Indications for administration of fibrinolytic therapy for acute PE:
Cardiac arrest presumed to be secondary to PE-tPA 50 mg bolus, may be repeated once.
Massive PE (hemodynamic instability)-arbitrarily defined by BP < 90 mm Hg systolic. Give 10 mg tPA bolus followed by 90 mg over 2 hours. Make sure heparin off during this time frame. tPA is the only FDA approved drug for this but some are starting to use Tenecteplase (single 0.5 mg/kg bolus).
Submassive PE (normal hemodynamics and evidence of RV strain). This tends to be the most controversial group, although many authorities are now advocating its use. Strongly suspect strain if the Troponin/BNP are elevated and get an ECHO if they are. Most studies that advocate for lytics in this group show significant improvement in PA pressures, RV wall dilatation, etc. What is currently missing is outcome data...i.e. how short of breath and disabled are people with submassive PE at 6, 9, and 12 months? Bottom line, enough evidence exists to support giving to stable patients with RV strain as long as they are carefully screened.
There is NO evidence that lytics are useful in stable patients without RV strain.
The administration of thrombolytic therapy for acute PE is within the scope of practice of emergency medicine.