HEMOSTASIS Flashcards
Maintenance of blood flow within the vascular system
Hemostasis
Bruising or bleeding tendency in patient care
Extend venipuncture site observation time from 1 to 5 minutes, apply pressure bandage before dismissal
Labile factors, easily destroyed
Factors V and VIII
Cold temperature (1-6°C) storage; effects on blood
Precipitates von Willebrand factor, activates Factor VIII, destroys platelets
Anticoagulant that increased stability of Factor V and VIII, stored in light blue top tubes (18-24°C)
Sodium Citrate concentration (0.105 to 0.109 M)
Found in light blue top tubes for coagulation tests, PF4 and β-TG assays
CTAD (Citrate, Theophylline, Adenosine, Dipyridamole)
Phlebotomist adjustment for high hematocrit
Use decreased anticoagulant volume for high hematocrit patients
Formula for adjusting anticoagulant volume
C = (1.85 X 10^-3) (100-H) V
Variables in anticoagulant volume formula
C = volume of sodium citrate, V = volume of whole blood-sodium citrate, H = hematocrit (%)
Hematocrit below 20% in anemic patients
No need to increase anticoagulant volume
Shortened PT/APTT test results
Hemolysis, excessive agitation, prolonged tourniquet application, excessive needle manipulation, platelet contamination
Prolonged PT/APTT test results
Presence of clots
Increased anticoagulant concentration is caused by
Short draw (underfilled), elevated hematocrit (>55%)
Adult with good veins, specimen < 25 mL Preferred Needle Gauge and Length
20 or 21 gauge, thin-walled, 1.0 or 1.25 inches long
Adult with good veins, specimens > 25 mL Preferred Needle Gauge and Length
19 gauge, 1.0 or 1.25 inches long
Child or adult with small, friable, or hardened veins Preferred Needle Gauge and Length
23 gauge, winged-needle set; minimal negative pressure
Transfer of blood from syringe to tube Preferred Needle Gauge and Length
19 gauge, slowly inject through tube closure
Syringe with winged-needle set Preferred Needle Gauge and Length
20, 21, or 23 gauge, thin-walled; for small, friable veins or specialized coagulation testing
PT with no unfractionated heparin (UFH) in specimen
18 to 24 C, 24 hours
PTT with no unfractionated heparin (UFH) in specimen
18 to 24 C, 4 hours
PTT for monitoring UFH therapy
18 to 24 C, Separate within 1 hour, test within 4 hours
PT when UFH is present in specimen
18 to 24 C, Separate within 1 hour, test within 4 hours
Petechiae size
1mm
Purpura size
3mm
