title: Elastin fibers and the diagnosis of bacterial pneumonia in the adult respiratory distress syndrome.
abstract: OBJECTIVE
  It has been inferred from previous work that 40% potassium hydroxide preparations of lower respiratory tract secretions that demonstrate elastin fibers have a 100% specificity and positive predictive value in diagnosing bacterial pneumonia in intubated, mechanically ventilated patients without the adult respiratory distress syndrome (ARDS). Our aim was to assess the specificity of 40% potassium hydroxide preparations in diagnosing bacterial pneumonia in patients with ARDS and suspected pneumonia.
  
  
  METHODS
  Prospective, case-referral clinical study.
  
  
  METHODS
  Referral hospital.
  
  
  METHODS
  Of 24 patients with ARDS who were intubated and mechanically ventilated with suspected bacterial pneumonia, 22 were assessable and evaluated for this report.
  
  
  METHODS
  Tracheo-bronchial aspirates were obtained from all patients and analyzed for elastin fibers using 40% potassium hydroxide.
  
  
  RESULTS
  Of the 22 assessable patients, ten patients did not have a complicating bacterial pneumonia. Six of these ten patients had potassium hydroxide preparations that demonstrated elastin fibers (false positives). The other four patients had preparations that did not demonstrate elastin fibers (true negatives). Specificity was 40%.
  
  
  CONCLUSIONS
  Elastin fiber preparations are not specific for diagnosing bacterial pneumonia in patients with ARDS.
authors.affiliation: Department of Anaesthesia, Harvard Medical School, Massachusetts General Hospital, Boston, USA.
authors.forename: K E
authors.initials: KE
authors.lastname: Shepherd
authors.forename: K E
authors.initials: KE
authors.lastname: Lynch
authors.forename: J C
authors.initials: JC
authors.lastname: Wain
authors.forename: E N
authors.initials: EN
authors.lastname: Brown
authors.forename: R S
authors.initials: RS
authors.lastname: Wilson
mesh_terms: D000328:Adult; D001980:Bronchi / Q000737:chemistry; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D016022:Case-Control Studies; D004549:Elastin / Q000032:analysis*; D006801:Humans; D006878:Hydroxides; D018410:Pneumonia, Bacterial / Q000175:diagnosis* / Q000209:etiology; D017680:Potassium Compounds; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012121:Respiration, Artificial; D012128:Respiratory Distress Syndrome / Q000150:complications* / Q000628:therapy; D012680:Sensitivity and Specificity
chemical_list: D006878:Hydroxides; D017680:Potassium Compounds; D004549:Elastin; C029943:potassium hydroxide