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Biomedical Diagnostics 1 Ch.1 related data INTEGRATING LAB DATA INTO TCM PRACTICE Healthcare: Complex Driven by technology Tests help formulate strategy Recognize Red Flags Prepare for evidence based practice 2 HIPPA AND LAB REPORTS Covers sharing of lab reports DNA tests? Web based tests? Point of Care (POC) tests CLIA (Clinical laboratory Improvement Act 1988) CLIA Waived 3 USING LABORATORY DATA CLINICIAN’S TASKMake reasoned decisionsIn certain situations diagnostic tests are mandated 4 Categories of testing Screening Diagnostic Patient management 5 SCREENING Helps in identifying risk factorsIn early detection of “occult” diseasesBenefits, Costs and Risks must be considered 6 CRITERIA FOR SCREENING POPULATION: NATURE OF THE DISEASE: TEST CHARACTERISTICS: GOOD SENSITIVITY & SPECIFICITY LOW COST AND RISK Home Test Kits- Txt Book Table 1-4 page 13 7 0.45 0.4 0.35 Page 5 Height of Curve 0.3 0.25 0.2 0.15 0.1 0.05 0 -3 -2 -1 0 1 2 3 Standardized Score (Z-score) Bell Curve and Standard Deviation (SD) 8 REFERENCE RANGE Method and laboratory specific Reflects results found in 95% of a healthy population Means 5% will have ‘false positive’ results Therefore ‘borderline’ results must be viewed critically 9 Main Criteria (page 7-9) Sensitivity & Specificity 10 SensitivitySensitivity= TP/(TP +FN) SpecificitySpecificity= TN/(TN + FP) TN= True Negatives TP= True Positives FP= False Positives Sensitivity & Specificity (SnNouts and SpPins) Definition Sensitivity refers to the proportion of people: with disease who have a positive test result. Specificity refers to the proportion of people: without disease who have a negative test result. 12 SpPins and SnNouts SpPin is a mnemonic applied to the finding that when a sign, test or symptom has a high Specificity, a Positive result rules in (SPin) the diagnosis. 13 SpPins and SnNouts SnNout is a mnemonic applied to the finding that when a sign, test or symptom has a high Sensitivity, a Negative result rules out (SNout) the diagnosis. 14 EVIDENCE BASED MEDICINE (page 19) FOR SOUND METHODOLOGY CRITICAL APPRAISAL OF RESEARCH DATA PUBLISH ACCURATE & CLINICALLY USEFUL SUMMARIES OF EVIDENCE 15 POINT OF CARE (POC) TESTS URINALYSIS ‘SCREENING TESTS’(page 2) SIMPLE BLOOD TESTS ?HOME TEST KITS DAT: Direct Access Testing 16 Collection Tubes Additives • Preservatives • Anticoagulants Gel separation tubes Serum tubes Plasma tubes Trace element-free tubes Pediatric tubes (3 mL) 17 B. BLOOD COLLECTION Site: Arteries, Veins, Capillaries Component Types used for testing: • Blood Whole Plasma Serum 18 PLASMA “... the river in which the blood cells travel.” Contains: 1. Water 2. Nutrients (sugars, amino acids, fats, electrolytes, minerals, etc.) 3. Waste products (CO2, lactic acid, urea, etc.) 4. Antibodies (immunoglobulins) 5. Clotting proteins (called clotting factors) 6. Hormones 7. Complement Proteins (inflammation, immune response) 8.Transport Proteins (albumin) 60% Total Blood Volume Plasma = serum + clotting components 19 Lipemia : Can cause factitious Hyponatremia, Hypokalemia, Hyperchloremia Turbidity -Due to lipid particles; causes light to scatter...interferes with photometry Partitioning Error -Analyte can enter lipid…making it inaccessible for chemical reaction Electrolyte Exclusion Effect -Triglycerides > 1500mg/dL (milky serum): Fat replaces serum water, which alters distribution & conc. of electrolytes 20 Some Lab Methods Microbiology- Gram staining- first stain with crystal violet- wash- then second stain with Grams iodinerinse after decolorizing with alcohol-counter stain with safranin and rinse and dry; Gram negative stain pink Gram positive stain purple 21 URINE & RENAL TESTS Discuss: A.Components of Urine B.Collection of Urine 22 A. Urine Components: Color: Yellow, Amber, Red,Orange Clarity: Clear, Cloudy Microscopy: Normal/Abnormal cells, crystals, Chemistry Testing: Electrolytes Kidney function testing Glucose Heavy metals Drug Screens Protein Uric Acid Calcium … & more 23 B. Collection of Urine: Random or timed Sterile plastic container With/without preservatives “Clean Catch” • Cleanse skin • Collect midstream sample Catheter Suprapubic 2 L collection jug Children 24 Timing of Urine Collection: 1.Random Urine Collection Examples: •First morning void: (best for drug analysis) •2- or 3-hour post-prandial: (glucosuria) •Afternoon: (urobilinogen) •Anytime: urinalysis, urine pregnancy 25 2. Timed Urine Collection: • Specified intervals (2-, 12-, 24-hour) • Special instructions - diet, drugs, collection technique, preservatives • How to collect? 1) empty bladder & discard (“first void” urine) 2) Record time and begin urine collection 3) Store container @ 4C between collections (preservative may be required) 4) Record time and volume at the end of collection interval 24-hour Why? diurnal variation of analyte 26 Urine test (page 31-32) 27 28 Urine Color Chart 29 30 31 32 33 Crystals Seen in Urine Normal: calcium oxalate, triple phosphate crystals and amorphous phosphates Very uncommon crystals include: cystine crystals in urine of neonates with congenital cystinuria or severe liver disease, tyrosine crystals with congenital tyrosinosis or marked liver impairment, or leucine crystals in patients with severe liver disease or with maple syrup urine disease 34 little envelopes or tetrahedrons – Oxalate (common) stop signs – Cystine (rare) rectangles – triple phosphates 35 36 37 38 39 ‘Renal’ Tests Creatinine Clearance, page 90 GFR, (198) CMP, BUN, (63) Creatinine, (89) 40 GFR Significance Kidney Damage Stage Description GFR Other findings 1 Kidney damage with normal or high GFR 90+ Protein or albumin in urine are high, cells or casts seen in urine 2 Mild decrease in GFR 60-89 3 Moderate decrease in GFR 30-59 4 Severe decrease in GFR 15-29 5 Kidney failure < 15 41 Serum assessment of Renal function BUN- 8-25 mg/dL Creatinine- 0.6-1.5 mg/dL >1.5 = 50% nephron loss >4.8 = 75% loss ~10 = 90% loss (ESRD) 42 BUN:Creatinine ratio Normal: 10:1 ~20:1. An increased ratio may be due to a condition that causes a decrease in the flow of blood to the kidneys: such as congestive heart failure or dehydration, increased protein, from gastrointestinal bleeding, or increased protein in the diet. The ratio may be decreased with liver disease (due to decrease in the formation of urea) and malnutrition. 43 ?Uric Acid (213) Produced by the breakdown of purines Purines are chemicals that come from nucleic acids (DNA)source:-cells and food Most uric acid is removed by the kidneys and disposed of in the urine Gouty arthritis, also known as gout, is a condition caused by the deposition and accumulation of needle-like uric acid crystals in the fluid and tissues of one or more joints. This causes inflammation, swelling, and severe pain in the joint. 44 Uric Acid Purine metabolism ‘Gout’ Diuretics- thiazides/lasix Pre eclampsia/eclampsia Excessive cell destruction –CCT Prolonged fasting M- 3.6-8.5 mg/dL ; W- 2.3-6.6 mg/dL 45 FOODS RICH IN PURINES ANCHOVIES ASPARAGUS KIDNEYS LIVER LENTILS SARDINES SPINACH SWEETBREADS Note!: Purines are part of nucleic acid metabolism Destruction of DNA as it happens in cancer chemotherapy can result in elevated serum uric acid levels 46 Do NOT Confuse! List Creatine- consumption of high glycemic carbohydrates in conjunction with creatine increases creatine muscle stores and performance. (Cell-TechⓇ-creatine-carbohydrate-alpha lipoic acid supplement ) Creatinine- Creatinine is a break-down product of creatine phosphate in muscle. Creatinine clearence measures kidney GFR Creatine Kinase (CK) Creatine phosphokinase (CK)- Creatine kinase (CK), also known as phosphocreatine kinase or creatine phosphokinase (CPK) is an enzyme expressed by various tissue types. It catalyses the conversion of creatine to phosphocreatine, consuming adenosine triphosphate (ATP) and generating adenosine diphosphate (ADP). Clinically, creatine kinase is assayed in blood tests as a marker of myocardial infarction (heart attack), rhabdomyolysis (severe muscle breakdown), muscular dystrophy and in acute renal failure. 47 Metabolic Panels 1. 2. 3. 4. 5. BASIC-information about the current status of kidneys, blood sugar, and electrolyte and acid/base balance. Glucose Calcium Sodium Potassium CO2 (carbon dioxide, bicarbonate) 6. Chloride 7. BUN (blood urea nitrogen) 8. Creatinine COMPREHENSIVE 1. Glucose 2. Calcium 3. Sodium 4. Potassium 5. CO2 (carbon dioxide, bicarbonate) 6. Chloride 7. Albumin 8. Total Protein 9. BUN (blood urea nitrogen) 10. Creatinine 11. ALP (alkaline phosphatase) 12. ALT (alanine amino transferase, SGPT) 13. AST (aspartate amino transferase, SGOT) 14. Bilirubin 48 ACID BASE BALANCE page 392-393 Renal Failure-462 Urinalysis in disease states-479 49