title: Pulmonary blood flow increases in damaged regions directly after acid aspiration in rats.
abstract: BACKGROUND
  After gastric aspiration events, patients are at risk of pulmonary dysfunction and the development of severe acute lung injury and acute respiratory distress syndrome, which may contribute to the development of an inflammatory reaction. The authors' aim in the current study was to investigate the role of the spatial distribution of pulmonary blood flow in the pathogenesis of pulmonary dysfunction during the early stages after acid aspiration.
  
  
  METHODS
  The authors analyzed the pulmonary distribution of radiolabeled microspheres in normal (n = 6) and injured (n = 12) anesthetized rat lungs using positron emission tomography, computed tomography, and histological examination.
  
  
  RESULTS
  Injured regions demonstrate increased pulmonary blood flow in association with reduced arterial pressure and the deterioration of arterial oxygenation. After acid aspiration, computed tomography scans revealed that lung density had increased in the injured regions and that these regions colocalized with areas of increased blood flow. The acid was instilled into the middle and basal regions of the lungs. The blood flow was significantly increased to these regions compared with the blood flow to uninjured lungs in the control animals (middle region: 1.23 [1.1; 1.4] (median [25%; 75%]) vs. 1.04 [1.0; 1.1] and basal region: 1.25 [1.2; 1.3] vs. 1.02 [1.0; 1.05], respectively). The increase in blood flow did not seem to be due to vascular leakage into these injured areas.
  
  
  CONCLUSIONS
  The data suggest that 10 min after acid aspiration, damaged areas are characterized by increased pulmonary blood flow. The results may impact further treatment strategies, such as drug targeting.
authors.affiliation: * Staff Anesthetist, # Professor and Head of the Intensive Care Unit, ** Professor and Chair of the Department, Department of Anesthesia and Intensive Care, Carl Gustav Carus University Hospital, University of Technology, Dresden, Germany. † Senior Scientist, ‖ Professor, Head of the Division of Radiopharmaceutical Biology, Institute of Radiopharmacy, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany. ‡ Senior Scientist, § Professor, Head of the Institute of Anatomy, University of Technology.
authors.forename: Torsten
authors.initials: T
authors.lastname: Richter
authors.forename: Ralf
authors.initials: R
authors.lastname: Bergmann
authors.forename: Lilla
authors.initials: L
authors.lastname: Knels
authors.forename: Frank
authors.initials: F
authors.lastname: Hofheinz
authors.forename: Michael
authors.initials: M
authors.lastname: Kasper
authors.forename: Martin
authors.initials: M
authors.lastname: Deile
authors.forename: Jens
authors.initials: J
authors.lastname: Pietzsch
authors.forename: Maximilian
authors.initials: M
authors.lastname: Ragaller
authors.forename: Thea
authors.initials: T
authors.lastname: Koch
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005710:Gallium Radioisotopes; D006851:Hydrochloric Acid / Q000008:administration & dosage; D008168:Lung / Q000000981:diagnostic imaging / Q000648:ultrastructure; D049268:Positron-Emission Tomography / Q000379:methods; D011652:Pulmonary Circulation; D051381:Rats; D053120:Respiratory Aspiration / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D005710:Gallium Radioisotopes; D006851:Hydrochloric Acid