title: Alveolar preservation with high inflation pressure and intermediate oxygen concentration reduces ischemia-reperfusion injury of the lung.
abstract: BACKGROUND
  This study investigated the optimal alveolar oxygen concentration and inflation pressure during ischemia that reduces lung ischemia-reperfusion injury (LIRI).
  
  
  METHODS
  Male Sprague-Dawley rats (n = 66) underwent 150 minutes of left lung ischemia by hilar clamping at an airway inflation pressure (P) of 5 or 30 cm H(2)O and an oxygen (O) concentration of 0%, 30%, or 100% (P(5)O(0), P(5)O(30), P(5)O(100), P(30)O(0), P(30)O(30) and P(30)O(100) groups). Lungs preserved with 0% oxygen were inflated with 100% nitrogen. Measurements of arterial blood gas values, pulmonary compliance, histology, flow cytometry of bronchoalveolar lavage fluid were performed on day 2 postoperatively.
  
  
  RESULTS
  Inflation with 30 cm H(2)O resulted in increased partial pressure of arterial oxygen (Pao(2)) and lung compliance, decreased diffuse alveolar damage, and less infiltration of CD4(+) and CD8(+) lymphocytes and major histocompatibility complex class II-positive (MHCII(+)) antigen-presenting cells (APCs) in the left lung on day 2 compared with clamping at an airway inflation pressure of 5 cm H(2)O. The 100% oxygen groups demonstrated a lower Pao(2) and a decreased pulmonary compliance than 30% oxygen groups. More CD8(+) lymphocytes and MHCII(+) APCs were found in the P(5)O(100) group than in the P(5)O(0) and P(5)O(30) groups.
  
  
  CONCLUSIONS
  Alveolar inflation with a pressure of 30 cm H(2)O and an oxygen concentration of 30% decreases the severity of LIRI. The protective effect is mainly due to hyperinflation and, to a lesser extent, through oxygen concentration.
authors.affiliation: Department of Cardio-Thoracic Surgery, Erasmus MC Rotterdam, the Netherlands. npvdkaaij@gmail.com
authors.forename: Niels P
authors.initials: NP
authors.lastname: van der Kaaij
authors.forename: Jolanda
authors.initials: J
authors.lastname: Kluin
authors.forename: Robert A
authors.initials: RA
authors.lastname: Lachmann
authors.forename: Michael A
authors.initials: MA
authors.lastname: den Bakker
authors.forename: Bart N
authors.initials: BN
authors.lastname: Lambrecht
authors.forename: Burkhard
authors.initials: B
authors.lastname: Lachmann
authors.forename: Ron W F
authors.initials: RW
authors.lastname: de Bruin
authors.forename: Ad J J C
authors.initials: AJ
authors.lastname: Bogers
mesh_terms: D000818:Animals; D006861:Hydrogen Peroxide; D008168:Lung / Q000378:metabolism*; D008170:Lung Compliance / Q000502:physiology; D008297:Male; D023421:Models, Animal; D010100:Oxygen / Q000378:metabolism*; D010313:Partial Pressure; D011650:Pulmonary Alveoli / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000378:metabolism / Q000517:prevention & control*
chemical_list: D006861:Hydrogen Peroxide; D010100:Oxygen