HEMA LAB: SPECIMEN COLLECTION

What is considered the most critical step in Specimen collection?

Patient Identification

How should the patient be identified?

Identify the patient by asking the patient to state his/her full name (including middle name)

What should be done if the patient cannot speak?

Verify the patient’s identity from the relative, attending physician, or nurse

What should be verified whenever possible for a positive patient identification?

A 2nd patient identifier (eg. Date of Birth / Social Security Number)

What are the physiologic factors affecting test results?

Posture, Diurnal Rhythm, Stress, Exercise, Diet, Smoking

What is the effect of Posture on test results?

Lipids, Enzymes, and Proteins

What is the effect of Diurnal Rhythm on test results?

In the afternoon, decreased levels of ACTH and cortisol and increased levels of eosinophils may be seen

What is the effect of Stress on test results?

Causes an increase in WBC counts, FI, FV, FVIII:c, and FXIII

What is the effect of Exercise on test results?

Causes an increase in WBC and Platelet counts, Creatine Kinase (CK), and Lactate Dehydrogenase (LD)

What is the effect of Diet on test results?

After a fatty meal, increased Alkaline phosphatase (ALP) may be seen, false increase in hemoglobin using the cyanmethemoglobin method

What is the effect of Smoking on test results?

Increases cortisol and WBC counts; Chronic smoking may increase RBC count, hemoglobin, and hematocrit

What are the sources of blood for Hematology testing?

Skin Puncture / Peripheral Puncture and Venipuncture

What is Skin Puncture / Peripheral Puncture?

Source of peripheral blood

What does peripheral blood contain?

A mixture of capillary blood from the capillaries, venous blood from the venules, arterial blood from the arteries, and interstitial and intercellular fluids

When is Skin Puncture / Peripheral Puncture used?

When only small quantities of blood sample are required

What are the indications of Skin Puncture?

Infants/neonates/pediatric patients; Geriatric patients; Adults who are/have extremely obese, a history of thromboembolism, stroke, Disseminated Intravascular Coagulation/Coagulopathy (DIC), or Transient Ischemic Attack (TIA), extensive burns; If the examination requested necessitates skin puncture

What type of patients are indications for Skin Puncture?

Infants/neonates/pediatric patients. Geriatric Patients

What adult condition is an indication for Skin Puncture?

Extremely obese

What adult medical histories are indications for Skin Puncture?

A history of thromboembolism, stroke, Disseminated Intravascular Coagulation/Coagulopathy (DIC), or Transient Ischemic Attack (TIA)

What adult injury is an indication for Skin Puncture?

Extensive burns

What examinations necessitate skin puncture?

Bleeding time, micro methods of clotting time

What is the recommended site for skin puncture in adults?

Distal portion on the palmar surface of the 3rd or 4th digits of the non-dominant hand from the thumb

Why are the middle and ring fingers usually used for skin puncture?

The middle and ring fingers are usually the least used and are less calloused compared to the thumb and index fingers

What is the recommended site for skin puncture in infants?

The plantar surface of the foot/sole (heel portion)

What site was traditionally used for skin puncture but is no longer recommended?

The free margin of the earlobe

Why was the free margin of the earlobe traditionally used?

There was less tissue juice and there were less nerve endings causing less pain

Why is the free margin of the earlobe no longer recommended?

Due to less capillary access

What is the recommended depth of puncture for adults?

2-3mm

What is the recommended depth of puncture for infants and small children?

<2mm

Why should you not milk or squeeze the site of puncture?

To avoid contamination with interstitial fluids

What sites should not be punctured?

Cyanotic, swollen, inflamed, or edematous sites

How may the site be warmed prior to disinfection?

By massage, warm compress, or warm water bath

What is the Order of Draw for Skin Puncture?

1. Tube for blood gas analysis

2. Slides

3. EDTA microcollection tubes

4. Other microcollection tubes with anticoagulants

5. Serum microcollection tubes

Which tube must be filled before other microcollection tubes?

EDTA microcollection tubes

Why must EDTA microcollection tubes be filled before other microcollection tubes?

To ensure adequate blood volume for testing

What is Venipuncture?

Source of venous blood; preferred when large volumes of blood are required for testing

What are the preferred sites of puncture for Venipuncture?

The veins in the antecubital area: median cubital vein, cephalic vein, and the basilic vein

What is the vein of choice for Venipuncture?

Median cubital vein

What is the angle between the skin and the needle during venipuncture?

15 degrees

How far from the venipuncture site should the tourniquet be applied?

3-4 inches, 7.5-10 cm

What is the maximum length of time for tourniquet application?

1 minute

What does prolonged tourniquet application cause?

Hemoconcentration, hemolysis, and shortened coagulation time

When should the tourniquet be released?

Once blood enters the hub

How many times must a phlebotomist never puncture the patient more than?

Twice

Twice

What should happen after the second attempt?

Endorse

What is the standard needle for phlebotomy?

21G

What are the most common needle lengths?

1 - 1.5 INCHES

What are the common causes of hemolysis?

Prolonged tourniquet application; Moisture or contamination on blood collection tubes; Using needles with too small bores; Excessive agitation during mixing of samples; Introduction of bubbles (frothing) during blood collection

What is one common cause of hemolysis related to tourniquet application?

Prolonged tourniquet application

What is one common cause of hemolysis related to blood collection tubes?

Moisture or contamination on blood collection tubes

What is one common cause of hemolysis related to needles?

Using needles with too small bores

What is one common cause of hemolysis related to sample mixing?

Excessive agitation during mixing of samples

What is one common cause of hemolysis related to blood collection?

Introduction of bubbles (frothing) during blood collection

What are the 4 categories of additives discussed?

Antiglycolytic Agents, Clot Activators, Separator Gel, Anticoagulants

What is the MOA of Antiglycolytic Agents?

Inhibits glycolysis

What is the color code for Sodium Fluoride?

Gray Top

What is Sodium Fluoride used for?

Blood glucose and blood alcohol level determinations

What does Sodium Fluoride preserve?

Preserves glucose for up to 3 days

What anticoagulant is used with Sodium Fluoride?

Potassium Oxalate

How many inversions are required for Sodium Fluoride?

8

What is the color code for Lithium Iodoacetate?

Gray Top

What does Lithium Iodoacetate preserve?

Preserves glucose for up to 24 hours

What is Lithium Iodoacetate used for?

Blood glucose and blood alcohol level determinations

What anticoagulant is used with Lithium Iodoacetate?

Potassium Heparin

How many inversions are required for Lithium Iodoacetate?

8

What are Clot Activators?

Accelerates clotting of samples

What are the clot activators used in the Glass tube or silica particles?

Glass tube or silica particles

What is the color code for Glass tube or silica particles?

Red Top

What is the Red Top used for?

Used for STAT serum determinations

How many inversions are required for Red Top?

5

What is the MOA of Thrombin?

Cleaves Fibrinogen into Fibrin

What is the color code of Thrombin?

Orange Top

What is Thrombin used for?

Used for STAT serum determinations

How many inversions are required for Thrombin?

5

What is Separator Gel?

Inert material that undergoes a temporary change in viscosity during the centrifugation process

What is Thixotropic Gel?

Separator Gel

What is the color code for Thixotropic Gel?

Gold Top

How many inversions are required for Thixotropic Gel?

5

What are Anticoagulants?

Prevent the blood from clotting

What is the color code for EDTA?

Lavender Top

What is the optimal anticoagulant concentration of EDTA?

1.5-2.2mg / mL of blood

What is the MOA of EDTA?

Chelates calcium

What is EDTA used for?

Routine hematological studies (most commonly used anticoagulant for Hematology testing) – CBC, Reticulocyte Count, modified Westergren method of ESR

What forms of EDTA can be used?

K2EDTA, K3EDTA, LiEDTA, or Na2EDTA can be used

Which EDTA is the most preferred?

K2EDTA

Which EDTA must never be used?

Na3EDTA

What is the effect of insufficient EDTA (overfilled tube)?

Presence of clots (or microclots)

What is the effect of excessive EDTA (underfilled tube)?

Falsely decreased Hematocrit and ESR, degenerative changes in WBC, and falsely increased MCHC and platelet count

What should be done when platelet clumping (platelet aggregation) is encountered when examining the smear?

Recollect a blood sample using 3.2% sodium citrate and repeat the platelet count

How many inversions are required for EDTA?

8

What is the color code for Heparin?

Green Top

What is the optimal anticoagulant concentration of Heparin?

15-20 units / mL of blood

What is the MOA of Heparin?

Inhibits thrombin

What is Heparin the anticoagulant of choice for?

Osmotic Fragility Testing and Blood Gas Analysis

What is Heparin also used for?

STAT Chemistry determinations

What are the three formulations of Heparin?

1. Ammonium Heparin

2. Sodium Heparin

3. Lithium Heparin

Which Heparin formulation causes the least interference in chemistry testing?

Lithium Heparin

Which Heparin formulation is most commonly used as an anticoagulant for plasma and whole blood chemistry assays?

Lithium Heparin

What must Lithium Heparin not be used for?

Lithium determinations