Hemostasis and Bleeding Disorders Flashcards
Factors in PTT Pathway
Intrinsic Pathway: Contact factors, XII, XI, IX, VIII
Factors in PT Pathway
EXTRINSIC Pathway: VII, tissue Factor
Common Pathway factors
X, V, Prothrombin (II), Thrombin (IIa), Fibrinogen (I), Fibrin (Ia)
Confirming Heparin contamination
prolonged PTT
1) check from direct venipuncture
2) Prolonged Thrombin Time, normal reptilase time.
Etiologies for isolated elevation in PT
Vit K def, Liver Insufficiency, poor nutrition, coumadin, factor VII def/inhibitor
two factor deficiencies which lead to very elevated PTT but no bleeding phenotype
HMWK and Factor XII
Patient comes in with bleed and prolonged PT. PT does not correct with mixing study. Lupus inhibitor is detected but patient is bleeding. What factor inhibitor is most likely present?
Factor II, Prothrombin
What does thrombin time measure?
What causes prolongation?
Conversion of fibrinogen to fibrin
Prolonged by heparin contamination (reptilase time normal) and Hypofibrinogenemia and dysfibrinogenemia (reptilase time prolonged)
PFA 100 test is performed in bleeding patient
1) what can cause false positive?
2) Col/Epi closure time is prolonged, Col/ADP time is normal. What is cause?
3) Col/Epi closure time is prolonged, Col/ADP time is prolonged. What is cause?
1) Anemia (HCT <28%), TCP (<100k)
2) Aspirin
3) VWD, Platelet defect, renal failure, BSD, Glanzmann’s
RIPA Study:
Normal- ADP, Collagen
No Response- Ristocetin
Giant platelets
Bernard Soulier
RIPA Study:
Normal- Ristocetin
Absent- ADP, Collagen
Normal Appearing Platelets
Glanzmann’s Thrombasthenia
RIPA Study-
Normal- Primary Wave with ADP, Collagen, Ristocetin
Blunted Secondary Wave
Abnormal Appearing platelets
Storage Pool Disease (like Grey Platelet syndrome)
RIPA Study:
Normal Primary ADP wave, Ristocetin
Blunted- secondary wave and response to collagen
Normal Platelet morphology
NSAID/ASA effect
Testing for Factor XIII def
Clot stability assay. Dissolution of clot in less than 24 hours by 5FU-Urea is consistent with factor XIII def
Normal PT, prolonged PTT, normal platelet count
VWF antigen low (20%), VWF:Rco activity normal, multimers normal, RIPA normal, low factor VIII activity
Type I VWD
Normal PT, Elevated PTT, normal platelet count
Low VWF antigen but lower VWF activity. No large VWF multimers, low FVIII activity, normal RIPA
Type IIa VWD
Normal PT, Prolonged PTT, decreased VWF antigen and activity, decreased large VWF multimers but increased ripa and low platelets
Type IIB VWD
don’t give DDAVP
Normal PT, Prolonged PTT, Decreased VWF antigen, pronounced drop in activity, normal multimers, decreased FVIII activity, normal RIPA, normal platelet count
Type IIM VWD
Normal PT, Elevated PTT, normal VWF Antigen and activity. Normal Multimers, very low FVIII level, normal RIPA, normal platelet count. Female patient
Type IIN VWD
Test VWF binding affinity to normal FVIII, will be low in this disease
Normal PT, Elevated PTT, extremely low VWF antigen and activity, complete absnce of large VWF multimers, decreased FVIII, normal platelets, normal RIPA
Type III VWD
47 yo man who just had CT surgery using fibrin glue. Post op he starts bleeding and PT/PTT are prolonged and don’t correct on mixing study.
FV inhibitor
Fibrin glue contains bovine FV which can lead to alloantibodies
Goal FVIII or IX level for:
Minor surgery-> _____% for _____ days
Major Surgery-> _____% for _____ days
Minor-> 50% x 3-5 days
Major-> 80% x 10-14 days
Newborn with delayed umbilical cord stump bleeding. Normal PT/PTT, normal platelet count
Diagnosis:
Confirmatory Lab:
Treatment:
Diagnosis: Factor XIII def
Lab: 5M urea clot lysis time (<24h)
Treatment: rFXIII (Tretten)
Child with easy bruising, oozing blood on heel stick
Normal PT/PTT, normal fibrinogen, VWF scree, platelet count, factor XIII level.
Platelet agg shows aggregation to ristocetin only
Diagnosis:
Pathophys:
Diagnosis: Glanzmann’s Thrombasthenia
Pathophys: deficiency of platelet GPIIb/IIIa receptor (diagnosed by flow cytometry)
treated with platelet transfusion and novoseven
Child with several months of easy bruising.
Normal PT/PTT, normal fibrinogen, VWF scree, platelet count, factor XIII level. Enlarged platelets noted
Platelet agg shows aggregation to ADP and collagen but no activity with Ristocetin
Diagnosis:
Pathophys:
Diagnosis:Bernard Soulier Disease
Pathophys: Deficiency of platelet GPIb receptor
Treatment with platelet transfusions and novoseven
How do you tell the difference between Glanzmann’s Thrombasthenia and Congenital Afibinogenemia?
Congenital Afibrinogenemia will have prolonged PT, PTT, and TT.
Both have same RIPA pattern (Normal with ristocetin but absent with collagen/ADP)
15 yo presents with recurrent nosebleeds. Normal PT, PTT. Thrombocytopenia. Platelets appear grey. Which platelet granules are missing?
alpha granule
Abnormal aggregation with collagen
15 yo Puerto Rican boy with albinism presents with recurrent epistaxis. Normal PT/PTT but low platelet agg with ADP. Second wave on platelet agg is completely absent with ADP and Epi
Diagnosis->
Gene Defect->
Dense Granule Deficiency. Defect in HPS-1 gene
23 yo woman with epistaxis and gume bleeding since childhood. Normal coag profile but abnormal aggregation of platelets with epinephrine.
Diagnosis:
Pathophys:
Diagnosis: Quebec Platelet D/o
Pathophys: increased Urokinase-type plasminogen activator
