title: Effects of high-frequency oscillatory ventilation on systemic and cerebral hemodynamics and tissue oxygenation: an experimental study in pigs.
abstract: BACKGROUND
  In this study, we compare the effects of high frequency oscillatory ventilation (HFOV) with those of lung-protective volume-controlled ventilation (VCV) on cerebral perfusion, tissue oxygenation, and cardiac function with and without acute intracranial hypertension (AICH).
  
  
  METHODS
  Eight pigs with healthy lungs were studied during VCV with low tidal volume (V(T): 6 ml kg(-1)) at four PEEP levels (5, 10, 15, 20 cm H(2)O) followed by HFOV at corresponding transpulmonary pressures, first with normal ICP and then with AICH. Systemic and pulmonary hemodynamics, cardiac function, cerebral perfusion pressure (CPP), cerebral blood flow (CBF), cerebral tissue oxygenation, and blood gases were measured after 10 min at each level. Transpulmonary pressures (TPP) were calculated at each PEEP level. The measurements were repeated with HFOV using continuous distending pressures (CDP) set at TPP plus 5 cm H(2)O for the corresponding PEEP level. Both measurement series were repeated after intracranial pressure (ICP) had been raised to 30-40 cm H(2)O with an intracranial balloon catheter.
  
  
  RESULTS
  Cardiac output, stroke volume, MAP, CPP, and CBF were significantly higher during HFOV at normal ICP. Systemic and cerebral hemodynamics was significantly altered by AICH, but there were no differences attributable to the ventilatory mode.
  
  
  CONCLUSIONS
  HFOV is associated with less hemodynamic compromise than VCV, even when using small tidal volumes and low mean airway pressures. It does not impair cerebral perfusion or tissue oxygenation in animals with AICH, and could, therefore, be a useful ventilatory strategy to prevent lung failure in patients with traumatic brain injury.
authors.affiliation: Department of Anaesthesiology, Emergency-and Intensive Care Medicine, University of Göttingen Medical School, Göttingen, Germany. jheuer@med.uni-goettingen.de
authors.forename: Jan Florian
authors.initials: JF
authors.lastname: Heuer
authors.forename: Philip
authors.initials: P
authors.lastname: Sauter
authors.forename: Jürgen
authors.initials: J
authors.lastname: Barwing
authors.forename: Peter
authors.initials: P
authors.lastname: Herrmann
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Crozier
authors.forename: Annalen
authors.initials: A
authors.lastname: Bleckmann
authors.forename: Tim
authors.initials: T
authors.lastname: Beißbarth
authors.forename: Onnen
authors.initials: O
authors.lastname: Moerer
authors.forename: Michael
authors.initials: M
authors.lastname: Quintel
mesh_terms: D000818:Animals; D001794:Blood Pressure; D001921:Brain / Q000098:blood supply*; D002302:Cardiac Output; D002560:Cerebrovascular Circulation / Q000502:physiology*; D006439:Hemodynamics; D006612:High-Frequency Ventilation; D019586:Intracranial Hypertension / Q000503:physiopathology*; D010100:Oxygen / Q000378:metabolism; D011175:Positive-Pressure Respiration; D011659:Pulmonary Gas Exchange; D013318:Stroke Volume; D013552:Swine; D013990:Tidal Volume
chemical_list: D010100:Oxygen