Transcript LABORATORY TESTINGx

LABORATORY TESTING
TESTING PROCESS
• DIVIDED INTO THREE IMPORTANT PARTS
• Preanalytical
• Analytical
• Post Analytical
• EACH PART HAS ESSENTIAL STEPS TO BE COMPLETED
• THE OUTCOME OF THE TESTS PERFORMED IS DEPENDENT ON THE
CORRECT EXECUTION OF EACH PART OF TESTING PROCESS
PREANALYTICAL
• Testing process begins with the order from the physician.
• Doctor’s order is documented on a written
• Preprinted form or electronic form
• Most commonly requested tests are indicated in logical sequence
• Patient information MUST be complete, accurate and legible.
• Medical Assistant Duty make be the generation of the
physician’s order.
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PREANALYTICAL
• Specimen collection:
• The Medical Assistant is responsible for the collection of many different types
of specimens.
• Remember ALL clinical laboratory results are only as good as the specimen
received.
• IMPERATIVE THAT SPECIMEN COLLECTION BE UNDERSTOOD AND FOLLOWED
EXACTLY.
PREANALYTICAL
• Common Specimens for laboratory testing
• Blood
• Urine
• Swab samples collected from wombs or mucous membranes.
• Less common samples:
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Feces (Stool specimens)
Gastric content
Cerebral Spinal Fluid (CSF)
Tissue samples and aspirates such as synovial fluid. Analyzed for chemicals,
drugs or cell content.
PREANALYTICAL – COLLECTION OF SAMPLE
• Essentials:
• Identification of the patient as important as correct collection of specimen.
• First and Last name (Correctly spelled)
• A second identifier for patient in the event of duplicate names.
• Birthdate
• Unique ID number; Medical Records number; Physician’s Office Client Number. Any form of
positive identification number that ties the sample directly to the patient for whom it was
ordered.
• Collection of specimen
• Appropriate collection container
• Example vacutainer tube system
PREANALYTICAL COLLECTION OF SPECIMENS
• Vacutainer tube system:
• Available in variety of sizes
• With or without preservatives or anticoagulants
• Color coded so that the color of the stopper denotes which if any additive is
included.
• Collection in an incorrect tube results in an unacceptable specimen and
recollection will be necessary.
PREANALYTICAL SPECIMEN COLLECTION
• Testing ordered for micro-organism presence
• Sterile containers are to be used.
• Specimen to be collected at patient’s home
• Provide appropriate container
• Provide detailed instructions that the patient or patient representative can
understand and follow.
• MA should keep in mind principles of patient education
• Be sensitive to individual patient factors which sometimes can effect the
patient’s understanding of instructions and ability to collect the proper
specimen.
PREANALYTICAL SPECIMEN COLLECTION
• Always check laboratory specimen requirement manual for any
unfamiliar test ordered.
• Manual should list all information on specimen requirements.
• Still questions; Contact the laboratory before collecting the specimen.
• Label the specimen container properly at time of collection
• `Unlabeled specimens are NEVER accepted
• Label to include:
• Patient’s full name
• Date and time of collection
• Type of specimen
PREANALYTICAL SPECIMEN COLLECTION
• Labelling of specimens sent to reference lab must include:
• Physician’s name, account number, address and phone number
• Patient’s full name, surname first, age, date of birth and gender address and insurance
information.
• Source of specimen
• Date and time of collection
• Specific test or tests requested
• Medications taken by the patient
• Whether the patient was fasting or following dietary restrictions if required and time of
last intake.
• Possible diagnosis
• Indication of whether the test is to be performed STAT (Status-Latin) = “Medical
abbreviation for immediately or at this moment”.
PREANALYTICAL SPECIMEN COLLECTION
AND PROCESSING
• Mailed specimens
• Carefully packaged to prevent breakage, damage or contamination by all persons
handling package.
• Specimen must be in unbreakable tubes with secure tops
• Wrap the containers in absorbent paper
• Tape lid shut so that no leakage occurs if the specimen container breaks.
• Place all specimens in a second container such as an impervious biohazard bag for
transport.
• Usually Styrofoam mailers are used because they cushion the sample and provide insulation.
• The complete requisition goes inside the outermost wrap.
• A warning label specifying the etiologic agent or biologic specimen is placed on the
outside of the container.
PRE ANALYTICAL – PROCESSING SAMPLE
• Shipped Samples are usually picked up by courier service.
• Sample should be properly stored until picked up by laboratory.
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Some samples need to be stored at refrigerated temperatures
Some samples need to be stored at room temperature.
Others away from light sources
Samples may need to have serum separated from RBCs
Be sure to check sample storage requirements. Questions that occur must be referred to
testing lab.
• Preventing Contamination:
• Medical Assistants must take care to prevent contamination of specimen and
themselves.
PRE ANALYTICAL PREVENTING
CONTAMINATION
• Expiration dates should be checked on swabs, tubes, transport media
and other collection container should be checked before using items.
• Use of outdated supplies for the collection of samples renders the sample
unsuitable for testing.
• Improperly handled specimen may become contaminated or may
contaminate the surrounding environment.
• Remember “Standard Precautions”.
• Sufficient sample should be collected for the tests requested by the
physician. A QNS (Quantity Not Sufficient) renders a sample
unsuitable for testing and another sample needs to be collected.
PREANALYTICAL COLLECTION OF SPECIMEN
• Specimen collected must be a true representative sample.
• A swab sample for a wound culture must be from the depths of the wound
• A hemolyzed sample of blood or one taken in an atypical area (hemotoma or
above or below IV) will yield erroneous results.
• Volumes of 24 hour urine specimen must be carefully measured and
recorded. Sample must be well mixed before an aliquot is removed for
testing.
• Specimen must be handled, processed and stored according to
individual guidelines to avoid causing any alterations that would
affect test results.
• Medical Assistant is usually responsible for proper handling and
storage of collected specimens.
CHAIN OF CUSTODY
• Chain of custody refers to the stepwise method used to collect,
process and test a specimen.
• Documentation must be signed by every person who has contact with
the specimen from collection to final reporting of results.
• Typical testing requiring “Chain of Custody” procedures are:
• Blood Alcohol
• Drug testing
ANALYTICAL PHASE
• Performance of tests
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Follow established procedures
Check sample for integrity
Perform Quality Control Procedures
Dispose of all samples and test according to safety guidelines.
POST ANALYTICAL PHASE
• Report results to physician according to procedures
• Patient’s chart should be updated with the results of the testing
• Physician is to interpret results of testing and make diagnosis based
on physical exam, symptoms, health history and laboratory testing.