Therapies for acute pulmonary embolism are determined based on the risk of death, risk of bleeding, and response to initial therapy. Pulmonary Embolism Response Team (PERT) streamline the care of acute pulmonary embolism as they merge the expertise of a variety of specialists, in real time to assist the primary providers with patient evaluation and enhanced clinical decision making.
The Risk of death is increased with hemodynamic instability. Patients with persistent hypotension with systolic blood pressure (SBP) <90 mmHg, vasopressor support, or a drop of ≥ 40 mmHg from baseline for more than 15 minutes, are considered to have a higher risk of death. In the absence of hemodynamic instability, those patients with evidence of right ventricular (RV) dilatation or dysfunction (echocardiography of CT findings) and/or elevated biochemical markers (troponin or brain natriuretic peptide) are at higher risk of death compared to those patients who lack such evidence. Other parameters that can supplement the available information and give the clinician more assurance of increased risk of death if present: a simplified pulmonary embolism severity index (sPESI) (age >80 years, history of cancer, chronic cardiopulmonary disease, pulse ≥110/min, systolic blood pressure <100 mmHg, or arterial oxygen saturation <90%), respiratory distress, lower extremity deep venous thrombosis, cardiac thrombus, or extensive clot burden (e.g,, large perfusion defects on ventilation/perfusion scan or extensive embolic burden on chest computed tomography). Patients with higher risk of death are good candidates for thrombolytic therapy or for catheter-directed interventions.
The Risk of bleeding should be evaluated relative to the strength of the indication. Patients with absolute contraindications and high risk of death, societal guidelines suggest catheter-directed therapies (i.e., ultrasound, saline, rotational device, or suction). Patients with moderate risk of bleeding and high risk of death can be considered for catheter-directed therapy (CDT) with or without thrombolytic therapy. Inferior vena cava filter can be considered in those patients. In the absence of high risk or intermediate risk of bleeding, systemic thrombolysis should be considered for hemodynamically unstable patients and CDT for hemodynamically stable patients at higher risk of death.
If the risk of death is determined to be low (absence of hemodynamic instability, normal RV function, and no elevated biomarkers) and in the absence of contraindication to anticoagulation, subcutaneous LMW heparin or fondaparinux, or the oral factor Xa inhibitors, rivaroxaban or apixaban, are preferred over intravenous UFH.
Response to initial therapy should be determined based on the resolution of hemodynamic instability within 2-4 hours of thrombolytic therapy. Catheter-directed thrombolytic intervention and/or clot removal interventions can be an escalation modality for those patients. Patients who deemed appropriate for anticoagulation should be monitored for signs of deterioration (hemodynamic instability, worsening oxygenation, or RV dysfunction) and if present, they should be evaluated for thrombolytic therapy and possibly catheter-directed interventions.
When deciding for catheter-directed interventions, multiple factors need to be taken into consideration including the size, age, risk, and location of the clot. Multiple interventions are present and selection of one of them is determined y the specific expertise in the hospital.