Chapter 39
syringe method
a. Children, infants, older adults, oncology patients, severely burned patients, obese patients, inaccessible veins, extremely fragile veins, when specimen requires blood drop b. Easier to perform, allows for smaller amount of specimen c. Not recommended for dehydrated patients or those with poor circulation. Cannot be used for blood cultures, erythrocyte sedimentation rate.
vacuum tube method
a. Routine collection, multiple tubes needed, whenever possible. b. Fast, relatively safe, best specimen quality, large collection amount c. May not work with small veins, fragile veins, difficult draws, small children, hand or feet draws.
cephalic vein location
lateral side of upper arm.
dark blue top tube
sodium heparin or Na2EDTA. Contains no contaminating metals. Toxicology, trace element testing.
Dark Green top tube
sodium heparin, lithium heparin. Inactivates thrombin and thromboplastin.
tan/brown top tube
sodium heparin. Serum lead determination.
diurnal rhythm
specimens drawn at specified time intervals. Exact time noted.
centrifuge
spins the test tube of blood, causing the blood to separate according to weight. Blood clots without anticoagulant, producing the following results. - Blood clots at the bottom - Clear serum on top. • Most laboratory tests performed on serum, plasma, or whole blood
55
% is liquid called plasma: fluid matrix for blood cells, electrolytes, proteins, and chemicals to travel through body
45
% of blood is formed elements
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
CLSI standard order of draw
- Blood culture tubes or vials: yellow top or culture bottles. - Sodium citrate: light blue top - Serum tubes: red top and red/gray and gold top (SST) - Heparin tubes: green tops, light and dark - EDTA tubes: lavender top, then pink, white, or royal blue - Glycolytic inhibitor: gray top - Fibrin degradable products: dark blue
tourniquet
- Constrict flow of blood in arm. Make veins more prominent and distributes pressure while not cutting into patient's arm - Can be disinfected or discarded
performing safe venipuncture
- Find site that will give best blood return - Palpate vein with tip of index finger, should be bouncy to the touch. - Differentiating between veins, tendons, nerves - Use tourniquet appropriately - Be sure to distinguish the vein from the artery (an artery will be pulsating. DO NOT puncture!) - Avoid scars and compromised arms (such as edematous arms from poor lymph action), deep insertions.
safety instructions for syringe venipuncture
- Never transfer to vacuum tube using a needle. Use safety transfer device - Never push blood into vacuum tube. It will fill on its own - Always wear gloves, goggles, and face guard.
preparing supplies for venipuncture
- Prepare before venipuncture - Place all tubes within easy reach - Keep spare tubes
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/withdraw needle slowly - Probing of site not recommended
alternative veins locations
- Superficial veins in hands or wrist - Veins in feet or legs - Arteries of arms
applying the tourniquet
- Tightly enough to slow flow of blood in veins but not so tightly as to prevent flow of blood in arteries - Remove as soon as blood flow established
criteria for specimen rejection
1. Each specimen must have its own label (on bottle, requisition) 2. Labels must be complete 3. Needles may not be attached to bottle. 4. Must have appropriate anticoagulant 5. Bottle must be at least 75 percent full, collection tubes for coagulation testing 90 percent full 6. Anticoagulant well mixed, free of clots 7. Recollect if results differ sharply from provider's diagnosis 8. Do not combine partially collected tubes or mix tubes of different additives. 9. Invert tubes 8-10 times to prevent microclots from forming 10. Mix tubes gently to prevent hemolysis.
obtaining blood culture
1. Identify patient, explain procedure 2. Ensure patient has not had antimicrobial therapy 3. Wash hands, gloves, assemble equipment 4. Place culture bottles on flat surface that will be within reach during the procedure. Mark fill line at 10mL per bottle (1-3mL for pediatric patients) 5. Prepare puncture site. Iodine must be on skin for 1 minute. 6. Cleanse bottle tops with alcohol and iodine solution. 7. Change gloves. 8. Perform venipuncture, fill to appropriate line. 9. Repeat on other sites as needed. Store samples at room temperature. 10. Label bottles, dispose of contaminated supplies, place specimen in biohazard bag. Complete requisition in the presence of the patient.
butterfly needle gauge
21-23G, has safety needle attached to syringe.
heart
A hollow, muscular organ that pumps blood throughout the body.
bone marrow
A soft tissue inside the bone that produces blood cells
Yellow top tube
ACD. Complement inactivation. Paternity testing, DNA studies.
venipuncture methods
All methods require the invasive procedure of puncturing a vein to obtain blood sample. Three main methods. - vacuum tube - butterfly - syringe
back of the hand
Alternative to antecubital is ______________________, where veins have more of a tendency to "roll" (need 3-5mL syringe, 22G needle)
sodium fluoride
An additive that preserves glucose and inhibits the growth of bacteria.
venipuncture sites
Antecubital space is the most common site for venipuncture. - median cubital vein - basilic vein - cephalic vein - median vein
6
Body contains about _______ liters of blood
lavender top tube
EDTA anticoagulant. Forms calcium salts to remove calcium. Hematology, blood bank cross-match.
capillary puncture
Method of obtaining one to several drops of blood. Method of choice when patient volume is of concern (infants) and when veins are difficult to access (burned, scarred patients).
capillaries
Microscopic vessel through which exchanges take place between the blood and cells of the body
serum, plasma, or whole blood
Most laboratory tests performed on (3)
syncope, nausea, insulin shock/hypoglycemia, convulsions
Patient reactions to blood draws
15-18
Rubber or elastic strip 1 inch wide by _____-______ inches long
- CBC, RBC, and WBC - Hemoglobin and hematocrit - Glucose testing - Phenylketonuria testing
Tests that use blood obtained by capillary puncture
Needlestick prevention devices (NPD's)
a common type of safety mechanism is a device in which a cover is snapped over a needle after it is removed from the vein.
butterfly method
a. Small, fragile veins, difficult draws, small children or older adults b. Least likely to collapse vein, less painful, can attach syringe or vacuum tube adapter, least likely to pass through small veins, good specimen quality c. Syringe attachment not as safe (tube transfer necessary), specimen can be hemolyzed (rupture of RBC's), not recommended for large collections.
Thixotropic gel plugs
act as separators between blood cells/clot and the serum/plasma. When centrifuged, the gel changes to a liquid.
no additives in this tube
additive in red tube. clot naturally forms
advantages of butterfly tube specimen collection
allows either a syringe draw or a vacuum tube collection. 21-23G needle with attached plastic wings. For small, fragile veins that are difficult to puncture with vacuum collection.
luer lock device
allows the needle to be securely twisted onto the syringe, may be preferred over push-on top.
Phlebotomy
also called venipuncture. Used to acquire the blood for testing. Testing can determine disease processes, levels of chemical and medications in the body, antibodies and blood cell activities.
Gray top tube
antiglycolytic agent (sodium fluoride, potassium oxalate). Preserves glucose up to 5 days.
nausea
apply cold compress to forehead. Give patient emesis basin, have facial tissues ready. Advise deep slow breathing.
20G
appropriate, but large for common phlebotomy
Brachial artery, radial artery, ulnar artery.
arteries to avoid
will
artery will/will not be pulsating to the touch.
specimen collection trays
available in a variety of shapes and sizes. Holds materials for proper specimen collection. OSHA's Bloodborne Pathogen Standard requires each tray be all red or prominently labeled with appropriate biohazard symbol.
Light blue top tube
sodium citrate. Form calcium salts to remove calcium. Coagulation tests.
potassium oxalate, SPS, sodium citrate, EDTA
bind calcium
factors affecting lab results
blood alcohol, diurnal rhythm, exercise, fasting, hemolysis, heparin, stress, tourniquet, volume.
arterioles
branch from arteries, connect to capillaries.
venule
branch from capillaries, connect blood to veins for transport back to heart.
Black Top Tube
buffered sodium citrate. Westergren sedimentation rate requires full draw.
If artery is punctured
calmly continue to draw the blood. Maintain pressure for a full 3-5 minutes. Do not let the patient leave while actively bleeding. If vein blood is specified on test, redraw blood.
clot activators
chemical additives to preserve blood or substance to accelerate clotting process.
heart, arteries, arterioles, capillaries, venules, veins, heart
circulatory system vessels
serum
clear straw colored liquid after the blood has clotted, does not contain fibrinogen
Thrombocytes (Platelets)
clotting cells, tiny fragments of cells formed in the bone marrow and are necessary for blood clotting
Insulin Shock (hypoglycemia)
cold sweat, pallor. Weak and shaky, sudden mental confusion. Call provider is consciousness is lost
Anatomy and physiology of the circulatory system
consists of the heart and blood vessels. Carries blood (with nutrients and waste products) to lungs, kidneys, liver, and skin for waste elimination.
fibrinogen
converted to fibrin when blood is exposed to air, as in an open wound. Becomes sticky spiderweb-like substance that traps formed elements into fibrin mass, forms clot.
positioning the patient
critical for proper patient blood collection. Lying down is preferred when patient experiences faint or dizzy sensations. Specially designed chairs also an option.
veins
deoxygenated blood flowing back to heart (except for pulmonary). Blood is dark red. Thin walls are less elastic. Contain valves. No pulse.
hemolysis
destruction and release of contents into serum/plasma caused by not allowing alcohol to dry at puncture site, using a needle that is too small, forcing blood into vacuum tube, or shaking collecting tube instead of gently rolling.
syncope
fainting. Immediately remove tourniquet, then needle, and stop patient from falling. Wipe patient's forehead and neck with cold compress, notify provider. Place pillow under patient's legs.
capillary puncture sites
fingertip, often ring finger (adults). Lateral or medial plantar surface of heel (infants).
tourniquet on too long
hemoconcentration occurs, causing change in chemical concentration
Light Green Top Tube
heparin anticoagulant (Na).
syringe technique action notes.
ideal for small volumes and smaller "rolling" veins. Vein collapse can be avoided by pulling slowly on plunger and allowing vein to rest and refill. No longer than 12mL on syringe.
fasting
if instructions not followed when required, erroneous results.
Gels
inert material that undergoes temporary change in viscosity during centrifuge (liquidation), moves up the side of the tube to create barrier between clot and liquid portion of blood. Then forms solid plug and separates cells/clot from plasma/serum, protecting serum from contamination from hemolyzed RBC's.
Lithium heparin, Ammonium heparin
inhibits prothrombin to thrombin
3, 4
tourniquet applied _____ to _____ inches above puncture site
Blood pressure cuff
may be used instead for veins that are difficult to locate. Maintained around 40 mmHg.
basilic vein location
medial side of upper arm.
composition of capillary blood
mixture of blood from arterioles, venules, interstitial blood, and capillaries.
21G
most common size used for vacuum tube
16G
most commonly used in blood banking/donations.
special needle
multidraw needle. Used with vacuum tube method. Double end (longer needle for vein, shorter needle for vacuum tube). Needles themselves come in a variety of gauges.
Red top tube
no added agents. Blood clots, serum separated by centrifugation
2
no more than ______ attempts of venipuncture
blood alcohol
non-alcohol antiseptic must be used for these tests
volume of blood
not enough blood will cause dilution factor, which changes cell size and produce variation in test results.
18G
not used for phlebotomy, but sometimes used in blood banking/donations
arteries
oxygenated blood flows away from heart. Thick wall helps withstand pressure of heart pumping action. Bright red blood. Elastic walls allow for expansion. No valves. Can feel pulse here.
1 minute
tourniquet on arm no longer than _____________
convulsions
patient loses consciousness and exhibits violent or mild convulsive motions. Do not restrain patient. Help patient into reclining position on floor. Patient recovers within a few minutes, notify provider.
22G
preferred for pediatric phlebotomy or very small veins of the hands or feet
anticoagulant
prevents blood from clotting, allows visible separation of plasma (fibrinogen), "buffy coat" (white blood cells, thrombocytes), and red blood cells.
Glass particles/silica
promotes clotting
advantages of vacuum tube specimen collection
quicker than syringe technique, allows for multiple tubes to be drawn. Held in the same manner as the syringe technique.
erythrocytes
red blood cells. Carry oxygen on hemoglobin proteins combined with iron.
approaching the patient
requires social, technical, administrative, and quality assurance skills. Interpersonal and therapeutic communication, greeting the patient guidelines: 1. Reassure the patient of simple procedure with slight inconvenience 2. Be friendly, outgoing, conversational. 3. Do not tell the patient that the procedure will not be painful. Explain slight discomfort, but you will take care to lessen the discomfort as much as possible. Check patient frequently. 4. Exhibit professional concern for patients, because this will increase patient satisfaction.
medican vein location
runs straight down the middle of the anterior forearm.
OSHA requirements
safety needles available to employees to prevent on-the-job needlesticks.
red/gray mottled top tube
serum separating tube with clot activator. Forms clots quickly. Blood type screenings.
Serum sample
serum separator vacuum tube with thixotropic gel used
exercise
strenuous exercise increases cardiac enzymes. Long-term exercise can cause erroneous results from patient anemia.
Hematology
study of blood and its components, fluids, and cells. Includes blood-forming organs and blood diseases.
5-10mL
syringes vary in size from 1mL to 10mL, commonly between ______-_______ mL.
Blood
the fluid matrix for chemicals and blood cells to travel to and from body cells, tissues, and organs. carries oxygen and nutrients to cells and removes waste products and carbon dioxide
Orange top tube
thrombin. Quickly clots blood. STAT serum chemistries.
Vacuum collection tube
tube used to show the separation of serum from plasma
23G
used sometimes with butterfly system
median cubital vein
used the majority of the time for venipuncture. Crosses from medial to lateral side of antecubital space of arm, just above fossa.
heparin
using incorrect additive can interfere with results.
vacuum tubes and adapters
vacuum-packed test tubes with either twist-on caps or rubber stoppers. Available in a variety of sizes depending on test ordered. - 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 - Replace frequently
selecting the appropriate site
varies depending on the patient. - Usual site is first checked in antecubital region of the arm. Primary vein is median cubital vein near the middle of the bend in the arm. Basilic or cephalic veins can be used as alternatives. - Check both arms, one may be better than the other.
will not
vein will/will not be pulsating to the touch.
venipuncture
veins near the surface of the skin, large enough to give access to blood.
order to draw
very important when combined with additives especially. - Clinical Laboratory Standards Institute (CLSI) establishes lab procedures - Latest publication 2011 - 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
stress
violent crying before specimen is collected can increase the WBC count.
2 minutes
wait to retie a tourniquet (if necessary) for minimum of __________
leukocytes
white blood cells
5-10
with butterfly collection technique, insert at _______-_______ degree angle instead of standard 15 degree angle.
specimen collection steps
• Hand washing critical step • Tie tourniquet • Apply gloves • Select a vein • Cleanse site firmly with 70% isopropyl alcohol pad • Allow area to air dry • Venipuncture is performed
The MA'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