Chapter 40

1. Chapter 40 Phlebotomy: Venipuncture and Capillary Puncture

2. Why Collect Blood? • Phlebotomy:for diagnostic purposes or bloodletting as therapeutic measure • Bloodletting dates to ancient Egyptians • Phlebotomy historically used to cure patients with “bad” blood • Also called venipuncture

3. The Medical Assistant’s Role in Phlebotomy • To collect blood as efficiently as possible for accurate and reliable test results • Role varies • Direct contact with patient • Provide high-quality care • Must act professionally

4. Anatomy and Physiologyof the Circulatory System • Blood forms in body’s organs and bone marrow • Blood carries oxygen and nutrients to cells and removes waste products and carbon dioxide • Please see the Animations/Videos button to view the clip.

5. Anatomy and Physiologyof the Circulatory System • Heart: pumps blood through body • Arteries: blood flows away from heart • Veins: blood flowing back to heart • Capillaries: connecting most arteries and veins

6. Anatomy and Physiologyof the Circulatory System • Arteries • Carry blood from heart, carry oxygenated blood (except pulmonary artery) • Normally bright red in color • Elastic walls that expand with surge of blood • No valves • Can feel a pulse

7. Anatomy and Physiologyof the Circulatory System • Veins • Carry blood to heart, carry deoxygenated blood (except pulmonary vein) • Normally dark red in color • Thin walls/less elastic • Valves • No pulse

8. Anatomy and Physiologyof the Circulatory System • Body contains about 6 liters of blood • 45% of blood is formed elements • Erythrocytes • Leukocytes • Thrombocytes (platelets)

9. Anatomy and Physiologyof the Circulatory System • 55% of blood is liquid • 2.5 milliliters (mL) blood will yield about 1 mL serum • Liquid part of blood is plasma • Clotting converts fibrinogen into fibrin

10. Anatomy and Physiologyof the Circulatory System • Centrifuge separates serum from blood • Vacuum collection tubes showing serum and plasma • Anticoagulant prevents blood from clotting • Buffy coat: leukocytes and thrombocytes

11. Blood Collection • Most laboratory tests performed on serum, plasma, or whole blood • Serum sample: serum separator vacuum tube with thixotropic gel used • Do not use serum separator tubes for therapeutic drug monitoring (TDM) or toxicology studies

12. Blood Collection • Plasma and whole-blood collection • Tubes containing anticoagulants used • Preparing plasma specimen for transport or testing similar to serum preparation

13. Blood Collection • Collection of blood specimens • Venipuncture commonly used method • Antecubital area • Median cubital vein • Superficial veins in hands or wrist • Veins in feet or legs • Arteries of arms

14. Venipuncture Equipment • Syringes and needles • Syringes usually made of plastic • Vary in size from 1 mL to 10 mL; Luer-Lok tip • Needles attach to syringes

15. Venipuncture Equipment • Syringes and needles • Needles vary in gauge and length • Special needle; multidraw needle • Winged infusion set (butterfly) with safety needle

16. Venipuncture Equipment • Safety needles and blood collection systems • OSHA requires safety needles • Prevent on-the-job needlestick injuries • Needlestick prevention devices (NPDs)

17. Venipuncture Equipment • Vacuum tubes and adapters/holders • Vacuum tubes: vacuum-packed test tubes with rubber stoppers • Plain or with added chemicals or substances necessary for appropriate test to be run • Plastic holders or tube adapters used in conjunction with vacuum tubes

18. Venipuncture Equipment • Anticoagulants, additives, and gels • Different tests require different types of blood specimens • Additive: • Anticoagulant to prevent clotting of blood • Chemical to help preserve blood • Substance to accelerate clotting process

19. Venipuncture Equipment • Anticoagulants, additives, and gels • Gel plugs: act as separators between blood cells/clot and serum/plasma • Anticoagulant: chemical substance that prevents clotting; identified by tube color • Clot activators: silica particles on sides of the tubes that initiate clotting process

20. Venipuncture Equipment • Anticoagulants, additives, and gels • When centrifuged, gel changes to liquid • Gel forms solid plug and separates cells/clot from plasma/serum • Separator thixotropic gel tube>>

21. Venipuncture Equipment • Order to draw • Revised Order of Draw published in 2003 by CLSI and is still the standard • Sterile collection bottles need to be filled first to prevent any contamination • After sterile culture tubes drawn, order for other tubes is related to additives in them

22. Venipuncture Equipment • Tourniquets • Constrict flow of blood in arm • Make veins more prominent • Rubber or elastic strip 1 inch wide by 15–18 inches long • Blood pressure cuff may be used instead

23. Venipuncture Equipment • Specimen collection trays • Hold all equipment necessary • Portable

24. Venipuncture Technique • Approaching the patient • Social skills • Technical skills • Administrative skills

25. Venipuncture Technique • Preparing supplies and greeting the patient • Prepare before venipuncture • Place all tubes within easy reach • Keep spare tubes

26. Venipuncture Technique • Patient and specimen identification • Ask patient to state full name • Check wristband if applicable • Label specimen tubes before leaving examination room • Check paperwork against tubes

27. Venipuncture Technique • Patient and specimen identification Computer label >> Aliquot specimen>>

28. Venipuncture Technique • Positioning the patient • Comfortable for patient and health care professional • Selecting the appropriate venipuncture site • Antecubital • Back of hand • Back of wrist (can be painful) • Ankle or foot (provider permission needed)

29. Venipuncture Technique • Applying the tourniquet • Applied 3 to 4 inches above intended puncture site • Tightly enough to slow flow of blood in veins but not so tightly as to prevent flow of blood in arteries • On arm no longer than 1 minute • Remove as soon as blood flow established

30. Venipuncture Technique • Performing a safe venipuncture • Find site that will give best blood return • Palpate vein with tip of index finger • Differentiating between veins, tendons, nerves • Use tourniquet appropriately • Avoid scars and compromised arms

31. Specimen Collection • Hand washing critical step • Tie tourniquet • Select a vein • Cleanse site firmly with alcohol pad • Allow area to air dry • Put on gloves • Palpate vein

32. Specimen Collection • The syringe technique • Ideal for collecting small volumes of blood from fragile, thin, or “rolling” veins • Blood placed in appropriate containers • Order of filling the tubes important • Use a safety system

33. Specimen Collection • The syringe technique Proper hand position to hold syringe >>

34. Specimen Collection • The syringe technique • After drawing blood into syringe, activate needle’s safety mechanism, then remove needle and dispose • Connect needleless syringe to transfer device • Insert vacuum tube to device • Allow blood to transfer from syringe to tube • After filling, mix any tubes containing additives

35. Specimen Collection • Vacuum tube specimen collection • Improvement over syringe method with only slight variations • Vacuum already in tube <<Proper hand position

36. Specimen Collection • Butterfly needle collection system • Combines benefits of syringe and vacuum tube methods • Used for small and fragile veins that are difficult to puncture • Winged needle inserted at 5- to 10-degree angle then threaded into vein • Works well on children

37. Specimen Collection • Blood cultures • Use surgical solution rather than alcohol • Use sterile techniques • Blood collected into special transport bottles • Aerobic bottle filled first, then anaerobic

38. Specimen Collection • Patient reactions • Vary • MA must anticipate reactions and respond appropriately • If pain persists, discontinue venipuncture

39. Specimen Collection • The unsuccessful venipuncture • Stimulate the vein • Change position of needle by rotating needle half a turn • Advance further into vein • Pull back a little • Try another tube

40. Specimen Collection • The unsuccessful venipuncture • Withdraw needle slowly • Probing of site not recommended • After two attempts, have someone else try • Notify patient’s provider if two MAs unsuccessful

41. Specimen Collection • Criteria for rejection of a specimen • Quality-assurance controls for specimen collection and processing • Retesting specimen or collecting another sample

42. Specimen Collection • Factors affecting laboratory values • Improper specimen handling and storage • Patient physiologic factors may contribute to inaccurate results • Special handling requirements not met • Patient alters results by certain actions

43. Capillary Puncture • Method of obtaining one to several drops of blood • Tests that use blood obtained by capillary puncture • CBC, RBC, and WBC • Hemoglobin and hematocrit • Glucose testing • Phenylketonuria testing

44. Capillary Puncture • Capillary blood collection sites

45. Capillary Puncture • Preparing capillary puncture site • Promoting circulation Cleaning and disinfecting >>

46. Capillary Puncture • Performing the puncture • Wear appropriate PPE Perform puncture in one quick, steady movement >> • Wipe away first drop of blood Collect in capillary tubes or other capillary collection device >>