title: Effect of partial liquid ventilation on bacterial clearance during Pseudomonas aeruginosa-induced lung injury in rats.
abstract: OBJECTIVE
  Partial liquid ventilation (PLV) has been shown to exhibit anti-inflammatory properties during non-infectious models of acute lung injury. The aim of this experimental study was to assess the effects of PLV on bacterial clearance during Pseudomonas aeruginosa-induced pneumonia in rats.
  
  
  METHODS
  The rats were assigned to four groups 4 h after bacterial challenge according to the kind of mechanical ventilation [gas ventilation (GV) or PLV, 6 ml/kg perflubron plus 2 ml/kg per h] and to the level of PEEP used (3 or 8 cm of water). Physiologic measures were recorded during anesthesia (arterial blood gases, airway and blood pressures) for 4 subsequent hours until sacrifice.
  
  
  RESULTS
  No improvement of oxygenation was demonstrated in any group. The bacterial counts were higher in PLV-PEEP 8 rats compared to GV-PEEP 8 rats: median, 1.7.10(4) cfu (25th-75th percentiles, 1.2.10(4)-1.8.10(4)) versus 1.1.10(4) (8.7.10(3)-1.3.10(4))/ml of BAL fluid and 4.0.10(6) cfu (2.0.10(6)-5.5.10(6)) versus 1.7.10(6) cfu (9.7.10(5)-3.2.10(6))/ml of lung homogenate, respectively ( P<0.05, n=8/10 surviving rats per group). PEEP 8 was associated with a significant decrease in neutrophil recruitment in BAL fluid compared to PEEP 3 in both GV and PLV groups. Additional in vitro experiments demonstrated that perflubron induced a decrease in phagocytosis of P. aeruginosa by alveolar neutrophils.
  
  
  CONCLUSIONS
  These results demonstrate that PLV is associated with an impaired bacterial clearance during early pneumonia in rats, which could have been favored by decreased bacterial phagocytosis by neutrophils.
authors.affiliation: Service d'Anesthésie-Réanimation Chirurgicale, Hôpital Henri Mondor, Assistance Publique, Hôpitaux de Paris, Université Paris XII, 51 avenue du Maréchal de Lattre de Tassigny, 94010, Créteil, France. ciditou@aol.com
authors.forename: Saïda
authors.initials: S
authors.lastname: Rezaiguia-Delclaux
authors.forename: Kun
authors.initials: K
authors.lastname: Yang
authors.forename: François
authors.initials: F
authors.lastname: Stephan
authors.forename: François
authors.initials: F
authors.lastname: Lemaire
authors.forename: Michel
authors.initials: M
authors.lastname: Meignan
authors.forename: Alain
authors.initials: A
authors.lastname: Harf
authors.forename: Philippe
authors.initials: P
authors.lastname: Duvaldestin
authors.forename: Christophe
authors.initials: C
authors.lastname: Delclaux
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D015169:Colony Count, Microbial; D005602:France; D021061:Liquid Ventilation; D008297:Male; D018410:Pneumonia, Bacterial / Q000382:microbiology* / Q000503:physiopathology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification / Q000472:pathogenicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015996:Survival Rate