Preexamination Considerations for Accurate Blood Testing

School

Forsyth Technical Community College**We aren't endorsed by this school

Course

PHLEBOTOMY 23291

Subject

Nursing

Date

Dec 12, 2024

Pages

Uploaded by GeneralKangaroo4342

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comObjectives1.Demonstrate basic knowledge of the preexamination/preanalytical variables that influence laboratory test results, define associated terminology, and identify the tests most affected by each one variable. 2.Discuss problem areas associated with site selection, including various vascular access sites and devices, and explain what to do when they are encountered. 3.Describe how to handle patient complications and conditions pertaining to blood collection, address procedural error risks and specimen quality concerns, and analyze reasons for failure to draw blood.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comOverviewPreexamination/Preanalytical Phase of TestingBegins when test is orderedEnds when testing beginsSkills Needed in PhlebotomistTechnical skills to perform blood drawAbility to recognize preanalytical factors and address them

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comOverview (cont.)Topics Presented in Chapter 9Physiologic variablesProblem venipuncture sitesTypes of vascular access devicesPatient complications and conditionsProcedural errorsSpecimen quality issuesTroubleshooting failed venipuncture

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comReference Ranges/IntervalsTests confirm health or screen, diagnose, and monitor diseaseTest results are compared with specimens of healthy peopleConsist of range of values with high and low limitsMost often based on healthy, fasting peopleOne way a physician evaluates a patient’s test results is by comparing them to reference ranges and, if available, previous results (i.e., Delta check) on the same patient.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comBasal StateDefinition: resting state of body early in the morning after fasting 12 hoursBasal-State SpecimenIdeal for establishing reference ranges on inpatientsEffects of diet, exercise, etc. on test result are minimizedBasal State Is Influenced By:AgeSexConditions of body

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comPhysiologic VariablesVariableExamplesof effect or tests affected AgeRBC, WBC, creatinine clearance, hormonesAltitudeIncreased: RBC, Hgb, Hct, CRP, uric acidDecreased: urine creatinine, reninDehydrationCauses hemoconcentrationIncreases RBCs, enzymes, Fe, Ca, Na+, K+, coag factorsDietGlucose, lipids, electrolytes,Diurnal/Circadian VariationTSH, cortisol, FeDrug TherapyEnzymes, hormonesExercisepH, PCO2, CK, LDH, glucoseFeverHormones, cortisol, insulinSexRBC, Hgb, HctIntramuscular InjectionCK, LDHJaundiceAbnormal yellow color can interfere in testingPositionAldosterone, bilirubin, blood cells, ca, K+, Pregnancylowers RBCSmokingChol., cortisol, glucose, GH, triglycerides, RBC, WBCStressWBC, Fe, ACTH, catecholamines, cortisolEnvironmental FactorsAcute heat exposure increases plasma volume Excessive sweating increases hemoconcentrationMatch physiologic effects with laboratory tests in the Matching 9-2 activity in the WORKBOOK

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comJaundiceAlthough there are several different causes, jaundice in a patient may indicate liver inflammation caused by hepatitis B or C virus.Figure 9-2Jaundice. Note patient’s yellow skin color in comparison with that of the examiner’s hand.Reprinted with permission from Bickley LS and Szilagyi P. Bates’ Guide to Physical Examination and History Taking, 12th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2016.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comProblem SitesBurns, Scars, and TattoosVeins are difficult to palpate hereMay have impaired circulationNew burns are painfulTattoos may be more susceptible to infection; dyes may interfereDamaged VeinsSclerosed:hardenedThrombosed:clottedDifficult to puncture and yield erroneous resultsIf you have no choice but to draw in an area with a tattoo, try to insert the needle in a spot that does not contain dye. Use another site if possible or draw below (distal to) damaged veins.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comProblem Sites (cont.)EdemaSwelling caused by abnormal accumulation of fluid in tissuesResults when fluid from IV infiltrates surrounding tissuesContaminates blood with tissue fluidVeins are harder to locate, and tissue is fragileHematomaA swelling or mass of bloodCaused by blood leaking from vessel during venipunctureCan be painful, contaminate blood sample, obstruct blood flowPhlebotomists on early-morning rounds in hospitals or nursing homes are often the first to notice edema from infiltrated IVs and should alert the appropriate personnel.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comHematoma•Hematomas resulting from venipunctureAfter you finish this section, do Matching 9-3 in the WORKBOOK to see if you can match problem sites with possible drawbacks. Figure 9-3Examples of bruising resulting from hematomas that formed during or immediately following venipuncture.Courtesy Monica Lewis.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comProblem Sites (cont.)MastectomySurgical breast removalLymph flow is obstructed with removal of lymph nodesSwelling and infection may be presentApplying tourniquet here can cause injuryCan change blood compositionObesityVeins on obesepatients may be deep and hard to findUse longer or bariatric tourniquet and try median cubital or cephalic veinParalysisAvoid drawing blood from paralyzed armIncreased chance of thrombosisDifficult to detect nerve injuryWhen a mastectomy has been performed on both sides, the patient’s physician should be consulted to determine a suitable site.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comVascular Access Devices and SitesIntravenous (IV) LineCatheter inserted in peripheral veinAvoid drawing blood from arm containing IV, if possibleIV Catheter LockNeedless connection device in the form of a stopcock or capSaline lockHeparin lock (heplock)Previously Active IV SitesPotential source of testing errorWait 24 to 48 hours

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comVascular Access Devices and Sites (cont.)Arterial Line (A-line or art-line)A catheter placed in an artery (usually radial)Provides accurate and continuous measurement of blood pressureNo tourniquet or venipuncture on an arm with an arterial lineArteriovenous (AV) Shunt/Fistula/GraphPermanent, surgical fusion of an artery and a veinCreated for dialysis accessLocated on the back of arm above wristOnly nurses and other specially trained personnel are allowed to draw blood specimens from vascular access devices (VADs). A phlebotomist typically assists by supplying the appropriate tubes, andif a syringe is used, safely transferring the blood to the tubes.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comVascular Access Devices and Sites (cont.)Blood Sampling DeviceConnected to arterial or central venous catheter to collect bloodReduces chance of infectionPrevents needlesticksMinimizes waste from line drawsFigure 9-8VAMP®blood sampling device.Courtesy of Edwards Lifesciences LLC, Irvine, CA. Edwards Lifesciences, the stylized E logo, VAMP, VAMP Flex, VAMP Jr., and VAMP Plus are trademarks of Edwards Lifesciences Corporation.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comVascular Access Devices and Sites (cont.)Central Vascular Access Devices (CVADs)Known as indwelling linesConsist of tubing inserted into a main vein or arteryUsed for:Administering fluids and medicationsMonitoring pressuresDrawing bloodCaution: Only specially trained personnel should access CVADs to draw blood. A phlebotomist may assist by transferring the specimen to the appropriate tubes.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comVascular Access Devices and Sites (cont.)Types of CVADsCentral venous catheter (CVC) or lineInserted into large vein (subclavian)Advanced into superior vena cavaExit end tunneled under the skin several inches away One or more lengths of capped tubing protrude from exit siteImplanted portA small chamber attached to indwelling lineSurgically implanted under skin (upper chest or arm)Self-sealing chamber located by palpating the skin and accessing with a special needlePeripherally inserted central catheter (PICC)Inserted in veins of extremities (e.g., AC vein) and threaded into a main vein leading to the heartDoes not require surgical insertion

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comCentral Venous CatheterFigure 9-9Central venous catheters (CVCs). A. CVC placement.B. Groshong®CVC. C. Hickman®CVC.A. Reprinted with permission from Taylor CR, Lillis C, Lemone P. Fundamentals of Nursing: The Art and Science of Nursing Care.6th ed. Lippincott Williams & Wilkins; 2008; B. andC. Courtesy and © Becton, Dickinson and Company.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comImplanted PortFigure 9-10Implanted port. A. Port placement. B. PowerPort®implanted port.C. PowerPort®duo implanted port.A. Reprinted with permission from Taylor CR, Lillis C, Lemone P. Fundamentals of Nursing: The Art and Science of Nursing Care.6th ed. Lippincott Williams & Wilkins; 2008;B. andC. Courtesy and © Becton, Dickinson and Company.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comPeripherally Inserted Central CatheterTest your VAD knowledge with Matching 9-4 and Labeling Exercise 9-2 in the WORKBOOK. Figure 9-11Peripherally inserted central catheter (PICC). A. PICC placement. B. PowerPICC®catheter.A. Reprinted with permission from Cohen BJ. Medical Terminology.4th ed. Lippincott Williams & Wilkins; 2003; B. Courtesy and © Becton, Dickinson and Company.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comPatient Complications and ConditionsAllergies to Equipment and SuppliesAdhesive allergyPlace gauze square over site; have patient remove in 15 minutesOr, have patient apply pressure for 5 minutes instead of bandageAntiseptic allergyUse alternate antisepticLatex allergyLook for sign indicating latex allergy on patient’s door or ask outpatientUse nonlatex equipment (e.g., gloves, tourniquet, and bandages)Patients with known allergies often wear special armbands or have allergy-specific warning signs posted in their hospital rooms.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comPatient Complications and Conditions (cont.)Excessive BleedingPatients on aspirin or anticoagulant may bleed longerMaintain pressure until bleeding stopsIf bleeding continues >5 minutes, notify appropriate personnelCaution:Never apply a pressure bandage instead of maintaining pressure until bleeding has stopped, and do not dismiss an outpatient or leave an inpatient until bleeding has stopped or the appropriate personnel have taken charge of the situation.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comPatient Complications and Conditions (cont.)Fainting (Syncope)A loss of consciousness and postural toneCaused by insufficient blood flow to brainHave patients with history of fainting lie down during venipunctureLower patient’s head and apply cold compress to back of neck (See text Procedure 9-9)Figure 9-12Phlebotomist caring for a patient who feels faint.© Wolters Kluwer.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comPatient Complications and Conditions (cont.)Nausea and VomitingDiscontinue blood draw until feeling subsidesGive patient emesis basin or wastebasketApply cold, damp washcloth to foreheadPainWarn patient before needle insertionAvoid excessive, deep, blind, or lateral redirection of needleExtreme pain or numbness indicates nerve involvement; remove needle immediately, apply ice, document incident if pain persists

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comPatient Complications and Conditions (cont.)PetechiaeTiny, nonraised red spotsAppear on arm when tourniquet is appliedFigure 9-13Petechiae. A.Adult arm. B.Hand of a child with low platelet count.A.Used with permission from medtraining.org; B.Reprinted with permission from McConnell TH. The Nature of Disease Pathology for the Health Professions.Lippincott Williams & Wilkins; 2007.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comPatient Complications and Conditions (cont.)Seizures/ConvulsionsDiscontinue draw immediatelyHold pressure over site without restricting patient’s movementDo not put anything in patient’s mouthProtect patient from self-injuryNotify first-aid personnel

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comProcedural Error RisksHematoma Formation and BruisingDiscontinue draw immediately and hold pressure over site 2 minutesOffer cold compress or ice pack if it is large and swollenIatrogenicAnemiaAnemia brought about by blood loss from blood drawsLife is threatened if >10% of blood volume is removed at onceCollect only minimum required specimen volumesInadvertent Arterial PunctureSigns: rapidly forming hematoma, blood filling tube quickly

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comProcedural Error Risks (cont.)InfectionAvoid by doing the following:Don’t open tape or bandages ahead of timeDon’t preload needles onto tube holders ahead of timeDon’t touch needle insertion site after sterilizing itMinimize time between needle cap removal and venipunctureRemind patient to keep bandage on at least 15 minutes

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comProcedural Error Risks (cont.)Nerve InjuryCaused by:Improper site or vein selectionInserting needle too deeply or quicklyExcessive lateral redirection of needleBlind probingIf initial vein entry is unsuccessful:Use slight forward or backward redirection of needleRemove needle and try an alternate siteFigure 9-14Abnormal hand position called “claw hand” caused by ulnar nerve injury.© Wolters Kluwer.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comProcedural Error Risks (cont.)Refluxof AdditiveBlood flows back into vein from collection tubeTube additives (e.g., EDTA) may cause adverse reactionKeep arm in downward position and tube below venipuncture siteVein DamageAvoid numerous venipunctures in the same area over timeAvoid blind probing and improper techniqueMatch risks to procedural errors in the WORKBOOK activity Matching 9-5.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comProcedural Error and Specimen Quality ConcernsHemoconcentrationA decrease in fluid content of bloodAn increase in nonfilterable large moleculesCaused by stagnation of normal venous flow due to tourniquetHemolysisDamage to or destruction of RBCsHemoglobin escapes into fluid part of specimenPartially Filled Tubes (short draw)Blood-to-additive ratio may be incorrect

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comProcedural Error and Specimen Quality Concerns (cont.)Specimen ContaminationAllowing alcohol residue, fingerprints, glove powder, baby powder, urine on newborn screening samplesGetting glove powder on blood films or capillary specimensDripping perspiration into capillary specimensFollowing improper antiseptic procedureUsing wrong antisepticWrong or Expired Collection TubeRoutinely check expiration datesAdditives in expired tubes may not work properly

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comTroubleshooting Failed VenipunctureTube PositionImproper seatingNeedle fails to penetrate stopperNeedle PositionNeedle not inserted far enoughBevel partially out of skinBevel partially into veinBevel partially through veinBevel completely through veinBevel against vein wallBevel in valveNeedle beside veinUndetermined positionRemember, the important steps to trouble shoot venipuncture: STOP, ASSESS, and CORRECT.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comNeedle PositionA.Correct needle position; blood can flow freely into the needle.Figure 9-19Needle position. A. Correct needle position; blood can flow freely into the needle.© Wolters Kluwer.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comNeedle Position (cont.)B:Needle not inserted far enough; needle does not enter the vein.Figure 9-19Needle position. B. Needle not inserted far enough; needle does not enter the vein.© Wolters Kluwer.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comNeedle Position (cont.)C: Needle bevel partially out of the skin; tube vacuum will be lost.Figure 9-19Needle position. C. Needle bevel partially out of the skin; tube vacuum will be lost.© Wolters Kluwer.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comNeedle Position (cont.)D: Needle bevel partially into the vein; causes blood leakage into tissue.Figure 9-19Needle position. D. Needlebevel partially into the vein; causes blood leakage into tissue.© Wolters Kluwer.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comNeedle Position (cont.)E: Needle bevel partially through the vein; causes blood leakage into tissue.Figure 9-19Needle position. E. Needle bevel partially through the vein; causes blood leakage into tissue.© Wolters Kluwer.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comNeedle Position (cont.)F: Needle bevel completely through the vein; no blood flow obtained.Figure 9-19Needle position. F. Needle bevel completely through the vein; no blood flow obtained.© Wolters Kluwer.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comNeedle Position (cont.)G: Needle bevel against the upper vein wall prevents blood flow.Figure 9-19Needle position. G.Needle bevel against theupper vein wall prevents blood flow.© Wolters Kluwer.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comNeedle Position (cont.)H: Needle bevel against the lower vein wall prevents blood flow. Figure 9-19Needle position. H. Needle bevel against the lower vein wall prevents blood flow.© Wolters Kluwer.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comNeedle Position (cont.)I: Needle bevel penetrating a valve prevents blood flow.Figure 9-19Needle position. I. Needle bevel penetrating a valve prevents blood flow.© Wolters Kluwer.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comNeedle Position (cont.)J: Needle beside the vein; caused when a vein rolls to the side.Figure 9-19Needle position. J.Needle beside the vein; caused when a vein rolls to the side, no blood flow obtained.© Wolters Kluwer.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comNeedle Position (cont.)K: Collapsed vein prevents blood flow despite correct needle position.Figure 9-19Needle position. K. Collapsed vein prevents blood flow despite correct needle position.© Wolters Kluwer.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comTroubleshooting Failed Venipuncture (cont.)Collapsed VeinVein walls draw together temporarily, shutting off blood flowCaused by:Vacuum of tube or plunger pressure is too strong for veinTourniquet is too tight or too close to siteTourniquet is removed during draw (especially with the elderly)Tube VacuumLoss of vacuum due to bevel partially out of skinLoss of vacuum due to damage of tubeThere are a lot of new terms in this chapter. See how many you can unscramble in the WORKBOOK Knowledge Drill 9-2 Scrambled Words activity.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comNAACLS Entry Level Competencies Met in This Chapter4.0Demonstrate understanding of the importance of specimen collection and specimen integrity in delivery of patient care. 4.4List the general criteria for suitability of a specimen for analysis and reasons for specimen rejection or recollection.4.5Explain the importance of timed, fasting, and STAT specimens, as related to specimen integrity and patient care. 5.4Describe substances that can interfere in clinical analysis of blood constituents and ways in which the phlebotomist can help to avoid these occurrences. 5.6 Identify special precautions necessary during blood collection by venipuncture and capillary (dermal) puncture.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comNAACLS Entry Level Competencies Met in This Chapter (cont.)6.0Follow standard procedures to collect specimens.6.1Identify potential sites for venipuncture and capillary (dermal) puncture.6.4List the effects of tourniquet, hand squeezing, and heating pads on specimens collected by venipuncture and capillary (dermal) puncture.6.7Describe the limitations and precautions of alternate collection sites for venipuncture and capillary (dermal) puncture. 6.8Explain the causes of phlebotomy complications.

Copyright©2024byJones&BartlettLearning,LLC,anAscendLearningCompany.www.jblearning.comNAACLS Entry Level Competencies Met in This Chapter (Cont.)6.9Describe signs and symptoms of physical problems that may occur during blood collection.7.0Demonstrate understanding of requisitioning, specimen transport, and specimen processing.7.4Explain methods for processing and transporting specimens for testing at reference laboratories. 7.5Identify and report potential preanalytical errors that may occur during specimen collection, labeling, transporting, and processing.