title: Exhaled breath condensate in mechanically ventilated brain-injured patients with no lung injury or sepsis.
abstract: BACKGROUND
  The inflammatory influence of prolonged mechanical ventilation in uninjured lungs remains a matter of controversy and largely unexplored in humans. The authors investigated pulmonary inflammation by using exhaled breath condensate (EBC) in mechanically ventilated, brain-injured patients in the absence of acute lung injury or sepsis and explored the potential influence of positive end-expiratory pressure (PEEP).
  
  
  METHODS
  Inflammatory EBC markers were assessed in 27 mechanically ventilated, brain-injured patients with neither acute lung injury nor sepsis and in 12 healthy and 8 brain-injured control subjects. Patients were ventilated with 8 ml/kg during zero end-expiratory pressure (ZEEP group, n = 12) or 8 cm H(2)O PEEP (PEEP group, n = 15). EBC was collected on days 1, 3, and 5 of mechanical ventilation to measure pH; interleukins (IL)-10, 1β, 6, 8, and 12p70; and tumor necrosis factor-α.
  
  
  RESULTS
  EBC pH was lower, whereas IL-1β and tumor necrosis factor-α were greater in both patient groups compared with either control group; IL-6 was higher, whereas IL-10 and IL-12p70 were sporadically higher than in healthy control subjects; no differences were noted between the two patient groups, except for IL-10, which decreased by day 5 during PEEP. Leukocytes, soluble IL-6, and soluble triggering receptor expressed on myeloid cells-1 in blood were constantly higher during zero end-expiratory pressure; EBC cytokines appeared mostly related to soluble IL-8 and inversely related to soluble triggering receptor expressed on myeloid cells-1.
  
  
  CONCLUSIONS
  In brain-injured, mechanically ventilated patients with neither acute lung injury nor sepsis, EBC markers appear to indicate the presence of subtle pulmonary inflammation that is mostly unaffected by PEEP. There is evidence for a systemic inflammatory response, especially in patients during zero end-expiratory pressure.
authors.affiliation: First Critical Care Department, Evangelismos Hospital and M. Simou Laboratory, Athens, Greece.
authors.forename: Ioanna
authors.initials: I
authors.lastname: Korovesi
authors.forename: Evangelos
authors.initials: E
authors.lastname: Papadomichelakis
authors.forename: Stylianos E
authors.initials: SE
authors.lastname: Orfanos
authors.forename: Evangellos J
authors.initials: EJ
authors.lastname: Giamarellos-Bourboulis
authors.forename: Olga
authors.initials: O
authors.lastname: Livaditi
authors.forename: Aimilia
authors.initials: A
authors.lastname: Pelekanou
authors.forename: Christina
authors.initials: C
authors.lastname: Sotiropoulou
authors.forename: Antonia
authors.initials: A
authors.lastname: Koutsoukou
authors.forename: Ioanna
authors.initials: I
authors.lastname: Dimopoulou
authors.forename: Foteini
authors.initials: F
authors.lastname: Ekonomidou
authors.forename: Ekaterini
authors.initials: E
authors.lastname: Psevdi
authors.forename: Apostolos
authors.initials: A
authors.lastname: Armaganidis
authors.forename: Charis
authors.initials: C
authors.lastname: Roussos
authors.forename: Nandor
authors.initials: N
authors.lastname: Marczin
authors.forename: Anastasia
authors.initials: A
authors.lastname: Kotanidou
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001930:Brain Injuries / Q000150:complications*; D001944:Breath Tests; D045853:Exhalation; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007378:Interleukins / Q000378:metabolism; D055370:Lung Injury / Q000150:complications; D008297:Male; D011014:Pneumonia / Q000150:complications / Q000378:metabolism*; D011175:Positive-Pressure Respiration / Q000379:methods*; D018805:Sepsis / Q000150:complications; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D055815:Young Adult
chemical_list: D015415:Biomarkers; D007378:Interleukins; D014409:Tumor Necrosis Factor-alpha