title: Early effect of tidal volume on lung injury biomarkers in surgical patients with healthy lungs.
abstract: BACKGROUND
  The early biological impact of short-term mechanical ventilation on healthy lungs is unknown. The authors aimed to characterize the immediate tidal volume (VT)-related changes on lung injury biomarkers in patients with healthy lungs and low risk of pulmonary complications.
  
  
  METHODS
  Twenty-eight healthy patients for knee replacement surgery were prospectively randomized to volume-controlled ventilation with VT 6 (VT6) or 10 (VT10) ml/kg predicted body weight. General anesthesia and other ventilatory parameters (positive end-expiratory pressure, 5 cm H2O, FIO2, 0.5, respiratory rate titrated for normocapnia) were managed similarly in the two groups. Exhaled breath condensate and blood samples were collected for nitrite, nitrate, tumor necrosis factor-α, interleukins-1β, -6, -8, -10, -11, neutrophil elastase, and Clara Cell protein 16 measurements, at the onset of ventilation and 60 min later.
  
  
  RESULTS
  No significant differences in biomarkers were detected between the VT groups at any time. The coefficient of variation of exhaled breath condensate nitrite and nitrate decreased in the VT6 but increased in the VT10 group after 60-min ventilation. Sixty-minute ventilation significantly increased plasma neutrophil elastase levels in the VT6 (35.2 ± 30.4 vs. 56.4 ± 51.7 ng/ml, P = 0.008) and Clara Cell protein 16 levels in the VT10 group (16.4 ± 8.8 vs. 18.7 ± 9.5 ng/ml, P = 0.015). Exhaled breath condensate nitrite correlated with plateau pressure (r = 0.27, P = 0.042) and plasma neutrophil elastase (r = 0.44, P = 0.001). Plasma Clara Cell protein 16 correlated with compliance (r = 0.34, P = 0.014).
  
  
  CONCLUSIONS
  No tidal volume-related changes were observed in the selected lung injury biomarkers of patients with healthy lungs after 60-min ventilation. Plasma neutrophil elastase and plasma Clara Cell protein 16 might indicate atelectrauma and lung distention, respectively.
authors.affiliation: From the Department of Anesthesiology and Webb-Waring Center, University of Colorado School of Medicine, Aurora, Colorado (A.F.-B.); Department of Anesthesiology and iC42 Integrated Solutions in Systems Biology, University of Colorado School of Medicine, Aurora, Colorado (J.K., U.C.); Department of Medicine and Webb-Waring Center, University of Colorado School of Medicine, Aurora, Colorado (J.E.R.); Department of Anesthesiology, University of Colorado School of Medicine, Aurora, Colorado (A.A., T.S.); Department of Pathobiology and Lerner Research Institute (NC22), the Cleveland Clinic Foundation and Case Western Reserve University School of Medicine, Cleveland, Ohio (A.J.J., S.C.E.); Case Western Reserve University School of Medicine, Cleveland, Ohio (C.S.); Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado (M.M., I.S.D.); and Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora, Colorado (Z.V.T.).
authors.forename: Ana
authors.initials: A
authors.lastname: Fernandez-Bustamante
authors.forename: Jelena
authors.initials: J
authors.lastname: Klawitter
authors.forename: John E
authors.initials: JE
authors.lastname: Repine
authors.forename: Amanda
authors.initials: A
authors.lastname: Agazio
authors.forename: Allison J
authors.initials: AJ
authors.lastname: Janocha
authors.forename: Chirag
authors.initials: C
authors.lastname: Shah
authors.forename: Marc
authors.initials: M
authors.lastname: Moss
authors.forename: Ivor S
authors.initials: IS
authors.lastname: Douglas
authors.forename: Zung Vu
authors.initials: ZV
authors.lastname: Tran
authors.forename: Serpil C
authors.initials: SC
authors.lastname: Erzurum
authors.forename: Uwe
authors.initials: U
authors.lastname: Christians
authors.forename: Tamas
authors.initials: T
authors.lastname: Seres
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D015415:Biomarkers; D016207:Cytokines / Q000097:blood; D005260:Female; D006801:Humans; D055370:Lung Injury / Q000097:blood / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000097:blood; D009569:Nitric Oxide / Q000378:metabolism; D009573:Nitrites / Q000097:blood; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000009:adverse effects*; D013990:Tidal Volume; D014598:Uteroglobin / Q000097:blood
chemical_list: D015415:Biomarkers; D016207:Cytokines; D009566:Nitrates; D009573:Nitrites; C556389:SCGB1A1 protein, human; D009569:Nitric Oxide; D014598:Uteroglobin