Mount Carmel Health Partners Clinical Guidelines Pulmonary Embolus

Recommendation for the Evaluation and Treatment of Pulmonary Embolus Definition: Pulmonary embolism (PE) is a thrombus, usually originating in a lower extremity vein, that embolizes to the pulmonary arterial circulation. Depending on the size, location and hemodynamic effects, a pulmonary embolus can have minor, catastrophic or lethal consequences. The majority of pulmonary emboli are undiagnosed ante-mortem. Patients present with seemingly typical exacerbations of chronic disease processes such as COPD, asthma or bronchitis which may mask symptoms of undiagnosed PE. The diagnosis of a PE can be difficult because the signs and symptoms are often nonspecific and subtle. Risk stratification for the pre-test probability or likelihood of pulmonary embolism is useful in guiding diagnostic testing and algorithms can assist in decision-making. Patient being evaluated for a PE must be determined to be at either low risk for PE or at moderate to high risk. The PERC algorithm i.e., “Pulmonary Embolus Rule-Out Criteria” can be applied to low risk patients. Patient’s with a low pretest probability can be safely ruled out for a PE with these decision rules or if testing with a negative d-dimer test. Patients with high pretest probability however, and a negative D-dimer cannot be ruled out because of negative predictive value of the D-dimer assay is not sufficient to rule-out a PE. Patients at risk should undergo CT pulmonary angiography or Ventilation/perfusion Scan (VQ Scan). Low Probability Hemodynamically stable Perform Quantitative D-Dimer PERC Positive Positive >500 ng/ml Negative <500 ng/ml PE Excluded  Chest X-Ray (CXR): Investigate for alternative etiologies of symptoms  Apply the PERC Rule (see Table 1) Perform CT pulmonary angiogram (CTPA) or VQ Scan with Chest x-ray Negative for PE or low/normal Probability VQ scan Positive for PE or High Probability VQ Scan Intermediate/ Indeterminate Probability VQ scan PE confirmed: Treat PE Excluded Perform CT pulmonary angiogram or serial lower extremity compression ultrasound or magnetic resonance pulmonary angiogram Negative for PE PE Excluded PERC Negative Positive for PE PE confirmed: Treat unfractionated or Fractionated heparin PE Excluded Quick Guide  Pulmonary embolus can be a diagnostic challenge because of its protean presentations  Risk stratification at presentation should guide management  Besides conventional anticoagulation, higher-risk patients maybe candidate for adjunctive therapies; surgical embolectomy, thrombolysis, or Ekos to optimize their outcome  Contraindication to CT angiogram (CTA): Glomerular Filtration Rate (GFR) < 60ml/ min/1.73m 2 or contrast allergy or morbid obesity Table 1: Pulmonary Embolism Rule-out Criteria (PERC):  Age > 50 years?  Heart Rate > 100 bpm?  O2 Saturation on Room Air < 95%?  Prior History of DVT/PE  Recent Trauma or Surgery?  Hemoptysis?  Exogenous Estrogen?  Unilateral Leg Swelling? If no to all criteria and with clinician’s pre-test probability < 15%, PERC Rule criteria are satisfied and no further workup needed with <2% probability of PE. December 2016