title: Evaluation of Patients With Suspected Acute Pulmonary Embolism: Best Practice Advice From the Clinical Guidelines Committee of the American College of Physicians.
abstract: METHODS
  Pulmonary embolism (PE) can be a severe disease and is difficult to diagnose, given its nonspecific signs and symptoms. Because of this, testing patients with suspected acute PE has increased dramatically. However, the overuse of some tests, particularly computed tomography (CT) and plasma d-dimer measurement, may not improve care while potentially leading to patient harm and unnecessary expense.
  
  
  METHODS
  The literature search encompassed studies indexed by MEDLINE (1966-2014; English-language only) and included all clinical trials and meta-analyses on diagnostic strategies, decision rules, laboratory tests, and imaging studies for the diagnosis of PE. This document is not based on a formal systematic review, but instead seeks to provide practical advice based on the best available evidence and recent guidelines. The target audience for this paper is all clinicians; the target patient population is all adults, both inpatient and outpatient, suspected of having acute PE.
  Clinicians should use validated clinical prediction rules to estimate pretest probability in patients in whom acute PE is being considered.
  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.
  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.
  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.
  Clinicians should not obtain any imaging studies in patients with a d-dimer level below the age-adjusted cutoff.
  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.
authors.forename: Ali S
authors.initials: AS
authors.lastname: Raja
authors.forename: Jeffrey O
authors.initials: JO
authors.lastname: Greenberg
authors.forename: Amir
authors.initials: A
authors.lastname: Qaseem
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Denberg
authors.forename: Nick
authors.initials: N
authors.lastname: Fitterman
authors.forename: Jeremiah D
authors.initials: JD
authors.lastname: Schuur
mesh_terms: D000367:Age Factors; D000792:Angiography; D002985:Clinical Protocols; D003661:Decision Support Techniques; D019317:Evidence-Based Medicine; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D006801:Humans; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed; D019564:Unnecessary Procedures
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D