Flashcards in Venous Thromboembolism Deck (66):
What is the most common preventable cause of hospital related death?
Medicare has classified VTE as a never event after which operations?
total hip or knee replacement
Which chronic conditions are acquired risk factors for VTE?
chronic diseases of course, malignancy, obesity, antiphospholipid antibody syndrome, advanced age, smoking, myeloproliferative disorders
Which transient states are acquired risk factors for VTE?
surgery, trauma, immobilization, infection, hospitalization, long haul air travel
Which female specific factors are acquired risk factors for venous thromboembolism?
pregnancy, post-partum, hormonal contraceptives and hormone replacement therapy
What are the inherited risk factors for venous thromboembolism?
factor V Leiden mutation, Prothrombin gene mutation, protein S deficiency, protein C deficiency, antithrombin deficiency, dysfibrinogenemia (rare)
What are DDx for DVT?
musculoskeletal injury, leg swelling in paralyzed leg, lymphangitis or lymph obstruction, venous insufficiency, popliteal (baker's) cyst, cellulitis, knee abnormality
Clinical presentation of DVT
often asymptomatic, swelling, pain, warmth, redness or discoloration
What should be obtained for a history in cases of suspected DVT?
obtain a good history for risk factors, get an Ob/GYN history in women, think about iccult malignancy, elicit a good family history
What should be included in physical exam for DVT?
vascular, extremities (including Homan's sign with its questionable reliability), chest, cardiac, abdominal, skin
Which clinical features earn a score of 1 on the Wells score?
-paralysis, paresis or recent plaster immobilization of the lower extremities
-recently bedridden for more than 3 days or major surgery w/in 4 weeks
-localized tenderness along the distribution of the deep venous system
-entire leg swollen
-calf swelling by more than 3 cm when compared to the asymptomatic leg
-pitting edema (greater in the symptomatic leg)
-collateral superficial veins (nonvaricose)
-alternative diagnosis as likely or more likely than that of deep venous thrombosis
What can a Wells score tell you?
pretest probibility of deep vein thrombosis
What do the scores mean? and the modified score?
3 or greater: high probability of DVT
1 or 2: moderate probability of DVT
0 or less: low probability of DVT
Modification also takes previously dovumented DVT into account: 2 or greater: DVT likely, 1 or less DVT unlikely
What labs might be used to determine DVT?
CBC (with platelets), coagulation studies (PT/INR, aPTT), metabolic panels (renal, liver), urinalysis, D-dimer
What is the D-dimer test about?
In the presence of DVT and PE, endogenous fibrinolysis causes release of D-dimers from fibrin clot
What is the sensitivity and specificity of the D-dimer test? Why do we use the D-dimer test?
High sensitivity (97%), low specificity (45%)
should be used as a "rule out" test
What are 4 causes of elevated D-dimer that the slides/instructor indicate that we should know?
venous thromboembolic disease, post-operative state, malignancy, normal pregnancy
What is the "test of CHOICE" to dx DVT?
compression ultrasonography will show loss of vein compressibility, doppler technique assesses blood flow
What is the "GOLD STANDARD" in DVT dx?
contrast venography, although this is rarely used
note: study the algorithm on slide 21, maybe make some flash cards in the future when less tired
slide 21 of the VTE lecture
What is the purpose of treating DVT?
to prevent clot propagation, PREVENT PE, decrease risk of recurrent VTE, decrease complications (such as post-thrombophlebitic syndrome and chronic venous insufficiency which cause significant morbidity over patient life)
How common is upper extremity DVT?
it is rarer than lower extremity DVT
1-4% of all upper extremity DVTs are _______
What can spontaneous DVTs can be associated with?
thoracic outlet syndrome
Name 2 causes of secondary upper extremity DVT
cathater placement, prothrombotic states
In what percentage of upper extremity DVTs do pulmonary embolisms occur?
Tx of upper extremity DVT includes:
anticoagulation, thrombolysis and/or surgical decompression of thoracic outlet
What is Vichow's triad and what does it cause?
Virchow's triad: stasis, vascular injury and hypercoagulability
the triad is a noted cause of DVT
What is the clinical presentation of DVT?
asymptomatic, SWELLING, pain, warmth, redness or discoloration
Name the mainstay of treatment for DVT
What is the MOST COMMON cause of superficial thrombophlebitis?
usually short term venous cath or PICC line
Causes of superficial thrombophlebitis
-usually short term venous cath or PICC line
-spontaneous (pregnant/postpartum, varicose veins, trauma, following IV tx)
Clincial presentation of superficial thrombophlebitis
-dull pain in region of involved vein
-EDEMA OF EXTREMITY IS UNCOMMON
How would one manage superficial thrombophlebitis
-generally subsides in 1-2 weeks
-anticoagulation RARELY required
What is a pulmonary embolism?
obstruction of the pulmonary artery or one of its branches by material that originated elsewhere in the body
What is the most common cause of pulmonary embolism?
DVT is the most common cause of pulmonary embolism
What percentage of proximal DVT will embolize?
50-60% of proximal DVT will embolize
What kind of DVTs rarely embolize?
isolated calf DVTs rarely embolize
How does a blood clot in some other area of the body become a pulmonary embolism?
it travels to either IVC or SVC, into the right atrium, then right ventricle
from the right ventricle, the malovent clot tries to flow from the pulmonary artery to the lungs, but becomes wedged in the smaller arteries of the lungs, causing a PE
What is a massive PE?
a massive PE is a/w: SBPor =40 mm Hg from baseline for more than 15 mins
-(not otherwise explained by hypovolemia, sepsis, acute MI, tension pneumothorax or new arrythmia)
-Results in acute right ventricular failure and possible DEATH
What is a submassive PE?
A submassive PE is all other PEs that don't meet criteria for massive PE
7 SYMPTOMS of pulmonary embolism and their prevalence in percentages
Pleuritic pain (44%)
Calf or thigh pain (44%)
calf or thigh swelling (41%)
>2 pillow orthopnea (28%)
7 SIGNS of pulmonary embolism
Decreased breath sounds (17%)
Accuntuated pulmonic component of the 2nd heart sound (15%)
Symptoms/signs of lower extremity deep vein thrombosis (47%)
What is the most common SYMPTOM of pulmonary embolism?
What is the most common SIGN of pulmonary embolism?
In PIOPED II results confirmed w/angiogram, 97% of pateints with pulmonary embolism had:
one or more of the following 3 findings: dyspnea, pleuritic chest pain and tachypnea
What should be done in initial evaluation of pulmonary embolism?
Review vital signs and perform a general exam (BP, HR, RR, mental status)
determine if pt is stable or unstable and act appropriately
What do you do when you have determined during initial evaluation of pulmonary embolism that a patient is UNSTABLE
oxygen, IV fluids, blood pressure suport, ICU, consider thrombolytics
What do you do if, upon initial evalution of pulmonary embolism, you determine that a patient is STABLE
proceed with further diagnostic work-up
Detail the dichotomous clinical probability prediction score interpretation for pulmonary embolism
greater than 4=PE likely
less than or equal to 4=PE is unlikely
Name 7 variables and their associated points in PE clinical prediction tools
Signs/Symptoms of DVT=3
Other dx less likely than PE=3
Heart rate greater than 100=1.5
immobilization for more than 3 days or surgery in past 4 weeks=1.5
previous DVT or PE=1.5
What labs may you want for diagnosis of pulmonary embolism
same as for DVT
consider troponin and BNP-both elevate the risk for mortality
What EKG finding strongly suggests pulmonary embolism
S1Q3T3 strongly suggests PE but is not always present in PE
What might you see on CXR of someone with pulmonary embolism?
-Hampton's hump (a wedge shaped infiltrate at the base of the pleura)
-Westermark sign (a really large PE that has stopped blood flow to one part of the heart, so one side is much more radiolucent)
Name 2 other things with may be done in dx of pulmonary embolism?
Chest CT with IV contrast (spiral CT)
Ventilation-Perfusion Lung Scanning (V/Q scan)
What is the GOLD STANDARD for diagnosis of pulmonary embolism? What are the pros and cons of this?
pulmonary angiography (not used frqntly b/c new generation CTs)
Pros: highly specific and sensitive
Cons: invasive, high contrast loan and contraindicated in ppl w/poor kidney fxn, technically demanding, costly
How is an echocardiogram useful in pulmonary embolism?
What is it not reliable as?
Echocardiogram is useful for DDx, but more usedful as a prognostic indicator
Echocardiogram is NOT reliable as diagnostic tool
You are concerned abt. PE and dichotomous probability assessment yields a score of 2. What do you do next? what will that tell you?
Rapid quantitative ELISA D-dimer assay.
If Neg, VTE excluded, search for alternative sx, follow off anticoagulation
If Pos, do helical CT-PA
You are concerned abt PE, heart rate is 104, the patient has been immobilized for 5 days and the patient reports dyspnea. What do you do now?
PE is likely, proceed with helical CT-PA
If helical CT-PA is normal and the study is of high quality, what does this mean for the patient?
PE is excluded, begin the search for alternative diagnosis, follow off anticoagulation
Helical CT-PA was completed and indicates findings consistent with PE. What now?
if you did everything prior to this according to the plan outlined on slide 42, the diagnosis of PE is established, treat the poor patient for PE
Name 5 treatment strategies for venous thromboembolism (VTE)
1. Anticoagulation medications
4. IVC filter
5. Prophylactic measures (such as TES hose, sequential compression devices, SC Heparin and lovenox)
What anticoagulation medications may be used in VTE
-IV unfractionated Heparin
-oral factor Xa inhibitors
-oral direct thrombin inhibitors
What anticoagulation med is indicated in initial tx of VTE?
IV unfractionated heparin (as a bridge to Warfarin)
Name the Indication and Action of IV Unfractionated Heparin
initial tx of VTE
inhibits clotting cascade by inactivating thrombin; potentiates antithrombin