Haemoglobin Estimation Methods

Haemoglobin Estimation

Importance of Haemoglobin Estimation

• Haemoglobin (Hb) is an essential component of red blood cells, carrying oxygen to tissues and organs.
• Hb estimation is crucial for diagnosing and monitoring anaemia, a common condition characterized by low Hb levels.
• Anaemia can lead to fatigue, weakness, and shortness of breath, and can be a sign of underlying diseases.

Methods of Haemoglobin Estimation

1. Cyanmethemoglobin Method

• Most widely used method for Hb estimation
• Based on the formation of cyanmethemoglobin, a stable complex formed by the reaction of Hb with potassium ferricyanide and potassium cyanide
• Absorbance of the complex is measured at 540 nm using a spectrophotometer

2. Sahli's Method

• Based on the oxidation of Hb to methemoglobin, which is then measured using a spectrophotometer
• Less accurate than the cyanmethemoglobin method, but still widely used in some laboratories

3. Automated Haemoglobin Analyzers

• Use spectrophotometry or other methods to measure Hb levels in whole blood samples
• Fast and accurate, allowing for high-throughput analysis

Interfering Factors

• Presence of bilirubin, lipemia, or methemoglobin can interfere with Hb estimation
• Certain medications, such as sulfonamides, can also affect Hb levels
• Sample collection and storage conditions can impact Hb stability and accuracy

Reference Range

• Normal Hb levels: 13.5-17.5 g/dL for adult males, 12-16 g/dL for adult females
• Variation in reference ranges may occur depending on age, sex, and altitude

Clinical Significance

• Hb levels < 13 g/dL in adult males and < 12 g/dL in adult females indicate anaemia
• Hb levels > 18 g/dL in adult males and > 16 g/dL in adult females indicate polycythaemia (excessive RBC production)