title: Early Chest Computed Tomography Scan to Assist Diagnosis and Guide Treatment Decision for Suspected Community-acquired Pneumonia.
abstract: BACKGROUND
  Clinical decision making relative to community-acquired pneumonia (CAP) diagnosis is difficult. Chest radiograph is key in establishing parenchymal lung involvement. However, radiologic performance may lead to misdiagnosis, rendering questionable the use of chest computed tomography (CT) scan in patients with clinically suspected CAP.
  
  
  OBJECTIVE
  To assess whether early multidetector chest CT scan affects diagnosis and management of patients visiting the emergency department with suspected CAP.
  
  
  METHODS
  A total of 319 prospectively enrolled patients with clinically suspected CAP underwent multidetector chest CT scan within 4 hours. CAP diagnosis probability (definite, probable, possible, or excluded) and therapeutic plans (antibiotic initiation/discontinuation, hospitalization/discharge) were established by emergency physicians before and after CT scan results. The adjudication committee established the final CAP classification on Day 28.
  
  
  RESULTS
  Chest radiograph revealed a parenchymal infiltrate in 188 patients. CAP was initially classified as definite in 143 patients (44.8%), probable or possible in 172 (53.8%), and excluded in 4 (1.2%). CT scan revealed a parenchymal infiltrate in 40 (33%) of the patients without infiltrate on chest radiograph and excluded CAP in 56 (29.8%) of the 188 with parenchymal infiltrate on radiograph. CT scan modified classification in 187 (58.6%; 95% confidence interval, 53.2-64.0), leading to 50.8% definite CAP and 28.8% excluded CAP, and 80% of modifications were in accordance with adjudication committee classification. Because of CT scan, antibiotics were initiated in 51 (16%) and discontinued in 29 (9%), and hospitalization was decided in 22 and discharge in 23.
  
  
  CONCLUSIONS
  In CAP-suspected patients visiting the emergency unit, early CT scan findings complementary to chest radiograph markedly affect both diagnosis and clinical management. Clinical trial registered with www.clinicaltrials.gov (NCT 01574066).
authors.affiliation: 1 Department of Emergency Medicine, Centre Hospitalier Princesse Grace, Principality of Monaco.
authors.forename: Yann-Erick
authors.initials: YE
authors.lastname: Claessens
authors.affiliation: 2 Department of Radiodiagnosis.
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Debray
authors.affiliation: 3 APHP, Hôpital Bichat, Département d'Epidémiologie et Recherche Clinique, University Paris Diderot, Sorbonne Paris Cité, UMR 1123 ECEVE, INSERM CIC-EC 1425, UMR 1123 ECEVE, Paris, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Tubach
authors.affiliation: 4 Department of Radiodiagnosis and.
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Brun
authors.affiliation: 5 Université Paris-Descartes, Sorbonne Paris Cité, APHP, Service des Maladies Infectieuses et Tropicales, Hôpital Necker-Enfants Malades, Centre d'Infectiologie Necker-Pasteur, Institut Imagine, Paris, France.
authors.forename: Blandine
authors.initials: B
authors.lastname: Rammaert
authors.affiliation: 6 Department of Emergency Medicine, Hôpital Pitié-Salpétriêre, AP-HP et Sorbonne Universités, UPMC University Paris 06, Paris, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Hausfater
authors.affiliation: 7 Department of Respiratory Diseases.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Naccache
authors.affiliation: 8 Department of Emergency Medicine, and.
authors.forename: Patrick
authors.initials: P
authors.lastname: Ray
authors.affiliation: 9 Department of Emergency Medicine, and.
authors.forename: Christophe
authors.initials: C
authors.lastname: Choquet
authors.affiliation: 10 Department of Radiodiagnosis, Hôpital Tenon, Paris, France; and.
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Carette
authors.affiliation: 7 Department of Respiratory Diseases.
authors.forename: Charles
authors.initials: C
authors.lastname: Mayaud
authors.affiliation: 11 Department of Infectious Diseases, Groupe Hospitalier Bichat-Claude Bernard, Paris, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Leport
authors.affiliation: 12 APHP, Hôpital Bichat, Département d'Epidémiologie et Recherche Clinique, University Paris Diderot, Sorbonne Paris Cité, UMR 1138, INSERM CIC 1425, Paris, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Duval
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care / Q000706:statistics & numerical data; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000066491:Clinical Decision-Making; D015331:Cohort Studies; D017714:Community-Acquired Infections / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy; D019468:Disease Management; D042241:Early Diagnosis; D004636:Emergency Service, Hospital; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D011014:Pneumonia / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy; D011446:Prospective Studies; D013902:Radiography, Thoracic
chemical_list: D000900:Anti-Bacterial Agents
keywords: chest radiograph; community-acquired pneumonia; diagnosis; emergency medicine; multidetector CT scan