Practical Blood Physiology 2024-2025 PDF

Blood Physiology/ Hb Estimation By: Hussein R. Alasady ____________________________________________________________________________ Jabir Ibn Hayyan Medical University Faculty of Medicine Practical Blood Physiology...

Blood Physiology/ Hb Estimation By: Hussein R. Alasady ____________________________________________________________________________ Jabir Ibn Hayyan Medical University Faculty of Medicine Practical Blood Physiology 2nd year 2024-2025 Hemoglobin Estimation Lecturer: Hematologist/ Hussein R. Alasady Jabir ibn hayyan medical university/ faculty of medicine  Blood Physiology/ Hb Estimation By: Hussein R. Alasady ____________________________________________________________________________ Hemoglobin is a protein in red blood cells that carries oxygen. Hemoglobin is a chromo protein consisting of the colorless globin and four red colored heme molecules. Hemoglobin is a metal complex, containing an iron atom in the center of a porphyrin structure. The globin molecule consists of two peptide chains (alpha and beta)-each made up of several amino acids. Heme synthesis occurs in most of the cells of the body, except the mature erythrocytes, but most abundantly in the erythroid precursors. The hemoglobin test measures how much hemoglobin is in your blood. Why the Test is performed The hemoglobin test is a common test and is almost always done as part of a complete blood count (CBC). Reasons or conditions for ordering the hemoglobin test include:  Before and after major surgery  Blood in your stools, or vomit.  Chronic medical problems, such as kidney disease or certain types of arthritis.  During pregnancy.  Fatigue, poor health, or unexplained weight loss.  Headaches.  Leukemia or other problems in the bone marrow.  Monitoring during treatment for cancer.  Monitoring medicines that may cause anemia or low blood counts. Sahli’s method for hemoglobin estimation Sahli’s method, also called as acid hematin method is the visual comparator method for the estimation of hemoglobin. As visual comparison may lead to unacceptable imprecision and accuracy. Principle: When the blood is added to dilute hydrochloric acid (HCl), hemoglobin present in the RBCs is converted into brown-colored acid hematin. The acid hematin solution is further diluted until it’s color matches exactly with the permanent standard brown glass compared by direct vision. Specimen: Capillary or venous blood. Venous blood should be anticoagulated with 1.5-1.8 mg EDTA per mL of blood and mixed immediately. Jabir ibn hayyan medical university/ faculty of medicine  Blood Physiology/ Hb Estimation By: Hussein R. Alasady ____________________________________________________________________________ Instruments:  Sahli’s hemoglobinometer:  Comparator.  Hemoglobin tube: Sahli’s graduated hemoglobin tube is graduated in one side in gram percentage (g%) from 2 to 24, and on the other side in percentage (%) from 20 to 140. The tube is also called Sahli-Adams tube.  Sahli’s pipette or hemoglobin pipette: It contains only one mark at 20μl or 0.02ml.  Stirrer: It is a thin glass rod used for stirring the mixture inside the hemoglobin tube. Reagents: We need (Hydrochloric acid (HCl) 0.1N and Distilled water). Procedure: 1. Ensure that the hemoglobin meter tubes and pipette are clean and dry. 2. Fill the hemoglobin meter tube with HCl up to its lowest mark i.e. 2 g% or 10% mark with the help of a dropper. 3. Take blood up to mark in the Sahli’s pipette (20 μl). Wipe the extra blood outside the pipette and deliver it to HCl in the hemoglobin tube. 4. Mix and leave it for 10 minutes in order for a complete conversion of hemoglobin to hematin. 5. Add distilled water drop by drop and stir till color matches with the standard glass of the comparator. https://www.youtube.com/watch?v=6CqptdZyUaU Advantages: 1. Easy to perform and convenient. 2. Not very time consuming. 3. Reagents and apparatus are cheap and easily available. Reagents are less harmful. Disadvantages: 1. Acid hematin is a suspension, not a true solution. So, some turbidity may result. 2. It estimates only oxyhemoglobin and reduced hemoglobin. But carboxyhb, methb and sulfhb are not converted to acid hematin. 3. HbF is not converted to acid hematin. Therefore, Sahli’s method is not suitable for measuring hemoglobin in infants up to 3 months. 4. The color of glass standard may fade over time. Jabir ibn hayyan medical university/ faculty of medicine  Blood Physiology/ Hb Estimation By: Hussein R. Alasady ____________________________________________________________________________ Normal Results  Normal results for adults vary, but in general are: o Male: 13.8 to 17.2 (g/dL) or 138 to 172 (g/L). o Female: 12.1 to 15.1 g/dL or 121 to 151 g/L.  Normal results for children vary, but in general are: o Newborn: 14 to 24 g/dL or 140 to 240 g/L. o Infant: 9.5 to 13 g/dL or 95 to 130 g/L. Abnormal Results: 1. Lower level of Hb:  Anemia  Bleeding  Bone marrow being unable to produce new red blood cells (cancers, drug toxicity, radiation therapy, infection).  Chronic illness  Chronic kidney disease  Malnutrition  Pregnancy 2. Higher level of Hb:  Bone marrow disease that causes abnormal increase in RBCs (polycythemia vera)  Cigarette smoking  Dehydration (for example, from severe diarrhea)  Kidney tumor (renal cell carcinoma)  Hypoxia.  Congenital heart disease.  Higher altitude. Jabir ibn hayyan medical university/ faculty of medicine