title: The effects of fenoterol inhalation after acid aspiration-induced lung injury.
abstract: BACKGROUND
  Acid aspiration is a serious complication that can occur during general anesthesia. Studies show that beta-agonists have beneficial effects on lung injury. Therefore, we tested the effect of the nebulized beta-agonist fenoterol on lung variables in a rodent model of acid-induced lung injury.
  
  
  METHODS
  In a prospective, randomized, and controlled study, we evaluated the effects of fenoterol inhalation on lung oxygenation, inflammation, and pulmonary histology in a rat model of acid-induced lung injury. Sprague-Dawley rats underwent sevoflurane anesthesia with tracheotomy and carotid catheter insertion. Lung injury was induced by instillation of 0.4 mL/kg 0.1 M hydrochloric acid. The lungs were ventilated for 6 h and randomized to receive either fenoterol inhalation 10 microg or saline inhalation, both at 15 and 180 min after acid aspiration. Mean arterial blood pressures and peak airway pressures were documented, arterial blood gases were determined at 30, 90, 180, 270, and 360 min, and postmortem histology was subsequently examined. Additionally, fenoterol concentrations in bronchoalveolar lavage fluid (BALF) and plasma were determined by liquid chromatography/tandem mass spectroscopy. After 360 min tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 were determined in the BALF, and lungs were dried for determination of the wet/dry ratio.
  
  
  RESULTS
  Inhalation treatment with 10 microg fenoterol significantly increased oxygenation after 270 and 360 min when compared with placebo. Fenoterol-treated rats showed a significant decrease in IL-6 and TNF-alpha levels and in the wet/dry weight ratio of the lungs. The histologic appearance showed significantly less interstitial edema and leukocyte infiltration in the fenoterol group. The concentration of fenoterol was 10.3 microg/L (median) in the BALF and <1 microg/L in the plasma.
  
  
  CONCLUSIONS
  Fenoterol inhalation improved oxygenation after 270 and 360 min, attenuated the release of TNF-alpha and IL-6, and diminished the lung edema and infiltration of polymorphonuclear leukocytes.
authors.affiliation: Department of Anesthesiology, University Hospital, University of Regensburg, Franz-Josef-Strauss-Allee 11, D-93053 Regensburg, Germany. michael.pawlik@klinik.uni-regensburg.de
authors.forename: Michael T
authors.initials: MT
authors.lastname: Pawlik
authors.forename: Thomas
authors.initials: T
authors.lastname: Schubert
authors.forename: Susanne
authors.initials: S
authors.lastname: Hopf
authors.forename: Matthias
authors.initials: M
authors.lastname: Lubnow
authors.forename: Michael
authors.initials: M
authors.lastname: Gruber
authors.forename: Christoph
authors.initials: C
authors.lastname: Selig
authors.forename: Kai
authors.initials: K
authors.lastname: Taeger
authors.forename: Karl P
authors.initials: KP
authors.lastname: Ittner
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D005280:Fenoterol / Q000008:administration & dosage*; D006851:Hydrochloric Acid / Q000633:toxicity*; D055370:Lung Injury / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D011015:Pneumonia, Aspiration / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism; D011446:Prospective Studies; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D005280:Fenoterol; D006851:Hydrochloric Acid