Treatment algorithm for hemodynamically unstable patients with suspected pulmonary embolism (PE)

RV: right ventricle.
* Resuscitation involves any combination of respiratory (oxygen, noninvasive or invasive mechanical ventilation) and hemodynamic support (intravenous fluids, vasopressors).
¶ The use of portable perfusion scanning is dependent upon institutional availability, but has a higher sensitivity for the diagnosis of PE than transthoracic echocardiography. Other alternative testing that may help the clinician make a presumptive diagnosis of PE and guide management decisions include transesophageal echocardiography and compressive ultrasound of the lower extremities, none of which are diagnostic of PE. Please refer to the UpToDate topic text for more details.
Δ Evidence of RV overload on echocardiography is supportive but not diagnostic of PE. Some experts may look for additional supportive evidence of PE (eg, deep venous thrombosis, thrombus in the right ventricle or main pulmonary artery). Please refer to the UpToDate topic text for more details.
◊ The decision to empirically anticoagulate this population depends upon the clinical suspicion for PE.
§ In this population, it is assumed that the suspicion for PE remains high and that PE is the likely cause of hemodynamic instability. 
¥ Patients not already on intravenous unfractionated heparin can proceed directly to thrombolysis, followed by anticoagulation. However, it is acceptable to proceed with thrombolytic therapy even while anticoagulated, particularly if the bleeding risk is deemed low and the patient is severely compromised.
‡ Combined catheter-directed embolectomy and thrombolysis is considered investigational and should be reserved for use in institutions with expertise.