title: Effects of pulmonary acid aspiration on the regional pulmonary blood flow within the first hour after injury: An observational study in rats.
abstract: BACKGROUND
  Gastric aspiration events are recognized as a major cause of pneumonitis and the development of acute respiratory distress syndrome. The first peak in the inflammatory response has been observed one hour after acid-induced lung injury in rats. The spatial pulmonary blood flow (PBF) distribution after an acid aspiration event within this time frame has not been adequately studied. We determined therefore PBF pattern within the first hour after acid aspiration.
  
  
  METHODS
  Anesthetized, spontaneous breathing rats (n = 8) underwent unilateral endobronchial hydrochlorid acid instillation so that the PBF distributions between the injured and non-injured lungs could be compared. The signal intensity of the lung parenchyma after injury was measured by magnetic resonance tomography. PBF distribution was determined by measuring the concentration of [68Ga]-radiolabeled microspheres using positron emission tomography.
  
  
  RESULTS
  Following acid aspiration, magnetic resonance images revealed increased signal intensity in the injured regions accompanied by reduced oxygenation. PBF was increased in all injured lungs (171 [150; 196], median [25%; 75%]) compared to the blood flow in all uninjured lungs (141 [122; 159], P = 0.0078).
  
  
  CONCLUSIONS
  From the first minute until fifty minutes after acid-induced acute lung injury, the PBF was consistently increased in the injured lung. These blood flow elevation was accompanied by significant hypoxemia.
authors.affiliation: Department of Anesthesia and Intensive Care, Carl Gustav Carus University Hospital, Technische Universität Dresden, Dresden, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Richter
authors.affiliation: Department of Radiopharmaceutical and Chemical Biology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum, Dresden-Rossendorf, Dresden, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Bergmann
authors.affiliation: Department of Radiopharmaceutical and Chemical Biology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum, Dresden-Rossendorf, Dresden, Germany.|Department of Chemistry and Food Chemistry, Technische Universität Dresden, Dresden, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Pietzsch
authors.affiliation: Department of Anesthesia and Intensive Care, Carl Gustav Carus University Hospital, Technische Universität Dresden, Dresden, Germany.
authors.forename: Michael Patrick
authors.initials: MP
authors.lastname: Mueller
authors.affiliation: Department of Anesthesia and Intensive Care, Carl Gustav Carus University Hospital, Technische Universität Dresden, Dresden, Germany.
authors.forename: Thea
authors.initials: T
authors.lastname: Koch
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D006851:Hydrochloric Acid / Q000633:toxicity*; D008168:Lung / Q000473:pathology*; D055370:Lung Injury / Q000150:complications*; D008297:Male; D049268:Positron-Emission Tomography; D011652:Pulmonary Circulation / Q000502:physiology*; D051381:Rats; D012039:Regional Blood Flow; D053120:Respiratory Aspiration / Q000503:physiopathology*; D013997:Time Factors; D014057:Tomography, X-Ray Computed
chemical_list: D006851:Hydrochloric Acid
keywords: Acute lung injury; magnetic resonance imaging; positron emission tomography; pulmonary blood flow; respiratory aspiration