Red blood cell (RBC) indices measure your red blood cells' size, shape, and quality. Red blood cells are also known as erythrocytes. They are made in your bone marrow (the spongy tissue inside your large bones). They contain hemoglobin, an iron-rich protein in your red blood cells that carries o...
Red blood cell (RBC) indices measure your red blood cells' size, shape, and quality. Red blood cells are also known as erythrocytes. They are made in your bone marrow (the spongy tissue inside your large bones). They contain hemoglobin, an iron-rich protein in your red blood cells that carries oxygen from your lungs to every cell in your body. Your cells need oxygen to grow, reproduce, and make energy.
Knowing the size and shape of your red blood cells can help your provider determine if you have a certain type of anemia, a condition in which your body does not make enough healthy red blood cells. There are four types of red blood cell indices:
Mean corpuscular volume (MCV), which measures the average size of your red blood cells.
Mean corpuscular hemoglobin (MCH), which measures the average amount of hemoglobin in a single red blood cell.
Mean corpuscular hemoglobin concentration (MCHC), which measures how concentrated (close together) the hemoglobin is in your red blood cells. It also includes a calculation of the size and volume of your red blood cells.
Red cell distribution width (RDW), which measures differences in the volume and size of your red blood cells. Healthy red blood cells are usually about the same size.
If one or more of these indices are not normal, it may mean you have some type of anemia.
Other names: erythrocyte indices
What are they used for?
Red blood cell (RBC) indices are part of a complete blood count, a group of tests that measures the number and type of cells in your blood. The results of RBC indices are used to diagnose different types of anemia. There are several types of anemia, and each type has a different effect on the size, shape, and/or quality of red blood cells.
Why do I need red blood cell indices testing?
You may get this test as part of a complete blood count, which is often included in a routine checkup. You may also need this test if you have symptoms of anemia, which may include:
Shortness of breath
Weakness or fatigue
Headache
Dizziness
Arrhythmia (a problem with the rate or rhythm of your heartbeat)
Pale skin
Cold hands and feet
What happens during a red blood cell indices test?
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This test usually takes less than five minutes.
Will I need to do anything to prepare for these tests?
You don't need any special preparations for a red blood cell (RBC) indices test.
Are there any risks to these tests?
There is very little risk to having a blood test. There may be slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
What do the results mean?
You will get results for each of the indices. Abnormal results may include one or more of the following:
Topics to be covered Introduction to blood What is anemia? Morphological classification of Anemia Etiological classification of Anemia PCV ESR . '
Blood is defined as liquid connective tissue that fills heart and blood vessels. The normal value in an average adult is 5-6 litres which accounts for 8% of the body weight. Introduction to blood
Composition of blood Two components: cells and fluid. Cellular components have formed elements. Formed elements are RBCs , WBCs and platelets. Fluid component is the plasma About 55% of the blood is plasma which is made up of water and solid particles.
When blood is collected in an anti coagulated tube and allowed to settle by centrifugation three layers are formed. Upper layer - plasma Lower - red cell mass Between them a thin buffy coat consist of WBCs and platelets Composition
Function of blood Respiratory function Transport medium Regulation of body temperature Excretory functions Water homeostasis Acid base buffers Storage Nutritive functions
What is anemia ? Anemia is a condition in which number of red cells or the haemoglobin concentration within them is lower than normal. Haemoglobin is needed to carry oxygen but if the no. of red cell and haemoglobin is too low, there will be a decreased capacity of blood to carry out oxygen.
Symptoms of anemia
Morphological classification of anemia Hypochromic microcytic - MCV MCH MCHC are below normal seen in iron deficiency anemia Thalassemia Normochromic normocytic - MCV MCH MCHC are within normal range. Seen in blood loss anemia Haemolytic anemia Aplastic anemia Hereditary spherocytosis Macrocytic normochromic - MCV is above the upper limit Seen in megsloblastic anemia
Etiological classification of anemia Blood loss anemia - could be acute haemorrhage or chronic haemorrhage Aplastic anemia - impaired red cell production Haemolytic anemia - increased red cell destruction
Haematocrit is the fractional volume of blood that erythrocyte occupy. It is the amount of packed red blood cell after centrifugation. Red cell are packed together at bottom of the tube by centritugal force , as cells are heavier than the plasma. PCV or Haematocrit .
Normal value of PCV Adult male - 46% ( 40 - 50 %) Adult female - 42% (37 - 47%) Hematocrit decreases in conditions of decreased red cell count and increase in conditions of increased red cell count
Erythrocyte sedimentation rate Rate at which red cell and fall sediment at the bottom is known ESR. Red cell have the property of rouleaux formation ( piling one on the other). ESR depends on 3 major factors : 1. Shape and no. of red cell 2. Size of rouleaux 3. Plasma factors
Shape and number of red cell Biconcave shape favours rouleaux formation. Alteration of shape of erythrocytes decreases rouleaux formation. Increase in cell mass increases viscosity which decreases ESR ESR decreases in polycythemia and increases in anemia (except in sickle cell anemia)
Size of rouleaux Larger the size of rouleaux , faster is the fall. Factor that increases the size of rouleaux facilitate. Increase in red cell size without change in shape increases the size of rouleaux therefore increase the ESR.
Plasma factor ESR also depends on concentration of fibrinogen in the plasma. Fibrinogen neutralises the the charges, thereby removes the repelling forces.
Normal values ESR is measured by two method: Wintrobe method: males. : 0-9mm/hr Females. : 0-20mm/hr Westergren method: males. : 3-5mm/hr Females : 5-12mm/hr -s
Physiological variation in ESR
Pathological variation in ESR
Ques1 : Heridatary spherocytosis is what type of anemia? 1. Normocytic normochromic 2. Microcytic hypochromic 3. Normocytic hypochromic 4. Macrocytic normochromic
Ques2: 9n which type of anemia the RBC are normocytic and normochromic? 1. Iron deficiency anemia 2. Thallesemia 3. Pernicious anemia 4. Blood loss anemia
Ques3 : ESR Increases in 1. Sickle cell anemia 2. Hereditary spherocytosis 3. Polycythemia 4. Blood loss anemia