title: Effect of low-bias flow oscillation with partial liquid ventilation on fluoroscopic image analysis, gas exchange, and lung injury.
abstract: OBJECTIVE
  To evaluate the effect of low-bias flow oscillation (LBFO) with partial liquid ventilation (PLV) on perfluorochemical evaporation, histopathology, and oxidative tissue damage in an animal model of acute lung injury.
  
  
  METHODS
  Prospective, randomized animal study.
  
  
  METHODS
  Research laboratory of a health sciences university.
  
  
  METHODS
  Twelve New Zealand White rabbits.
  
  
  METHODS
  Juvenile rabbits were anesthetized, paralyzed, and ventilated through a tracheostomy with either high-frequency oscillatory ventilation or LBFO. Lung injury was induced by repeated saline lavage, after which perflubron was instilled through a side port of the endotracheal tube. Lateral fluoroscopic images were performed at baseline and at various postfill intervals of animals in the high-frequency oscillatory ventilation-PLV and LBFO-PLV groups. The images were digitalized for computer analysis of the Lung Lucency Index, a surrogate marker of perflubron evaporation. Histopathologic evaluation was performed using a lung-injury scoring system. Malondialdehyde was measured in lung homogenates to assess oxidative damage.
  
  
  RESULTS
  There were no significant differences in gas exchange and ventilator settings between groups throughout the experiment. At 300 mins, the high-frequency oscillatory ventilation-PLV group had a significantly higher Lung Lucency Index compared with the LBFO-PLV group in both dependent and nondependent lung regions (a high Lung Lucency Index correlates with increased perflubron loss). Malondialdehyde measurements were not different between groups. Animals treated with LBFO-PLV had a lower histopathologic lung-injury score compared with high-frequency oscillatory ventilation-PLV.
  
  
  CONCLUSIONS
  LBFO-PLV is a viable mode of ventilation in a model of acute lung injury and is associated with significant preservation of perflubron in comparison with high-frequency oscillatory ventilation-PLV. The lower evaporative losses during LBFO-PLV were associated with improved histology scores.
authors.affiliation: Division of Pediatric Critical Care, The Women and Children's Hospital of Buffalo, State University of New York at Buffalo, NY, USA.
authors.forename: Budi
authors.initials: B
authors.lastname: Wiryawan
authors.forename: Mark S
authors.initials: MS
authors.lastname: Dowhy
authors.forename: Bradley P
authors.initials: BP
authors.lastname: Fuhrman
authors.forename: Alexandre T
authors.initials: AT
authors.lastname: Rotta
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005466:Fluorocarbons; D005471:Fluoroscopy; D006612:High-Frequency Ventilation / Q000009:adverse effects*; D006842:Hydrocarbons, Brominated; D021061:Liquid Ventilation / Q000009:adverse effects*; D011659:Pulmonary Gas Exchange; D011817:Rabbits; D011897:Random Allocation; D012128:Respiratory Distress Syndrome / Q000097:blood / Q000209:etiology / Q000473:pathology*
chemical_list: D005466:Fluorocarbons; D006842:Hydrocarbons, Brominated; C003072:perflubron