HemoCue Education Center Hb, Anemia, October 2004 Anemia The first sign of a physical disorder.

HemoCue Education CenterHb, Anemia, October 2004

Anemia

The first sign of a physical disorder


The Blood

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~45%

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Red Cells

• Red cells, or erythrocytes, transport oxygen from the lungs to the living tissues of the body and carry away carbon dioxide.

• 95% of the red cells consists of hemoglobin molecules.

• Each red cell contains about 270 000 hemoglobin molecules.


Red Cells

• Shaped as a biconcave disc• Made in the bone marrow• Average lifespan of 120 days• The production is controlled by Erythropoietin• Requires supply of vitamins (Folate and B12),

nutrients and essential minerals (Iron)

• Recycled in the spleen and liver

• Contains the protein Hemoglobin


White Cells

• White cells, or leukocytes, provides a physical defence against infection, numbers increase under attack by viruses or bacteria.

• Exists in variable numbers and types but make up a very small part of the blood volume.


Platelets

• Platelets, or thrombocytes, are cells that clot blood at the site of wounds.

• Platelets are only about 1/3 the size of red cells


Plasma

• Plasma is the relatively clear liquid medium which carries the red cells, white cells, and platelets.

• Most blood volume is made up of plasma.• Plasma brings nourishment and removes waste

products to and from the cells.


Hemoglobin (Hb)

Transports oxygen (O2) from the lungs to peripheral tissues and carbon dioxide (CO2) back to the lungs


Hemoglobin Molecule

Consists of:

– 4 Polypeptide globin chains (2, – each with an iron containing heme molecule


Hemoglobins

• There are different types of hemoglobin - Hb A, Hb A2 and Hb F

• Hb F mainly exist in newborn babies• HemoCue hemoglobin methods measures the total

amount of all types of hemoglobin mentioned above.


Anemia

• An = No• Aemia = blood


What is Anemia ?• Anemia = when the level of circulating hemoglobin in

a patient is lower than that in healthy persons of the same age group and sex in the same environment.

• Anemia is a symptom - not a disease.• The WHO estimates that over 1/3 of the world’s

population are anemic, mainly due to iron deficiency. In developing countries, the most affected population groups are pregnant woman and school-age children.


Anemia Reference Values

• Influenced by sex, age and altitude

• Definition by WHO:– women 12.0 - 16.0 g/dL

(120-160 g/L, 7.4-9.9 mmol/L)

– men 13.0 - 17.0 g/dL(130-170 g/L, 8.0-10.5 mmol/L)


The Clinically Anemic Person

Symptoms in anemia• Pallor• Fast heart rate• Shortness of breath on exercise• Tiredness, weakness or fatigue

Symptoms in severe anemia• Faintness• Dizziness• Tinnitus• Headache• Spots before the eyes/dimmed vision


Main Causes of Anemia• Decreased red cell production by the bone marrow

– shortage of raw material (Iron, B12, Folate)

• Increased red cell destruction

– hereditary (Thalassemia, Sickel Cell)

– hemolysis (anti bodies, drugs, Malaria)

• Bleeding or blood loss – menstruation– gastric ulcer

– trauma


How is Anemia Diagnosed?

• From a simple blood sample anemia can be detected by measuring hemoglobin or the hematocrit

• To determine the cause of anemia a wide range of tests are necessary


Hemoglobin Measurement

Hemoglobin measurement is considered to be more precise, accurate, and useful compared to hematocrit measurement due to reliable standardization.

Potential sources of technical and inherent errors are also fewer.


Hematocrit Measurement

Is the volume of red cells expressed as a fraction of the total blood volume


Major Types of Anemia

• Iron Deficiency Anemia• Vitamin Deficiency Anemia• Hemolytic Anemia• Inherited Anemia• Miscellaneous Anemia

HemoCue Education Center Hb, Anemia, October 2004 Anemia The first sign of a physical disorder.

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