globin genes, can lead to altered oxygen affinity, which may result in clinical conditions. For instance, hemoglobin variants with a high affinity for oxygen can hinder the release of oxygen to tissues, potentially causing hypoxia and stimulating increased production of erythropoietin, which can lead to benign hereditary polycythemia. Conversely, variants with low oxygen affinity may be associated with conditions such as anemia and cyanosis. The test involves generating an oxygen dissociation curve (ODC) and determining the P50 value, which is the partial pressure of oxygen at which hemoglobin is 50% saturated with oxygen. To ensure accuracy, the blood sample for testing must be accompanied by a control sample from a non-smoking, biologically unrelated individual. The blood sample is obtained through a venipuncture, which is reported separately. The analysis is conducted using a Clark electrode to measure the oxygen partial pressure and spectrophotometry to assess the degree of hemoglobin saturation with oxygen, ultimately producing a comprehensive oxygen dissociation curve based on multiple measurements from an oxygen sensor.