BL - Hemostasis Defects Flashcards
aPTT, Protime (INR), Thrombin time platelet count are all?
Common Screening tests
Activated Partial Thromboplastin Time(aPTT) pathway
Citrated Plasma
–>
**Kaolin (surface activator)
phospholipid
–> incubated
–> recalcified
Measure time to clot
aPTT Measures the activity of the entire pathway except _________
Factor VII
Test Useful to detect Factor VIII, IX, XI, XII deficiencies
Activated Partial Thromboplastin Time(aPTT)
Prothrombin Time(protime, PT) pathway
Citrated Plasma
–>
**Thromboplastin
(Tissue Factor)
–> incubated
–> recalcified
Measure time to clot
Excess thrombin is added to plasma
Detects low or abnormal fibrinogen, fibrin split products or heparin
Fibrinogen activity should also be measured
Thrombin Time
Protime/International Normalized Ratio(PT/INR)
Thromboplastin varies by manufacturer and the time in seconds is “normalized” by adjusting for known potency
PT/INR Prolonged with II, VII, V, X and ____ deficiencies
fibrinogen
PT/INR Prolonged with vitamin K deficiency and________
liver disease
_______ measures platelet function, vessel wall and skin integrity
Bleeding Time/PFA
Common Congenital Disorders of Coagulation
Hemophilia A – Factor VIII (Classical)
Hemophilia B – Factor IX (Christmas Disease)
Hemophilia C – Factor XI
Von Willebrand Disease
genetic deficiency in clotting factor VIII, which causes increased bleeding and usually affects males.
Hemophilia A – Factor VIII (Classical)
a blood clotting disorder caused by a mutation of the factor IX gene, leading to a deficiency of factor IX. It is the second-most common form of haemophilia
Hemophilia B – Factor IX (Christmas Disease)
arises from a qualitative or quantitative deficiency of von Willebrand factor (vWF), a multimeric protein that is required for platelet adhesion.
Von Willebrand Disease
Unusual Congenital Disorders of Coagulation
Less Common
- Factor VII
- Hypo or dysfibrinogenemia
Rare
-Factor XIII, V, X, and II
Differential Diagnosis of Long PTT- non bleeder
Non bleeders:
Factor XII deficiency Lupus anticoagulant (thrombophilic!)
Differential Diagnosis of Long PTT- Bleeder
- Hemophilia A or B
- Factor 11 deficiency
- Acquired Hemophilia Factor 8 autoimmune
- Severe von Willebrand Disease
- *Heparin in sample
- Fibrin split products
Long PTT means
It took “too long” for blood clotting
Hemophilia A or B can only be tested with
Elevated PTT is ONLY abnormal screening te
Hemophilia Bleeding Complications
Soft tissue hematoma
Joint bleeding
CNS bleeds – cause of death
Retroperitoneal or psoas bleeds
Post surgical or traumatic bleeds
Ecchymoses
a subcutaneous purpura (extravasation of blood) larger than 1 centimeter or a hematoma, commonly called a bruise
________cause muscle damage, calcified pseudotumors and atrophy
Hematomas
Hemophilia Treatment
Recombinant synthetic factor treatment is effective and given 2-3 times per week IV to prevent disability.
Causes of a Prolonged PT ± PTT
Liver disease
Vitamin k deficiency
Warfarin or rat poison ingestion
Decreased vitamin k dependent carboxylation of II, VII, IX and X can be a result of
Abnormalities in Liver Disease
Factor 11 deficiency
Hemophilia C
Post prostate surgery with bleeding can be
Hemophilia C
Decreased fibrinogen production and increased fibrinolysis can be a result of
Abnormalities in Liver Disease
The ______measures the procoagulant
activity of the factors VII, X, V, II and fibrinogen. This is the extrinsic pathway
protime (PT)
measures the procoagulant activity of
fibrinogen and is also very sensitive to the anticoagulant effect of heparin or fibrin split
products.
Thrombin Time (TT)
measures the platelet and vessel interaction, as well as the number and the function of platelets.
Bleeding Time (BT)
A new device, the _________, can perform an in vitro bleeding time. It also can determine platelet response to agonists.
Platelet Function Analyzer
Less than 1% factor activity – Severe _____
Hemophilia
2% to 5% factor activity- _______ Hemophilia
Moderate
In Factor VII deficiency only the protime (PT) is prolonged. The______is normal.
PTT
hepatic function can cause deficiencies of the clotting factors. This is especially true for Factor V and for the ______dependent Factors, II, VII, IX, and X.
vitamin K
> 10% factor activity- _______- Hemophilia
Mild
diagnosed after a bad traumatic event or after a bad result from surgery.
Vitamin K deficiency and _____ administration which interfere with the vitamin K utilization, are very common causes of a prolonged protime with normal or slightly prolonged PTT.
warfarin
Long acting fat soluble rat poisons are used in suicide attempts.
These patients present with _____ labs and require very intensive vitamin K therapy for months
extremely prolonged protime and PTT
Massive trauma, hemorrhagic or septic shock, amniotic fluid embolism, burns, acute leukemia or transfusion and drug reactions can all cause _________
disseminated intravascular coagulation
________is the formation and propagation of clot within the vasculature; this term refers to an abnormal or pathologic process with imbalance in the hemostatic system.
Thrombosis
a very common acquired abnormality which results in a hypercoaguable state. The anticoagulant is an IgG antibody, which reacts against phospholipid in the platelet membrane or endothelial cell.
The Lupus Anticoagulant
Factor V Leiden hypercoagulability results from a mutation in Factor V so that it is not inactivated by______.
protein C
deficiencies of antithrombin, protein C and protein S or resistance to protein C (Factor V Leiden) have what in common
The four most common familial
congenital conditions which cause a hypercoagulable syndrome
DIC mantra
treat the underlying disorder
Replace platelets and fibrinogen
Rarely: stop progression with anticoagulation
_____________hypercoagulability results from a mutation in Factor V so that it is not inactivated by protein C.
Factor V Leiden
Hypercoagulable States
Impairment of blood flow
Congenital deficiencies of endogenous anticoagulants
Cancer
Thrombocytosis – high platelets (P vera)
Antiphospholipid Syndrome – Lupus Anticoagulant
in vitro prolonged PTT but causes in vivo thrombotic disorders
Lupus Anticoagulant
Associated with lupus sometimes
Venous and arterial thrombosis
Hepatic vein thrombosis
Recurrent miscarriage
Migraine headaches
may indicate?
Antiphospholipid Syndrome – Lupus Anticoagulant
Russell Viper Venom Test (RVVT) or Platelet Neutralization Test with correction are common tests for?
Confirmation of Lupus Anticoagulant
Even though the PTT is prolonged in vitro, the patients do not have bleeding. instead they have a thrombotic syndrome which includes deep vein thrombosis, pulmonary embolism, thrombotic strokes and recurrent miscarriage due to thrombotic disease of the _________.
placental blood vessels
The most consistent laboratory findings are that the fibrinogen level has decreased markedly and the platelet count is low.
Disseminated Intravascular Coagulation (DIC)
Acquired Factor Inhibitors
acquired Factor VIII inhibitor
only laboratory test to be abnormal will be the PTT
excellent long-term prognosis
von Willebrand protein has two functions.
adhere platelets to exposed collagen
carry Factor VIII
The classic presentation is post-operative hemorrhage since most people do not have spontaneous bleeding.
Factor XI Deficiency
