title: Effects of superimposed tissue weight on regional compliance of injured lungs.
abstract: Computed tomography (CT), together with image analysis technologies, enable the construction of regional volume (VREG) and local transpulmonary pressure (PTP,REG) maps of the lung. Purpose of this study is to assess the distribution of VREG vs PTP,REG along the gravitational axis in healthy (HL) and experimental acute lung injury conditions (eALI) at various positive end-expiratory pressures (PEEPs) and inflation volumes. Mechanically ventilated pigs underwent inspiratory hold maneuvers at increasing volumes simultaneously with lung CT scans. eALI was induced via the iv administration of oleic acid. We computed voxel-level VREG vs PTP,REG curves into eleven isogravitational planes by applying polynomial regressions. Via F-test, we determined that VREG vs PTP,REG curves derived from different anatomical planes (p-values<1.4E-3), exposed to different PEEPs (p-values<1.5E-5) or subtending different lung status (p-values<3E-3) were statistically different (except for two cases of adjacent planes). Lung parenchyma exhibits different elastic behaviors based on its position and the density of superimposed tissue which can increase during lung injury.
authors.affiliation: Department of Emergency and Organ Transplant, Bari University, Bari, Italy; Hedenstierna Laboratoriet-Surgical Sciences, Uppsala University, Uppsala, Sweden. Electronic address: mariangela.pellegrini@surgsci.uu.se.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Pellegrini
authors.affiliation: Department of Emergency and Organ Transplant, Bari University, Bari, Italy. Electronic address: savioderosa@hotmail.it.
authors.forename: Savino
authors.initials: S
authors.lastname: Derosa
authors.affiliation: Department of Emergency and Organ Transplant, Bari University, Bari, Italy. Electronic address: principia78@libero.it.
authors.forename: Angela
authors.initials: A
authors.lastname: Tannoia
authors.affiliation: Department of Anaesthesia and Intensive Care Medicine, Sahlgrenska University Hospital, Göteborg, Sweden. Electronic address: christian.rylander@vgregion.se.
authors.forename: Christian
authors.initials: C
authors.lastname: Rylander
authors.affiliation: Department of Emergency and Organ Transplant, Bari University, Bari, Italy. Electronic address: tommaso.fiore@uniba.it.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Fiore
authors.affiliation: Hedenstierna Laboratoriet-Surgical Sciences, Uppsala University, Uppsala, Sweden. Electronic address: anders.larsson@surgsci.uu.se.
authors.forename: Anders
authors.initials: A
authors.lastname: Larsson
authors.affiliation: Hedenstierna Laboratoriet-Medical Sciences, Uppsala University, Uppsala, Sweden. Electronic address: goran.hedenstierna@medsci.uu.se.
authors.forename: Göran
authors.initials: G
authors.lastname: Hedenstierna
authors.affiliation: Department of Emergency and Organ Transplant, Bari University, Bari, Italy; Hedenstierna Laboratoriet-Surgical Sciences, Uppsala University, Uppsala, Sweden. Electronic address: gaetano.perchiazzi@uniba.it.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Perchiazzi
mesh_terms: D055371:Acute Lung Injury / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D000818:Animals; D062485:Breath Holding; D004195:Disease Models, Animal; D004548:Elasticity; D006112:Gravitation; D006439:Hemodynamics / Q000502:physiology; D008168:Lung / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*; D008170:Lung Compliance; D008176:Lung Volume Measurements; D008955:Models, Cardiovascular; D019301:Oleic Acid; D009929:Organ Size; D011312:Pressure; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012044:Regression Analysis; D012121:Respiration, Artificial; D013552:Swine; D014057:Tomography, X-Ray Computed
chemical_list: D019301:Oleic Acid
keywords: Acute lung injury; Computed tomography; Gravity; Image registration; Lung compliance; Mechanical ventilation