What is red cell parameter
It’s very important to know what is red cell. Most automated blood cell counters measure the number of red cells, the mean red cell volume (MCV), and hemoglobin concentration. The other red cell parameters, including the hematocrit, mean cell hemoglobin (MCH), and mean cell hemoglobin concentration (MCHC) are derived from these primary measurements.
What is red cell count and Hematocrit
In electronic instruments, the hematocrit (Hct; proportional volume of blood occupied by erythrocytes) is calculated from the product of direct measurements of the erythrocyte count and the MCV (Hct [µL/100 µL] = RBC [x 10–6/µL] x MCV [fl]/10). Falsely elevated MCV and decreased red cell counts can be observed when red cell autoantibodies are present and retain binding capability at room temperature (cold agglutinins and some cases of autoimmune hemolytic anemia). This causes red cells to clump and affects the accuracy of both red blood cell (RBC) count and MCV, as well as the resultant hematocrit.MCV, and hence measured hematocrit, can increase up to 5 percent after 24 hours of storage at room temperature.
The hematocrit may also be determined by subjecting the blood to sufficient centrifugal force to pack the cells while minimizing trapped extracellular fluid. This approach was traditionally done in capillary tubes filled with blood and centrifuged at very high speed in a small tabletop centrifuge, and the technique was referred to as the “microhematocrit.” Although the hematocrit is the volume (mL) of red cells per volume (100 mL)of blood, it is usually expressed as a per-cent.
What is red cell hemoglobin
Hemoglobin is intensely colored, and this property has been used in methods for estimating its concentration in blood. Erythrocytes contain a mixture of hemoglobin, oxyhemoglobin, carboxyhemoglobin, methemoglobin, and minor amounts of other forms of hemoglobin.
Hemoglobin measurement is accurate and preferable to the hematocrit for the diagno-sis of anemia. In practice, the major interference with this measurement is chylomicronemia, but newer instruments identify and minimize this interference.
The hemoglobin level varies with age. After the first week or two of extrauterine life, the hemoglobin falls from levels of approximately 17 g/dL to levels of approximately 12 g/dL by 2 months of age. Thereafter, the levels remain relatively constant throughout the first year of life. Any child with a hemoglobin level below 11 g/dL should be considered anemic.
What is red cell morphology
Normal erythrocytes on dried films are nearly uniform in size, with a normal distribution of about a mean diameter of 7.2 to 7.9 µm. The normal sized erythrocyte is about the diameter of the nucleus of a small lymphocyte. The MCV is a more sensitive measure of red cell volume than the red cell diameter. However, an experienced observer should be able to recognize abnormalities in average red cell size when the MCV is significantly elevated or decreased.