title: Effects of perfluorohexan vapor on gas exchange, respiratory mechanics, and lung histology in pigs with lung injury after endotoxin infusion.
abstract: BACKGROUND
  Inhaled perfluorohexan vapor has been shown to improve gas exchange and pulmonary mechanics in oleic acid- and ventilator-induced lung injury. However, in the clinical setting, lung injury frequently occurs in the context of systemic inflammation and consecutive lung injury, which may be induced experimentally by intravenous administration of endotoxin. The authors studied whether vaporized perfluorohexan is efficacious during endotoxin-induced lung injury in domestic pigs.
  
  
  METHODS
  Twenty-two pigs (29 [23, 31] kg body weight [first, third interquartile]; tracheostomy) were anesthetized and mechanically ventilated. In the endotoxin (n = 8) and perfluorohexan groups (n = 7), we administered endotoxin of Escherichia coli 111:B4, 1 mg.kg . h for 1 h and 10 microg.kg.h for 5 h in consecutive order. In the perfluorohexan group, inhalation of the test drug was started 2 h 30 min after the start of the intravenous endotoxin and terminated after 30 min. In a control group (n=7), animals were instrumented and observed over time without further intervention. Oxygenation function was assessed from oxygen partial pressures (Po2, blood gases) and calculated shunt fraction. Respiratory compliance was calculated from airway pressure and tidal volume. Measurements were performed before and every hour during endotoxin infusion.
  
  
  RESULTS
  After 6 h of endotoxin, gas exchange and pulmonary compliance were deteriorated in the endotoxin group (Pao2: 184 [114, 289] vs. 638 [615, 658] mmHg, pulmonary shunt fraction: 30 [23, 38] vs. 4 [3, 6]%, respiratory compliance: 12 [11, 14] vs. 22 [19, 23] ml/mbar; P < 0.05, endotoxin vs. control). Inhalation of vaporized perfluorohexan did not improve Pao 2 (107 [60, 221] mmHg), pulmonary shunt fraction (32 [26, 58]%), or respiratory compliance (14 [10, 17] ml/mbar) when compared with intravenous endotoxin (not significant, perfluorohexan vs. endotoxin).
  
  
  CONCLUSIONS
  Inhalation of vaporized perfluorohexan does not improve pulmonary gas exchange or respiratory compliance in endotoxin-induced porcine lung injury.
authors.affiliation: Institute for Surgical Research and Clinic of Anesthesiology, Ludwig-Maximilians-University, Munich, Germany. gregor.kemming@med.uni-muenchen.de
authors.forename: Gregor I
authors.initials: GI
authors.lastname: Kemming
authors.forename: Michael
authors.initials: M
authors.lastname: Flondor
authors.forename: Anja
authors.initials: A
authors.lastname: Hanser
authors.forename: Sabine
authors.initials: S
authors.lastname: Pallivathukal
authors.forename: Markus
authors.initials: M
authors.lastname: Holtmannspötter
authors.forename: Florian F
authors.initials: FF
authors.lastname: Kneisel
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Reuter
authors.forename: Hille
authors.initials: H
authors.lastname: Kisch-Wedel
authors.forename: Bernhard
authors.initials: B
authors.lastname: Zwissler
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D004731:Endotoxins / Q000633:toxicity*; D005466:Fluorocarbons / Q000008:administration & dosage*; D008168:Lung / Q000187:drug effects* / Q000473:pathology; D011659:Pulmonary Gas Exchange / Q000187:drug effects*; D015656:Respiratory Mechanics / Q000187:drug effects*; D013552:Swine; D014835:Volatilization
chemical_list: D004731:Endotoxins; D005466:Fluorocarbons; C078626:perflexane