title: Utility of transbronchial biopsy in patients with acute respiratory failure: a postmortem study.
abstract: OBJECTIVE
  To determine the diagnostic yield of histologic specimens obtained by postmortem transbronchial biopsy (TBB) in patients with acute respiratory failure requiring mechanical ventilation.
  
  
  METHODS
  Standard postmortem histologic examination of lung tissue specimens.
  
  
  METHODS
  An urban university-affiliated hospital.
  
  
  METHODS
  Thirty patients with diffuse pulmonary infiltrates and acute respiratory failure, who underwent postmortem examination.
  
  
  METHODS
  Following removal of the lungs from the thorax. TBBs were obtained from the lower lobe of each deflated lung and comparison was made to a 1-cm3 tissue block obtained from the ipsilateral lower lobe.
  
  
  RESULTS
  Standard postmortem histologic examination provided a specific diagnosis in 85% of the 60 lungs examined, and histologic evidence of acute pneumonia was present in 30% of the lungs. The overall yield of TBB was 48% for establishing a specific histologic diagnosis and 15% for the diagnosis of acute pneumonia. Using standard postmortem histologic examination as the gold standard, the sensitivity and specificity of TBB for making a specific diagnosis were 57% and 100% respectively, with corresponding positive and negative predictive values of 100% and 29%. For the histologic diagnosis of acute pneumonia, the sensitivity of TBB was 50%, the specificity was 100%, and the positive and negative predictive values were 100% and 82%, respectively. The kappa statistic for the agreement between the two diagnostic methods was 0.28 for establishing a specific diagnosis and 0.58 for the diagnosis of acute pneumonia. Obtaining 12 TBBs rather than six TBBs did not increase the diagnostic yield for TBB.
  
  
  CONCLUSIONS
  These findings suggest poor overall agreement between standard postmortem histologic examination and TBB specimens. Although not performed in a clinical setting, this postmortem investigation suggests that TBB may be of limited value in mechanically ventilated patients with acute respiratory failure because of its low sensitivity.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: V K
authors.initials: VK
authors.lastname: Rao
authors.forename: J
authors.initials: J
authors.lastname: Ritter
authors.forename: M H
authors.initials: MH
authors.lastname: Kollef
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001999:Bronchoscopy; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008168:Lung / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000175:diagnosis; D015203:Reproducibility of Results; D012131:Respiratory Insufficiency / Q000209:etiology / Q000473:pathology*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity