title: Analysis of regional compliance in a porcine model of acute lung injury.
abstract: Lung protective ventilation in acute lung injury (ALI) focuses on using low tidal volumes and adequate levels of positive end-expiratory pressure (PEEP). Identifying optimal pressure is difficult because pressure-volume (PV) relations differ regionally. Precise analysis demands local measurements of pressures and related alveolar morphologies. In a porcine model of surfactant depletion (n=24), we combined measuring static pressures with endoscopic microscopy and electrical impedance tomography (EIT) to examine regional PV loops and morphologic heterogeneities between healthy (control group; CON) and ALI lungs ventilated with low (LVT) or high tidal volumes (HVT). Quantification included indices for microscopy (Volume Air Index (VAI), Heterogeneity and Circularity Index), EIT analysis and calculation of regional compliances due to generated PV loops. We found that: (1) VAI decreased in lower lobe after ALI, (2) electrical impedance decreased in dorsal regions and (3) PV loops differed regionally. Further studies should prove the potentials of these techniques on individual respiratory settings and clinical outcome.
authors: Department of Anesthesiology, University Hospital RWTH, Aachen, Germany. mczaplik@ukaachen.de
authors: Michael
authors: M
authors: Czaplik
authors: Ingeborg
authors: I
authors: Biener
authors: Rolf
authors: R
authors: Dembinski
authors: Paolo
authors: P
authors: Pelosi
authors: Thomas
authors: T
authors: Soodt
authors: Wolfgang
authors: W
authors: Schroeder
authors: Steffen
authors: S
authors: Leonhardt
authors: Gernot
authors: G
authors: Marx
authors: Rolf
authors: R
authors: Rossaint
authors: Johannes
authors: J
authors: Bickenbach
mesh_terms: D055371:Acute Lung Injury / Q000503:physiopathology*; D000818:Animals; D004195:Disease Models, Animal; D017097:Electric Impedance; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D008170:Lung Compliance; D013552:Swine