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ALL / Clinical Sciences
Abnormal coagulation
Abnormal coagulation
| Cause | Factors affected |
|---|---|
| Heparin | Prevents activation factors 2,9,10,11 |
| Warfarin | Affects synthesis of factors 2,7,9,10 |
| DIC | Factors 1,2,5,8,11 |
| Liver disease | Factors 1,2,5,7,9,10,11 |
Interpretation blood clotting test results
| Feature | Haemophilia A | Haemophilia B | Von Willebrand Disease | Factor XI Deficiency | Factor VII Deficiency |
|---|---|---|---|---|---|
| Inheritance | X-linked recessive | X-linked recessive | Autosomal dominant (mostly) | Autosomal recessive (mainly Ashkenazi Jews) | Autosomal recessive |
| Factor Affected | Factor VIII | Factor IX | vWF ± Factor VIII | Factor XI | Factor VII |
| Pathway Affected | Intrinsic | Intrinsic | Platelet adhesion & intrinsic | Intrinsic | Extrinsic |
| PT | Normal | Normal | Normal | Normal | ↑ Prolonged |
| aPTT | ↑ Prolonged | ↑ Prolonged | Normal or ↑ | ↑ Prolonged | Normal |
| Bleeding Time | Normal | Normal | ↑ Prolonged | Normal | Normal |
| Bleeding Type | Deep tissue, joints | Deep tissue, joints | Mucocutaneous (e.g. epistaxis, menorrhagia) | Variable; often post-surgical | Mucocutaneous ± deep tissue |
| Severity | Severity correlates with factor level | Severity correlates with factor level | Variable | Variable, often mild | Variable; does not always correlate with factor level |
| Diagnosis | aPTT ↑, factor VIII assay | aPTT ↑, factor IX assay | vWF antigen/activity + factor VIII | Isolated ↑ aPTT + factor XI assay | Isolated prolonged PT + factor VII assay |
| Treatment | Recombinant FVIII | Recombinant FIX | Desmopressin (Type 1), vWF concentrates | Antifibrinolytics ± FXI concentrate or FFP | Recombinant FVIIa, plasma-derived FVII |
Pathophysiology of Von Willebrand
+PassMedicine Notes
Cause_Factors affected|
Heparin_Prevents activation factors 2,9,10,11|
Warfarin_Affects synthesis of factors 2,7,9,10|
DIC_Factors 1,2,5,8,11|
Liver disease_Factors 1,2,5,7,9,10,11|
Interpretation blood clotting test results
Feature_Haemophilia A_Haemophilia B_Von Willebrand Disease_Factor XI Deficiency_Factor VII Deficiency| Inheritance_X-linked recessive_X-linked recessive_Autosomal dominant (mostly)_Autosomal recessive (mainly Ashkenazi Jews)_Autosomal recessive| Factor Affected_Factor VIII_Factor IX_vWF ± Factor VIII_Factor XI_Factor VII| Pathway Affected_Intrinsic_Intrinsic_Platelet adhesion & intrinsic_Intrinsic_Extrinsic| PT_Normal_Normal_Normal_Normal_↑ Prolonged| aPTT_↑ Prolonged_↑ Prolonged_Normal or ↑_↑ Prolonged_Normal| Bleeding Time_Normal_Normal_↑ Prolonged_Normal_Normal| Bleeding Type_Deep tissue, joints_Deep tissue, joints_Mucocutaneous (e.g. epistaxis, menorrhagia)_Variable; often post-surgical_Mucocutaneous ± deep tissue| Severity_Severity correlates with factor level_Severity correlates with factor level_Variable_Variable, often mild_Variable; does not always correlate with factor level| Diagnosis_aPTT ↑, factor VIII assay_aPTT ↑, factor IX assay_vWF antigen/activity + factor VIII_Isolated ↑ aPTT + factor XI assay_Isolated prolonged PT + factor VII assay| Treatment_Recombinant FVIII_Recombinant FIX_Desmopressin (Type 1), vWF concentrates_Antifibrinolytics ± FXI concentrate or FFP_Recombinant FVIIa, plasma-derived FVII|