Cardio: DVT Flashcards
what kind of problem is a DVT?
cardiac/pulmonary - venous fibrin clotting (will need anti-coag > anti-plt)
what is vichor’s triad?
- venous stasis/ turbulent flow
- hypercoag state
- endothelial damage
aka abnormalities in Flow (1) , blood composition (2) , vessel wall (3)
*three things that are often in the history of someone w/ DVT
what are 3 endogenous anti-coags ?
protein C & S
TFPI (tissue factor path inhib)
anti-thrombin III
significance of protien C or S deficiency
serious genetic condition with excessive clotting b/c you dont have the protein that naturally breaks down clots
- multiple clotting events in life
- can happen at young age
tPA vs PAI-1
opposites (natural influencers of clots)
tPA: cleaves plasminogen into ACTIVE plasmin which then DISSOLVES CLOT
PAI-1:(PROTHROMBOTIC) pLT activating inhibitor- inhibits plasmin creation (so you can’t dissolve clots) (there will be an inc. level of this in someone w/ HTN)
pts w/ excessive clotting may present with what major venous or arterial problems?
vein: DVT/PE
artery: stroke/MI/PVD (prothromic state or stasis (Afib))
…also may have family history of stroke or other CVD
PE: DVT usually presents as…
- often after minor trauma or immobilization
- unilateral lower extremity
- inflamm. (blood causes inflamm response), pain, warmth
Dx of DVT - what can you use to localize the clot?
doppler US
medication txt for DVT
anti-coag
SOB, pleuritic CP, Right-side HF, Virchow’s triad…. all could be indications of …
DVT
sudden right sided heart failure and rapid peripheral edema and JVD could be indications of …
DVT
what are you weighing when consider whether to image test for DVT?
how highly you suspect there to be one
what is the GOLD STANDARD Dx test for DVT?
contrast venography … but we dont really use it
what is plasma D-Dimer ?
degradation product of fibrinolysis (elevation in plasma will indicate that this is happening)
- normal? low likelihood of DVT/PE
- negative? MOST useful b/c you can r/o DVT/PE
*almost all pt’s have _____D-dimer
elevated (means you can get many false positives w/ this test)
homan’s sign is usually used to test ___ not ____ (according to Hadley)
thrombophlebitis NOT DVT
what do you do to estimate pre-test probability of DVT?
wells score.
>2 = 28% likelihood of DVT
<1 = 6% liklihood of DVT
when is D-Dimer a “high value test” over venous doppler?
when you have LOW PRE-TEST PROBABILITY (from wells score) , negative D-dimer gives you an answer at 1/10 the cost of Venous doppler US
what is Duplex doppler scanning? what is it best for?
combo of US and pulsed doppler- moving while it takes imaging to see the change (if any) in flow
-best for proximal disease (e.g. femoral and up)
what is prevention for DVT for …
1. short/uncomplex surgery
vs
2. long/high-risk surgery or pt w/ risk factors?
- early ambulation
- heparin, (quick onset, easily reversible) (short term)
- warfarin/direct thrombin inhibit (for long term)
how long is the “longterm” for warfarin for DVT txt/prophylaxis? and what are you monitoring?
3 months - checking PT/INR
what would you use for MI/stroke prophylaxis is ASA fails?
warfarin
how long does it take to get therapeutic levels of warfarin ?
4-5 days
what two situations would someone need lifelong prophylaxis for DVT?
- recurrent DVT
2. no clear cause of the DVT
anti-coag for ____ DVT helps prevent PE. for ____DVT it is less clear
proximal
distal (much lower probability of getting a PE from distal)
anti-coag for distal DVT? if symptomatic vs asymptomatic?
symptomatic: anticoag as you would for proximal
asymptomatic: maybe surveillance, maybe txt w/ anti-plt ASA
* *which prevents “sticking” (clot progression) but not the cascade (clot initiation)
pulmonary embolism: pt often has preceding ____ that may be ____
DVT, asymptomatic
etiology of pulmonary emb.
embolization from venous system through right V to lung
tachycardia, tachypnea, low O2, low grade fever from inflamm., possible DVT signs… what may this be?
PE
what is the “gold standard” for Pulm. embolism and what do we actually use more commonly?
gold: pulmonary angiography (invasive and expensive)
actually: spiral CT (spins around body)
____ of PE arise from ____ in deep venous system
> 90% of PE arise from venous thrombi in deep venous system (thigh > calf)
3 presentations of PE
- acute cor pulmonale (massive pulmonary embolism that obstructs >50% pulmonic circulation)
- pulmonary infarction
- acute unexplained dyspnea
what can pulmonary infarction be easily confused with? and what S&S does it present with?
pneumonia, pleuritis, MI
S&S: pleuritic (sharp local) CP, dyspnea, tachy, hemoptysis
AKA hard to Dx
what 2 things are important for Dx unexplained dyspnea?
history and risk factors (b/c S&S are very vague and confusing)
Dx test for “unexplained dyspnea”?
arterial blood gas (ABG) : classic drop in PO2 and PCO2
* PO2 can be WNL at expense of PCO2 (very low CO2)
what is a ventilation/perfusion (VQ) scan? what are you trying to Dx between? what do results indicate?
examines air and bloodflow in lungs: shows ventilation:perfusion mismatch (trying to Dx unexplained dyspnea to see if its a PE)
- normal scan is helpful ( r/o PE)
- high probability scan is helpful (r/i PE)
- low probability scan = not helpful
what is unexplained dyspnea?
sub massive embolism w/out infarction
what is MUD (medically unexplained dyspnea)? how are they presenting?
pt presents with dyspnea but no cardio-pulmonary explanation for it.
“submassive embolism w/out infarction” - “no infarction but poor perfusion” (hadley)
-usually presenting w/ anxiety and hyperventilation, tachypnea, tachycardia (nervous friggin nelly)
suspect a PE? what do you need to give RIGHT AWAY?
heparin at least 10,000 unit bolus
Txt for stable pts w/ PE ?
O2 and close monitoring in ICU
heparin
then warfarin/ other non-vitk anticoag (NOAC) (longterm anti-coag)
IVC filter
used for high risk PE - small device placed in center of Vena Cava to prevent PE
order to tests once you suspect PE…
D-dimer - if its elevated –> spiral chest CT –> pos? txt for PE
Txt:
continue anticoag- for non high risk
thrombolysis or IVC filter for high-risk
