HEMOSTASIS SPECIMEN COLLECTION ERRORS THAT REQUIRE COLLECTION OF A NEW SPECIMEN

whole-blood volume less than 90% of required volume or less than manufacturer specified minimum

short draw

leads to prolonged result for clot-based

PT or PTT

each specimen must be visually inspected prior to centrifugation; the presence of even a small clot requires that the specimen be recollected

clot in specimen

hemolysis, pink or red plasma indicates in-vitro activation of platelets and coagulation, results are unreliable

visible hemolyzed

optical instruments may not measure clot in cloudy or highly colored specimens, especially chromogenic substrate methods

lipemia or ecterus

hemostasis elevates the concentration of von Willebrand factor and factor VIII; falsely decreases fibrinolytic parameters and falsely shortens clot-based test results

prolonged tourniquet application

storage at refrigerator temp causes precipitation of large von Willebrand factor multimers, activation of coagulation factor VII and destroys platelet integrity

specimen at 1 C - 6 C

storage at above standard room temp causes coagulation factors V and VIII to deteriorate

specimen storage at more than 25 C