title: Clearance of bile and trypsin in rat lungs following aspiration of human gastric fluid.
abstract: OBJECTIVE
  In the clinical setting, there is no reliable tool for diagnosing gastric aspiration. A potential way of diagnosing gastric fluid aspiration entails bronchoalveolar lavage (BAL) with subsequent examination of the BAL fluid for gastric fluid components that are exogenous to the lungs. The objective of this study was to determine the longevity of the gastric fluid components bile and trypsin in the lung, in order to provide an estimate of the time frame in which assessment of these components in the BAL might effectively be used as a measure of aspiration.
  
  
  METHODS
  Human gastric fluid (0.5 mg/kg) was infused in the right lung of intubated male Fischer 344 rats (n = 30). Animals were sacrificed at specified times following the experimentally induced aspiration, and bronchoalveolar lavage fluid (BALF) was collected. Bile concentrations were analyzed by an enzyme-linked chromatogenic method, and the concentration of trypsin was quantified using an ELISA. Data were analyzed using non-linear regression and a one-phase decay equation.
  
  
  RESULTS
  In this experimental model, the half-life of bile was 9.3 hours (r(2) = 0.81), and the half-life of trypsin was 9.0 hours (r(2) = 0.68).
  
  
  CONCLUSIONS
  The half-lives of bile and trypsin in the rodent aspiration model suggest that the ability to detect aspiration may be limited to a few days post-aspiration. If studies using rats are any indication, it may be most effective to collect BAL samples within the first 24 hours of suspected aspiration events in order to detect aspiration.
authors.affiliation: a Department of Surgery , Duke University Medical Center , Durham , North Carolina , USA.|b Department of Pathology , Duke University Medical Center , Durham , North Carolina , USA.
authors.forename: Jason H
authors.initials: JH
authors.lastname: Leung
authors.affiliation: a Department of Surgery , Duke University Medical Center , Durham , North Carolina , USA.|b Department of Pathology , Duke University Medical Center , Durham , North Carolina , USA.|c Division of Thoracic and Cardiovascular Surgery, Hualien Tzu Chi Hospital , Hualien , Taiwan.|d Department of Surgery , Tzu Chi University , Hualien , Taiwan.
authors.forename: Jui-Chih
authors.initials: JC
authors.lastname: Chang
authors.affiliation: a Department of Surgery , Duke University Medical Center , Durham , North Carolina , USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Foltz
authors.affiliation: a Department of Surgery , Duke University Medical Center , Durham , North Carolina , USA.
authors.forename: Sadé M
authors.initials: SM
authors.lastname: Bell
authors.affiliation: a Department of Surgery , Duke University Medical Center , Durham , North Carolina , USA.
authors.forename: Cinthia
authors.initials: C
authors.lastname: Pi
authors.affiliation: e Toronto General Research Institute, Toronto General Hospital , Toronto , Ontario , Canada.
authors.forename: Sassan
authors.initials: S
authors.lastname: Azad
authors.affiliation: a Department of Surgery , Duke University Medical Center , Durham , North Carolina , USA.
authors.forename: Mary Lou
authors.initials: ML
authors.lastname: Everett
authors.affiliation: a Department of Surgery , Duke University Medical Center , Durham , North Carolina , USA.
authors.forename: Zoie E
authors.initials: ZE
authors.lastname: Holzknecht
authors.affiliation: a Department of Surgery , Duke University Medical Center , Durham , North Carolina , USA.
authors.forename: Nathan L
authors.initials: NL
authors.lastname: Sanders
authors.affiliation: a Department of Surgery , Duke University Medical Center , Durham , North Carolina , USA.
authors.forename: William
authors.initials: W
authors.lastname: Parker
authors.affiliation: a Department of Surgery , Duke University Medical Center , Durham , North Carolina , USA.
authors.forename: R Duane
authors.initials: RD
authors.lastname: Davis
authors.affiliation: e Toronto General Research Institute, Toronto General Hospital , Toronto , Ontario , Canada.
authors.forename: Shaf
authors.initials: S
authors.lastname: Keshavjee
authors.affiliation: a Department of Surgery , Duke University Medical Center , Durham , North Carolina , USA.|b Department of Pathology , Duke University Medical Center , Durham , North Carolina , USA.|f Department of Immunology , Duke University Medical Center , Durham , North Carolina , USA.
authors.forename: Shu S
authors.initials: SS
authors.lastname: Lin
mesh_terms: D000818:Animals; D001646:Bile / Q000378:metabolism*; D001826:Body Fluids / Q000378:metabolism*; D018893:Bronchoalveolar Lavage / Q000379:methods; D001992:Bronchoalveolar Lavage Fluid; D006801:Humans; D008168:Lung; D008297:Male; D019152:Paracentesis / Q000379:methods; D051381:Rats; D011916:Rats, Inbred F344; D014357:Trypsin / Q000378:metabolism*
chemical_list: D014357:Trypsin
keywords: aspirate; bile acid; lung; rat; trypsin