HEMOSTASTIS SPECIMEN COLLECTION AND MANAGEMENT ERRORS Flashcards
Whole-blood volume less than 90% of required volume or less than manufacturer specified minimum. PT and PTT are falsely prolonged.
Short draw
Inaccurate anticoagulant to blood ratio
must be full draw to be accurate
3.2% can be 1:9 but 4:1blood to anticoagulant ratio (depends on the percentage of sodium citrate in the tube)
Citrated tubes
Each specimen is inspected visually before centrifugation or during analysis; even a small clot interferes with hemostasis test results.
Specimen Clot
consumed and other coagulation factor
Fibrinogen
Pink or red plasma indicates in vitro activation of platelets and coagulation; unpredictable hemostasis test interference.
Visible Hemolysis
interferes with optical endpoint coagulometer results
hemolysis
Optical instruments may fail to measure clots in cloudy or highly colored specimens. Interferes with chromogenic substrate methods.
Lipemia or Icterus
T/F. In Lipemia or Icterus specimen, the practitioner must employ an electro-mechanical detection method instrument.
True
Blood stasis activates endothelial cells and elevates the concentration of von Willebrand factor and fibrinogen, falsely shortening clot-based test results.
Torniquet application >1minute
Storage at refrigerator temperatures causes precipitation of large von Willebrand factor multimers, activation of coagulation factor VII, activation of platelets, and destruction of platelet integrity.
Specimen storage at 1-6degC`
Storage at above standard room temperature causes coagulation factors V and VIII to deteriorate
Specimen storage at >25 degC
activates the intrinsic pathway because of the negative charge therefore, not used for coagulation studies
Glass tube
