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  1. 1. Clinical Laboratory Antonio Rivas PA-C 2009
  2. 2. Clinical or Medical Laboratory <ul><li>Laboratories that perform chemical and microscopic tests on: </li></ul><ul><li>blood </li></ul><ul><li>other body fluids </li></ul><ul><li>tissues </li></ul>
  3. 3. Clinical Laboratories <ul><li>Play a major role in patient care </li></ul><ul><li>Variety of settings </li></ul><ul><li>Two types of Clinical.Laboratory </li></ul><ul><ul><li>Hospital lab. </li></ul></ul><ul><ul><li>Non hospital lab. </li></ul></ul><ul><ul><ul><li>POLs </li></ul></ul></ul><ul><ul><ul><li>Reference laboratories(LABCORP/QUEST D.) </li></ul></ul></ul><ul><ul><ul><li>Government laboratories - federal </li></ul></ul></ul><ul><ul><ul><ul><li>Center for Disease control and Prevention(CDC) </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Epidemiology labs </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Laboratory Response Network </li></ul></ul></ul></ul>
  4. 4. <ul><li>Government Laboratories- state </li></ul><ul><ul><ul><li>Premarital blood testing </li></ul></ul></ul><ul><ul><ul><li>PKU testing in newborns </li></ul></ul></ul><ul><ul><ul><li>Fungi,virus, and mycobacteria culture </li></ul></ul></ul>
  5. 5. Regulations of Clinical Laboratory <ul><li>All laboratories, but research labs.are regulated by Federal and State agencies </li></ul><ul><li>CLIA’88- Clinical Laboratory Improvement Amendments of 1988: </li></ul><ul><li>Is a revision to the original CLIA of 1967, specifies the minimum performance standards for all Clinical Laboratories </li></ul>
  6. 6. Objectives of CLIA’88 <ul><li>To ensure quality Laboratory Testing, amendments are continually revised, updated, clarified and refined </li></ul><ul><li>CMS:Center for Medicare and Medicaid Services,agency within the Department of Health and Human Services responsible for implementing CLIA’88 </li></ul>
  7. 7. CMS <ul><li>Any Laboratory performing Lab.tests in humans ,except for research Labs. Must obtain a certificate from CMS (center for medicare-medicaid services) to be allowed to operate </li></ul>
  8. 8. Laboratory Personnel <ul><li>Director of the Lab.- Pathologist, MD, DO, or hold a doctorate in a related clinical field. Hold certification and have supervisory and clinical laboratory experience </li></ul><ul><li>Technical supervisor/Lab.Manager-someone educated in the clinical laboratory sciences who has additional business experience </li></ul>
  9. 9. Laboratory personnel <ul><li>General supervisor for each area </li></ul><ul><li>Testing personnel: </li></ul><ul><ul><ul><li>Medical Technologists(MT/CLS) </li></ul></ul></ul><ul><ul><ul><li>Medical Lab.Technicians(MLT/CLT) </li></ul></ul></ul><ul><ul><ul><li>Medical assistants/nursing staff(POLs) </li></ul></ul></ul>
  10. 10. Departments of the Clinical Laboratory <ul><li>Clinical Chemistry </li></ul><ul><li>Hematology </li></ul><ul><li>Microbiology </li></ul><ul><li>Blood Bank </li></ul><ul><li>Supports Services (Phlebotomy/Specimen Processing) </li></ul>
  11. 11. Clinical Chemistry <ul><li>Tests perform in serum, plasma, urine and other body fluids such as spinal fluid, or joint fluid </li></ul><ul><li>Largest department in the Lab. </li></ul><ul><li>Toxicology </li></ul><ul><li>Special chemistry </li></ul>
  12. 12. Hematology <ul><li>Studying of the cellular components of the blood </li></ul><ul><li>Quantitative or Qualitative </li></ul><ul><li>Coagulation </li></ul><ul><li>Urinalysis </li></ul><ul><li>Special hematology </li></ul>
  13. 13. Microbiology <ul><li>Culture/identification microorganisms </li></ul><ul><li>From sputum, wounds, blood, urine and other body fluids </li></ul><ul><li>Inoculated in culture media </li></ul><ul><li>Organisms are identified and susceptibility test are performed </li></ul><ul><li>Bacteriology, virology, serology, parasitology </li></ul>
  14. 14. Blood Bank <ul><li>Also called immunohematology or transfusion services </li></ul><ul><li>ABO group and Rh typing </li></ul><ul><li>Antibody testing </li></ul><ul><li>Storage of packed cells units </li></ul><ul><li>Processing of some components like platelets and cryoprecipitate </li></ul>
  15. 15. Support Services <ul><li>Phlebotomists </li></ul><ul><li>Accessioning </li></ul>
  16. 16. POCT <ul><li>Point of care testing brings the laboratory to the patient, also called bed-side testing </li></ul><ul><li>Use small simple analyzers </li></ul><ul><li>Portable instruments </li></ul><ul><li>Hgb, glucose, electrolytes,and cholesterol </li></ul>
  17. 17. Quality Assessment System <ul><li>QA.is incorporated to each department’s procedure manuals and day to day operation </li></ul><ul><li>Standardized material are analyzed on each instrument to document precision, and reproducibility </li></ul><ul><li>Calibration, maintenance and repair of the instruments is recorded </li></ul><ul><li>Participate in proficiency testing programs </li></ul>
  18. 18. <ul><li>Health care agencies have very specific standards, rules and regulations governing the education and job responsibilities of the laboratory personnel </li></ul><ul><li>Lab.professionals are required to complete an authorized program and certification </li></ul><ul><li>Lab. Personnel need to observe/protect patient privacy </li></ul>
  19. 19. safety <ul><li>Occupational Safety and Health Administration(OSHA) began in 1970 as a legislation and subsequent rules that mandate increased attention to safety in workplaces </li></ul><ul><li>The Clinical laboratory has, physical, chemical and biological hazards </li></ul>
  20. 20. PPE <ul><li>Employees in the clinical lab are required to use personal protective equipment: </li></ul><ul><ul><ul><li>Gloves </li></ul></ul></ul><ul><ul><ul><li>Mask </li></ul></ul></ul><ul><ul><ul><li>Gowns </li></ul></ul></ul>
  21. 21. Biohazards <ul><li>In 1980 clinical laboratory safety training concentrated in protection from chemical, physical,and contagious diseases such as tuberculosis </li></ul><ul><li>The discovery of AIDS, increased in Hepatitis B virus(HBV) and Hepatitis C virus(HCV) brought an emphasis on biological safety </li></ul><ul><li>The term Biohazard came into use </li></ul><ul><li>A Biohazard symbol was adopted that indicates the presence of biological hazard or biohazardous condition </li></ul>
  22. 22. Evolution on Biological safety <ul><li>By 1960 infectious patients were placed in ISOLATION rooms </li></ul><ul><li>1970-CDC outlined isolation guidelines and listed isolation categories </li></ul><ul><li>1985-in response to the increasing AIDS/HIV epidemic CDC adopted Universal Blood and Body fluids precautions, to be applied in all patients regardless of their infectious status </li></ul><ul><li>1987- Body substance Isolation, included all body fluid even if not visibly contaminated with blood </li></ul>
  23. 23. Evolution on Biological safety <ul><li>1991-OSHA issued “Bloodborne pathogens standard”, not included on previous regulation </li></ul><ul><li>1996- CDC implemented “Standard Precautions” that includes a comprehensive set of safety guidelines for Health care workers rendering care to patients, this is the current terminology </li></ul><ul><ul><ul><li>To control nosocomial(inst.acquired) infections </li></ul></ul></ul><ul><ul><ul><li>Transmission-based precautions(additional practices for pathogens that spread by air, droplets, and contact </li></ul></ul></ul>
  24. 24. Evolution on Biological safety <ul><li>2001-OSHA revised the BBP(blood borne pathogen) standard to prevent accidental needle-sticks in the workplace </li></ul>
  25. 25. Standard Precautions <ul><li>Requires that every patient and every body fluid, body substance, organ, or unfixed tissue be regarded as potentially infectious </li></ul><ul><ul><li>Hands wash(plain soap) </li></ul></ul><ul><ul><ul><li>After touching body fluids and contaminated items, after removing gloves and between patient contact </li></ul></ul></ul><ul><ul><li>Wear gloves </li></ul></ul><ul><ul><ul><li>When touching blood/body fluids/secretions, wear clean gloves when touching mucous membranes and nonintact skin </li></ul></ul></ul><ul><ul><li>Wear mask/eye protection/face shield </li></ul></ul><ul><ul><ul><li>Activities that could generate splashes, spray of blood, body fluids , or secretions </li></ul></ul></ul>
  26. 26. Standard Precautions,cont. <ul><li>Patient care equipment </li></ul><ul><ul><li>should be handled to prevent transfer of microorganisms to other patients and environment </li></ul></ul><ul><li>Linen </li></ul><ul><ul><li>Handle,transport,and process in a manner to avoid contamination of clothing and other patients or environment </li></ul></ul><ul><li>Occupational health and blood-borne pathogens </li></ul><ul><ul><li>Prevent injuries when using, handling, cleaning and disposing sharps </li></ul></ul><ul><ul><li>NEVER RECAP A USED NEEDLE </li></ul></ul><ul><ul><li>Do not removed used needle from syringe by hand </li></ul></ul><ul><ul><li>Disposed used sharps on puncture resistant containers </li></ul></ul>
  27. 27. Standard Precautions,cont. <ul><ul><li>Use resuscitation devices as an alternative to mouth to mouth resuscitation </li></ul></ul><ul><li>Patient placement </li></ul><ul><ul><li>Use a private room for patients who can be a source of contamination or patients who are not expected to maintain hygiene or environmental control </li></ul></ul><ul><li>Environmental control </li></ul><ul><ul><li>Follow hospital procedures for routine care and cleaning/desinfection of any soiled device, equipment or environmental surface </li></ul></ul>
  28. 28. General laboratory equipment <ul><li>Centrifuges- spin samples at high speeds forcing the heavier particles to the bottom of the container,e.g..separating plasma and blood cells </li></ul><ul><ul><li>Safety tips </li></ul></ul><ul><ul><ul><li>Use Standard Precautions/PPE </li></ul></ul></ul><ul><ul><ul><li>Load must be balanced </li></ul></ul></ul><ul><ul><ul><li>Tubes must be capped during operation </li></ul></ul></ul><ul><ul><ul><li>Do not open the centrifuge while rotor is moving </li></ul></ul></ul><ul><ul><ul><li>Clean spills immediately with surface disinfectants </li></ul></ul></ul>
  29. 29. General laboratory equipment <ul><li>Autoclaves- use steam under pressure to sterilize medical/surgical instruments, or contaminated materials before disposal </li></ul><ul><ul><li>Never open unless the chamber pressure reads zero </li></ul></ul><ul><ul><li>Use heat-proof gloves to remove items </li></ul></ul><ul><ul><li>When sterilizing liquids use loosely capped, heat resistant containers, no more than half full </li></ul></ul><ul><ul><li>Use an autoclave tray to prevent liquids from spilling </li></ul></ul>
  30. 30. General laboratory equipment <ul><li>Laboratory balances </li></ul><ul><ul><li>Used to measure chemicals </li></ul></ul><ul><ul><li>Use PPE and chemical safety precautions </li></ul></ul><ul><ul><li>Be gentle, Balances are delicate equipment </li></ul></ul>
  31. 31. General laboratory equipment <ul><li>Other equipments </li></ul><ul><ul><li>Refrigerators </li></ul></ul><ul><ul><li>Water baths </li></ul></ul><ul><ul><li>PH meters </li></ul></ul><ul><ul><li>Incubators </li></ul></ul><ul><ul><li>Thermometers </li></ul></ul><ul><ul><li>freezer </li></ul></ul>
  32. 32. The Microscope <ul><li>Is a delicate and expensive instrument , special care must be taken in its use </li></ul><ul><li>Various types of microscopes, two categories based on type of illumination </li></ul><ul><ul><li>Light microscopes </li></ul></ul><ul><ul><ul><li>Bright-field- stained specimens </li></ul></ul></ul><ul><ul><ul><li>Phase-contrast-unstained cells,urine sediment </li></ul></ul></ul><ul><ul><ul><li>Epi-fluorescence microscope,specimens treated with fluorescent dyes, syphilis, mycobacteria </li></ul></ul></ul><ul><ul><li>Electron microscopes:provides greater magnification in medical research </li></ul></ul>
  33. 33. Light microscope images A-stained cell seen with bright field microscope B-phase contrast image C-epi-fluorescence microscopy,Borrelia burgdorferi
  34. 34. Parts of the Microscope
  35. 35. Parts of the Microscope <ul><li>Oculars: monocular or binocular </li></ul><ul><li>Objective lenses: attached to the revolving nose piece, at least 3 present: low, high dry, and oil immersion lenses </li></ul><ul><li>Light condenser which focuses and directs light to the objectives, iris diaphragm that regulates the amount of light that strikes the object observed </li></ul><ul><li>Field diaphragm:help align the light </li></ul><ul><li>Coarse and fine adjustments:focusing knobs </li></ul><ul><li>Stage:support for the object been viewed </li></ul>
  36. 36. Microscope safety <ul><li>Safety </li></ul><ul><ul><li>observe electrical safety rules </li></ul></ul><ul><ul><li>Glass slide handle with care to avoid breaking </li></ul></ul><ul><ul><li>Unfixed specimens should be treated with standard precautions,disinfect stage after use </li></ul></ul><ul><li>QA </li></ul><ul><ul><li>Scheduled maintenance should be performed and documented </li></ul></ul><ul><li>Care and cleaning of lenses </li></ul><ul><ul><li>Use only lens paper, clean lenses before and after each use </li></ul></ul><ul><ul><li>Do not allowed immersion oil to touch the low and high dry lenses </li></ul></ul><ul><li>Transporting and storing </li></ul>
  37. 37. Transporting the Microscope
  38. 38. Using the Microscope <ul><li>Use low power objective to locate and to view large objects </li></ul><ul><li>With the coarse adjustment knob bring the objective and the slide as close together as possible </li></ul><ul><li>While looking through the oculars, move the coarse adjustment knob to bring the objective and slide apart until the object on the slide comes into focus </li></ul><ul><li>Use the fine adj.knob to bring the image into sharp focus </li></ul>
  39. 39. Using the Microscope <ul><li>If you need to use the high power(40x), to see cells and sediments, after initial focusing with the low power(20x), rotate the high power into position </li></ul><ul><li>Never use the coarse adjustment knob with high power, the distance between the objective and slide is very small and the slide could break. </li></ul><ul><li>Oil immersion lenses(100x) give the highest magnification of the bright field objectives </li></ul>
  40. 40. Using oil immersion lenses <ul><li>After initially focusing with the low power, rotate the objective to the side and place a small drop of immersion oil on the slide </li></ul><ul><li>The oil immersion objective is rotated into the drop of oil been careful no other objective touch the oil </li></ul><ul><li>use only fine adjustment knob with oil </li></ul><ul><li>Condenser should be all the way up </li></ul><ul><li>Maximum light source </li></ul><ul><li>Open the iris diaphragm to the maximum </li></ul>
  41. 41. After using the Microscope <ul><li>Always switch to the low magnification objective </li></ul><ul><li>With lens paper clean the oil immersion objective, stage and condenser if oil has become in contact with it </li></ul><ul><li>Turn the light source off </li></ul><ul><li>Unplug the microscope </li></ul><ul><li>Store in proper location or cover as appropriate </li></ul>
  42. 42. Calculate Magnification <ul><li>Degree of magnification on the ocular multiplied by the degree of magnification on the objectives </li></ul><ul><li>Example: </li></ul><ul><li>10x(ocular) x 100x(oil immersion)= 1000x </li></ul><ul><li>The object viewed would be magnified </li></ul><ul><li>1000 times its original size </li></ul><ul><li>Resolving power: the ability of a microscope to produce separate images of closely spaced details in the object being viewed </li></ul>
  43. 43. Blood collection <ul><li>Capillary puncture: small amount of blood collected for glucose, K, electrolytes, Hgb, Htc, Plt count, or when a larger sample is difficult to obtain as in newborns </li></ul><ul><li>Routine venipuncture: most common method of obtaining blood, a superficial vein is punctured with a hypodermic needle and blood is collected into a syringe or vacuum tube </li></ul>
  44. 44. Capillary Puncture <ul><li>Safe </li></ul><ul><li>Quick </li></ul><ul><li>Small amount of blood </li></ul><ul><li>Increased use </li></ul><ul><ul><li>Point-of-care testing (POCT) </li></ul></ul><ul><ul><li>Physician Office Laboratories </li></ul></ul>
  45. 45. Capillary Puncture Sites <ul><li>Fingertip </li></ul><ul><li>Great toe </li></ul><ul><li>Heel </li></ul>
  46. 46. Capillary Puncture Sites
  47. 47. Lancets <ul><li>Sterile </li></ul><ul><li>Single-use </li></ul><ul><li>Different lengths </li></ul>
  48. 48. Collection Containers
  49. 49. Procedure
  50. 50. Routine Venipuncture <ul><li>Phlebotomy </li></ul><ul><li>Superficial vein </li></ul><ul><li>Large sample of blood </li></ul><ul><li>Skill and experience </li></ul><ul><ul><li>Preserve vein integrity </li></ul></ul>
  51. 51. Venipuncture Supplies <ul><li>Needles </li></ul><ul><ul><li>Various safety designs </li></ul></ul><ul><ul><li>21 ga, 1 inch </li></ul></ul><ul><li>Needle holders </li></ul><ul><li>Phlebotomy tray </li></ul>
  52. 52. Venipuncture Supplies
  53. 53. Venipuncture Supplies <ul><li>Vacuum tubes and anticoagulants </li></ul><ul><ul><li>Sizes </li></ul></ul><ul><ul><li>Stopper color: </li></ul></ul><ul><ul><ul><li>Red: no anticoagulant, to collect serum for blood chemistries and serology tests </li></ul></ul></ul><ul><ul><ul><li>Lavender: containing EDTA for hematologycal and blood typing tests(ethylenediaminetetraacetic acid ) </li></ul></ul></ul><ul><ul><ul><li>Green: contains heparin, for lymphocytes studies and special chemistry </li></ul></ul></ul><ul><ul><ul><li>Light blue: sodium citrate for coagulation studies </li></ul></ul></ul><ul><ul><ul><li>Gray :potasium oxalate, for glucose and legal alcohol </li></ul></ul></ul><ul><ul><ul><li>Black: for westergren ESR </li></ul></ul></ul><ul><ul><li>Draw exact amount </li></ul></ul>
  54. 54. Safety Precautions <ul><li>Observe standard precautions </li></ul><ul><ul><li>Wear gloves and other PPE </li></ul></ul><ul><ul><li>Never recap needles </li></ul></ul><ul><ul><li>Use proper technique </li></ul></ul><ul><li>Avoid </li></ul><ul><ul><li>Hemoconcentration: do not leave tourniquet in place for more than 1-2 minutes </li></ul></ul><ul><ul><li>Hemolysis: do not shake tubes, mix by gently inverting a few times </li></ul></ul>
  55. 55. Select Equipment
  56. 56. Patient Preparation <ul><li>Patient I.D. </li></ul><ul><li>Explain procedure </li></ul><ul><li>Support patient and arm </li></ul><ul><li>Be prepared! for any sudden reaction from the patient, or occasional patient who may faint </li></ul>
  57. 57. Patient Preparation
  58. 58. Apply Tourniquet <ul><li>3-4 inches above elbow </li></ul><ul><li>Use quick release tie </li></ul>
  59. 59. Identify Suitable Vein <ul><li>Veins commonly used </li></ul><ul><ul><li>Median cubital </li></ul></ul><ul><ul><li>Basilic </li></ul></ul><ul><ul><li>Cephalic </li></ul></ul><ul><li>Palpate vein: </li></ul><ul><li>carefully inspect </li></ul><ul><li>both arms to find </li></ul><ul><li>the better site </li></ul>
  60. 60. Perform Venipuncture <ul><li>Alcohol-cleanse site, let air dry, do not touch the site after cleaning </li></ul><ul><li>Observe bevel up </li></ul><ul><li>Anchor vein with thumb 1inch below the puncture site </li></ul><ul><li>Enter vein in the same direction of it, in a15-25 degree angle, in a smooth motion </li></ul><ul><li>Insert vacuum tube </li></ul><ul><ul><li>Clot tube first </li></ul></ul><ul><ul><li>Invert anticoagulant tubes softly 5-7 times </li></ul></ul>
  61. 61. Perform Venipuncture
  62. 62. Adverse situations <ul><li>In case of patient developing a large hematoma while venipuncture procedure is being done, withdraw the needle, apply pressure, and intent the procedure in a different site </li></ul><ul><li>In case of failure to obtain the blood, ask the patient permission for a second intent, if he agrees try in a different site </li></ul><ul><li>After the second non-productive intent,inform the patient and find another person to draw the specimen </li></ul>
  63. 63. Complete Procedure <ul><li>Activate safety feature </li></ul><ul><li>Immediate disposal </li></ul><ul><li>Label tubes before leaving the room </li></ul><ul><li>Patient care </li></ul>
  64. 64. Patient care <ul><li>The tourniquet is always release before needle is withdraw </li></ul><ul><li>Gauze should be applied over the puncture site and pressure maintained for 1-3 minutes or until bleeding stops </li></ul><ul><li>Ask patient to keep arm extended </li></ul><ul><li>Offer a small bandage if necessary </li></ul>
  65. 65. In Case of Accident <ul><li>Immediately clean exposed area </li></ul><ul><ul><li>Flood with water </li></ul></ul><ul><ul><li>Clean with antiseptic soap </li></ul></ul><ul><li>Report immediately to supervisor </li></ul><ul><li>Seek medical attention </li></ul>
  66. 66. Label the samples <ul><ul><li>Must contain patient information </li></ul></ul><ul><ul><ul><li>Name </li></ul></ul></ul><ul><ul><ul><li>Date of birth </li></ul></ul></ul><ul><ul><li>Date and time of collection </li></ul></ul><ul><ul><li>And initials of the person drawing the blood </li></ul></ul><ul><ul><li>Tubes should never be prelabeled to avoid using the prelabeled tube in the wrong patient </li></ul></ul><ul><ul><li>Make sure the tubes are clean and no blood has contaminated the outer part of the tubes </li></ul></ul><ul><ul><li>Place specimen in a biohazard labeled bag and proceed as required by the institution </li></ul></ul>
  67. 67. Clinician's Role <ul><li>Era of high technology, clinicians must have an understanding and working knowledge of modalities other than their own area of expertise: </li></ul><ul><ul><li>includes diagnostic evaluation and diagnostic services </li></ul></ul>
  68. 68. Laboratory and diagnostic tests are tools to gain additional information about the patient <ul><li>By themselves, tests are not therapeutic </li></ul><ul><li>used in conjunction with history and physical examination,tests: </li></ul><ul><ul><li>may confirm a diagnosis or </li></ul></ul><ul><ul><li>provide valuable information about a patient's status and </li></ul></ul><ul><ul><li>response to therapy </li></ul></ul><ul><ul><li>that may not be apparent from the history and physical examination alone. </li></ul></ul>
  69. 69. selecting tests to use: <ul><li>Test selections are based on : </li></ul><ul><ul><li>subjective clinical judgment, </li></ul></ul><ul><ul><li>national recommendations, </li></ul></ul><ul><ul><li>and evidence-based health care. </li></ul></ul><ul><ul><li>Often diagnostic tests or procedures are used as predictors of surgical risk or morbidity and mortality rates because, in some cases, the risk may outweigh the benefit. </li></ul></ul>
  70. 70. selecting tests to use: <ul><li>1.Basic screening (frequently used with wellness groups and case finding) </li></ul><ul><li>2.   Establishing (initial) diagnoses </li></ul><ul><li>3.   Differential diagnosis </li></ul><ul><li>4.   Evaluating current medical case management and outcomes </li></ul><ul><li>5.   Evaluating disease severity </li></ul>
  71. 71. <ul><li>6.   Monitoring course of illness and response to treatment </li></ul><ul><li>7.   Group and panel testing </li></ul><ul><li>8.   Regularly scheduled screening tests as part of ongoing care </li></ul><ul><li>9.   Testing related to specific events, certain signs and symptoms, or other exceptional situations (eg, infection and inflammation , sexual assault, drug screening, postmortem tests, to name a few) </li></ul>
  72. 72. Basic screening (frequently used with wellness groups and case finding) <ul><li>Cervical Papanicolaou (Pap) test </li></ul><ul><li>Yearly for all women 18 years of age; more often with high-risk factors (eg, dysplasia, human immunodeficiency virus [HIV], herpes simplex); check for human papillomavirus (HPV), chlamydia, and gonorrhea using DNA </li></ul>
  73. 73. Establishing (initial) diagnoses <ul><li>Serum amylase </li></ul><ul><ul><li>In the presence of abdominal pain, suspect pancreatitis </li></ul></ul><ul><li>Thyroid-stimulating hormone (TSH) test </li></ul><ul><ul><li>Suspicion of hypothyroidism, hyperthyroidism, or thyroid dysfunction in patients 50 years of age </li></ul></ul>
  74. 74. Differential diagnosis <ul><li>Chlamydia and gonorrhea </li></ul><ul><ul><li>In sexually active persons with multiple partners; monitor for pelvic inflammatory disease </li></ul></ul>
  75. 75. Evaluating current medical case management and outcomes <ul><li>Tuberculosis (TB) blood test QuantiFERON Gold TB </li></ul><ul><ul><li>Blood test to assess TB exposure in risk population </li></ul></ul><ul><li>Syphilis serum fluorescent treponemal antibody (FTA) test </li></ul><ul><ul><li>Positive rapid plasma reagin (RPR) test result </li></ul></ul>
  76. 76. Grading Guidelines for Scientific Evidence <ul><li>A. Clear evidence from all appropriately conducted trials </li></ul><ul><ul><li>Measure plasma glucose through an accredited lab to diagnose or screen for diabetes </li></ul></ul><ul><li>B.Supportive evidence from well-conducted studies or registries </li></ul><ul><ul><li>Draw fasting blood plasma specimens for glucose analysis </li></ul></ul>
  77. 77. <ul><li>C.No published evidence; or only case, observational, or historical evidence • </li></ul><ul><ul><li>Self-monitoring of blood glucose may help to achieve better control </li></ul></ul><ul><li>E.Expert consensus or clinical experience or Internet polls </li></ul><ul><ul><li>Measure ketones in urine or blood to monitor and diagnose diabetic ketoacidosis (DKA) (in home or clinic) </li></ul></ul>
  78. 78. The diagnostic testing model <ul><li>incorporates three phases: </li></ul><ul><ul><li>pretest, </li></ul></ul><ul><ul><ul><li>emphasis on appropriate test selection, </li></ul></ul></ul><ul><ul><ul><li>obtaining proper consent, </li></ul></ul></ul><ul><ul><ul><li>proper patient preparation, </li></ul></ul></ul><ul><ul><ul><li>individualized patient education, </li></ul></ul></ul><ul><ul><ul><li>emotional support, and effective communication. </li></ul></ul></ul><ul><ul><ul><li>These interventions are key to achieving the desired outcomes and preventing misunderstandings and errors. </li></ul></ul></ul>
  79. 79. <ul><li>Intratest Phase: Elements of Safe, Effective, Informed Care </li></ul><ul><li>Posttest Phase: Elements of Safe, Effective, Informed Care </li></ul>
  80. 80. The clinical value of a test is related to <ul><li>sensitivity, specificity, and the incidence of the disease in the population tested. </li></ul><ul><li>Sensitivity and specificity do not change with different populations of ill and healthy patients </li></ul><ul><li>The predictive value of the same test can vary significantly with age, gender, and geographic location. </li></ul>
  81. 81. <ul><li>Specificity refers to the ability of a test to identify correctly those individuals who do not have the disease. </li></ul><ul><li>The division formula for specificity is as follows: </li></ul><ul><li>Specificity%=persons w/o dis.who test neg./total # of persons w/o dis. X 100 </li></ul>
  82. 82. <ul><li>Sensitivity refers to the ability of a test to correctly identify those individuals who truly have the disease. </li></ul><ul><li>The division formula for sensitivity is as follows: </li></ul><ul><li>Sensitivity% = persons with dis.who test positive/ total # persons tested with disease x 100 </li></ul>
  83. 83. <ul><li>Incidence refers to the number of new cases of a disease, during a specified period of time, in a specified population or community. </li></ul><ul><li>Prevalence refers to the number of existing cases of a disease, at a specific period of time, in a given population. </li></ul>
  84. 84. Predictive values <ul><li>Predictive values refer to the ability of a screening test result to correctly identify the disease state. </li></ul><ul><li>The predictive value of the same test can be very different when applied to people of differing ages, gender, geographic locations, and cultures. </li></ul>
  85. 85. test outcome deviations <ul><li>Minimize test outcome deviations </li></ul><ul><ul><li>following proper test protocols. </li></ul></ul><ul><ul><li>Make certain the patient and his or her significant others know what is expected of them. </li></ul></ul><ul><ul><li>Written instructions are very helpful. </li></ul></ul>
  86. 86. Reasons for deviations may include the following <ul><li>Incorrect specimen collection, handling, storage, or labeling </li></ul><ul><li>Wrong preservative or lack of preservative </li></ul><ul><li>Delayed specimen deliver </li></ul>
  87. 87. Reasons for deviations may include the following <ul><li>Incorrect or incomplete patient preparation </li></ul><ul><li>Hemolyzed blood samples </li></ul><ul><li>Incomplete sample collection, especially of timed samples </li></ul><ul><li>Old or deteriorating specimens </li></ul>
  88. 88. Patient factors that can alter test results may include the following <ul><li>Incorrect pretest diet </li></ul><ul><li>Current drug therapy </li></ul><ul><li>Type of illness.   </li></ul><ul><li>Dehydration </li></ul><ul><li>Position or activity at time of specimen collection </li></ul>
  89. 89. Patient factors that can alter test results may include the following <ul><li>Postprandial status (ie, time patient last ate) </li></ul><ul><li>Time of day </li></ul><ul><li>Pregnancy </li></ul><ul><li>Age and Gender </li></ul>
  90. 90. Patient factors that can alter test results may include the following <ul><li>Level of patient knowledge and understanding of testing process </li></ul><ul><li>Stress </li></ul><ul><li>Nonadherence or noncompliance with instructions and pretest preparation </li></ul><ul><li>Undisclosed drug or alcohol use </li></ul>
  91. 91. avoid costly mistakes <ul><li>Communication errors account for more incorrect results than do technical errors. </li></ul><ul><li>Properly identify and label every specimen as soon as it is obtained. </li></ul>
  92. 92. Educate the patient and family <ul><li>Educate regarding the testing process and what will be expected </li></ul><ul><li>Record the date, time, type of teaching, information given, and person to whom the information was given. </li></ul>
  93. 93. Educate the patient and family <ul><li>Giving sensory and objective information that relates to what the patient will likely physically feel and the equipment that will be used is important so that patients can envision a realistic representation of what will occur. </li></ul>
  94. 94. Educate the patient and family <ul><li>Avoid technical and medical jargon </li></ul><ul><li>and adapt information to the patient's level of understanding. </li></ul><ul><li>Slang terms may be necessary to get a point across. </li></ul>
  95. 95. Educate the patient and family <ul><li>Encourage questions and verbalization of feelings, fears, and concerns </li></ul><ul><li>Do not dismiss, minimize, or invalidate the patient's anxiety </li></ul><ul><li>Develop listening skills, and be aware of nonverbal signals (ie, body language) </li></ul>
  96. 96. Educate the patient and family <ul><li>Above all, be nonjudgmental. </li></ul><ul><li>Emphasize that there is usually a waiting period (ie, turn-around time) before test results are relayed back to the clinicians and nursing unit. </li></ul><ul><li>Offer listening, presence, and support during this time of great concern and anxiety </li></ul>
  97. 97. Educate the patient and family <ul><li>Because of factors such as anxiety, language barriers, and physical or emotional impairments, the patient may not fully understand and assimilate instructions and explanations </li></ul>
  98. 98. Educate the patient and family <ul><li>To validate the patient's understanding of what is presented, ask the patient to repeat instructions given to evaluate assimilation and understanding of presented information. </li></ul>
  99. 99. normal or reference values <ul><li>Normal values are those that fall within 2 standard deviations (ie, random variation) of the mean value for the normal population. </li></ul><ul><li>Normal ranges can vary to some degree from laboratory to laboratory. Frequently, this is because of the particular type of equipment used </li></ul>
  100. 100. normal or reference values <ul><li>The reported reference range for a test can vary according to the laboratory used, the method employed, the population tested, and methods of specimen collection and preservation. </li></ul>
  101. 101. normal or reference values <ul><li>Interpretation of laboratory results must always be in the context of the patient's state of being. </li></ul><ul><li>Circumstances such as hydration, nutrition, fasting state, mental status, or compliance with test protocols are only a few of the situations that can influence test outcomes. </li></ul>
  102. 102. clinical laboratory data values <ul><li>may be reported in conventional units, SI units(Systéme International (SI) units), or both </li></ul><ul><li>The SI system uses seven dimensionally independent units of measurement to provide logical and consistent measurements </li></ul>
  103. 103. clinical laboratory data values <ul><li>SI concentrations are written as amount per volume </li></ul><ul><ul><li>(moles or millimoles per liter) </li></ul></ul><ul><li>rather than as mass per volume (grams, milligrams, or milliequivalents per deciliter, 100 milliliters, or liter) </li></ul>
  104. 104. <ul><li>Numerical values may differ between systems or may be the same. </li></ul><ul><li>For example, chloride is the same in both systems: 95 to 105 mEq/L (conventional) </li></ul><ul><li>and 95 to 105 mmol/L (SI). </li></ul>
  105. 105. Recognize margins of error <ul><li>possibility exists that some tests will be abnormal owing purely to chance </li></ul><ul><li>because a significant margin of error arises from the arbitrary setting of limits. </li></ul><ul><li>Moreover, if a laboratory test is considered normal up to the 95th percentile, then 5 times out of 100, the test will show an abnormality even though a patient is not ill </li></ul>
  106. 106. Cultural Sensitivity <ul><li>Many cultures have diverse beliefs about diagnostic testing that requires blood sampling </li></ul><ul><li>Preserving the cultural well-being of any individual or group promotes compliance with testing and easier recovery from routine as well as more invasive and complex procedures </li></ul>
  107. 108. END

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