[LAB] Hemostasis Lab Testing (Part 1) Flashcards
(47 cards)
What type of plasma is used for the hemostasis procedure whereby platelet count is less than 10,000/ μL prepared from whole venous blood collected by venipuncture?
Platelet-poor plasma (PPP)
What type of plasma is used for light transmittance platelet aggregometry whereby platelet count is approximately 200,000/μL?
Platelet-rich plasma (PRP)
Hemostasis testing begins in ____ and ____.
bleeding and thrombosis risk assessment
Patients under drug therapies and dietary supplements are instructed to discontinue nonprescription drugs ____ prior to blood collection.
at least a week
If the patient has multiple bruises, mention a tendency to bleed, or possesses a high-risk BAT score, the phlebotomist should extend the time for observing the venipuncture site from the usual 1 minute to _____ and should apply a pressure bandage before dismissing the patient.
5 minutes
Patients are advised to avoid caffeine and exercise for ____ before collection.
2 hours
Patients are advised to avoid smoking for ____ before collection.
30 minutes
What is the usual gauge size for hemostasis collection on adults with good veins?
20-21 gauge
What gauge size will you use in the case of small, scarred, or fragile veins?
23-gauge
When transferring blood from a syringe to tube, what is the preferred needle gauge?
19-gauge
What is the top color of the collection tube used for the hemostasis specimen?
blue-top
What is the anticoagulant used for most hemostasis testing?
buffered 3.2% sodium citrate
What is the mechanism of a sodium citrate anticoagulant?
binds calcium ions to prevent coagulation
What is the purpose of the buffer?
stabilize specimen pH
What is the ratio of anticoagulant and blood?
9:1 (9 parts whole blood to 1 part anticoagulant)
What is the usual concentration of the anticoagulant and blood collected in evacuated plastic collection tubes?
0.3 mL of anticoagulant
2.7 mL of whole blood
What is the final citrate concentration following the ratio?
10.5-10.9 mM
The formula for computing the amount of anticoagulant.
C = (1.85 X 10^–3) (100-HCT) V
What is the mechanism of EDTA?
irreversibly chelates calcium ions
True or False.
EDTA is one of the anticoagulants used for hemostasis testing.
False.
(Laboratory practitioners do not use EDTA for clot-based coagulation testing because EDTA irreversibly chelates calcium ions)
Identify the anticoagulant.
- produce accurate platelet counts in cases of platelet satellitosis (satellitism) as a substitute for specimens collected in EDTA.
Heparin (green)
Identify the anticoagulant.
- suppress in vitro platelet or coagulation activation for specialty assays
Citrate theophylline adenosine dipyridamole (CTAD, blue closure)
True or False.
If a series of evacuated tubes is to be filled from a single venipuncture site, the hemostasis specimen must be collected before a nonadditive tube.
False.
(hemostasis specimen must be collected first or immediately after a nonadditive tube)
What is the minimum required volume of blood during collection?
90%
