title: Thoracoscopic findings and pharmacokinetics of inhaled fluorescein in a pig model.
abstract: BACKGROUND
  Fluorescein-enhanced autofluorescence thoracoscopy (FEAT) reveals regions of abnormal fluorescence in patients with primary spontaneous pneumothorax and in normal subjects. Some of these lesions are undetectable by white light thoracoscopy and it has been hypothesized that they represent underlying pleural and/or parenchymal abnormalities.
  
  
  OBJECTIVE
  In order to standardize and evaluate this novel technique, we developed an animal model.
  
  
  METHODS
  Six pigs underwent thoracoscopy after the inhalation of nebulized sodium fluorescein by either volume-controlled mechanical ventilation or spontaneous ventilation. Pleural cavity and lung surface were inspected by white light thoracoscopy and FEAT during a period of 90 min. Fluorescence intensities were quantified in pleura and in blood. Regions of interest were examined postmortem for a histological assessment of the lesions.
  
  
  RESULTS
  FEAT lesions were observed in all animals, with a maximum intensity of the lesions 20-30 min after the onset of fluorescein administration. The plasma concentrations of sodium fluorescein reached a maximum after approximately 20 min. The microscopic findings suggest that fluorescein accumulates in the subpleural space of better ventilated lung areas.
  
  
  CONCLUSIONS
  This is the first animal model using FEAT. Valuable information has been gathered but further investigations are required to explain the phenomena observed in humans and pigs.
authors.affiliation: Department of Internal Medicine, University Hospital Brussels, Laarbeeklaan 101, Brussels, Belgium.
authors.forename: Liv
authors.initials: L
authors.lastname: Vandermeulen
authors.forename: Demosthenes
authors.initials: D
authors.lastname: Makris
authors.forename: Serge
authors.initials: S
authors.lastname: Mordon
authors.forename: Annieta
authors.initials: A
authors.lastname: Goossens
authors.forename: Charles-Hugo
authors.initials: CH
authors.lastname: Marquette
authors.forename: Patrick
authors.initials: P
authors.lastname: Haentjens
authors.forename: Marc
authors.initials: M
authors.lastname: Noppen
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D019793:Fluorescein / Q000008:administration & dosage / Q000493:pharmacokinetics; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000008:administration & dosage / Q000493:pharmacokinetics; D008168:Lung / Q000473:pathology; D010994:Pleura / Q000378:metabolism; D013552:Swine; D013906:Thoracoscopy
chemical_list: D005456:Fluorescent Dyes; D019793:Fluorescein