Heme/Onc Flashcards
(70 cards)
Virchow’s triad
- Vessel injury
- venous stasis
- hypercoagulability
Top 5 hereditary RFs for thrombophilia
- Factor V Leiden
- Prothrombin mutation
- Protein C deficiency
- Protein S deficiency
- Antithrombin deficiency
Top 5 acquired RFs for thrombophilia (RR)
- Antiphospholipid Abs (10)
- Active cancer (7)
- Pregnancy (6)
- Estrogen (OCPs/HRT) (4)
- Smoking
Multiple RFs (either hereditary or acquired) have a additive/synergistic effect on RR of first VTE event?
synergistic
What clinical AND laboratory info is necessary to make a dx of Antiphospholipid syndrome?
- Clinical criteria: arterial/venous thrombosis OR pregnancy loss/ recurrent miscarriage
- Labs criteria: (+) APLA test (any of the 3) detected on 2 or occasions separated by at least 12 weeks
Why do you need a (+) APLA test (any of the 3) detected on 2 or occasions separated by at least 12 weeks?
can be falsely elevated d/t dz
MC inherited thrombophilia
Factor V Leiden
Homozygous neonates may present clinically with neonatal purpura fulminans (DIC) w/ these 2 hereditary thrombosis RFs:
- Protein C deficiency
- Protein S deficiency (cofactor for APC)
What effect does warfarin have on activated protein C (APC)? Why?
↓ levels because protein C is dependent on Vitamin K and warfarin is a Vitamin K antagonist
Name the dz based on clinical presentation:
- VTE (may be recurrent) @ unusual sites
- Recurrent thrombosis may occur despite absence of additional RFs
- Some patients are resistant to heparin therapy
antithrombin deficiency
How does the presence of APLAs mess with the following coagulation labs: aPTT, PT, 1:1 mixing study
- aPTT: prolongs aPTT → makes heparin dosing difficult
- PT: may prolong PT → makes warfarin dosing difficult
- 1:1 mix: does NOT correct BUT causes CLOTTING not bleeding (unlike clotting factor deficiency disorders)!!
Do APLAs act as anti- or pro- coagulants?
PROCOAGULANTS!! 1:1 mixing study does NOT correct but causes CLOTTING not bleeding!
What is the initial therapy for tx of VTE (2 components)?
- heparin or LMWH for ~5 days
- Warfarin/coumadin for 3-6 mo.
When should you test for abnormal hypercoagulable states in the clinic?
When results could change management!
- Young age (<45 yo) w/ unprovoked VTE questions regarding need for long term anti-coagulation therapy
- Thrombosis in unusual sites (arterial, upper extremities)
What are the 3 new anti-coagulation drugs that may change the risk/benefit analysis that is currently an issue with warfarin? What is one potential problem with these drugs?
- Dabigatran (Pradaxa)
- Rivaroxaban (Xarelto)
- Apixaban (Eliquis)
NO OD REVERSAL AGENT!!
What are the 3 APLAs?
- Lupus anticoagulant
- Anticardiolipin Abs
- anti-β2GPI Abs
What is the biggest thrombophilia RF contributing to recurrent clotting events
persistent APLAs
What are 4 modifiable RFs that can be addressed during tx of thrombophilia?
- smoking cessation
- maintaining healthy weight
- staying active (lack of immobilization)
- avoiding estrogen/ progesterone
Which 2 hereditary VTE RFs likely need additional RFs in order to provoke thrombosis?
- Protein C deficiency
- Protein S deficiency
What are 3 lab tests we have to test platelet function?
- PFA-100
- Platelet aggregation testing
- Thromboelastography
What is the most important lab test for differentiating b/w a coagulation factor deficiency and a coagulation factor inhibitor?
1:1 mixing study
Does a 1:1 mix study correct if a coagulation factor deficiency or inhibitor is present?
deficiency: 1:1 mix corrects to normal
inhibitor: 1:1 mix does NOT correct to normal
leading cause of renal failure in children worldwide
HUS d/t shiga toxin in E. Coli
What are the 3 requirements for proper RBC prdn. (erythropoiesis)?
- bone marrow cells working
- EPO from kidney
- substrate supplies (iron, Vit. B12, folic acid)
