Physiology-Thromboembolism Flashcards
What are the core things you analyze in a patient with suspect venous thrombosis? What puts patients at risk for these things?
Virchow’s triad: Stasis, endovascular injury and hypercoaguability.
How do symptoms of DVT differ from PE?
DVT (pain, swelling, redness or asymptomatic). PE (asmymptomatic, dyspnea, pleuritic chest pain or hemoptysis)
What signs do you look for in a patient with DVT during the physical exam?
Asymmetric edema, erythema, warmth, palpable cord, Homan’s sign (pain w/dorsiflexion of the foot) and phelgmasia (seen below, result of deoxygenated blood pooling in the distal extremity).
What signs do you look for in a patient with PE during the physical exam?
Tachycardia, tachypnea, decreased breath sounds, pleuritic rub or signs of rapid right heart dysfunction.
What is the Wells rule for DVT?
A very likely alternative diagnosis allows you subtract 2 points. High probability = 3+ points. Intermediate = 1-2 points. Low = 0 or negative points.
What is the Wells rule for PE?
Total score 6 = high. Dichotomized score >4 is likely and less than or equal to 4 is unlikely.
What is your gold standard diagnostic criteria when you have a patient with high pretest probability for DVT? What other methods may be used?
CT Angiography (allows you to look for PE and DVT at the same time). Lower extremity ultrasound and V/Q perfusion scan (looking for V/Q mismatch) may also be used.
What test can you do for patients with low pretest probability for DVT?
D-Dimer. This measures the activity of fibrin clot formation in the blood.
You see a patient in the ED with shortness of breath. CTPA reveals bilateral pulmonary emboli and a right DVT. What do you recommend for initial treatment?
Low molecular weigh heparin. (Rivaroxaban or subcutaneous enoxaparin). IV unfractioned heparin is difficult to get into a therapeutic range and can cause increased recurrence of PE.
What are long term consequences of DVT and PE?
Post-thrombotic syndrome (chronic swelling, redness and pain in the leg). Pulmonary hypertension. Right heart failure. Shock.
What patients need tPA?
Patients in shock with low bleeding risk. It can cause mass bleeding so you only use it in very urgent cases.
What blood markers are not specific for but may point you towards acute PE?
Increased BNP due to RV pooling of blood and troponin.
