Acute pulmonary embolism is a frequently seen diagnosis in both the inpatient and outpatient settings. There are a number of diagnostic modalities and models for prediction but selection of the right one can be tricky at times. The ACP recently released new Best Practice Guidelines for diagnosis and workup of suspected acute PE. These guidelines were adopted after an extensive meta-analysis of clinical trials addressing this diagnostic dilemma. New advisories can be found below in addition to an easy to follow algorithm:
Best Practice Advice 1: Clinicians should use validated clinical prediction rules to estimate pretest probability in patients in whom acute PE is being considered.
Best Practice Advice 2: Clinicians should not obtain d-dimer measurements or imaging studies in patients with a low pretest probability of PE and who meet all Pulmonary Embolism Rule-Out Criteria.
Best Practice Advice 3: Clinicians should obtain a high-sensitivity d-dimer measurement as the initial diagnostic test in patients who have an intermediate pretest probability of PE or in patients with low pretest probability of PE who do not meet all Pulmonary Embolism Rule-Out Criteria. Clinicians should not use imaging studies as the initial test in patients who have a low or intermediate pretest probability of PE.
Best Practice Advice 4: Clinicians should use age-adjusted d-dimer thresholds (age × 10 ng/mL rather than a generic 500 ng/mL) in patients older than 50 years to determine whether imaging is warranted.
Best Practice Advice 5: Clinicians should not obtain any imaging studies in patients with a d-dimer level below the age-adjusted cutoff.
Best Practice Advice 6: Clinicians should obtain imaging with CT pulmonary angiography (CTPA) in patients with high pretest probability of PE. Clinicians should reserve ventilation–perfusion scans for patients who have a contraindication to CTPA or if CTPA is not available. Clinicians should not obtain a d-dimer measurement in patients with a high pretest probability of PE.