Medical Technologist Exam Secrets Study Guide 2024

Quality Assurance - ANSWER-Monitoring and checking machines, equipment, specimen collection/labeling, supplies and water for precision and accuracy. Standard - ANSWER-Materials with known qualities and high degree of purity that helps define, identify, and describe other materials or samples. Control - ANSWER-A substance with known concentrations and amounts that are measured in testing. It will usually be made similar chemically and physically to the sample being tested. Out of Control Test Results - ANSWER-When controls are out of range, follow the trouble shooting procedures in place for the lab. -Check Calculations -Visual Inspection of reagents -Inspect instrument -Rerun controls/new controls CLSI - ANSWER-Clinical and Laboratory Standards Institute What does CLSI do? - ANSWER-Sets standards of performance and testing. Labeling Standards - ANSWER-Label must be 2inx1in with patient name in the upper left corner, unique identifiers, birth date, and time of collection Security and Information Technology - ANSWER-Operation and implementation for testing analytical equipment and data management. MUST follow essential elements and de-identification practices. Toxicology and Drug Testing - ANSWER-Protocols for collection, analyzing, interpreting and reporting results should be used for development of procedures. Statical Quality Control and Quantitative Measurements - ANSWER-Guidelines for quality control of measurement procedures to ensure accuracy and safety of lab personnel. Shifts - ANSWER-Short timeframe during which a control value changes. Trend - ANSWER-Longer timeframe during which a control value changes. Upward shift - ANSWER-When the points of control shift above the mean. Downward Shift - ANSWER-When the points of control shift below the mean. Accuracy - ANSWER-The ability of a test to obtain a true value Random Error - ANSWER-A departure from accurate values. ex: air bubbles Precision - ANSWER-Reproducibility of result Repeat testing provides same result time after time. Standard Deviation - ANSWER-a computed measure of how much scores vary around the mean score. Variance - ANSWER-standard deviation squared Sensitivity - ANSWER-The ability to correctly ID the presence of a disease. Ratio of Tests with positive outcomes to the total. Specifcity - ANSWER-The ability to correctly identify the absence of disease. Predictive Value - ANSWER-When a test has both high sensitive and specificity. True Positive (TP) - ANSWER-positive result for patients who have the disease. False Positive (FP) - ANSWER-Positive result for patients who do not have the disease. True Negative (TN) - ANSWER-a negative test result for someone without the disease False Negative (FN) - ANSWER-Have disease but have negative test. Level of Sensitivity - ANSWER-Probability of positive test when patient has disease. TP/(TN+FN) Degree of Specificty - ANSWER-Probability that a negative test truly indicates disease free patient. TN/(TN+FP) Positive Predictive Value - ANSWER-Probability that a test will produce a positive result for the patient with the disease. TP/(TP+FP) Negatice Predictive Value - ANSWER-Probability that a test will produce a negative result for the patient that has no disease. TN/(TN+FN) Total Quality Management (TQM) - ANSWER-a management philosophy that focuses on satisfying customers through empowering employees to be an active part of continuous quality improvement Continuous Quality Improvement (CQI) - ANSWER-A system of internal and external reviews and audits of all aspects of an EMS system. Performance Improvement Council (PIC) - ANSWER-A collaborative effort to share information in order to improve performance and management. Proficiency Testing - ANSWER-Sample tests performed in a clinical laboratory to determine with what degree of accuracy tests are being performed. Testing samples are checked in the same manner as patient specimens. Preanalytical Functions - ANSWER-Actions taken before sample testing. ex: labeling, collection, transport, and preservation. Analytical Functions - ANSWER-Quality assurance program during patient testing. Postanalytical Function - ANSWER-Quality assurance program after patient testing ex: proper documentation ensuring correct result, or any actions taken in interpretation of results. Compliance - ANSWER-encompasses policies, practices, and procedures that must be followed to ensure accurate results and good patient care. Clinical Laboratory Improvement Amendments (CLIA) - ANSWER-Federal standards that regulate laboratory testing, handling, and processing *except research laboratories *Must certify every 2 years Competency assessment - ANSWER-A program that periodically evaluates staff and testing personnel. Competency Testing - ANSWER-A method of evaluating an individual's ability to meet job-specific requirements using their knowledge, skills, and experience. *Laboratories are required to do competency 60 days after fire, then annually. Proficiency Surveys - ANSWER-Required by laboratory accrediting associations to monitor and improve the quality of routine analytics performed by a laboratory. Medical Director - ANSWER-Is responsible for the laboratory's scope, standard of service, and quality of service with regard to legal, moral, and ethical aspects. *PhD, MD, or DO Laboratory Manager - ANSWER-are responsible for technical, administrative and legal aspects of a laboratory. *MLS certified with administrative experience. Laboratory Supervisors - ANSWER-Manage the technical aspects of the lab including quality control, analytes, and instrument maintenance. Technologists and technicians - ANSWER-perform clinical assays as well as teach, train, and supervise support staff. Support Staff - ANSWER-Can include clerical, specimen processing, laboratory assisting, and phlebotomy. Reagent Grade Water - ANSWER-I- highest quality and is used in cases when precision is most important. II- can be used for basic laboratory practices and can only be stored for brief periods of time before contamination. III- Only used to rinse glassware in laboratory. Types of fire extinguishers - ANSWER-A-fired caused by combustible materials (paper, plastic, wood, rubber, and cloth) B-fire caused by flammable liquid (paint thinner, grease, and oil) C-fired from electrical origins D-fire caused by combustible metals (potassium, magnesium, titanium, sodium, and lithium) Multipurpose- fires caused by combustible metals, materials, or flammable liquids. Centrifuge calculation - ANSWER-RCF=1.12xRRx(RPM/1000)^2 RCF-relative centrifugal force RR-Radius of Revolution RPM-Revolutions per minute Molarity (M) - ANSWER-moles of solute/liters of solution Molality (m) - ANSWER-moles of solute/kg of solvent Molarity to Grams - ANSWER-Moles of solute (mol)/Liters of solution (L) Molality to Grams - ANSWER-moles of solute (mol)/kilograms of solvent (Kg) Preparing Dilution from Stock - ANSWER-V(stock)xM(stock)=V(dilute)xM(dilute) V(stock)-unknown M(stock)-molarity of stock solution V(dilute)-needed volume M(dilute)-needed molarity of diluted solution Light Microscope - ANSWER-Light that passes through the background so that the specimen appears darker on a lighter background. (Most common) phase contrast microscope - ANSWER-light microscope that enhances contrast; useful in examining living, unstained cells Dark field mircoscope - ANSWER-Uses a dark field condenser that makes the specimen light against the dark background ex: spirochetes Fluorescent microscope - ANSWER-cells are tagged or dyed with fluorescent dye and stand out as fluorescent against a dark background under the UV light ex: antibody testing Ocular micrometer - ANSWER-small glass disk with thin lines numbered and etched in a row used for measurement. Ammonia - ANSWER-Herpin or EDTA plasma transported on ice centrifuged and separated within 20 minutes of collection *assay immediately for nitrogenous constituents quickly metabolized into ammonia *false increase from nitrogen metabolism due to not placing specimen on ice, not centrifuging, analyzing immediately, or poor venipuncture technique. BUN - ANSWER-Serum or plasma centrifuged and separated within 2 hrs of collection *DO NOT USE sodium fluoride as an anticoagulant for enzymatic testing samples due to the potential inhibition of enzymatic activity. Creatinine, total protein, albumin, and uric acid - ANSWER-serum/plasma centrifuged and separated within 2 hrs of collection, random or 24-hr urine -creatinine interference from noncreatinine chromogens (glucose, ascorbic acid, and acetoacetate) -total protein/albumin How to collect body fluids/CSF for total protein and albumin testing? - ANSWER-Body fluid testing/CSF has to be collected in a sterile container. What can interfere with uric acid testing? - ANSWER-Interfering substances for uric acid are lipids and several pharmaceutical drugs can interfere with the colorimetry. How are tumor markers collected and processed? - ANSWER-Tumor markers can be either serum or plasma. Centrifuged and separated within 2 hours of collection. What testing is under Cardiac markers? - ANSWER-Troponin, hsCRP, BNP, and Homocysteine How is troponin collected and processed? - ANSWER-Troponin testing can be serum or plasma. Needs to be centrifuged and separated within two hours of collecting. Results can falsely decrease from gross hemolysis. How is hsCRP collected and processed? - ANSWER-hsCRP can be serum or plasma. Needs to be centrifuged within two hours of collection. Falsely increased results can be caused by other inflammatory processes like gross hemolysis, lipemia, and icterus. How does BNP need to be collected? - ANSWER-BNP needs to be whole blood or plasma. How is Homocystine collected and processed? - ANSWER-Homocystine is serum only. The sample needs to be separated from the cells within one hour of collection. What testing falls under Endocrine testing? - ANSWER-Thyroid hormone assays (TSH, T3, & T4) What tests for Stress Hormones in the body? - ANSWER-ACTH and Cortisol When is the best time to collect for stress hormone testing? - ANSWER-Stress hormones should be collected between when concentrations are at the highest. Fluctuations throughout the day can cause incorrect levels. ACTH collection and processing - ANSWER-ACTH is collected in an EDTA plasma tube. Centrifuged within 2 hours of collection Needs to be frozen immediately to preserve. What kind of samples can you use for Cortisol tesing? - ANSWER-Cortisol testing can be done with a 24 hour urine, random urine, or serum. What testing falls under Sex Hormones? - ANSWER-Testosterone, Estrone/Estradiol, and Aldosterone How is Testosterone collected and processed? - ANSWER-Testosterone is serum testing and needs to be spun down within 2 hours of collection Reject if grossly hemolyzed, lipemic, or icterus. Estrone/Estradiol collection and processing - ANSWER-Estrone/Estradiol Serum collection and spun down within 2 hours of collection. How does Aldosterone differ in it collection method than the other hormones? - ANSWER-Aldosterone can be a 24 hour urine or serum Patient needs to discontinue potassium-sparing diuretics 4-6 weeks before testing. It also needs to be drawn between after patient has be active. Patient must not ingest multivitams containing Biotin (B7) at least 12hrs prior because of assay method inference. Heme-Derivative testing - ANSWER-Hemoglobin testing Hemoglobin is collected and tested how? - ANSWER-Hemoglobin testing is collected in an EDTA tube and kept in whole blood. What interferes with hemoglobin testing? - ANSWER-interfering with hemoglobin testing 1: Clotted samples 2: Hemolysis (rule of 3) 3: Lipemia (can increase due to abnormal light scatter) 4: Extremely high WBC Count (can increase due to abnormal light scatter.) 5: Hemoglobin variants (can decrease results) What is the rule of 3? - ANSWER-The rule of 3 is RBC x 3 = Hgb Hgb x 3 = Hct How is urine bilirubin and urobilinogen collected? - ANSWER-Urine bilirubin and urobilinogen is collected in a sterile screw-top lid What are interfering circumstances for bilirubin and urobilinogen? - ANSWER-1: Medication and highly pigmented urine can cause false positives 2: if bilirubin is exposed to light or ascorbic acid may result in a false neg result 3: If urobilinogen is stored in formalin it can cause a false neg result. Bilirubin collection and process - ANSWER-Bilirubin can be serum/plasma venipuncture or capillary collection. What can interfere with the testing of bilirubin? - ANSWER-Bilirubin interfering processes 1: light exposure can falsely decrease result from degrading 2: Hemolysis " " 3: Lipemia can falsely increase results due to light scattering How is Myoglobin collected? - ANSWER-Myoglobin can be serum or plasma venipuncture or capillary collection. What can falsely increase myoglobin? - ANSWER-Hemolysis can falsely increase myoglobin Enzyme Testing collection and sample quality - ANSWER-Serum or plasma Hemolysis: - falsely increase ACP, ALP, ALT, AST, CK & LD - falsely decrease Amylase Lipemia: - falsely decrease LD Icterus: -falsely decrease GGT Basic requirements for accurate enzyme testing - ANSWER-Concentration of reactant, temperature (37C), cofactors, coenzymes, ionic strength, and pH Therapeutic Drug Monitoring (TDM) - ANSWER-Serum, plasma,& whole blood Most effective when timed Aminoglycosides TDM - ANSWER-Trough IV infusion peak: 30 minutes after completion IM injection peak: 1 hr after Carbamazepine, phenytoin, phenobarbital, and quinidine are all measured by - ANSWER-Trough Digoxin in measured - ANSWER-At random 6-24 hrs after dose Theophylline can be measured by what 3 ways? - ANSWER-IV infusion: 30 min after loading does then at 4-8 hr intervals during infusion IV bolus: 30 minutes after completion Oral peak: 1.5 hrs after completion Urine TDM must meet the following criteria - ANSWER-Temperature (90-100F) within 4 minutes of collection pH (4.5-8) Specific gravity (1.002-1.030) Creatinine (20-400mg/dL) Lipid testing - ANSWER-Serum or plasma Recommended to fast for 12 hrs prior What can falsely increase lipid testing? - ANSWER-Not fasting for 12 hrs can result in falsely elevated triglycerides. It can also falsely decrease LDL and HDL. Chylomicrons are present and cause interference 6-9 hrs after eating.