title: Alveolar recruitment assessed by positron emission tomography during experimental acute lung injury.
abstract: OBJECTIVE
  To compare changes in aerated lung volumes measured by positron emission tomography (PET) and inflation volume-pressure curve (V-P) of the respiratory system, and to evaluate the reliability of PET to assess alveolar recruitment.
  
  
  METHODS
  Experimental study in six anesthetized and mechanically ventilated pigs in a PET facility in an experimental university laboratory.
  
  
  METHODS
  Lung injury was induced by oleic acid. Animals were randomly studied in four conditions: PEEP 0cmH(2)O (ZEEP) in supine position (SP), PEEP 10cmH(2)O in SP, ZEEP in prone position (PP) and PEEP in PP, each applied for 30min.
  
  
  RESULTS
  With PET aerated lung volume was obtained from pulmonary density analysis using transmission scan (VA(trans)) and from nitrogen-13 kinetics on emission scan (VA(em)). Changes in VA(trans) and VA(em) were computed as the difference in aerated volume between conditions. VA(trans) and VA(em) did not differ between SP and PP, on either ZEEP or PEEP, suggesting no modification in relaxation volume of the respiratory system induced by posture. Changes in VA(trans) or VA(em) were significantly correlated with changes in aerated volume assessed from superimposed V-P curves (R (2)=0.74 and 0.75, respectively). Alveolar recruitment assessed by PET was significantly correlated with both PaO(2) (R (2)=0.61) and PaCO(2) (R (2)=0.40) variations induced by PEEP.
  
  
  CONCLUSIONS
  PET is a new reliable tool of scientific interest to image lung volume and alveolar recruitment during acute lung injury.
authors.affiliation: Service de Réanimation Médicale et d'Assistance Respiratoire, Hôpital de la Croix Rousse, 93 Grande Rue de la Croix Rousse, 69004, Lyon, France.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Richard
authors.forename: Didier
authors.initials: D
authors.lastname: Le Bars
authors.forename: Nicolas
authors.initials: N
authors.lastname: Costes
authors.forename: Fabienne
authors.initials: F
authors.lastname: Bregeon
authors.forename: Christian
authors.initials: C
authors.lastname: Tourvieille
authors.forename: Franck
authors.initials: F
authors.lastname: Lavenne
authors.forename: Marc
authors.initials: M
authors.lastname: Janier
authors.forename: Gérard
authors.initials: G
authors.lastname: Gimenez
authors.forename: Claude
authors.initials: C
authors.lastname: Guerin
mesh_terms: D000818:Animals; D008176:Lung Volume Measurements; D019301:Oleic Acid; D011175:Positive-Pressure Respiration; D049268:Positron-Emission Tomography; D011187:Posture; D001261:Pulmonary Atelectasis / Q000517:prevention & control*; D011659:Pulmonary Gas Exchange; D011897:Random Allocation; D012128:Respiratory Distress Syndrome / Q000000981:diagnostic imaging* / Q000628:therapy*; D012129:Respiratory Function Tests / Q000379:methods*; D013552:Swine
chemical_list: D019301:Oleic Acid