BACKGROUND: Strategies to attenuate ventilator-associated lung injury have been tested in various experimental methods of acute lung injury (ALI). Conclusions are often drawn from physiologic and biologic effects, but the influence of the model on these results is not known. Our aim in this study was to characterize frequently used models of experimental ALI. METHODS: Twenty Sprague Dawley rats were anesthetized and their lungs mechanically ventilated for 5 hours. Three models of ALI (surfactant washout, acid aspiration, and high tidal volume ventilation) were investigated with regard to hemodynamics, respiratory mechanics, gas exchange, lung pathology, and inflammatory reactions. Animals without ALI served as controls. RESULTS: Five animals in each group were analyzed. Dynamic compliance and Pao(2)/fraction of inspired oxygen ratio decreased by at least 50% in all groups after 1 hour. Whereas compliance remained decreased in all models, oxygenation returned to baseline values in the lavage group after 5 hours. Diffuse alveolar damage was worse in the high tidal volume model and was not different between the control and lavage animals. Interleukin-6 was increased in bronchoalveolar lavage fluid in the aspiration and high tidal volume models. CONCLUSIONS: Although comparable physiologic effects meeting acute respiratory distress syndrome criteria were achieved in all models, the biologic responses varied among lung injury models. The acid aspiration model created both respiratory and inflammatory responses typically seen in ALI; these data suggest that it may be the most clinically applicable model to study the intermediate-term effects of ventilator-associated lung injury in rats.
BACKGROUND: Strategies to attenuate ventilator-associated lung injury have been tested in various experimental methods of acute lung injury (ALI). Conclusions are often drawn from physiologic and biologic effects, but the influence of the model on these results is not known. Our aim in this study was to characterize frequently used models of experimental ALI. METHODS: Twenty Sprague Dawley rats were anesthetized and their lungs mechanically ventilated for 5 hours. Three models of ALI (surfactant washout, acid aspiration, and high tidal volume ventilation) were investigated with regard to hemodynamics, respiratory mechanics, gas exchange, lung pathology, and inflammatory reactions. Animals without ALI served as controls. RESULTS: Five animals in each group were analyzed. Dynamic compliance and Pao(2)/fraction of inspired oxygen ratio decreased by at least 50% in all groups after 1 hour. Whereas compliance remained decreased in all models, oxygenation returned to baseline values in the lavage group after 5 hours. Diffuse alveolar damage was worse in the high tidal volume model and was not different between the control and lavage animals. Interleukin-6 was increased in bronchoalveolar lavage fluid in the aspiration and high tidal volume models. CONCLUSIONS: Although comparable physiologic effects meeting acute respiratory distress syndrome criteria were achieved in all models, the biologic responses varied among lung injury models. The acid aspiration model created both respiratory and inflammatory responses typically seen in ALI; these data suggest that it may be the most clinically applicable model to study the intermediate-term effects of ventilator-associated lung injury in rats.
Authors: Yi Xin; Maurizio Cereda; Nadir Yehya; Shiraz Humayun; Paolo Delvecchio; Jill M Thompson; Kevin Martin; Hooman Hamedani; Paul Martorano; Ian Duncan; Stephen Kadlecek; Mehran Makvandi; Jacob S Brenner; Rahim R Rizi Journal: Am J Physiol Lung Cell Mol Physiol Date: 2022-04-19 Impact factor: 6.011
Authors: Dietrich Henzler; Alf Schmidt; Zhaolin Xu; Nada Ismaiel; Haibo Zhang; Arthur S Slutsky; Paolo Pelosi Journal: Intensive Care Med Exp Date: 2019-11-05
Authors: Nada Ismaiel; Sara Whynot; Laurette Geldenhuys; Zhaolin Xu; Arthur S Slutsky; Valerie Chappe; Dietrich Henzler Journal: Front Physiol Date: 2022-04-21 Impact factor: 4.566
Authors: Mario Menk; Jan Adriaan Graw; Clarissa von Haefen; Hendrik Steinkraus; Burkhard Lachmann; Claudia D Spies; David Schwaiberger Journal: J Inflamm Res Date: 2018-05-01