title: In vivo microscopy in a porcine model of acute lung injury.
abstract: Regional inhomogeneity and alveolar mechanics in a porcine model of acute lung injury (ALI) was evaluated using confocal laser scanning microscopy (CLSM). CLSM was performed through thoracic windows of the upper and lower lobes. Image quantification was conducted by use of a volume air index (VAI). Twelve anesthetized, mechanically ventilated pigs were randomized to non-injury (control group, n = 6) or ALI induced by surfactant depletion (ALI group, n = 6). CLSM was performed at baseline, after 1 h at 5 mbar and after 2 h at 15 mbar positive end-expiratory pressure (PEEP). Haemodynamics, respiratory mechanics and calculation of pulmonary ventilation-perfusion distribution by MIGET were determined. At baseline, VAI was not different. In the upper lobes, VAI significantly decreased in ALI compared to control group, with no changes after PEEP application. In the lower lobes, VAI significantly decreased in ALI compared to control group. Incremental PEEP significantly increased VAI in ALI, but not in control group. Haemodynamics were significantly compromised in the ALI group. A significant deterioration in oxygenation and ventilation-perfusion distribution could be seen being restored after PEEP adjustment. The VAI may help to assess regional inhomogeneity of the acutely injured lung.
authors.affiliation: Department of Intensive Care, University Hospital RWTH Aachen, Aachen, Germany. jbickenbach@ukaachen.de
authors.forename: Johannes
authors.initials: J
authors.lastname: Bickenbach
authors.forename: Michael
authors.initials: M
authors.lastname: Czaplik
authors.forename: Rolf
authors.initials: R
authors.lastname: Dembinski
authors.forename: Paolo
authors.initials: P
authors.lastname: Pelosi
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schroeder
authors.forename: Gernot
authors.initials: G
authors.lastname: Marx
authors.forename: Rolf
authors.initials: R
authors.lastname: Rossaint
mesh_terms: D055371:Acute Lung Injury / Q000473:pathology*; D000818:Animals; D001831:Body Temperature; D003627:Data Interpretation, Statistical; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D007091:Image Processing, Computer-Assisted; D018613:Microscopy, Confocal; D010366:Peak Expiratory Flow Rate / Q000502:physiology; D011650:Pulmonary Alveoli / Q000502:physiology; D011651:Pulmonary Artery / Q000502:physiology; D011652:Pulmonary Circulation / Q000502:physiology; D015656:Respiratory Mechanics / Q000502:physiology; D013552:Swine