What is HCT?
HCT is the abbreviation used for hematocrit, or erythrocyte volume fraction (EVF) or packed cell volume (PCV), which refers to the percentage of blood that holds red blood cells. To understand it better, take for example a hematocrit of 30%. This would mean 30 milliliters of red blood cells is contained in 100 milliliters of blood. Humans have normal values for hematocrit, depending on several factors: age, subsequent to adolescence and sex of a person.
Below are the following normal hematocrit ranges:
Infants ‘“ 55-68 percent
A week of age ‘“ 47-65 percent
A month of age ‘“ 37-49 percent
Three months of age ‘“ 30-36 percent
A year of age ‘“ 29-41 percent
Ten years of age ‘“ 36-40 percent
Male (adult) ‘“ 42-54 percent
Women (adult) ‘“ 38-46 percent
Hematocrit came from the Greek words hema and krites, which means blood and judge, respectively. Combining the two Greek words form the word hematocrit, which means to judge or gauge the blood.
To determine the hematocrit, a centrifuge is utilized. The process involves heparinized blood contained in a microhematocrit tube is centrifuged for about 5 minutes at a speed of 10,000 rounds per minute. The process will result the blood to be separated in layers. The hematocrit is determined by dividing the amount of packed red blood cells by the full amount of the sample of blood.
Due to modern technology, hematocrit is now calculated differently. An automated analyzer is utilized, which indirectly measure hematocrit. The automated analyzer multiplies mean cell volume by the count of the red blood cell. The calculation is considered a little more accurate. This is for the reason that packed cell volume contains a few blood plasmas are contained between red blood cells. Using the method, tripling the concentration of hemoglobin in g/dL will arrive at an estimated hematocrit percentage. Blood banks utilize the hemoglobin as standard measurement.
Hematocrit is an important part of the whole blood count. Any circumstance that its level goes beyond or below the normal range can pose health risk to an individual. There are several dangers associated to both elevated and lowered hematocrit values.
Elevated Hematorcrit Level
- The risk of dengue shock syndrome is high on people with dengue fever.
- A person is also at risk of PV or polycythemia vera, a condition where the bone marrow produces too much red blood cells. The disorder is associated with elevated hematocrit percentage.
- Several pulmonary conditions, chronic obstructive pulmonary disease in particular may cause an excessive reproduction of red blood cells. Such condition may occur if the pulmonary disorder is associated with hypoxia. However, the increase of red blood cells is intervened by the kidney producing excessive erythropoietin. This is the kidney’s way of responding to hypoxia.
- Dehydrated individuals are also in risk of hematocrit elevation.
Lowered Hematocrit Level
- A person is in risk of extreme hemorrhage if hematocrit level gets excessively low.
- Groups of people are also at risk of developing anemia when hematocrit level is below the normal range. Below are groups of individuals that are in greater risk of anemia development:
- Infants with inadequate iron ingestion.
- Children undergoing a quick growth when iron is inadequate for the demands of rapid growth.
- Women in their monthly period who need extreme amount of iron due to blood loss
- Pregnant women with growing fetus, which is in need of excessive iron