Hematocrit Measurement: Cause and Effects of Hematocrit Levels
A hematocrit measures the percentage of blood that is comprised of RBC’s and can determine a needed transfusion. Fluid volume in the blood affects hematocrit values. Hematocrit levels rise with an increase in the number of RBC’s or a decrease in the plasma volume. An elevated hematocrit is most often associated with severe burns, diarrhea, and dehydration, where water in tissues decreases. The low level of plasma water concentrates the RBC’s leading to the condition, hemoconcentration. An elevated hematocrit may also be caused by an absolute increase in blood cells, called polycythemia. Decreased levels can be due to conditions including chronic and recent acute blood loss, kidney and liver diseases, and pregnancy.
Another term for hematocrit is packed cell volume, or PCV. Values obtained in this test are dependent on the number and size of red blood cells. Normal hematocrit levels are 38.8% to 50% for adult men and 34.9% to 44.5% for adult women. Children 15 years old and younger will differ according to age and gender.
The lab technician will draw a blood sample from a vein by tying an elastic band around the arm to cause the vein to swell with blood. A needle will be inserted into the vein, causing blood to collect in a vial. When the blood sample has been obtained, the needle will be removed and a bandage is placed over the puncture to stop bleeding.
After the blood sample has been drawn, the process of determining whether it contains normal hematocrit levels begins by a centrifuge. This machine will spin a test tube, which will result in the blood separating into three components. The three parts of blood consist of plasma, the red blood cells, and the remaining blood cells. Once the blood has divided into its component parts, the lab technician can determine the percentage of red blood cells.
b. Measurements
The hematocrit measurement depends on the number of red blood cells and the size of red blood cells. The hematocrit is typically measured from a
Another term for hematocrit is packed cell volume, or PCV. Values obtained in this test are dependent on the number and size of red blood cells. Normal hematocrit levels are 38.8% to 50% for adult men and 34.9% to 44.5% for adult women. Children 15 years old and younger will differ according to age and gender.
The lab technician will draw a blood sample from a vein by tying an elastic band around the arm to cause the vein to swell with blood. A needle will be inserted into the vein, causing blood to collect in a vial. When the blood sample has been obtained, the needle will be removed and a bandage is placed over the puncture to stop bleeding.
After the blood sample has been drawn, the process of determining whether it contains normal hematocrit levels begins by a centrifuge. This machine will spin a test tube, which will result in the blood separating into three components. The three parts of blood consist of plasma, the red blood cells, and the remaining blood cells. Once the blood has divided into its component parts, the lab technician can determine the percentage of red blood cells.
b. Measurements
The hematocrit measurement depends on the number of red blood cells and the size of red blood cells. The hematocrit is typically measured from a