If PE is the primary diagnosis in an unstable patient, consider massive PE. Proceed with imaging directly and consider empirical anticoagulation therapy if no contraindications exist. If the patient remains hemodynamically unstable despite adequate resuscitation and/or unsafe for definitive imaging and PE suspicion is high, arrange for an urgent beside echocardiography (TTE or TEE) to obtain a presumptive diagnosis for PE and consideration of empirical thrombolytic therapy. Consult with subspecialist personnel when available.

The decision rule applies to first episode of VTE.
Patients suspected to have a recurrent VTE event may have special risk factors and may require comparative review of prior imaging and biochemical studies. An approach similar to first episode event could be followed for patients suspected to have a recurrent event but proceed with your own clinical judgment.

Patient is currently on anticoagulant for more than 24 hours.The decision rule does not apply to your patient. Proceed with your own clinical judgment.

This decision rule does not apply to your patient.Proceed with your own clinical judgement.

This decision rule does not apply to your patient.Proceed with your own clinical judgement.

This decision rule does not apply to your patient.Proceed with your own clinical judgement.