PLT AND HEMOSTASIS Flashcards
maintenance of blood flow within the vascular system
hemostasis
t or f. the phlebotomist should stay for 1 to 5 minutes after the venipuncture on patient who requested for a hemostasis test.
true
2 labile coagulation factors
factors V and VIII
3 things that may happen when a light blue top specimen is placed inside a refrigerator (1-6 C)
- precipitation of von Willebrand factor
- activation of factor VII
- destruction of platelets
anticoagulant that increases the stability of factors V and VIII
3.2% buffered sodium citrate
light blue top no. of inversions
3 to 4 inversions
blood:light blue top anticoagulant ratio
9:1
transcribe CTAD anticoagulant
citrate, theophyline, adenosine, dipyridamole
CTAD is found in where
light blue top
CTAD is utilized for? (2)
- platelet factor 4
- beta-thromboglobulin
factors that may affect coagulation test results:
shortened test results: (5)
- hemolysis
- excessive agitation
- prolonged tourniquet app
- excessive needle manipulation
- platelet contamination
factors that may affect coagulation test results:
prolonged test results: (2)
- presence of clots
- increased AC concentration
causes of increased AC concentration
- short draw
- elevated hematocrit (>55%)
t or f. we dont adjust the AC volume even if the patient has high hematocrit.
false
formula for adjusting AC volume
C = (0.00185) (100-hct) V
needles for hemostasis specimens:
adult with good veins, specimen <25 mL
20 or 21 gauge
needles for hemostasis specimens:
adult with good veins, specimen >25mL
19 gauge
needles for hemostasis specimens:
Child or adult with small, friable, or hardened veins
23 gauge, winged needle set
needles for hemostasis specimens:
transfer of blood form syringe to tube
19 gauge
what happens in primary hemostasis?
- constriction of damaged blood vessels
- formation of platelet plugs
what happens in secondary hemostasis?
- formation of fibrin meshwork through activated coagulation factors
- inhibition of activated coagulation factors
composition of a blood vessel wall:
it is lined with a simple squamous epithelium called endothelium (lines the inner tubular cavity)
tunica intima
composition of a blood vessel wall:
thickest coat, composed of smooth muscle and elastic fibers
tunica media
composition of a blood vessel wall:
composed of fibrous connective tissue that contains autonomic nerve endings and the vasa vasorum
tunica adventitia
largest type of blood vessels
veins (5mm)
