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Clinical Laboratory Antonio Rivas PA-C 2009

Clinical or Medical Laboratory Laboratories that perform chemical and microscopic tests on: blood other body fluids tissues

Clinical Laboratories Play a major role in patient care Variety of settings Two types of Clinical.Laboratory Hospital lab. Non hospital lab. POLs Reference laboratories(LABCORP/QUEST D.) Government laboratories - federal Center for Disease control and Prevention(CDC) Epidemiology labs Laboratory Response Network

Government Laboratories- state Premarital blood testing PKU testing in newborns Fungi,virus, and mycobacteria culture

Regulations of Clinical Laboratory All laboratories, but research labs.are regulated by Federal and State agencies CLIA’88- Clinical Laboratory Improvement Amendments of 1988: Is a revision to the original CLIA of 1967, specifies the minimum performance standards for all Clinical Laboratories

Objectives of CLIA’88 To ensure quality Laboratory Testing, amendments are continually revised, updated, clarified and refined CMS:Center for Medicare and Medicaid Services,agency within the Department of Health and Human Services responsible for implementing CLIA’88

CMS 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

Laboratory Personnel 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 Technical supervisor/Lab.Manager-someone educated in the clinical laboratory sciences who has additional business experience

Laboratory personnel General supervisor for each area Testing personnel: Medical Technologists(MT/CLS) Medical Lab.Technicians(MLT/CLT) Medical assistants/nursing staff(POLs)

Departments of the Clinical Laboratory Clinical Chemistry Hematology Microbiology Blood Bank Supports Services (Phlebotomy/Specimen Processing)

Clinical Chemistry Tests perform in serum, plasma, urine and other body fluids such as spinal fluid, or joint fluid Largest department in the Lab. Toxicology Special chemistry

Hematology Studying of the cellular components of the blood Quantitative or Qualitative Coagulation Urinalysis Special hematology

Microbiology Culture/identification microorganisms From sputum, wounds, blood, urine and other body fluids Inoculated in culture media Organisms are identified and susceptibility test are performed Bacteriology, virology, serology, parasitology

Blood Bank Also called immunohematology or transfusion services ABO group and Rh typing Antibody testing Storage of packed cells units Processing of some components like platelets and cryoprecipitate

Support Services Phlebotomists Accessioning

POCT Point of care testing brings the laboratory to the patient, also called bed-side testing Use small simple analyzers Portable instruments Hgb, glucose, electrolytes,and cholesterol

Quality Assessment System QA.is incorporated to each department’s procedure manuals and day to day operation Standardized material are analyzed on each instrument to document precision, and reproducibility Calibration, maintenance and repair of the instruments is recorded Participate in proficiency testing programs

Health care agencies have very specific standards, rules and regulations governing the education and job responsibilities of the laboratory personnel Lab.professionals are required to complete an authorized program and certification Lab. Personnel need to observe/protect patient privacy

safety Occupational Safety and Health Administration(OSHA) began in 1970 as a legislation and subsequent rules that mandate increased attention to safety in workplaces The Clinical laboratory has, physical, chemical and biological hazards

PPE Employees in the clinical lab are required to use personal protective equipment: Gloves Mask Gowns

Biohazards In 1980 clinical laboratory safety training concentrated in protection from chemical, physical,and contagious diseases such as tuberculosis The discovery of AIDS, increased in Hepatitis B virus(HBV) and Hepatitis C virus(HCV) brought an emphasis on biological safety The term Biohazard came into use A Biohazard symbol was adopted that indicates the presence of biological hazard or biohazardous condition

Evolution on Biological safety By 1960 infectious patients were placed in ISOLATION rooms 1970-CDC outlined isolation guidelines and listed isolation categories 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 1987- Body substance Isolation, included all body fluid even if not visibly contaminated with blood

Evolution on Biological safety 1991-OSHA issued “Bloodborne pathogens standard”, not included on previous regulation 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 To control nosocomial(inst.acquired) infections Transmission-based precautions(additional practices for pathogens that spread by air, droplets, and contact

Evolution on Biological safety 2001-OSHA revised the BBP(blood borne pathogen) standard to prevent accidental needle-sticks in the workplace

Standard Precautions Requires that every patient and every body fluid, body substance, organ, or unfixed tissue be regarded as potentially infectious Hands wash(plain soap) After touching body fluids and contaminated items, after removing gloves and between patient contact Wear gloves When touching blood/body fluids/secretions, wear clean gloves when touching mucous membranes and nonintact skin Wear mask/eye protection/face shield Activities that could generate splashes, spray of blood, body fluids , or secretions

Standard Precautions,cont. Patient care equipment should be handled to prevent transfer of microorganisms to other patients and environment Linen Handle,transport,and process in a manner to avoid contamination of clothing and other patients or environment Occupational health and blood-borne pathogens Prevent injuries when using, handling, cleaning and disposing sharps NEVER RECAP A USED NEEDLE Do not removed used needle from syringe by hand Disposed used sharps on puncture resistant containers

Standard Precautions,cont. Use resuscitation devices as an alternative to mouth to mouth resuscitation Patient placement 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 Environmental control Follow hospital procedures for routine care and cleaning/desinfection of any soiled device, equipment or environmental surface

General laboratory equipment Centrifuges- spin samples at high speeds forcing the heavier particles to the bottom of the container,e.g..separating plasma and blood cells Safety tips Use Standard Precautions/PPE Load must be balanced Tubes must be capped during operation Do not open the centrifuge while rotor is moving Clean spills immediately with surface disinfectants

General laboratory equipment Autoclaves- use steam under pressure to sterilize medical/surgical instruments, or contaminated materials before disposal Never open unless the chamber pressure reads zero Use heat-proof gloves to remove items When sterilizing liquids use loosely capped, heat resistant containers, no more than half full Use an autoclave tray to prevent liquids from spilling

General laboratory equipment Laboratory balances Used to measure chemicals Use PPE and chemical safety precautions Be gentle, Balances are delicate equipment

General laboratory equipment Other equipments Refrigerators Water baths PH meters Incubators Thermometers freezer

The Microscope Is a delicate and expensive instrument , special care must be taken in its use Various types of microscopes, two categories based on type of illumination Light microscopes Bright-field- stained specimens Phase-contrast-unstained cells,urine sediment Epi-fluorescence microscope,specimens treated with fluorescent dyes, syphilis, mycobacteria Electron microscopes:provides greater magnification in medical research

Light microscope images A-stained cell seen with bright field microscope B-phase contrast image C-epi-fluorescence microscopy,Borrelia burgdorferi

Parts of the Microscope Oculars: monocular or binocular Objective lenses: attached to the revolving nose piece, at least 3 present: low, high dry, and oil immersion lenses Light condenser which focuses and directs light to the objectives, iris diaphragm that regulates the amount of light that strikes the object observed Field diaphragm:help align the light Coarse and fine adjustments:focusing knobs Stage:support for the object been viewed

Microscope safety Safety observe electrical safety rules Glass slide handle with care to avoid breaking Unfixed specimens should be treated with standard precautions,disinfect stage after use QA Scheduled maintenance should be performed and documented Care and cleaning of lenses Use only lens paper, clean lenses before and after each use Do not allowed immersion oil to touch the low and high dry lenses Transporting and storing

Using the Microscope Use low power objective to locate and to view large objects With the coarse adjustment knob bring the objective and the slide as close together as possible 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 Use the fine adj.knob to bring the image into sharp focus

Using the Microscope 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 Never use the coarse adjustment knob with high power, the distance between the objective and slide is very small and the slide could break. Oil immersion lenses(100x) give the highest magnification of the bright field objectives

Using oil immersion lenses After initially focusing with the low power, rotate the objective to the side and place a small drop of immersion oil on the slide The oil immersion objective is rotated into the drop of oil been careful no other objective touch the oil use only fine adjustment knob with oil Condenser should be all the way up Maximum light source Open the iris diaphragm to the maximum

After using the Microscope Always switch to the low magnification objective With lens paper clean the oil immersion objective, stage and condenser if oil has become in contact with it Turn the light source off Unplug the microscope Store in proper location or cover as appropriate

Calculate Magnification Degree of magnification on the ocular multiplied by the degree of magnification on the objectives Example: 10x(ocular) x 100x(oil immersion)= 1000x The object viewed would be magnified 1000 times its original size Resolving power: the ability of a microscope to produce separate images of closely spaced details in the object being viewed

Blood collection 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 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

Capillary Puncture Safe Quick Small amount of blood Increased use Point-of-care testing (POCT) Physician Office Laboratories

Capillary Puncture Sites Fingertip Great toe Heel

Lancets Sterile Single-use Different lengths

Routine Venipuncture Phlebotomy Superficial vein Large sample of blood Skill and experience Preserve vein integrity

Venipuncture Supplies Needles Various safety designs 21 ga, 1 inch Needle holders Phlebotomy tray

Venipuncture Supplies Vacuum tubes and anticoagulants Sizes Stopper color: Red: no anticoagulant, to collect serum for blood chemistries and serology tests Lavender: containing EDTA for hematologycal and blood typing tests(ethylenediaminetetraacetic acid ) Green: contains heparin, for lymphocytes studies and special chemistry Light blue: sodium citrate for coagulation studies Gray :potasium oxalate, for glucose and legal alcohol Black: for westergren ESR Draw exact amount

Safety Precautions Observe standard precautions Wear gloves and other PPE Never recap needles Use proper technique Avoid Hemoconcentration: do not leave tourniquet in place for more than 1-2 minutes Hemolysis: do not shake tubes, mix by gently inverting a few times

Patient Preparation Patient I.D. Explain procedure Support patient and arm Be prepared! for any sudden reaction from the patient, or occasional patient who may faint

Apply Tourniquet 3-4 inches above elbow Use quick release tie

Identify Suitable Vein Veins commonly used Median cubital Basilic Cephalic Palpate vein: carefully inspect both arms to find the better site

Perform Venipuncture Alcohol-cleanse site, let air dry, do not touch the site after cleaning Observe bevel up Anchor vein with thumb 1inch below the puncture site Enter vein in the same direction of it, in a15-25 degree angle, in a smooth motion Insert vacuum tube Clot tube first Invert anticoagulant tubes softly 5-7 times

Adverse situations 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 In case of failure to obtain the blood, ask the patient permission for a second intent, if he agrees try in a different site After the second non-productive intent,inform the patient and find another person to draw the specimen

Complete Procedure Activate safety feature Immediate disposal Label tubes before leaving the room Patient care

Patient care The tourniquet is always release before needle is withdraw Gauze should be applied over the puncture site and pressure maintained for 1-3 minutes or until bleeding stops Ask patient to keep arm extended Offer a small bandage if necessary

In Case of Accident Immediately clean exposed area Flood with water Clean with antiseptic soap Report immediately to supervisor Seek medical attention

Label the samples Must contain patient information Name Date of birth Date and time of collection And initials of the person drawing the blood Tubes should never be prelabeled to avoid using the prelabeled tube in the wrong patient Make sure the tubes are clean and no blood has contaminated the outer part of the tubes Place specimen in a biohazard labeled bag and proceed as required by the institution

Clinician's Role Era of high technology, clinicians must have an understanding and working knowledge of modalities other than their own area of expertise: includes diagnostic evaluation and diagnostic services

Laboratory and diagnostic tests are tools to gain additional information about the patient By themselves, tests are not therapeutic used in conjunction with history and physical examination,tests: may confirm a diagnosis or provide valuable information about a patient's status and response to therapy that may not be apparent from the history and physical examination alone.

selecting tests to use: Test selections are based on : subjective clinical judgment, national recommendations, and evidence-based health care. 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.

selecting tests to use: 1.Basic screening (frequently used with wellness groups and case finding) 2. Establishing (initial) diagnoses 3. Differential diagnosis 4. Evaluating current medical case management and outcomes 5. Evaluating disease severity

6. Monitoring course of illness and response to treatment 7. Group and panel testing 8. Regularly scheduled screening tests as part of ongoing care 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)

Basic screening (frequently used with wellness groups and case finding) Cervical Papanicolaou (Pap) test 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

Establishing (initial) diagnoses Serum amylase In the presence of abdominal pain, suspect pancreatitis Thyroid-stimulating hormone (TSH) test Suspicion of hypothyroidism, hyperthyroidism, or thyroid dysfunction in patients 50 years of age

Differential diagnosis Chlamydia and gonorrhea In sexually active persons with multiple partners; monitor for pelvic inflammatory disease

Evaluating current medical case management and outcomes Tuberculosis (TB) blood test QuantiFERON Gold TB Blood test to assess TB exposure in risk population Syphilis serum fluorescent treponemal antibody (FTA) test Positive rapid plasma reagin (RPR) test result

Grading Guidelines for Scientific Evidence A. Clear evidence from all appropriately conducted trials Measure plasma glucose through an accredited lab to diagnose or screen for diabetes B.Supportive evidence from well-conducted studies or registries Draw fasting blood plasma specimens for glucose analysis

C.No published evidence; or only case, observational, or historical evidence • Self-monitoring of blood glucose may help to achieve better control E.Expert consensus or clinical experience or Internet polls Measure ketones in urine or blood to monitor and diagnose diabetic ketoacidosis (DKA) (in home or clinic)

The diagnostic testing model incorporates three phases: pretest, emphasis on appropriate test selection, obtaining proper consent, proper patient preparation, individualized patient education, emotional support, and effective communication. These interventions are key to achieving the desired outcomes and preventing misunderstandings and errors.

Intratest Phase: Elements of Safe, Effective, Informed Care Posttest Phase: Elements of Safe, Effective, Informed Care

The clinical value of a test is related to sensitivity, specificity, and the incidence of the disease in the population tested. Sensitivity and specificity do not change with different populations of ill and healthy patients The predictive value of the same test can vary significantly with age, gender, and geographic location.

Specificity refers to the ability of a test to identify correctly those individuals who do not have the disease. The division formula for specificity is as follows: Specificity%=persons w/o dis.who test neg./total # of persons w/o dis. X 100

Sensitivity refers to the ability of a test to correctly identify those individuals who truly have the disease. The division formula for sensitivity is as follows: Sensitivity% = persons with dis.who test positive/ total # persons tested with disease x 100

Incidence refers to the number of new cases of a disease, during a specified period of time, in a specified population or community. Prevalence refers to the number of existing cases of a disease, at a specific period of time, in a given population.

Predictive values Predictive values refer to the ability of a screening test result to correctly identify the disease state. The predictive value of the same test can be very different when applied to people of differing ages, gender, geographic locations, and cultures.

test outcome deviations Minimize test outcome deviations following proper test protocols. Make certain the patient and his or her significant others know what is expected of them. Written instructions are very helpful.

Reasons for deviations may include the following Incorrect specimen collection, handling, storage, or labeling Wrong preservative or lack of preservative Delayed specimen deliver

Reasons for deviations may include the following Incorrect or incomplete patient preparation Hemolyzed blood samples Incomplete sample collection, especially of timed samples Old or deteriorating specimens

Patient factors that can alter test results may include the following Incorrect pretest diet Current drug therapy Type of illness. Dehydration Position or activity at time of specimen collection

Patient factors that can alter test results may include the following Postprandial status (ie, time patient last ate) Time of day Pregnancy Age and Gender

Patient factors that can alter test results may include the following Level of patient knowledge and understanding of testing process Stress Nonadherence or noncompliance with instructions and pretest preparation Undisclosed drug or alcohol use

avoid costly mistakes Communication errors account for more incorrect results than do technical errors. Properly identify and label every specimen as soon as it is obtained.

Educate the patient and family Educate regarding the testing process and what will be expected Record the date, time, type of teaching, information given, and person to whom the information was given.

Educate the patient and family 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.

Educate the patient and family Avoid technical and medical jargon and adapt information to the patient's level of understanding. Slang terms may be necessary to get a point across.

Educate the patient and family Encourage questions and verbalization of feelings, fears, and concerns Do not dismiss, minimize, or invalidate the patient's anxiety Develop listening skills, and be aware of nonverbal signals (ie, body language)

Educate the patient and family Above all, be nonjudgmental. Emphasize that there is usually a waiting period (ie, turn-around time) before test results are relayed back to the clinicians and nursing unit. Offer listening, presence, and support during this time of great concern and anxiety

Educate the patient and family Because of factors such as anxiety, language barriers, and physical or emotional impairments, the patient may not fully understand and assimilate instructions and explanations

Educate the patient and family 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.

normal or reference values Normal values are those that fall within 2 standard deviations (ie, random variation) of the mean value for the normal population. Normal ranges can vary to some degree from laboratory to laboratory. Frequently, this is because of the particular type of equipment used

normal or reference values 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.

normal or reference values Interpretation of laboratory results must always be in the context of the patient's state of being. 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.

clinical laboratory data values may be reported in conventional units, SI units(Systéme International (SI) units), or both The SI system uses seven dimensionally independent units of measurement to provide logical and consistent measurements

clinical laboratory data values SI concentrations are written as amount per volume (moles or millimoles per liter) rather than as mass per volume (grams, milligrams, or milliequivalents per deciliter, 100 milliliters, or liter)

Numerical values may differ between systems or may be the same. For example, chloride is the same in both systems: 95 to 105 mEq/L (conventional) and 95 to 105 mmol/L (SI).

Recognize margins of error possibility exists that some tests will be abnormal owing purely to chance because a significant margin of error arises from the arbitrary setting of limits. 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

Cultural Sensitivity Many cultures have diverse beliefs about diagnostic testing that requires blood sampling 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

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