Venous Thromboembolism (VTE): Pulmonary Embolism (PE) Treatment

Acute respiratory failure 2/2 acute B/L pulmonary embolism.
Hemodynamically stable
-admit to ICU (if hemodynamically unstable)
-ABG
-LMWH (if nonmassive and normal renal function. Otherwise, use start heparin gtt). LMWH will be continued for 5 days AND until the INR is >2.0 for 24 hours. Pharmacy to dose Coumadin. 
–TnIs, cardiac enzymes and evaluate for right ventricular dysfunction (w/ echo).
–Echocardiogram (TTE) to look at right heart strain (esp. if the patient has tachycardia, tachypnea).
–Bilateral LE U/S to look for DVT as a source of the PE.
-Consider IR for possible catheter-directed tpa if the patient becomes hemodynamically unstable.
-cont assisted mechanical ventilation with intensivist consult
-consult vascular surgeon in am for possible IVC filter, if indicated.

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Hypercoagulable States Workup.

**If the PE is 2/2 to cancer, Enoxaparin is the drug of choice (DOC).

Q: How long should a patient be anticoagulated after a VTE?

Acute Deep-Vein Thrombosis (DVT)

Two key questions to ask of every PE:
1) Is the PE small, sub-massive, or massive? PEs are categorized into three groups: small, sub-massive, and massive. Distinguishing these three categories of pulmonary embolisms is important because it affects the type of management.
2) Is the PE provoked or unprovoked? This affects the length of treatment and the workup that may be done.

Hemodynamically Unstable Patient
“The decision to use thrombolysis for pulmonary embolism is not based on its location but on the patient’s hemodynamic status. Hemodynamically unstable patients benefit from this therapy, whereas hemodynamically stable patients (generally those with a systolic blood pressure >90 mm Hg) are usually treated with anticoagulation alone (low molecular weight or unfractionated heparin) (SOR B). In hemodynamically stable patients, the risk of hemorrhage probably outweighs the benefits of treatment.”

“Patients with recent streptococcal infections or those who have had prior exposure to streptokinase have streptococcal antibodies, which predispose them to potentially severe allergic reactions. Other agents (e.g., rt-PA) should be used for thrombolysis (SOR B). There is no evidence that one agent is a better thrombolytic than the others. Despite this, the American College of Chest Physicians recommends using the agent with the shortest infusion time, which is rt-PA. For thrombolytic therapy in pulmonary embolism, the infusion protocol for rt-PA is 2 hours, compared to 12 hours for urokinase and 24 hours for streptokinase.

Thrombolytic therapy with rt-PA preferentially activates plasminogen attached to the surface of a clot. This selectivity limits fibrinolysis to the embolism itself, potentially reducing the risk for hemorrhage (SOR B). However, in practice, this may not be a clinically significant risk reduction. The other two approved thrombolytic agents, streptokinase and urokinase, have a nonselective action.”

“Elevated troponins or right ventricular dysfunction. Both of these portend a worse prognosis in patients with acute submassive pulmonary embolism, including significantly higher mortality rates. This is true even in patients who, at the time, are hemodynamically stable compared to those without RV dysfunction or myocardial ischemia.”

“In patients with an acute nonmassive PE and normal renal function, low molecular weight heparin (LMWH) is preferred over unfractionated heparin for initial treatment. LMWH should be continued for 5 days AND until the INR is >2.0 for 24 hours. This patient had a reversible risk factor (surgery) that caused her PE and thus requires treatment for only 3 months (SOR C). Use of a vena cava filter is recommended only if anticoagulant therapy is not possible because of an increased risk of bleeding (SOR C). Routine monitoring with anti–factor-Xa levels is not necessary for patients treated with LMWH unless there is an indication such as abnormal renal function (SOR B)” The ABFM

Important Info:
Use the Wells Criteria to the calculate probability of PE to determine whether to get D-dimer or CTA.
The diagnostic test of choice: CT angiogram of the chest with IV contrast is the preferred diagnostic modality in patients with suspected PE. However, if the creatinine is high (renal failure), you cannot give the patient IV contrast. In that case, V/Q Scan is preferred.

Question 1: How long should an individual undergo treatment for an isolated pulmonary embolism with no other risk factors? 3 months.
Question 2: How long should an individual undergo anticoagulation for a VTE in general? See Anticoagulation Length in VTE

Facts