Average erythrocyte volume

The mean corpuscular volume (MCV) is measured in femtoliters (fl) or cubic micrometers. In hematology analyzers, MCV is calculated by dividing the sum of cellular volumes by the number of erythrocytes. This parameter can also be calculated using the formula: Ht (%)×10/RBC (10 ¹² /l).

MCV values in the range of 80-100 fL characterize the erythrocyte as a normocyte, less than 80 fL - as a microcyte, more than 100 fL - as a macrocyte. MCV cannot be reliably determined if there is a large number of abnormal erythrocytes (e.g. sickle cells) or a dimorphic population of erythrocytes in the blood being examined.

The mean corpuscular volume is one of several erythrocyte indices that allows one to fairly accurately estimate the quantity and size of red cells, which are so important for health in general and for blood in particular. The most significant and numerous, these blood cells perform many functions, including the following:

• Transport of oxygen and carbon dioxide, that is, the respiratory function;
• Transportation of adsorbed amino acids and lipids to tissues, that is, nutritional;
• Transport of enzymes;
• Regulation of acid-base balance carried out by hemoglobin;
• Adsorption of microbial toxins, antibodies;
• Active participation in fibrinolysis and in the work of hemostasis in general.

The mean corpuscular volume is a part of the general hematological, clinical blood test. This index is designated by the abbreviation MCV – Mean Corpuscular Volume, which is translated as corpuscular (from the word "corpuscle" - a very small particle) average volume. Such an indicator helps to reliably determine the number and volume of erythrocytes in the bloodstream, as well as objectively assess their size. However, the mean corpuscular volume sometimes cannot be an absolutely reliable source of information, this happens with some deviations in the composition and formula of the blood. For example, anisocytosis (change in the size of red blood cells) or poikilocytosis (erythrocytes of different shapes) do not allow to accurately determine the MCV.

Why is the mean corpuscular volume determined?

This information is necessary for the doctor, because by the average size of the red blood cell he can specify the type of hematological problem - anemia, if it is assumed by clinical symptoms. For example, if there is an acute shortage of iron in the body, then most likely MCV will confirm a microcytic hematological problem. If a person has a deficiency of cyanocobalamin, that is, vitamin B12, then the average volume index argues for the presence of macrocytic anemia. In addition to differentiating types of anemia, the average volume of the red blood cell clearly shows the ratio of water and electrolyte balance, especially in the intravascular zone and intracellular sector. If MCV is significantly higher than the normal age limit, this means the presence of hypotonic disorders, with a decrease in the norm, we can talk about hypertonic dehydration (dehydration).

What is the procedure for collecting blood to determine mean corpuscular volume?

MCV is additional, specifying information in the overall picture of a clinical examination; such tests are not prescribed separately. In general, a hematological section is important and necessary for assessing blood parameters, and the procedure for conducting it is most likely familiar to many. Depending on the suspected diagnosis and the number of parameters required by the doctor, blood as a laboratory material for a comprehensive study is taken from a vein, but sometimes only capillary blood is needed. There are no special requirements for the patient, except that the analysis is taken on an empty stomach and is carried out in the morning.

How is mean corpuscular volume calculated?

The unit of MCV is the femtoliter, which, oddly enough, was previously a Dutch unit of measurement for alcohol-containing liquids. The mean corpuscular volume is often measured in cubic micrometers. The study of the mean volume is carried out in conjunction with the calculation of all erythrocytes by the pulses that occur when the cells pass through the microscopic holes (apertures) of the hemolytic analyzer. The result is a histogram showing how the erythrocytes are distributed over the total volume.

What is the normal value for the mean corpuscular volume?

The average volume of an erythrocyte, according to established standards, fluctuates between 80 and 100 femtoliters. Thus, if the indicator fits into the designated limits, the erythrocyte is designated as a normocyte. If below 80 femtoliters, the erythrocyte is characterized as a microcyte, above - a macrocyte. It should be taken into account that the average volume of an erythrocyte in a person can change throughout life, but there are also normal limits. Thus, in newborn babies, this indicator starts with 128 femtoliters, and then decreases to 100. Already at the age of one year, the baby's MCV can be about 77 fl, and by the age of five it levels out to the norm - 80 fl. Most often, the average volume of an erythrocyte as a clarification of the type and stage of anemia is studied in conjunction with the color index and MCH - an indicator of the quantitative content of hemoglobin in the erythrocyte. These are quite specific calculations, so you should not study the laboratory form on your own; it is better if this necessary and important information falls into the hands of a professional, that is, a doctor.