Handout - 2 - Intro to Clin MED Diagnostic Tests (Part 1).pdf

Intro to Clinical Medicine Before we test: How do we arrive at a clinical diagnosis? Diagnostic Tests...

Intro to Clinical Medicine Before we test: How do we arrive at a clinical diagnosis? Diagnostic Tests Information about the current illness/problem of the patient – Most important: is it an emergency/life threatening The patient history Thomas G. Forsthuber, M.D. Dr. Med. The physical examination Professor of Immunology, Adjunct Professor of Molecular Microbiology, and Immunology Office: BSE 3.250B Diagnostic tests E-mail: [email protected] Office Hours: Monday 4:30 – 5:30 pm Current illness: The patient history When did the symptoms/signs start? Circumstances? – Current and past medical history Is this the first time the patient had these symptoms? – Are there other concurrent medical problems? Are the symptoms getting worse, better, or remain stable? – Other patient issues that could be relevant: Smoking? What steps did the patient take? Did anything help or change? Alcohol, Drugs Social issues, employment, job loss If the patient had this in the past, was there a significant change? – Family history – Any other information that might help with the case  The physical examination Diagnostic tests and procedures – Cultivate the art of observation Non-invasive procedures: – Be systematic in your examination – Eye/ear/throat inspection, neurological test of reflexes, – Develop a routine that you follow – Urine test, throat swab – Know your tools (i.e. the stethoscope!) – X-ray, ultrasound, MRI, CT, ECG, – The future: mobile ultrasound devices – Note: If it does not break the skin it is considered non-invasive (fancy!) Invasive procedures: – Blood draw, spinal tap, biopsy, endoscopy, – Note: If it breaks the skin it is considered invasive! Note: There is no generally accepted definition for “invasive procedure” I. Common Lab tests: Common blood tests: - CBC – Complete blood count (+ Diff) Other important lab tests: - CMP - Comprehensive metabolic panel - Urine: protein, microorganisms, pH, blood, Electrolytes (Na, K, Cl, Ca), glucose, - Stool – blood, parasites, fat blood urea nitrogen (BUN), creatinine - Cerebrospinal fluid, cells, proteins, microorganisms (Crea), liver enzymes (AST, ALT), etc. - Plasma proteins (albumin, enzymes, immunoglobulins - Antibodies (serologic tests) - Hormones (e.g. thyroid hormones) - Disease biomarkers (e.g. for myocardial infarct, pancreatitis, liver disease, renal Pictures courtesy WebPath (Utah) disease) Dr. Edward Klatt, MD - Erythrocyte sedimentation rate = ESR (today only useful for myeloma, temporal arteritis, polymyalgia rheumatica) - Drugs  Blood is routinely analyzed in medicine White Blood Cells (WBC) Sysmex analyzer for CBC (complete blood count): Blood: CBC (complete blood count): RBC: 5 x 10e6/ul Hb: g/100 ml (normal 14 – 16 g/ dL = dL = 100 ml (1/10 of a liter) Pictures courtesy WebPath (Utah) Dr. Edward Klatt, MD Common terms for abnormal CBC CBC in medical charts (Fishbone) Type of Cell Increase Decrease erythrocytosis or anemia or Red Blood Cells (RBC) polycythemia erythroblastopenia White Blood Cells Hgb leukocytosis leukopenia (WBC): 16 -- lymphocytes -- lymphocytosis -- lymphocytopenia WBC Plt -- granulocytes: -- granulocytosis -- granulocytopenia or 8.9 275 agranulocytosis -- --neutrophils -- --neutrophilia -- --neutropenia -- --eosinophils -- --eosinophilia -- --eosinopenia Platelets thrombocytosis thrombocytopenia All cell lines --- pancytopenia www.wikipedia.com  II. Measuring electrical activity for diagnostic purposes Electrocardiogram (ECG, EKG): Measures electrical activity of the heart Electroencephalogram (EEG): electrical activity of the brain Electromyogram (EMG): electrical activity of muscle ECG (also EKG) Electric conduction of the heart Typical ECG strip Sinus node QRS (+) (SA node) ECG T AV node P P wave: atrial depolarization QRS complex: ventricular depolarization T wave: repolarization of the ventricle SA node = sinoatrial node AV node = atrioventricular node Mnemonic: Dog and the cookie  II. Measuring electrical activity ST-elevation in MI Not good: Bad: Ventricular flutter 250-300 beats/min Sinusoidal waves V-FIB Worse: Ventricular Fibrillation: no clear electrical activity