title: Acute effects of intracranial hypertension and ARDS on pulmonary and neuronal damage: a randomized experimental study in pigs.
abstract: OBJECTIVE
  To determine reciprocal and synergistic effects of acute intracranial hypertension and ARDS on neuronal and pulmonary damage and to define possible mechanisms.
  
  
  METHODS
  Twenty-eight mechanically ventilated pigs were randomized to four groups of seven each: control; acute intracranial hypertension (AICH); acute respiratory distress syndrome (ARDS); acute respiratory distress syndrome in combination with acute intracranial hypertension (ARDS + AICH). AICH was induced with an intracranial balloon catheter and the inflation volume was adjusted to keep intracranial pressure (ICP) at 30-40 cmH2O. ARDS was induced by oleic acid infusion. Respiratory function, hemodynamics, extravascular lung water index (ELWI), lung and brain computed tomography (CT) scans, as well as inflammatory mediators, S100B, and neuronal serum enolase (NSE) were measured over a 4-h period. Lung and brain tissue were collected and examined at the end of the experiment.
  
  
  RESULTS
  In both healthy and injured lungs, AICH caused increases in NSE and TNF-alpha plasma concentrations, extravascular lung water, and lung density in CT, the extent of poorly aerated (dystelectatic) and atelectatic lung regions, and an increase in the brain tissue water content. ARDS and AICH in combination induced damage in the hippocampus and decreased density in brain CT.
  
  
  CONCLUSIONS
  AICH induces lung injury and also exacerbates pre-existing damage. Increased extravascular lung water is an early marker. ARDS has a detrimental effect on the brain and acts synergistically with intracranial hypertension to cause histological hippocampal damage.
authors.affiliation: Department of Anaesthesiology, Emergency and Intensive Care Medicine, University of Göttingen Medical Center, Göttingen, Germany. jheuer@med.uni-goettingen.de
authors.forename: Jan Florian
authors.initials: JF
authors.lastname: Heuer
authors.forename: Paolo
authors.initials: P
authors.lastname: Pelosi
authors.forename: Peter
authors.initials: P
authors.lastname: Hermann
authors.forename: Christina
authors.initials: C
authors.lastname: Perske
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Crozier
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Brück
authors.forename: Michael
authors.initials: M
authors.lastname: Quintel
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D015633:Extravascular Lung Water; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics; D019586:Intracranial Hypertension / Q000150:complications* / Q000503:physiopathology*; D008168:Lung / Q000503:physiopathology*; D011175:Positive-Pressure Respiration; D011659:Pulmonary Gas Exchange; D011897:Random Allocation; D012121:Respiration, Artificial; D012128:Respiratory Distress Syndrome / Q000150:complications* / Q000503:physiopathology*; D018709:Statistics, Nonparametric; D013552:Swine; D014057:Tomography, X-Ray Computed
chemical_list: D015415:Biomarkers