1. 혈액응고 검사의 정도관리
혈액학계 윤 미 경

2. Check Points [sources of error]
Preanalytical variables
specimen
Testing variables
instrument, Reagent, Control material
standard material, Methodology
QC program
Patient reports/interpretation

3. Specimen collection Prolonged venostasis
activation of clotting & fibrinolytic factors
shortened aPTT(Ⅷ)
Under-filling (>70% aPTT, >60% PT)
Elevated Hct (low plasmacrit)
citrate effect
prolonged aPTT

4. Specimen collection Insufficient mixing Excessive mixing
micro-clots or fibrin strand (plasma)
clotting factor consumption
Excessive mixing
hemolysis, clumps(preactivated)
clotting factor activation

5. Specimen collection Buffered Citrate Siliconised glass
Plastic PET tube
Age-end of storage (shelf life)

6. Specimen collection (경험)
Patient samples with heparin therapy
:No prolongations of aPTT
Repeat with old collection tube(BD)
Repeat with new collection tube(BD)
Expiry date of evacuated tubes
Rubber stopper-neutralize heparin

7. Specimen processing Cold promoted activation(CPA)
FⅦ( ), PT shortening
Platelet poor plasma(PPP): centrifuge
platelet contamination(esp LA)
aPTT. false elevation (Ⅰ,Ⅴ,vWF)
only upper layer (3/4)
Rapidly frozen/thawing

8. Specimen processing(경험)
Bleeding case
Specimen from commercial lab
Two aliquots for each test
Aliquot A Aliquot B
vWF:Ag D N(false)
vWF:RCO D N(false)
Centrifugation : only upper layer (3/4)
Platelet contamination

9. Specimen storage Plasma or WB (RT, 4℃)
PT stable for 24hr
APTT stable for 8~12hr
Heparin therapy (centrifuge within 1hr, assay within 4hr)
Frozen plasma : Rapid thawing

10. Specimen for platelet function test
Collection
hemolysis
Centrifugation
PRP, PPP at RT
Influence of time
30min~3hr(RT)
Ristocetin(imm.), epinephrine(1hr)

11. Instrument (ACL, Futura)
Methodology
semiautomated (electro-mechanical)
automated (photo-optical)
Reagent systems
Economic factors
Test volume
Computer interface
Technologist acceptance

12. Instrument (경험) DIC (activated clotting factor)
Short aPTT from ACL(IL) coagulyzer
Clot formation : shorter than lag phase
No change in light transmission
Artifactual prolongation mimicking coagulopathy
Visual confirmation (clot)

13. Reagent Instrument + reagent system Total system(same manufacturer)
Thromboplastin for PT/APTT
PT-Fib reagent : unopened –expire date
after reconstitution-2~8℃ 3days
15 ℃ 8hrs
aPTT reagent : after reconstitution-2~8 ℃ 7days
15 ℃ 8hrs
CaCl : 25mMol/L, 30days(2~8 ℃)

14. Control & standard material
Reconstitution
Pipette quality assurance
Pooled normal plasma(PNP)
Healthy, fasting, no medication
>n=20(M:F) pool aliquot, -70 ℃
Minimum time for labile factors
Commercial Reference Plasma

15. QC Program Reporting & Results Delta check
Repeat if abnormal (not routine)

16. Conclusion Awareness Customize to each patient
interpretative medical knowledge
possibility-open
coexist or superimposed
acquired > congenital
Customize to each patient
age, sex, clinical conditions
치료(약제, 마취제, 수혈)
Future : near patient testing(POCT)