Chapter 3 - ROUTINE HEMATOLOGY PROCEDURES Flashcards
Materials for Blood Collection:
- Tourniquet
- Needles
- Evacuated Tube System
- Solutions for Skin Antisepsis
Applied to distend the veins makes veins larger and easier to find, and stretches the walls so they become thinner and easier to pierce.
Tourniquet
Application of tourniquet should not exceed ______.
1 min
Test/s that strictly does/do not require the use of tourniquet: _______
With color-coded hub indicating the gauge (Gauge is inversely related to the size/bore)
Needles
: considered standard for routine venipuncture
Gauge 21
Gauge 21-23 (? for children; ? for butterfly/winged infusion set)
23
21, 23 & 25
: for the collection of blood from scalp or other small veins of infants
Gauge 25
Needles Length: ? (G21-23); ? (butterfly needles)
1 or 1.5 inches
½ to ¾ inch
Basic components: multisample needle, tube holder, evacuated tubes (with premeasured vacuum that draws the indicated volume of blood
Evacuated Tube System
are color-coded to identify a type of additive, or absence of additive, or special tube property.
Tube stoppers
Routine collection:
70% isopropyl alcohol
Test for legal blood alcohol level:
non-alcohol-based antiseptic
30- to 60-second scrub with 70% isopropyl alcohol then 1% - 10% povidone-iodine pads, tincture of iodine, chlorhexidine compounds, or another isopropyl alcohol preparation.
Blood culture: Two-step procedure
Blood culture: One-step application
chlorhexidine gluconate/isopropyl alcohol or povidone-70% ethyl alcohol
admixture of venous, arterial and capillary blood with interstitial and intracellular fluids
Capillary blood
may be used as substitute for arterial blood gas determinations provided that the site is warmed prior to collection (blood enters capillaries under pressure and the arterial portion is highest)
Capillary blood
SOURCES OF BLOOD SPECIMENS:
Capillary blood
Arterial blood
Venous blood
Normally uniform throughout the body.
Arterial blood
For blood gas analysis and pH measurement
Arterial blood
Affected by metabolic activity of the tissue it drains and varies by collection site
Venous blood
Mostly used in chemistry analyses
Venous blood
MICROSAMPLING
SKIN PUNCTURE
MACROSAMPLING: Methods of Collection
- Evacuated tube system (ETS)
- Needle and syringe
- Winged infusion set (butterfly)
Method of collection for pediatric patients, obese patients, patients with thrombotic tendencies, with severe burns, geriatric patients and in routine assay requiring small amount of blood (POCT)
MICROSAMPLING (SKIN PUNCTURE)
MICROSAMPLING (SKIN PUNCTURE) Sites:
Infants:
Adults:
medial or lateral plantar heel surface; plantar surface of big toes
3rd or 4th finger; margins of the ear lobe
MICROSAMPLING (SKIN PUNCTURE)
Sites to be avoided:
(Infant) -
(Adult) -
Central arch area of the heal and fingers
Thumb, index, 5th finger, fingers on the site of mastectomy, edematous or a previous puncture site.
MICROSAMPLING (SKIN PUNCTURE)
Length of lancet:
1.75 mm
If using a lancet, the blade should not be longer than (?) to avoid injury to the heel bone)
2 mm
preferred method
Evacuated tube system (ETS):
minimizes the risk of specimen contamination and exposure to the blood
Evacuated tube system (ETS)
Discouraged by CLSI due to safety and specimen quality issues.
Needle and syringe
May be used on small, fragile, or damaged veins.
Needle and syringe
Can be used with the Evacuated tube system or a syringe.
Winged infusion set (butterfly)
Often used to draw blood from infants and children, from hand veins, and in other difficult-draw situations.
Winged infusion set (butterfly)
For arterial blood gas analysis
ARTERIAL PUNCTURE
ARTERIAL PUNCTURE
Sites:
radial artery, brachial artery, femoral artery, scalp artery and umbilical artery
Performed without a tourniquet.
ARTERIAL PUNCTURE
This is technically more difficult to perform than venous puncture and it is prone to hematoma.
ARTERIAL PUNCTURE
: Done before a radial arterial collection is performed.
Modified Allen Test
This determines whether the ulnar artery can provide collateral circulation to the hand after radial artery puncture
Modified Allen Test
Modified Allen Test Anticoagulant:
0.05 ml liquid Heparin/ml blood
Place blood in ice water/coolant (1-5OC) to minimize consumption of O2 by leukocytes
Modified Allen Test
(Substitute): earlobe is the preferred site because of vascularity, low metabolic requirements & ease with which it can be arterialized by first warming at 39 42OC.
Arterialized Capillary blood
Newborn up to 18 months:
Superior longitudinal sinus; External jugular vein; Temporal vein
18 months to 3 years:
Femoral vein; Long saphenous vein; Ankle vein; Popliteal vein; External Jugular vein; Temporal vein
3 years to adult:
Antecubital fossa: Median cubital, Cephalic, Median basilic
Wrist veins; Hand (dorsal aspect) veins;
Ankle veins
Contraindications of venipuncture at the LOWER EXTREMETIES:
Poorly-controlled diabetes mellitus
Hemoglobinopathies
Thrombosis
Use opposite arm or perform fingerstick.
IV or blood transfusion running
Ask attending the nurse to stop IV for at least 2 minutes; select vein other than the one with the IV. Draw and discard first 5 mL.
IV or blood transfusion running
Causes an increase of infused substance like glucose, chloride, potassium and sodium, with a decrease in urea and creatinine.
IV or blood transfusion running
Draw from opposite arm.
Fistula
Lab may draw below heparin lock if nothing is being infused.
Indwelling lines and catheters, heparin locks, cannulas
The first 5 mL of blood drawn should be discarded.
Indwelling lines and catheters, heparin locks, cannulas
Select another site.
Sclerosed veins, Scars, burns, tattoos, Edema
Draw below
Hematoma
Minimize venipuncture.
Streptokinase/TPA
Hold pressure until bleeding has stopped.
Streptokinase/Tissue plasminogen activator
Draw from opposite arm
Mastectomy
If you are unable to obtain a specimen on the first attempt, try again (?) the first site, on the (?), or on a (?) vein.
Multiple venipuncture attempt
below
other arm
hand or wrist
If the second attempt is unsuccessful, ask someone else to take over.
Multiple venipuncture attempt
Needle may not be placed at the center of the stopper causing blockage.
No Blood seen or Too little blood flow into the tube
Needle bevel may be flushed against the wall of the vein causing blockage.
No Blood seen or Too little blood flow into the tube
Tourniquet applied too tightly or too long, thus stopping blood flow.
No Blood seen or Too little blood flow into the tube
Tube may have been prematurely punctured.
No Blood seen or Too little blood flow into the tube
Tube may have previously been opened.
No Blood seen or Too little blood flow into the tube
Needle is not completely in the vein or has not reached the vein
No Blood seen or Too little blood flow into the tube
Transfixation
No Blood seen or Too little blood flow into the tube
Excessive probing
Hemolysis
Hematoma
Underfilling of tubes
Hemolysis
Alcohol contamination
Hemolysis
Vigorous mixing of the sample
Hemolysis
Use of too small needle during a difficult draw
Hemolysis
Drawing the blood through an existing hematoma
Hemolysis
Pulling back too quickly on the plunger of a syringe
Hemolysis
Transferring from syringe & needle to evacuated tubes
Hemolysis
Contamination of the specimen with alcohol or water at the venipuncture site or in the tubes.
Hemolysis
Physiologic cause: hemolytic anemias.
Hemolysis
Premature removal of the tubes
Underfilling of Tubes
Long lines of tubing containing air
Underfilling of Tubes
Vein may have collapsed
Blood stops flowing halfway during blood collection
Needle may have been repositioned or out of the vein
Blood stops flowing halfway during blood collection
Tourniquet placed too near the venipuncture site
Hematoma
Failure to remove the tourniquet before removing the needle
Hematoma
Failure to apply enough pressure to the site after venipuncture
Hematoma
Inadvertent puncture of an artery.
Hematoma
Needle may not be completely in the vein/bevel of the needle is only partially in the vein
Hematoma
Transfixation resulting to leakage of large amount of blood around the puncture site causing the area to swell
Hematoma
COMPLICATIONS of Phlebotomy:
Ecchymosis
Immediate Local complication
Localized Hemoconcentration or Venous stasis
Immediate Local complication
Circulatory failure
Immediate Local complication
Syncope or Fainting
Immediate Local complication
Thrombosis
Late Local Complications
Thrombophlebitis
Late Local Complications
Allergies
Late Local Complications
Patients can be allergic to antiseptics, adhesive glue in bandages, and latex. Use an alternate antiseptic if required; (?9 can be used in place of adhesive bandages
paper tape placed over folded gauze or self-adhesive bandage material
transmission of blood-borne infections
Delayed General Complications
Physiologic factors that may cause variations in hematology test results:
: Changing from a supine to a (?) results in a shift of body water from inside the blood vessels to the interstitial spaces.
Posture
sitting or standing position
: Eosinophil count is lower in the (?) and increase in the(?).
Diurnal Rhythm
morning; afternoon
: can increase white blood cell count
Exercise
: can cause a temporary increase in the white blood cell count.
Stress
: increased lipids may cause turbidity (lipemia) in the serum or plasma, affecting some tests that require photometric measurement.
Diet
smoking before blood collection may increase (?)
Long-term smoking can result in increased (?).
white blood cell counts and cortisol levels
hemoglobin levels
: Used in routine and special chemistry tests
- Serum
: Used in coagulation studies
- Plasma
: Must be collected in an anticoagulant tube to prevent it from clotting;
- Whole blood
Used in complete blood count (CBC)
- Whole blood
Removes Ca++ chelation
EDTA
spray-dried in plastic tubes
K2EDTA
EDTA: liquid form
K3EDTA
EDTA Commercial preparations:
Versene; Sequestrene
1 - 2 mg/ml blood
EDTA
Oxalate
Lavender
EDTA
Hematology procedures (CBC; Platelet count, blood smears)
Pink (dry K2EDTA)
(EDTA & Gel)
White
(Plastic- K2EDTA)
Tan
Blood Bank
Tan
Molecular Diagnostics
Tan
Lead testing
Tan (Plastic -K2EDTA)
EDTA
(dry K2EDTA)
Pink
Prevents platelet aggregation
EDTA
does not preserve factor V
EDTA
Excess causes red cells to shrink and platelets to break
EDTA
After 3 hrs @ room temperature: vacuolation of cytoplasm; more homogenous nuclei; irregular or poorly defined cytoplasmic borders and irregularly-shaped nuclei.
EDTA
Possible platelet satellitism
EDTA
Binds with Ca++ in a nonionized form
Sodium Citrate
What is the ratio of sodium citrate to blood?
Light Blue (1:9)
Black (1:4)
0.1 - 0.2 mg/ml of blood
Heparin
Acts as antithrombin
Heparin
Li or Na heparin preparations
Heparin
10 mg/mL blood
Na Fluoride Li iodoacetate
Combines w/ Ca++ into insoluble calcium oxalate salt
Oxalate
Erythrocyte sedimentation rate
Sodium citrate
Black
Coagulation Tests
Light Blue
(Na or Li)
Green
(Li Heparin & Gel)
Light Green/Black
(Na Heparin, Na2EDTA
Royal Blue
(Glass Na Heparin)
Tan
Chemistry; Lead testing
Tan (Glass - Na Heparin)
Glucose test; Ethanol specimens
Gray
Preserves labile coagulation factors
Sodium Citrate
Helps retain functional capabilities of platelets
Sodium Citrate
Best for Osmotic fragility test (OFT)
Heparin
Prevents hemolysis
Heparin
Causes blue background on Wright-stain blood smear
Heparin
May cause clumping of WBCs and platelets
Heparin
will yield serum.
Na Fluoride
Distorts cell morphology
Oxalate
((Paul-Hellers)
K oxalate
(Wintrobe)
NH4 Oxalate
Light Blue - Hematology
Thrombin & Soybean Trypsin Inhibitor
Test for Fibrin Degradation Products
Thrombin & Soybean Trypsin Inhibitor
None
Red (Glass)
Chemistry & Serology
Red (Glass)
Silica Clot Activator
Red (Plastic/ Hemogard)
STAT Chemistry & Serology
Red (Plastic/ Hemogard)
STAT Chemistry
Yellow/Gray & Orange
Red/ Gray & Gold
Thrombin
Yellow/Gray & Orange
Silica & Separation Gel
Red/ Gray & Gold
Microbiology (bacterial culture)
Sterile, with Sodium polyanethol sulfonate (SPS)
BB, HLA phenotyping, Paternity testing
ACD
A special sequence of tube collection that reduces the risk of specimen contamination by microorganisms and additive carry-over, which may affect some chemistry tests
Order of Draw of Tubes
Order of Draw from Catheter lines
- Draw 35 mL in a syringe and discard.
- Blood for blood culture
- Blood for anticoagulated tubes (lavender, green, light blue, etc.)
- Blood for clot tubes (red, SST, etc.)
Order of Draw for Skin Puncture
- Tube for blood gas analysis
- Slides, unless made from specimen in the EDTA microcollection tube
- EDTA microcollection tube
- Other microcollection tubes with anticoagulants
- Serum microcollection tubes
Read on the Order of Draw of blood and the rationale of each. (Clinical Chemistry by Bishop 6th ed., p. 47)
Serum or plasma should be separated from cells within (?) from collection, unless collected in a gel separator, to prevent glycolysis, lipolysis, shift of electrolytes, hemolysis and loss of some unstable substances
1 hour
Centrifugation:
3000 RCF for 10 mins
Reasons for specimen rejection:
(?) do not match.
Tube is (?), or the labeling, including patient identification number, is incorrect .
Specimen is (?).
Specimen was collected at the (?).
Specimen was collected in the (?).
Specimen was (?), while the test requires whole blood or plasma.
Specimen was contaminated with (?).
Specimen is (?) (depends on the test)
Test order requisition and the tube identification
unlabeled
hemolyzed
wrong time
wrong tube
clotted
intravenous fluid
lipemic
