title: Hyperoxia during one lung ventilation: inflammatory and oxidative responses.
abstract: BACKGROUND
  It is common practice during one lung ventilation (OLV) to use 100% oxygen, although this may cause hyperoxia- and oxidative stress-related lung injury. We hypothesized that lower oxygen (FiO(2) ) during OLV will result in less inflammatory and oxidative lung injury and improved lung function.
  
  
  METHODS
  Twenty pigs (8.88 ± 0.84 kg; 38 ± 4.6 days) were assigned to either the hyperoxia group (n = 10; FiO(2)  = 100%) or the normoxia group (n = 10; FiO(2)  < 50%). Both groups were subjected to 3 hr of OLV. Blood samples were tested for pro-inflammatory cytokines and lung tissue was tested for these cytokines and oxidative biomarkers.
  
  
  RESULTS
  There were no differences between groups for partial pressure of CO(2) , tidal volume, end-tidal CO(2) , plasma cytokines, or respiratory compliance. Total respiratory resistance was greater in the hyperoxia group (P = 0.02). There were higher levels of TNF-α, IL-1β, and IL-6 in the lung homogenates of the hyperoxia group than in the normoxia group (P ≤ 0.01, 0.001, and 0.001, respectively). Myeloperoxidase and protein carbonyls (PC) were higher (P = 0.03 and P = 0.01, respectively) and superoxide dismutase (SOD) was lower in the lung homogenates of the hyperoxia group (P ≤ 0.001).
  
  
  CONCLUSIONS
  Higher myeloperoxidase, PC, and cytokine levels, and lower SOD availability indicate a greater degree of injury in the lungs of the hyperoxia animals, possibly from using 100% oxygen. In this translational study using a pig model, FiO(2)  ≤ 50% during OLV reduced hyperoxic injury and improved function in the lungs.
authors.affiliation: Nemours Biomedical Research, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE19803, USA. aolivant@nemours.org
authors.forename: Alicia
authors.initials: A
authors.lastname: Olivant Fisher
authors.forename: Kamran
authors.initials: K
authors.lastname: Husain
authors.forename: Marla R
authors.initials: MR
authors.lastname: Wolfson
authors.forename: Terrence L
authors.initials: TL
authors.lastname: Hubert
authors.forename: Elena
authors.initials: E
authors.lastname: Rodriguez
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Shaffer
authors.forename: Mary C
authors.initials: MC
authors.lastname: Theroux
mesh_terms: D055371:Acute Lung Injury / Q000201:enzymology / Q000209:etiology / Q000503:physiopathology; D000818:Animals; D002245:Carbon Dioxide / Q000097:blood; D016207:Cytokines / Q000097:blood; D018496:Hyperoxia / Q000097:blood / Q000209:etiology* / Q000503:physiopathology*; D007249:Inflammation / Q000097:blood / Q000503:physiopathology*; D008168:Lung / Q000201:enzymology / Q000502:physiology*; D061810:One-Lung Ventilation / Q000009:adverse effects*; D018384:Oxidative Stress; D010100:Oxygen / Q000009:adverse effects*; D009195:Peroxidase / Q000032:analysis; D050050:Protein Carbonylation / Q000502:physiology; D013482:Superoxide Dismutase / Q000032:analysis; D013552:Swine
chemical_list: D016207:Cytokines; D002245:Carbon Dioxide; D009195:Peroxidase; D013482:Superoxide Dismutase; D010100:Oxygen