Clinical Biochemistry Lecture 2 PDF

Clinical Biochemistry Lecture 2 Dr. Mohamed Hemdan 1 1 Biochemistry Lab uses chemical processes to measure levels of chemical components (i.e. Biochemicals, Analytes) in body fluids....

Clinical Biochemistry Lecture 2 Dr. Mohamed Hemdan 1 1 Biochemistry Lab uses chemical processes to measure levels of chemical components (i.e. Biochemicals, Analytes) in body fluids. 2 Types of Measurements: A) Qualitative Measurement, e.g. - The liver enzymes are high. - Glucose in urine +++, None, trace B) Quantitative measurement, e.g. - The blood glucose is 100 mg/dL. - Na+ in blood is 120 m Equivalent /ml The most common specimens tested in clinical chemistry are: blood and urine. 2 2 1  Types of Specimens used in Clinical Chemistry Labs Serum Semen, Plasma Amniotic fluid Urine Gastric Juice Other body fluids: Stool - Cerebro Spinal Fluid Saliva (CSF) Synovial Fluid - Sweat 3 3 Commonly metabolites used as Tools in Biochemistry Lab Diagnosis 1. Blood glucose. 2. Electrolytes. 3. Enzymes. 4. Hormones 5. Lipids (fats). 6. Proteins. 4 4 2  Some Common Clinical Chemistry Tests The following is a description of some of the most common clinical chemistry tests (used on blood and urine specimens), including some of the uses and indications: 1) Blood glucose, or blood sugar, levels indicate how the body handles glucose. Measuring glucose levels after fasting (when the patient has not eaten anything for 8 hours) can help diagnose diabetes or hypoglycemia (low blood sugar). 2) Electrolytes include sodium, potassium, chloride, bicarbonate, calcium, phosphorus, and magnesium. Measuring electrolytes can specifically indicate certain metabolic and kidney disorders. 5 5 3) Enzymes: are released into the blood by organs that are damaged or diseased. The type of enzyme released can indicate which organ is affected: Enzyme Organ Affected Creatine Kinase (CK) - Can signal damage to heart muscle or skeletal muscle - CK-MB, an isoenzyme of CK, is used to distinguish heart muscle damage Alanine aminotransferase (ALT, SGPT), Can signal liver disorders aspartate aminotransferase (AST, SGOT) Amylase and lipase Can signal inflammation or the possibility of cancer of the pancreas 6 6 3  4) Hormones: Hormones are secreted by the various endocrine glands to regulate the processes of the body. Raised or lowered levels of certain hormones can indicate over- or under-activity of those glands Hormone Gland Affected Cortisol adrenal glands Thyroxine (T4), TSH thyroid gland ACTH, Growth Hormone (GH) pituitary gland 7 7 5) Lipids & Fatty substances: such as triglycerides (body fat), phospholipids (part of cell membranes), and sterols (such as cholesterol). Lipids can help signal coronary heart disease and liver disease: Lipid Organ Affected Total cholesterol - High total cholesterol is a risk factor for cardiovascular disease (CVD) High-density lipoprotein (HDL or "good" cholesterol) - High HDL cholesterol is a protective factor Low-density lipoprotein (LDL or against CVD "bad" cholesterol) Triglycerides - High triglycerides is another independent risk factor for CVD 8 8 4  6) Other metabolic substances (Metabolites) can be measured to evaluate organ function: Metabolic Product (Metabolite) Organ Affected BUN - Kidney function (blood urea nitrogen) Creatinine - Kidney function Bilirubin - Indirect Bilirubin - Prehepatic Jaundice (Hemolytic jaundice) - Mixed Direct & Indirect Bilirubin - Hepatic jaundice - Direct Bilirubin - Posthepatic jaundice (Obstructive jaundice) Uric acid - Can signal gout, kidney disease, and other tissue damage 9 9 7) Proteins: can indicate metabolic and nutritional disorders, as well as certain cancers: Protein Organ Affected Total protein and albumin - Can signal liver or kidney disease, or malnutrition Globulins and albumin to - Can signal infection, autoimmune globulin (A/G) ratio. disease, inflammation, and certain blood cancers 10 10 5  The “Laboratory Testing Cycle” & Turn- Around Time (TAT) The “laboratory testing cycle” consists of 3 steps: Pre-analytic Analytic Post-analytic 11 11 Why Analytical Results Vary? Pre-analytical Analytical Variation Post-analytical Variation Random errors Transcriptions errors — Transport Systematic errors Results reported to — Exposure to UV wrong patient light — Standing time Inter-individual before Variation separation of Age cells Sex — Centrifugation Race time Genetics — Storage Long term health conditions status. 12 12 6  Turn-Around Time (TAT) of the Lab TAT is counted as the time from patient’s sample for testing is obtained (e.g., a blood specimen taken from an antecubital vein) and the results of the testing are returned to the clinician. 13 13 Reasons for Ordering a Laboratory Test 4 major reasons for ordering a laboratory test: 1. Diagnosis: - to rule in or rule out a diagnosis. 2. Monitoring: - the effect of drug therapy. 3. Screening: (in New born) - for congenital diseases. 4. Research: - to understand the pathophysiology of a disease. 14 14 7  Major 10 Types of Diagnostic Tests Top 10 Diagnostic Tests 1. Mammography. (https://www.radiologyinfo.org/en/info.cfm?pg=mammo) A mammogram is a special type of X-ray of the breasts. 2. Echocardiography. 3. Complete Blood Count (CBC) 4. Colonoscopy. 5. Prothrombin Time (PT) 6. Bone Density Study. 7. Magnetic Resonance Imaging (MRI) 8. Computer Axial Tomography (CT or CAT Scan) 9. Electrocardiogram (ECG) 10. Prostate Specific Antigen (PSA Test) 15 15 1) Mammography https://www.mayoclinic.org/tests-procedures/mammogram/about/pac-20384806 (Mayo Clinic) A mammogram is a special type of X-ray of the breasts. Mammograms can show cysts or tumours long before they are big enough for your physician to feel. Mammograms are recommended every year or two for women older than 40. They are also recommended for younger women who have symptoms of breast cancer or who have a high risk of the disease. 16 16 8  Mammography Procedure 17 17 2) Echocardiography https://www.mayoclinic.org/testsprocedures/echocardiogram/about/pac-20393856 (Mayo Clinic) Echocardiography is a test that uses sound waves to make a moving picture of the heart chambers, valves and surrounding structures. A small device is used to make images that will show how the heart is working. There is no exposure to radiation during this test. 18 18 9  Echocardiography https://en.wikipedia.org/wiki/Echocardiography https://www.webmd.com/heart-disease/video/echocardiogram Echocardiography Echocardiogram 19 19 3) Complete Blood Count (CBC) https://www.mayoclinic.org/tests-procedures/complete-blood-count/about/pac-20384919 (Mayo Clinic) A complete blood count (CBC) is a common blood test used to diagnose a number of medical conditions and to detect a wide range of disorders, including anemia, infection and leukaemia. This test measures red blood cells, white blood cells, hemoglobin (iron in the blood), and others. Specimens are collected by a specially trained person called a phlebotomist. Blood is taken from a vein in the arm, from finger, or heel (in infants). Red blood cell count Male: 4.3 - 5.7 X 10 6 cells / µL Female: 3.9 - 5.0 X 10 6 cells / µL Hemoglobin Male: 13.5 - 17.5 g/dL Female: 12.0 - 15.5 g/dL Haematocrit Male: 38.8 - 50.0 % Female: 34.9 - 44.5 % White blood cell count 3,500 - 10.500 / µL 20 Platelet count 150,000 - 450,000 / µL 20 10  4) Colonoscopy https://www.mayoclinic.org/tests-procedures/colonoscopy/about/pac-20393569 (Mayo Clinic) A test to look into the rectum and colon. The doctor uses a long narrow tube that bends with a light and tiny lens on the end. This tube is called a colonoscope. A colonoscopy is helpful in finding colon cancer, ulcers, swelling and other problems in the colon. For colon cancer screening, a colonoscopy is recommended every 10 years after age 50. 21 Colonoscope Colonoscopy 21 Colonoscope Colonoscopy 22 22 11  5) Prothrombin Time and International Normalized Ratio (PT/INR) https://www.mayoclinic.org/tests-procedures/prothrombin-time/about/pac-20384661 (Mayo Clinic) The prothrombin time (PT) test is a blood test measures the time it takes for you’re the blood to clot. The international normalized ratio or INR is a calculation based on results of a PT that is used to monitor individuals who are being treated with the anticoagulant warfarin (Coumadin®). The INR is a calculation that adjusts for changes in the PT reagents and allows for results from different laboratories to be compared. Most laboratories report both PT and INR values whenever a PT test is performed. If you take a blood-thinning medication such as warfarin (Coumadin), your prothrombin time test results will be expressed as a ratio called the international normalized ratio (INR). However, the INR should be only applicable for those taking the anticoagulant medication – warfarin (Coumarin). 23 23 DIC = Disseminated Intravascular Coagulation 24 24 12  6. Bone Density Test (Study) https://www.bones.nih.gov/health-info/bone/bone-health/bone-mass-measurement- what-numbers-mean https://www.mayoclinic.org/tests-procedures/bone-density-test/about/pac-20385273 (Mayo Clinic) A Bone Density Study is a type of X-ray to measure bone loss. Certain diseases, medications, or conditions cause bones to become thin (less dense). These include osteoporosis, taking drugs like steroids for a long time, and thyroid disease. It's normal for bones to become less dense with age. A bone density test uses X-rays to measure how many grams of calcium and other bone minerals are packed into a segment of bone. The bones that are most commonly tested are in the spine, hip and sometimes the forearm. 25 25 Bone Density Tests Bone density tests are usually done on bones that are most likely to break because of osteoporosis, including: 1) Lower spine bones (lumbar vertebrae) 2) The narrow neck of your thighbone (femur), next to the hip joint 3) Bones in the forearm. 26 26 13  7. Magnetic Resonance Imaging (MRI) https://en.wikipedia.org/wiki/Magnetic_resonance_imaging https://www.mayoclinic.org/tests-procedures/mri/about/pac-20384768 (Mayo Clinic) Magnetic Resonance Imaging (MRI) is a picture of the inside of the body. It's like an X-ray, but is much more detailed. This test lets the doctor see pictures of the inside of the body (muscles, nerves, bones and other organs such as the gall bladder). MRI machines are tube-shaped magnets when the patient lies inside, the magnetic field realigns hydrogen atoms in his body. Radio waves cause these aligned atoms to produce signals, that create cross-sectional MRI images. The MRI machine can also be used to produce 3-D images that may be viewed from many different angles. 27 27 28 28 14  8. Computer Axial Tomography (CAT) Scan https://www.mayoclinic.org/tests-procedures/ct-scan/about/pac-20393675 (Mayo Clinic) A computerized tomography (CT) scan combines a series of X-ray images taken from different angles around the body and uses computer processing to create cross-sectional images (slices) of the bones, blood vessels and soft tissues inside the body. CT scan images provide more-detailed information than plain X-rays. 29 29 9) Electrocardiogram (ECG) https://en.wikipedia.org/wiki/Electrocardiography https://www.mayoclinic.org/tests-procedures/ekg/about/pac-20384983 (Mayo Clinic) https://nursingcrib.com/medical-laboratory-diagnostic-test/basic-ecg- interpretation-made-easy/ An electrocardiogram is a test that shows how the heart is pumping. A number of electrodes (leads) are put on the skin and connect them to a machine. The machine's printout will show conditions like a heart attack, a heart that beats too slow (bradycardia) or fast (tachycardia), and more. An electrocardiogram monitors your heart rhythm for problems. Electrodes are taped to the chest to record heart's electrical signals, which cause the heart to beat. The signals are shown as waves on an attached computer monitor or printer. 30 30 15  31 31 10) Prostate Specific Antigen Test (PSA Test) https://www.mayoclinic.org/tests-procedures/psa-test/about/pac-20384731 (Mayo Clinic) PSA or prostate specific antigen is an antigen made by cells in a man's prostate gland. A high level of PSA can suggest prostate disease (especially prostate cancer). This test is recommended to be made from time to time. The PSA test is a blood test used primarily to screen for prostate cancer. The test measures the amount of prostate-specific antigen (PSA) in your blood. PSA is an antigen protein produced by both cancerous and non- cancerous tissue in the prostate gland that is located below a man's bladder. 32 32 16  33 33 Rich Information Resources to Build up your Medical Knowledge Health Library Guide to the diagnosis, treatment and prevention of conditions from A to Z. https://www.hopkinsmedicine.org/healthlibrary/ Mayo Clinic – Tests & Procedures https://www.mayoclinic.org/tests-procedures 34 34 17  Special Chemistry Lab Instrumentation and Analytical Methods 1. Electrophoresis : Is used in the assessment of body tissue functions: - Used to separate serum proteins into 5 distinct bands. - Used to separate Lipoproteins into 4 distinct bands. - Often used to separate isoforms of enzymes (isoenzymes/isozymes) 2. High Performance Liquid Chromatography (HPLC): Used to measure vitamins and hemoglobin variants. 3. Infrared Spectroscopy (IRS): Used to analyze components of Kidney stones. 35 35 4. Radioimmunoassay (RIA): Still employed for those analytes present in minute amounts (pmol) in the blood (i.e. testosterone) 5. GC-MS (Gas chromatography-mass spectroscopy) and/or LC-MS (liquid chromatography- mass spectroscopy: Used for quantitative drug measurement 36 36 18  Blood samples — Whole blood — Solid fraction — Fluid fraction — Site of extraction Vein: most common Artery: CO2 and O2 levels Capillaries 37 37 Laboratory analysis — Biochemical analysis (Na+, K+, glucose, cholesterol,….) — Molecular analysis (DNA and RNA) — Cellular evaluation (CBC, ESR, blood culture) 38 38 19  Blood samples — Precautions — Acceptable and unacceptable blood drawing sites — Preparation — Equipment — Blood extraction (venipuncture, finger prick, heel prick) 39 39 Phlebotomy is the process of making an incision in a vein with a needle (to draw blood samples) Phlebotomy Tubes with Different Colored Caps 40 40 20  Cap Color Use Red Serum testing Violet Plasma testing Grey Blood glucose level Black ESR (Erythrocyte sedimintation rate) Blue Prothrombin time Pink Blood bank tests Green Blood chemistry 41 41 42 42 21  43 43 THANK YOU 44 44 22