W1 - Impact of Phlebotomy Practice on Pre-Analytical Variation

What is Basal State?

Resting state of body early in the morning after fasting 12 hours

What is the basal-state specimen?

• Specimen ideal for establishing reference ranges on inpatients

• Effects of diets / exercise ect on test results are minimized

What are some factors affect the Basal state?

• Age

• Gender

• Condition of the body

What are the 3 layers of normal anitcoagluated blood?

1) Plasma

2) Buffy coat

3) Erythrocytes

What is the order of draw?

Blood —> Light Blue —> Red —> Green —> Lavender —> Gray

What is the additive in the light blue top tube?

Sodium Citrate

What is the mode of action for the light blue top?

Forms calcium salts to remove calcium

What is the light blue top for?

Coagulation test [prothrombin time (PT) and partial thromboplastin time (PTT)]

Why is it important to get a full draw for a light blue top?

Because you need the right amount of blood to anti-coagulation ratio or else the sample will clot

What is the additive in the red top tubes?

None

What is the mode of action for red tube?

Blood clot by activators and serum is seperated by centrifugation

When do you use red top tube?

Chemistries, serology, blood bank

What is the short cut to remember the order of draw?

Big Lazy Racoons Grab Little Grapes

What is the additive in a green top tube?

Sodium heparin or lithium heparin

What is the mode of action for green top tube?

Inactivates thrombin and thromboplastin

What are the usage of green top tubes?

For lithium levels or ammonia levels

What is the additive of purple top?

EDTA
Ethylenediaminetetraacetic Acid

What is the mode of action of purple top?

Form calcium salt to remove calcium (purple)

What is the usage of purple top?

Hematology (CBC), Blood bank (cross match)

What is important about drawing purple top?

It requires a full draw and needs to be inverted 8 times to prevent clotting and platelet clumping

What is hemoconcentration?

• A decrease in fluid content of blood

• increase in nonfilterable large molecules

What is hemolysis?

Damage to or destruction of RBCS

• Hemoglobin escape into fluid part of specimen

What is the most abundant protein in the body

Albumin; Immunoglobin; Hemaglobin

What’s the difference between plasma vs serum?

Plasma has fibrinogens

Serum does not

Which blood tubes gives you plasma?

Purple; Green; Light Blue top

Which blood tubes give you serum?

Red

Why is it important that blue top is drawn 2nd?

To reduce tissue factor contamination

Why is blood culture collected first?

To prevent contamination

What happens if the light blue top is underfilled?

Excess citrate —> Falsely prolonged clotting time

What happen if the blue top is overfilled?

Insufficient citrate —> may clot

Why is IV fluid dilution important?

False increase in corresponding analyte, dilution of other analytes

What is EDTA effect on the chemical make up?

Increase K+, decrease Ca2+, Mg+2, ALP

What is Sodium citrate effect on the chemical make up?

Increase Na+, anion gap

What is Heparin effect on the chemical make up?

Inhibits PCR reactions

What is the consequences of a long tourniquet time?

Concentration analytes, false increase in K+, Ammonia, lactate

Why is there an increase in ammonia due to long tourniquet time?

Because arterial blood is blocked and not moving, so your body kicks into panic mode and it starts the anaerobic cycle cause its not getting blood :(

What are some chemicals that needs to be drawn in the morning?

Cortisol, Norepinephrine

What happens if a tube’s cap is not fully closed?

Then O2 increases, CO2 leaves, pH increase