Practical Physiology Lab(1) Part (1) RBC and PCV Count PDF

12/23/2024 Practical Physiology Lab(1) Part (1) RBC count and PCV Estimation Department of Basic sciences Physiology Unit 2024-2025 2nd stage Complete blood count (CBC) : A complete blood count (CBC) : is a blood test used to eva...

12/23/2024 Practical Physiology Lab(1) Part (1) RBC count and PCV Estimation Department of Basic sciences Physiology Unit 2024-2025 2nd stage Complete blood count (CBC) : A complete blood count (CBC) : is a blood test used to evaluate overall health and detect a wide range of disorders, including anemia and leukemia. RBCs count is done as a part of CBC test. CBC test measures the number of all components in the blood, including: Red blood cells White blood cells Hemoglobin Hematocrit Platelets 1  12/23/2024 CBC test : CBC test is done by an automated analyzer : What is a red blood cell count? A red blood cell count is a blood test that used to find out how many red blood cells you have. It’s also known as an erythrocyte count. The test is important because RBCs contain hemoglobin, which carries oxygen to your body’s tissues. The number of RBCs you have affects how much oxygen your tissues receives. 2  12/23/2024 Red blood cell count is; a count of the erythrocytes in a specimen of whole blood, commonly made with an electronic counting device. Why Get Tested? To evaluate the number of red blood cells (RBCs); used to screen for, help diagnose, or monitor conditions affecting red blood cells. Since an RBC count is performed as part of a complete blood count (CBC), results from other components are taken into consideration. A rise or drop in the RBC count must be interpreted in conjunction with other parameters, such as hemoglobin, hematocrit, reticulocyte count, and/or red blood cell indices. 3  12/23/2024 Packed Cell Volume (PCV) Proportion of blood volume that is occupied by RBCs Normal PCV values: - At Birth 46 - 66 % - Adult male 42 - 52 % - Adult female 37- 47 % 4  12/23/2024 Why the test is done? 1/ An integral part of a person's complete blood count results, along with hemoglobin concentration, (RBC, WBC, and platelet) counts. 2/ Simple screening test of anemia. 3/ Rough guide to the accuracy of Hb estimation. 4/ Used for calculation of blood indices (MCV, MCH, MCHC). Microhaematocrit method of PCV estimation : 5  12/23/2024 Equipment's: 6  12/23/2024 Principle : A volume of uncoagulated blood is centrifuged at high speed in a capillary tube. The level of packed cell is read directly from the graphic reader, and the reading is expressed in percentage (%). Procedure : 1. Fill a heparinized capillary tube with blood up to 80 % of its length. 2. Seal one end of the capillary tube with sealing clay. 3. Centrifuge for (3-5) min. 4. Use the graphic reader to read the PCV in %. 7  12/23/2024 Results: Accuracy of test results: ▪ A number of factors can affect the outcome of a hematocrit test and yield inaccurate or misleading results, including: Living at a high altitude Pregnancy Significant recent blood loss Recent blood transfusion Severe dehydration 8  12/23/2024 What is the difference between Hemoglobin and Hematocrit? Hemoglobin is a protein but hematocrit is not ; it is a measurement. Hemoglobin is part of hematocrit because hematocrit is measure of total red blood cells where hemoglobin is only a component. Hemoglobin count and hematocrit changes parallelly (If one is low, the other too is low and vice versa.) Physiological causes of increased PCV level; Chronic hypoxia; e.g. living at high altitude Severe dehydration Immediately after exercise Physiological causes of decreased PCV level; Hemodilution; pregnancy 9