title: Sonographic patterns of lung consolidation in mechanically ventilated patients with and without ventilator-associated pneumonia: a prospective cohort study.
abstract: OBJECTIVE
  Thoracic ultrasound (TUS) has been successfully used in the diagnosis of community-acquired pneumonia. Little is known about its diagnostic potential in ventilator-associated pneumonia (VAP). The purpose of this study was to systematically describe the morphology and temporal changes of sonographic patterns in mechanically ventilated patients and to evaluate the diagnostic performance characteristics of TUS-based VAP diagnoses.
  
  
  METHODS
  Patients who were placed on invasive ventilation for reasons other than pneumonia and who were considered at risk for the development of VAP received daily TUS examinations while being closely monitored for the development of pneumonia.
  
  
  RESULTS
  Fifty-seven patients were studied. The incidence of VAP was 21.1%. Sonographic patterns of reduced or absent lung aeration were found in 64.2% of examinations. The sonographic pattern of lung consolidation with either dynamic or static air bronchograms was 100% sensitive and 60% specific for VAP in those patients who developed clinical signs and symptoms compatible with pneumonia. The pretest and posttest probabilities were 0.38 and 0.6, respectively.
  
  
  CONCLUSIONS
  Sonographic patterns of abnormal aeration are frequently observed in mechanically ventilated patients. If sonographic lung consolidation with either static or dynamic air bronchograms is absent, VAP is highly unlikely. The presence of these sonographic patterns in patients with signs and symptoms suggestive of pneumonia significantly increases the probability of VAP.
authors.affiliation: Department of Intensive Care Medicine, Inselspital/Bern University Hospital and University of Bern, 3010 Bern, Switzerland. Electronic address: thomas.berlet@insel.ch.
authors.forename: Thomas
authors.initials: T
authors.lastname: Berlet
authors.affiliation: Department of Intensive Care Medicine, Inselspital/Bern University Hospital and University of Bern, 3010 Bern, Switzerland. Electronic address: reto.etter@insel.ch.
authors.forename: Reto
authors.initials: R
authors.lastname: Etter
authors.affiliation: Department of Intensive Care Medicine, Inselspital/Bern University Hospital and University of Bern, 3010 Bern, Switzerland. Electronic address: tobias.fehr@insel.ch.
authors.forename: Tobias
authors.initials: T
authors.lastname: Fehr
authors.affiliation: Department of Intensive Care Medicine, Inselspital/Bern University Hospital and University of Bern, 3010 Bern, Switzerland. Electronic address: david.berger@insel.ch.
authors.forename: David
authors.initials: D
authors.lastname: Berger
authors.affiliation: Department of Infectious Diseases, University of Bern, 3010 Bern, Switzerland. Electronic address: parham.sendi@insel.ch.
authors.forename: Parham
authors.initials: P
authors.lastname: Sendi
authors.affiliation: Department of Intensive Care Medicine, Inselspital/Bern University Hospital and University of Bern, 3010 Bern, Switzerland. Electronic address: tobias.merz@insel.ch.
authors.forename: Tobias M
authors.initials: TM
authors.lastname: Merz
mesh_terms: D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D053717:Pneumonia, Ventilator-Associated / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000453:epidemiology; D011446:Prospective Studies; D012121:Respiration, Artificial; D012680:Sensitivity and Specificity; D014463:Ultrasonography
keywords: Pneumonia, ventilator-associated; Technology assessment, biomedical; Ultrasonography