Chapter 45: Introduction to the Clinical Laboratory Questions and Answers

Chapter 45: Introduction to the Clinical Laboratory Questions and Answers analyte the substance or chemical being analyzed or detected in a specimen anticoagulants category of medication or a chemical that prevents clotting of blood aseptically free from living pathogenic organisms aspirate to withdraw fluid using suction; the material removed using suction; example: a specimen that has been removed from the body using a needle and syringe calibration determining the accuracy of an instrument by comparing its output with that of a known standard or another instrument known to be accurate caustic capable of burning, corroding, or damaging tissue by chemical action control materials manufacturer-prepared samples that have a known quantity of a specific analyte; used for quality control purposes; testing results should fall within a manufacturer-defined range of results; also called controls or quality controls corrosive causing or tending to cause the gradual destruction of a substance by chemical action culture media a solid, liquid, or semi-solid medium designed to support the growth of microorganisms, especially bacteria and fungus cytology the study of cells using microscopic methods exudates fluids with high concentrations of protein and cellular debris that have escaped from the blood vessels and have been deposited in tissues or on tissue surfaces forensic scientific tests or techniques used regarding the detection of crime hemolyzed a blood sample in which the red blood cells have ruptured histology the study of tissues inhalant any substance that can be breathed into the lungs INR international normalized ratio; also called prothrombin time (PT); used to test the effectiveness of blood-thinning medication in vitro Latin term meaning "in glass" and commonly known as "in the laboratory" pathologist a physician specially trained in the nature and cause of disease pure culture the growth of only one microorganism in a culture or on a nutrient surface quality control a process to ensure the reliability of test results often using manufactured samples with known values reagent a substance for use in a chemical reaction referral laboratory a laboratory that performs testing for another laboratory; testing varies from high-volume routine testing to low-volume unique or unusual testing; also called reference, diagnostic, or commercial testing laboratories; often privately owned sharps medical term for devices with sharp points or edges that can puncture or cut skin; examples include needles, scalpels, or broken glass standard operating procedures also known as SOP; a set of step-by-step instructions to help employees carry out routine operations with efficiency, high quality, and uniformity of performance sterile free from all living organisms toxicology the study and science that deal with the effects, antidotes, and detection of poisons or drugs specimen a sample of body fluid, waste product, or tissue collected for analysis American Society for Clinical Pathologists (ASCP) MT: medical technologist MLT: medical laboratory technician MLT-AD: medical laboratory technician associate's degree American Medical Technologists (AMT) MT- medical technologist MLT- medical laboratory technician MLA- medical laboratory assistant RMA- registered medical assistant Department of Health and Human Services (DHHS) CLT- clinical laboratory technologist National Certification Agency for Medical Laboratory Personnel (NCA) CLS- certified laboratory scientist CLT- certified laboratory technician American Association of Medical Assistants (AAMA) CMA- certified medical assistant National Healthcareer Association (NHA) CCMA- certified clinical medical assistant CPT- certified phlebotomy technician CMLA- certified medical laboratory assistant international society for clinical laboratory technology (ISCLT) RMT- registered medical technologist RLT- registered laboratory technician four main purposes for laboratory tests 1. to document the good health of a patient 2. to screen patients for diseases and conditions such as diabetes, high cholesterol, or urinary tract infections (UTIs) 3. to help the provider diagnose a medical disease, disorder, or condition 4. to help the provider decide the most appropriate treatment, to monitor the effects of medications and treatments, and to monitor a disease process the body is healthy when a state of equilibrium exists in the internal environment homeostasis perfect balance that occurs when the physical and chemical characteristics of body substances are within a certain acceptable range, known as the normal range, or reference range normal or reference range a numeric range of test values for which the general population consistently shows similar results 95% of the time abnormal values for a test may be seen with more than one pathologic condition complex profile testing more than one analyte is tested from a single sample screening test examines a specimen for the presence of an analyte that may indicate a disease state; done routinely based on a patient's age, history, or gender qualitative results a numeric value is not attached to the result; reported as positive or negative fetal occult blood (FOB) test looks for blood in a stool specimen; example of a screening test; if the test is positive, further testing is needed to diagnose the cause of the condition quantitative result result is expressed as a number, usually with units of measure attached to numeric values urinalysis 1. includes the physical, chemical, and microscopic examination of urine 2. physical exam notes color, clarity, and specific gravity 3. microscopically, the provider can examine urine for the presence of RBCs, WBCs, epithelial cells, mucus, casts, crystals, and microorganisms 4. used to assess or diagnose diseases such as diabetes mellitus, kidney disease, and UTIs urine dipstick tests the following analytes in urine 1. glucose 2. protein 3. ketones 4. blood 5. bilirubin 6. urobilinogen 7. nitrites 8. pH hematology 1. study of blood cells and coagulation 2. lab testing results may be qualitative or quantitative 3. reference labs perform blood cell counts that determine number of RBCs, WBCs, and platelets in a blood sample 4. microscopic tests determine the characteristics of cells such as size, shape, and maturity chemistry analyzes the chemicals found in blood, cerebrospinal fluid (CSF), urine, and joint fluid (synovial fluid) LDL/HDL low density lipoprotein and high density lipoprotein microbiology the study of very small, infectious organisms such as bacteria, fungi, yeasts, parasites, and viruses; specimens include blood, urine, sputum, CSF, stool, wound material, etc.; specimens must be collected aseptically in sterile containers sensitivity testing performed on organisms to establish an appropriate antibiotic therapy for specific bacterium or fungi clinical laboratory improvement amendments (CLIA) law that established quality standards for all clinical laboratory testing and is designed to ensure the accuracy, precision, reliability, and timeliness of patient test results, regardless of which laboratory performed the testing a clinical laboratory is defined as any facility that performs laboratory testing on human specimens to provide information about the diagnosis, prevention, and treatment of disease or the impairment of health CLIA test categories 1. waived (simple and easily interpreted) 2. moderate complexity 3. high complexity CLIA waived tests 1. can be done in lab or at home 2. designed to have straightforward directions and procedures so that they have a minimal risk of incorrect results 3. reduce the likelihood of incorrect user results 4. pose no immediate risk of harm to the patient if performed incorrectly erythrocyte sedimentation rate (ESR) diagnoses inflammatory process, increases in arthritis, infection, leukemia, and most cancers spun microhematocrit measures RBCs; screening for certain types of anemia cholestech LDX measures total blood cholesterol, triglycerides, HDL, and glucose levels whole-blood i-STAT chem8+ cartridge measures ionized calcium, carbon dioxide, chloride, creatinine, glucose, potassium, sodium, urea nitrogen, and hematocrit in whole blood whole-blood thyroid-stimulating hormone (TSH) assay qualitative determination of thyroid-stimulating hormone (TSH) in whole blood blood mononucleosis antibodies rapid whole-blood test to detect heterophile antibodies to help diagnose infectious mononucleosis helicobacter pylori antibodies rapid whole-blood test to detect H. pylori antibodies to determine the cause of peptic ulcer borrelia burgdorferi antibodies rapid whole-blood test to detect b. burgdorferi antibodies to diagnose Lyme disease trinity biotech uni-gold recombigen HIV test detects HIV-1 in a blood specimen nasal influenza A and B quick qualitative diagnosis of influenza antigens in nasal secretions or swab streptococcus A throat swab rapid strep test urine or blood drug tests multiple tests for the presence of a variety of substance abuse agents urine fertility and menopause tests detect follicle-stimulating hormone (FSH) in urine moderate complexity tests performed in POL normally, include: 1. hematology and chemistry: testing done on an automated analyzer 2. microbiology: gram stain procedures 3. urinalysis: microscopic analysis of urine sediment QA: prenanalytic stage 1. the provider orders a test to screen, monitor, or diagnose a patient's condition 2. a written or electronic requisition is filled out, showing the test requested, the specimen required, and where the specimen will be tested 3. the specimen is collected, labeled, and processed 4. the specimen is transported to the laboratory in the POL or properly prepared for off-site laboratory pick-up QA: analytic stage 1. instruments are maintained and calibrated 2. controls are run and analyzed for each test method 3. the specimen is tested and the results are compared with reference ranges 4. the test results are logged and documented in the patient's health record QA: post-analytic stage 1. specimens are properly discarded 2. analyses of control results are compared over time 3. patient reports from outside laboratories are logged or documented 4. the provider interprets and signs all lab reports 5. the patient is notified of the results in the office or is contacted by laboratory personnel 6. the final report and all communication with the patient is documented in the patient's health record quality control (QC) ensures the reliability of test results while detecting and eliminating error accuracy how close a test result is to the true value of the control material precision the ability to consistently reproduce a test result OSHA hazard communication standard (HCS) 1. known as the employee "right to know" rule; became law in 1991 2. ensures that laboratory workers are made fully aware of the hazards associated with their workplace 3. requires a safety plan for safe practices; a safety data sheet (SDS) must be on file for all chemicals used. 4. SDSs supply information about chemical safety and hazard information in case of an accident, spill, or fire to the user or emergency personnel