Canis ISSN: 2398-2942

Hematology: hemoglobin concentration

Synonym(s): Hb

Contributor(s): Kathleen P Freeman

Overview

  • The amount of hemoglobin (Hb) in a stated volume is a measure of the oxygen-carrying ability of erythrocytes.
  • Associated with packed cell volume (PCV) Hematology: packed cell volume.

Sampling

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Tests

Methodologies

Cyanomethemoglobin

  • Ferricyanide converts hemoglobin iron from the ferrous to the ferric state to form methemoglobin which combines with potassium cyanide to form the stable pigment cyanomethemoglobin.
  • Error 1-2% in automated systems and 2-5% in manual methods.
  • Measures all forms of Hb likely to be in blood.

Oxyhemoglobin

  • Uses Spencer Hb meter to measure oxyhemoglobin by its light absorption in the green portion of the spectrum using a filter and matching the color with a colored glass standard.
  • Practical, quick and accurate (+/- 5-10%).
    Does not measure methemoglobin and carboxyhemoglobin.

Other methods

  • Acid hematin and direct matching are outmoded and unsatisfactory.

Availability

  • Widely available at commercial laboratories.

Validity

Sensitivity

  • Good.

Specificity

  • High.

Predictive value

  • Good.

Technique (intrinsic) limitations

  • These techniques do not differentiate between different types of Hb.

Technician (extrinsic) limitations

  • Results needs to be repeatable.
  • Technical skill required.

Result Data

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Further Reading

Publications

Refereed papers

Other sources of information

  • Cowell R J, Tyler R D & Meinkoth J H (1999) Diagnostic Cytology and Hematology of the Dog and Cat. 2nd edn. St Louis: Mosby.
  • Duncan J R, Prasse K W & Mahaffey E A (1994) Veterinary Laboratory Medicine Clinical Pathology. 3rd edn. Ames, Iowa: Iowa University Press.
  • Jain N C (1993) Essentials of Veterinary Hematology. Philadelphia: Lea & Febiger.


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