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

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

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

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

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

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

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

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)

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

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

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

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

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

Venipuncture Equipment Safety needles Required Protects patient and health care worker

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

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

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

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

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

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

Venipuncture Technique Approaching the patient Social skills Technical skills Administrative skills

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)

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

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

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

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

Venipuncture Technique Click Here to play the video

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

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

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

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

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

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

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

Venipuncture Technique Patient reactions Vary Stop if pain persists

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

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

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

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

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

Capillary Puncture Puncture sites

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

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 >>