title: Airway surface liquid recovered by lavage with perfluorocarbon liquid in cats.
abstract: BACKGROUND
  Airway surface liquid (ASL) is difficult to sample. Lavage with an immiscible perfluorocarbon (PFC) liquid to recover ASL was evaluated in cats.
  
  
  METHODS
  Six wild-type cats underwent bronchoscopic lavage with a PFC (perfluorohexane), with the bronchoscope wedged in the feline equivalent of the right lower lobe. Two cats (control animals) were lavaged with a saline vehicle only. Four procedures were performed on each animal at 2-3-week intervals. Ionic composition of ASL was determined by flame photometry.
  
  
  RESULTS
  Cats lavaged with PFC showed significantly more acute respiratory distress than those lavaged with saline (respiratory rate following procedure: PFC, 47 +/- 5 min-1 vs. saline, 27 +/- 2 min-1, P < 0.05; O2 saturation: PFC 80 +/- 1% vs. saline, 91 +/- 1%, P < 0.01). The PFC group also had clinical evidence of chronic respiratory compromise (mean respiratory rate before next anaesthetic; PFC, 37 +/- 2 min-1 vs. saline, 20 +/- 3 min-1, P < 0.01). The PFC-lavaged lungs demonstrated persistent radiographic changes and histological evidence of small airways obstruction with distal alveolar damage. Six PFC lavages yielded ASL samples (> 100 microL) which were sufficient for analysis. Mean (+/- SEM) ionic concentrations in these samples were Na+ 157.4 +/- 14.5 mmol L-1, Cl- 150.5 +/- 16.8 mmol L-1 and K+ 10.1 +/- 1.7 mmol L-1.
  
  
  CONCLUSIONS
  Perfluorocarbon lavage can be used to collect unmodified ASL from the distal lung. However, repeated lavage with perfluorohexane was associated with significant pathological changes in this study.
authors.affiliation: Departmentof Paediatrics, University of Liverpool, Liverpool, UK. kwsouth@liv.ac.uk
authors.forename: K W
authors.initials: KW
authors.lastname: Southern
authors.forename: W K
authors.initials: WK
authors.lastname: Funkhouser
authors.forename: I
authors.initials: I
authors.lastname: Kazachkova
authors.forename: V L
authors.initials: VL
authors.lastname: Godfrey
authors.forename: L A
authors.initials: LA
authors.lastname: Fordham
authors.forename: J T
authors.initials: JT
authors.lastname: Gatzy
authors.forename: P M
authors.initials: PM
authors.lastname: Barker
mesh_terms: D000818:Animals; D018893:Bronchoalveolar Lavage / Q000379:methods*; D001992:Bronchoalveolar Lavage Fluid; D002415:Cats; D005466:Fluorocarbons; D023421:Models, Animal
chemical_list: D005466:Fluorocarbons