Hemoglobin Measurement in the Laboratory

Hemoglobin (Hb) measurement results can be affected by various issues related to the integrity of the specimen.
Errors that can lead to inaccurate Hb readings include:
- Lipemia: Presence of high levels of fat in the blood, which can interfere with the measurement techniques and lead to falsely elevated readings.
- Icterus: High bilirubin levels in the blood, often seen in liver disease, can also cause inaccurate measurements by affecting optical density readings in spectrophotometric methods.
- Hemolysis: The breakdown of red blood cells (RBCs), releasing hemoglobin into the plasma. This can result in artificially inflated Hb values because the measurement can include free hemoglobin, leading to discrepancies.
- High White Blood Cell (WBC) Counts: Elevated WBC counts can potentially disturb the measurement mechanisms, affecting the accuracy of the Hb readings.
- Presence of Hemoglobin S or C: Specific variations of hemoglobin (Hb S, which is associated with sickle cell disease, and Hb C) in RBCs can alter standard measurement techniques and lead to erroneous results.

Lipemic Samples: Indicate improper fasting in patients, often seen in samples taken shortly after meals.
Icteric Samples: Focus on evaluating liver function; may indicate underlying conditions such as jaundice or hemolytic anemia.
Hemolyzed Samples: Involves how blood samples are handled pre-analytically, which must be minimized to prevent artificially high results.
RBC Variants: Understanding patient history is crucial when interpreting hemoglobin concentrations in relation to known variants such as sickle cell or hemoglobin C disease.

These various sources of error underline the importance of proper specimen handling and processing in the laboratory to ensure accurate hemoglobin measurement, which is critical for diagnosing and monitoring various medical conditions.