文档介绍：APPROACH TO COAGULATION DISORDERS
, MD, DM
Assistant Professor,Dept of Hematology
Medical College Hospital
Trivandrum-695011, India
Clinical approach
1. Is the bleeding significant ?
2. Local Vs Systemic ?
3. Platelet Vs Coagulation disorder ?
4. Inherited Vs Acquired ?
1. Demonstration of the defect
2. Identification of the defect(s)
3. Assessment of severity
4. Consequential studies eg. carrier detection
5. Monitoring of treatment
Laboratory Approach
1. Platelet count & morphology
2. Bleeding Time
3. Clotting Time
4. Prothrombin Time
5. Activated Partial Thromboplastin Time
6. Thrombin Time
Screening Tests
Collection of blood sample
1. Minimum circulatory stasis
2. Clean venous puncture
3. Proper anticoagulant
4. Proportion of blood to anticoagulant
5. Separation of plasma and storage
6. Effect of stress, pregnancy, drugs
7. Effect of PCV on the proportion of plasma to anticoagulant
Coagulation factor deficiency/inhibitor
Test plus control plasma - 1:1
Repeat PT/APTT
> 50% correction
Yes - Factor deficiency
No - inhibitor
Prolonged PT/APTT
timed incubation
abnormally increasing
specific inhibitor
no change
Lupus Anticoagulant
PT
TT
APTT
PT -
APTT, TT, PLC - N
HMWK
XII
PK
XI
IX
VIII
VII
X
V
II
I
* Factor VII deficiency
* Anticoagulant therapy
APTT -
PT, TT, PLC - N
* Factor deficiency
* vWD
* Inhibitors
* Heparin therapy
PT
TT
APTT
HMWK
XII
PK
XI
IX
VIII
VII
X
V
II
I
Mixing tests with APTT
APTT of test plasma +
Aged plasma Adsorbed plasma Diagnosis
No correction Corrected VIII
Corrected No correction IX
Corrected Corrected XI,XII
Prolonged APTT, BT
von Willebrand’s disease
Ristocetin Induced Platelet Agglutination
VIII:C
vWF:Ag
vWF multimeric analysis
Type 1 - Partial deficiency of vWF
2A - Absence of large and interm. multimers
2B - Absence of large multimers
2M- multimers normal, pl. function
2N - affinity for FVIII
3 - severe deficiency of vWF