Hemostasis/Thrombosis Flashcards
Virchow’s Triad
vascular trauma: trauma, sx, line, inf
Hypercoagulability: hereditary thrombophilia, malig, preg, infl, estrogen, dehydration
Reduced blood flow: immobility, prolonged travel, obesity, preg, congenital anomalies, Fontan, catheter
List the inherited thrombophilias (including anatomic)
FVL
Prothrombin gene mutation
Protein C/S deficiency
Antithrombin deficiency
PCV, PNH, hemoglobinopathies, SCD
Anatomic:
- IVC atresia
- May Thurner Syndrome: narrowed L iliac vein 2o compression from R iliac artery against lumbar spine
- Thoracic Outlet Syndrome: extra rib or muscle group compressing veins
FVL inheritance, mechanism, risk
aut dom
G1691A mutation
APC resistance - Protein C can’t inactivate FVa
5% lifetime risk
4x general population
low recurrence risk
Prothrombin gene mutation inheritance, mechanism, risk
aut dom
G20210A GOF mutation
3-4x general population
low recurrence risk
Protein C/S deficiency inheritance, mechanism, risk
aut dom
no inactivation of Va and VIIIa
severe congenital: 100%
PC: 7x general population
PS: 5x general population
high recurrence risk
Antithrombin deficiency inheritance, mechanism, risk
aut dom
quant or qual deficiency in antihrombin –> increased thrombin
8x general population
1% annual risk
high recurrence risk
Acquired thrombophilia states
Acquired Protein C/S deficiency
APS
pregnancy
Cancer
inflammation - acute phase reactants FVIII, VWF, TF
CVL
cardiac disease
trauma/surgery
Obesity
immobilization - stasis
nephrotic syndrome - loss of antithrombin in urine
liver failure - decreased synthesis of protein C/S
medications (OCP, asparaginase)
Thrombophilia workup
Hx, P/E, FHX
CBC
INR, PTT, fibrinogen
Protein C and S Ag and activity
FVL and prothrombin genetics
Antithrombin (chromogenic)
APS: LA, anti-cardiolipin, anti-beta2 glycoprotein
FVIII, VWF
Thrombophilia workup indications
unprovoked or recurrent VTE
VTE and SLE
VTE and strong FHx
purpura fulminans
VTE compression US findings
failure to compress vein
loss of phasic flow on Valsalva
absent flow (fully occlusive)
Kids-DOTT trial results
6w for acute provoked and resolved clot (not malignancy or PE)
Otherwise 3mo
Thrombolysis indications and contraindications
life/limb threatening arterial clot/DVT
- bilateral RVT, occlusive IVC, large iliofemoral
PE w hypotension or RH strain
bleeding risk, surgery <10d (NSx<60d), intracranial malig, seizure <48h, sepsis
What is warfarin induced skin necrosis etiology and prevention
transient hypercoagulability 2o reduction in Protein C/S (shortest half lives of K-dept factors) -> microvascular thromboses and tissue infarct
- need 5d UFH bridge at start of warfarin
HIT etiology, presentation, tx
autoAb against heparain:plt factor 4 compelx -> plt activation
thrombosis
Tx: stop heparin, start another anticoagulation; avoid plt transfusion
- 2nd line IVIG, PLEX
APS criteria
thrombosis or pregnancy related morbidity
and
1+ LA/cardiolipin/beta2 glycoprotein
on 2 checks 12+ w apart
Lupus anticoagulant dx
mixing study - no PTT correction
RVVT: venom directly activates Xa, but excess phospholipid will overwhelm LA and create clot
1o Thromboprophylaxis indications
APS with SLE
homozygous protein C/S deficiency
dilated cardiomyopathy (warfarin)
primary pHTN (warfarin)
neonate with CVAD or UAC (UFH)
neonate cardiac cath (UFH)
long term home TPN (warfarin)
hemodialysis via arteriovenous fistula or CVAD (warfarin or LMWH)
KD moderate/giant aneurysm (warfarin/ASA)
post thrombotic syndrome s/s, epi, RF
venous insufficiency - pain/heaviness, paresthesia, cramping, pruritis, dilated veins, swelling, redness, edema
25% post extremity DVT
RF: young, obese, large clot, untreated/partially treated, delayed tx, elevated D-D or FVIII
RVT presentation and tx
palpable flank mass (45% neonates), hematuria, thrombocytopenia, kidney dysfunction, anuria
unilat: anticoagulate
bilat: thrombolysis -> anticoagulation