What are the precautions for checking mean corpuscular volume

The mean corpuscular volume test is mainly used in the diagnosis and treatment of suspected anemia in clinical practice. From a literal meaning, we can understand the mean corpuscular volume as the volume ratio of red blood cells in a certain unit. Changes in mean corpuscular volume can be divided into two categories: physiological and pathological. Usually doctors will make a judgment based on the results of the mean corpuscular volume test combined with specific physical symptoms. At the same time, you must pay attention to your diet before doing the mean corpuscular volume test. You cannot eat too greasy food or drink alcohol. These details will affect the test results and interfere with the diagnosis of the disease. So here is a detailed introduction to the precautions for the mean corpuscular volume test. I hope it will be helpful to everyone.

Increased mean corpuscular volume is often seen in macrocytic anemia caused by a deficiency of folic acid and vitamin B12. A decrease in mean corpuscular volume is often seen in microcytic anemias such as iron deficiency anemia and thalassemia. The diameter of human red blood cells is about 6-8um.

Mean corpuscular volume (Note: 1 ml = 10^12 fl) MCV = Hct/RBC (L) × 10^15 (fl), where Hct is the hematocrit, that is, the ratio of the volume occupied by red blood cells in the blood; MCV together with MCH (mean corpuscular hemoglobin content) and MCHC (mean corpuscular hemoglobin concentration) can be used for the morphological classification diagnosis of anemia.

Mean corpuscular volume test notes

1. Precautions before blood drawing

Do not eat too greasy or high-protein food and avoid drinking too much alcohol the day before blood drawing. The alcohol content in the blood will directly affect the test results. You should fast after 8 pm the day before the physical examination. You should relax when having blood drawn to avoid blood vessel constriction due to fear, which will increase the difficulty of blood collection.

2. Pay attention after blood drawing

After drawing blood, local pressure should be applied on the needle hole for 3-5 minutes to stop the bleeding. Note: Do not rub to avoid causing subcutaneous hematoma. The pressing time should be sufficient. The clotting time varies from person to person, and some people need a little longer time to clot. Therefore, if you stop applying pressure immediately when the surface of the skin seems to be not bleeding, the bleeding may not stop completely, and the blood may seep into the subcutaneous layer, causing bruises. Therefore, pressing for a longer time can completely stop the bleeding.

If you experience symptoms of needle phobia after blood drawing, such as dizziness, blurred vision, fatigue, etc., you should lie down immediately and drink a small amount of sugar water, and then have a physical examination after the symptoms are relieved. If local bruising occurs, apply a warm towel for wet compress after 24 hours to promote absorption.