1. Phlebotomy: Venipuncture and Capillary Puncture
Chapter 40
Phlebotomy: Venipuncture and Capillary Puncture

2. Why Collect Blood? Phlebotomy used to determine disease and treatment
Bloodletting dates back to ancient Egyptians
Phlebotomy historically used to cure patients with “bad” blood

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

4. The Medical Assistant’s Role in Phlebotomy
Provide high-quality care
Focus on safety

5. Anatomy and Physiology of 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
Click here to see an animation

6. Anatomy and Physiology of the Circulatory System
Veins
Usually carry deoxygenated blood, containing carbon dioxide and other cellular wastes
Thin-walled (thinner than arteries)
Carry blood back to the right side of the heart from the cells
No pulse
Capillaries connect most arteries and veins

7. Anatomy and Physiology of the Circulatory System
Arteries
Usually carry oxygenated blood
Thick-walled
Branch to form arterioles, which branch to form capillaries
Have pulse
Path of blood away from the heart

8. Anatomy and Physiology of the Circulatory System
Body contains about 6 liters of blood
Forty-five percent of blood is formed elements
Erythrocytes
Leukocytes
Thrombocytes (platelets)

9. Anatomy and Physiology of the Circulatory System
Two mL of blood will yield about 1 mL of fluid
Liquid part of blood is plasma
Clotting converts fibrinogen into fibrin

10. Anatomy and Physiology of the Circulatory System
Centrifuge separates serum from blood
Anticoagulant prevents blood from clotting to produce plasma specimen
Buffy coat

11. Anatomy and Physiology of the Circulatory System
How to obtain blood sample
Antecubital area
Median cubital vein
Superficial veins in hand
Veins in wrist
Veins in feet or legs
Arteries of arms

12. Venipuncture Equipment
Syringes and needles
Do not destroy integrity of vein
Syringes vary in volume from 1 mL to 50 mL
Pull plunger of syringe to create vacuum within barrel

13. Venipuncture Equipment
Syringes and needles
Avoid causing vein collapse
Use with butterfly collection set
Recommended length of needle

14. Venipuncture Equipment
Safety needles
Required
Protects patient and health care worker

15. Venipuncture Equipment
Vacuum tube system
Closed system
Tube with vacuum already in it attaches to needle
Tube’s vacuum is replaced by blood
Double-pointed needle with different-length needle on each end and screw hub near center

16. Venipuncture Equipment
Vacuum tube system
Needle acts as pipeline to deliver blood from patient to tube
Bevel of needle should face upward when inserted into vein
Insert at 15° angle
Safety tube holders

17. Venipuncture Equipment
Additives, anticoagulants, and gels
Different tests require different types of blood specimens
Anticoagulants prevent clotting of blood
Steps to a clot
Basic anticoagulant tubes
Other additives improve quality of specimen

18. Venipuncture Equipment
Additives, anticoagulants, and gels
Thixotropic separator gel >>
Separator gel tube: centrifuging process
Glass particles activate clotting

19. 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

20. Venipuncture Equipment
Specimen collection trays
Hold all equipment necessary
Carts also used

21. Venipuncture Technique
Approaching the patient
Social skills
Technical skills
Administrative skills

22. Venipuncture Technique
Preparing supplies and greeting the patient
Prepare before venipuncture
Keep spare tubes
Put patient at ease
(see “Greeting the Patient” in the text)

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

24. Venipuncture Technique
Patient and specimen identification
Computer label >>
Aliquot specimen

25. Venipuncture Technique
Positioning the patient
Selecting the appropriate venipuncture site
Order of preferred sites
Antecubital
Back of hand
Wrist (difficult)
Ankle or foot (needs a doctor’s written order)
Use of tourniquet

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

27. Venipuncture Technique
Click Here to play the video

28. Venipuncture Technique
Syringe specimen collection
Identify patient
Verify paperwork and tubes
Assemble equipment
Situate patient in comfortable position
Wash hands

29. Venipuncture Technique
Syringe specimen collection
Select vein
Tie tourniquet
Don gloves
Clean site and allow to air-dry
Palpate for vein

30. Venipuncture Technique
Syringe specimen collection
Hand position to hold syringe >>

31. Venipuncture Technique
Syringe specimen collection
Place blood in appropriate containers
Fill tubes according to recommended order
Activate safety device immediately
Place empty syringe and needle into sharps container

32. Venipuncture Technique
Vacuum tube specimen order of draw
Procedure follows syringe method with only slight variations
Proper hand position >>
Order of draw

33. Venipuncture Technique
Butterfly collection system
Combines benefits of syringe and vacuum methods
Used for small or fragile veins that are difficult to draw
Winged needle inserted at about 5° angle then threaded into vein

34. Venipuncture Technique
Blood Cultures
Use a surgical solution rather than alcohol
Use sterile techniques
Blood is collected into special transport bottles
Aerobic bottle is filled first, then anaerobic

35. Venipuncture Technique
Patient reactions
Vary
Stop if pain persists

36. Venipuncture Technique
The unsuccessful venipuncture
Try another tube
Change position of needle by rotating needle half a turn
Advance further into vein

37. Venipuncture Technique
The unsuccessful venipuncture
Pull back a little
Methods of vein stimulation
Probing of vein not recommended
After two attempts, have someone else try

38. Venipuncture Technique
Criteria for rejection of a specimen
Quality assurance for specimen collection and processing
Another specimen often obtained to recheck results

39. Venipuncture Technique
Factors affecting laboratory values
Incorrect specimen handling and storage
Patient factors
Not fasting
Drawing procedure incorrect
Alcohol in specimen
Tourniquet on too long
Wrong tube

40. 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

41. Capillary Puncture
Puncture sites

42. Capillary Puncture Preparing the puncture site Promoting circulation
Cleaning and disinfecting >>

43. Capillary Puncture Performing the puncture Wear appropriate PPE
Perform the puncture in one steady motion >>
Wipe away the first drop of blood
Collect in capillary tubes or other capillary collection device >>