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 Requisition. REQUISITION: 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 Requisition per physician’s order.

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: 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. 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 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.