HEMA LEC - Phlebotomy Flashcards
Double oxalate
Salts of ammonium & potassium(NH4K) in 3:2 ratio
ratio of ammonium to potassium in double oxalate
3:2 ratio
Ammonium oxalate only –
RBC swelling
Potassium oxalate only –
shrinkage of RBC
type of oxalate used for coagulation studies
Sodium oxalate
-for RBC ct., Hgb, Hct, ESR (all RBC evaluation tests since there is no effect on RBCs)
oxalates
only an in vitro anticoagulant,
Oxalates –
3 forms of oxalate
- Double oxalate – most common
- Lithium oxalate – collecting bloody body fluids
- Sodium oxalate – coagulation studies
recommended amount when using oxalate
1 – 2 mg/ml of blood
oxalate color
gray
oxalate MoA
binds Ca
citrate MoA
binds Ca
most common oxalate
Double oxalate
oxalate for collecting bloody body fluids
lithium oxalate
other names of oxalate (3)
Balance oxalate, Wintrobe fluid, Paul-Heller’s fluid
oxalate not for blood transfusion because
it’s toxic
Causes agglutination or clumping of WBC & platelets hence causing erroneous counting
oxalate
Not recommended for peripheral blood smear because it has same ill effects EDTA when used for more than 2 hours
oxalate
oxalate has has same ill effects with ??? when used for more than 2 hours
EDTA
– most commonly used for OFT (sickle cell anemia) & immunophenotyping
heparin
recommended amount when using heparin
• 10-20 units/ml of blood
color of heparin
green
• MoA of heparin
inihibits thrombin
• 2 Forms of heparin
- Lithium heparin
2. Sodium heparin
heparin
Not recommended for coagulation studies because
it affects all stages of blood coagulation
heparin
Not recommended for blood smear preparation because It
causes blue background when stained with Romanowsky stains
heparin
Not for WBC count, causes
agglutination of WBCs
heparin
Not for Plt ct.
enhances platelet aggregation
most expensive additive
heparin
– most common & preferred for coagulation studies
Citrates
citrate color
light blue
blood anticoagulant ratio for light blue
3.2% or 0.109 M NaCitrate (9:1)
blood anticoagulant ratio for black for standard westergreen method for ESR
0.105M NaCitrate (4:1)
• Changes in old EDTA blood:
o Vacuolization of leukocyte cytoplasm o Artefact/crystal formation o Phagocytosis of crystals by WBCs o Cloverleafing of WBC nucleus o RBC crenation o Platelet disintegration
• Platelet may adhere to neutrophils In old EDTA blood, phenomenon called
PLATELET SATELLITISM
• Standard time for EDTA:
2 hrs
• Not recommended for coagulation studies BC
(interferes with fibrinogen-thrombin reaction)
• Recommended amount of EDTA:
•
1.2 mg/ml of blood
Uses of EDTA:
RBC, WBC Hgb, Hct, ESR, Plt, Peripheral smear
• 3 forms of EDTA
i. Dipotassium EDTA – most soluble, hence preferred
ii. Disodium EDTA
iii. Tripotassium EDTA
EDTA MoA
• MoA: binds the non-ionized Ca then chelates Ca molecules in a complex (No Calcium no clotting)
– chemical substance which interferes in blood coagulation through various mechanisms
Anticoagulant
Orange
- faster clotting than usual red tube (usual clotting time: 10-15 mins)
- with clot activator (opposite of anticoagulant)
Rapid Serum Tube
Gold
-with gel that separates serum from RBC when centrifuged
SST (Serum separator tube)
Keynotes to Remember in Venipuncture
needle insertion
needle gauge
tourniquet
Prolonged application of tourniquet may lead to
hemoconcentration
Methods of blood collection through Venipuncture
- Syringe method – open system, two-way needle
- Evacuated tube method – closed system, less exposure to air
- evacuated tube: with vacuum
