Y khoa - Dược - Chapter 48: Collecting, processing, and testing blood specimens

48Collecting, Processing, and Testing Blood Specimens48.1 Discuss the role of the medical assistant when collecting, processing, and testing blood samples. 48.2 Carry out the procedure for collecting a blood specimen. 48.3 Discuss ways to respond to patients’ needs when collecting blood.48.4 Carry out the procedure for performing blood tests. Learning OutcomesIntroduction Medical assistantCollects blood specimensPerforms waived testingKnowledge neededDealing with patientsHow to obtain a blood sampleAppropriate supplies and equipmentHow to perform and screen common blood testsThe Role of the Medical AssistantPhlebotomyPutting the patient at easeProcessing specimens and conduct testingCompleting necessary paperwork Apply Your KnowledgeWhat is the role of the medical assistant related to collecting blood samples?ANSWER: The medical assistant will put the patient at ease during the procedure, process specimens, conduct testing, complete necessary paperwork, and make sure specimens are handled properly.Very Good!Collecting Blood SpecimensReview the test orderAssemble equipment and suppliesVaries with test typeCollection devices ~ label correctlyAlcohol wipes; adhesive bandage Tourniquet for venipunctureCollecting Blood SpecimensPreparing the patientGreet and identify the patient Confirm pretest preparationExplain the procedure and safety precautionsEstablish chain of custodyHandle an exposure incidentDrawing BloodKnow your scope of practice for your state Phlebotomy Use Standard PrecautionsUse appropriate PPEDrawing Blood (cont.)Venipuncture Evacuation systems Double-pointed needle and collection tube holderDecreased chance of accidental exposure Drawing Blood (cont.)Needle and syringe systemsButterfly systemWinged infusion setLess trauma to veinDrawing Blood (cont.)Collection tubes Color-coded to identify appropriate additive such as EDTABe sure to select the correct tubesDraw in correct orderDrawing Blood (cont.)Engineered safety devicesReduce the possibility of needlestick injuriesTypes Retracting needlesHinged or sliding shieldsSelf-blunting needlesRetractable lancetsDrawing Blood (cont.)Capillary puncture Superficial puncture of the skinSites ~ outer edge of finger or heelLancet Automatic puncturing deviceDrawing Blood (cont.)MicropipettesMICROTAINER tubesReagent productsSmear slides Apply Your KnowledgeWhat precautions should you take when collecting a blood specimen?ANSWER: You should use Standard Precautions and appropriate personal protective equipment.excellent!Responding to Patient NeedsRespond with sensitivity and competenceProvide information appropriate to patient’s needsAnswer questions that are within your scope of practicePatient Fears and ConcernsPain Bruises or scars – hematomaSerious diagnosisContracting a disease from the procedureSpecial Considerations (cont.)Patients at risk for uncontrolled bleedingHemophilia or taking blood-thinning medicationHold site for at least 5 minutesContact physician if bleeding does not stopSpecial Considerations (cont.)Difficult patientsDifficult venipuncture ~ do not stick more than twiceFainting patients ~ position to avoid injuryAngry or violent patient ~ do not argueApply Your Knowledge ANSWER: After drawing blood on a patient taking anticoagulants, you should hold a cotton ball over the puncture site for at least 5 minutes, monitor the site carefully, and notify the physician if bleeding does not stop.What is one precaution you can take when drawing blood from a patient who is taking anticoagulants?Correct!Performing Common Blood TestsResults aid in diagnosisPOLs – waived testsBe familiar with other tests alsoPerforming Common Blood Tests (cont.)Chemicals in labAnticoagulants Serum separatorsStainsRange of normal test valuesHematologic TestsVenous or capillary bloodWhole bloodFormed elementsPlasmaPhysician can orderIndividual testsComplete blood (cell) countHematologic TestsComplete blood (cell) countRBC countWhite blood cellsDifferential WBCcountHematologic TestsComplete blood (cell) countPlateletHematocritHemoglobinHematologic TestsDifferential Cell countPrepare a smear slide and stain the smearStaining kits Cell type / 100 leukocytes countedHematologic Tests (cont.)HematocritCentrifuge microhematocrit tubePacked red blood cellsBuffy coatPlasma Compare column of packed RBCs to hematocrit gaugeAutomated Hematocrit readersHematologic Tests (cont.)Hemoglobin Sample must undergo hemolysisColor then evaluatedAutomated hemoglobin analyzersMeasure amount of hemoglobin in whole bloodFollow manufacturer’s instructionsHematologic Tests (cont.)Cell morphology – requires special trainingCoagulation testsPT and PTTAutomated devices ~ calculate International Normalized ratio (INR)Hematologic Tests (cont.)Erythrocyte sedimentation rate (ESR)Measures rate of RBCs falling to the bottom of the blood sampleTube must contain an anticoagulantRead after one hourRecord as mm/hr.Chemical TestsSpecialized equipment and techniques Subject to CLIA ‘88 regulationsNew automated equipmentMore readily availableSimpler to operateDevelopment of new waived testsChemical Tests (cont.)Blood glucose monitoringRoutinely performed in POLGlucometerPatient educationChemical Tests (cont.)Hemoglobin A1cGlucose molecules bind to hemoglobinProvides overall picture of effectiveness of diabetes treatmentOptionsSent to outside laboratoryPerform in officeHome testingChemical Tests (cont.)Cholesterol testsRoutinely performed in POLAutomated devicesPOLHome testingUse a capillary sampleSerologic TestsDetection a reaction to an antigen or antibody Immunoassays Western blotRadioimmunoassay (RIA)Enzyme-linked immunosorbent assay (ELISA)Immunofluorescent antibody (IFA) testSerologic Tests (cont.)Rapid screening testsDetect antibodies to certain infectionsInfectious mononucleosisHIVHelicobacter pyloriFollow manufacturer’s instructionApply Your KnowledgeMatching:___ Hemoglobin A1c A. ESR___ Lysing RBCs/evaluating the color B. Serology test___ Shape or form of objects C. Coagulation tests___ Identify bleeding problems D. Chemical test___ Rate at which RBCs fall E. Differential___ Percentage of each type of WBC F. Morphology___ ELISA G. HemoglobinANSWER:GFEDCBASuper!In Summary48.1 As a medical assistant, you will collect and process blood specimens for examination, make sure the test results are handled efficiently and accurately, and complete the necessary paperwork before and after each test. In Summary (cont.)48.2 Blood is collected by venipuncture or capillary puncture. When collecting blood specimens, it is essential that you: confirm the patient’s identitycleanse the skin prior to collectionfollow standard precautionscollect the sample needed in the appropriate tube or containerensure the patient’s safety. In Summary (cont.)48.3 Patients may have concerns when having blood drawn. Good communication by the medical assistant is the key to easing these fears. There are always patients who will have special needs. Each patient will present a special set of challenges and should be treated with the utmost care and concern. In Summary (cont.)48.4 Hematologic, chemical, and serologic tests require special care when performing them. The medical assistant should review the manufacturer’s instructions carefully for important information about correctly performing each test. End of Chapter 48Blood will tell, but often it tells too much. ~ Don Marquis