Laboratory Evaluation on Hemostasis Flashcards
(67 cards)
ratio of venous whole blood collected thru venipuncture
9:1 with 3.2% solution of sodium citrate
volume of liquid part
0.3 ml
volume of blood part
2.70 ml
a type of specimen that is
used for clot-based test such as PT, Thrombin, and PTT.
platelet poor plasma
most vulnerable stages of the hemostasis blood testing process because every stage is manual and thus error fraught
Blood specimen collection and management
Venipuncture is the method of choice in collecting blood
ETS - evacuated tube system
The clinician asks about the following:
- Family clotting and bleeding history, blood group (Group O, pregnancy
- liver or kidney disease
- leukemia
- anemia
- malnutrition)
- 2 week drug history (anticoagulants (blood thinners), antiplatelet drugs,
especially aspirin (ASA) and nonsteroidal anti-inflammatory drugs (NSAIDS), contraceptives, and hormone replacement therapy) - over-the-counter remedies and dietary supplements (garlic, vitamin K, ginger, and St. John’s wort)
- evidence of bleeding; bruises and swelling.
Bleeding and clotting characteristics
location, frequency, volume, and whether
events are spontaneous or follow an injury or a surgical or dental procedure.
nonprescription drugs should be discontinue at least
at least 1 week prior to blood collection.
o Avoid caffeine and exercise for _____
o Avoid smoking for _____ before collection.
o Patients should be inactive for ____ before collection
- 2 hours
- 30 minutes
- 5 minutes
The most important material for hemostasis blood specimen collection
needle
Adult with good veins,
specimen ≤25 mL
20 or 21 gauge, thin-walled, 1.0
or 1.25 inches long
Adult with good veins,
specimen ≥25mL
19 gauge, 1.0 or 1.25 inches
long
Child or adult with small,
fragile, or hardened veins
23 gauge, winged-needle set;
apply minimal negative pressure
Transfer of blood from
syringe to tube
19 gauge, slowly inject through
tube closure
Syringe with winged
needle set
20, 21, or 23 gauge, thin
walled; use only for small,
friable, or hardened veins or
specialized coagulation testing.
Why searching or fishing on the
vein of the patient is not recommended if the test is PT/PTT?
sample will become traumatic
unsuitable tubes for PT/PTT
uncoated soda-lime glass
why uncoated soda-lime glass is unsuitable for use?
their negative surface charge activates platelets and plasma procoagulants
Siliconized (plastic-coated) glass tubes are available, but their use is declining because
potential breakage, with consequent risk of exposure to bloodborne pathogens.
Most hemostasis specimens are collected in
plastic blue closure (blue-top, blue-stopper) sterile evacuated blood
collection tubes
The anticoagulant used for most
hemostasis testing is
(3.2%) sodium citrate
Sodium citrate binds ______ to
______, and the buffer _______
- calcium ions
- prevent coagulation
- stabilizes specimen pH
The amount of anticoagulant may be
computed by using this formula
C = (1.85 x 10^ -3) (100 - HCT) V
