title: Relationship between gas exchange response to prone position and lung recruitability during acute respiratory failure.
abstract: OBJECTIVE
  To clarify whether the gas exchange response to prone position is associated with lung recruitability in mechanically ventilated patients with acute respiratory failure.
  
  
  METHODS
  In 32 patients, gas exchange response to prone position was investigated as a function of lung recruitability, measured by computed tomography in supine position.
  
  
  RESULTS
  No relationship was found between increased oxygenation in prone position and lung recruitability. In contrast, the decrease of PaCO(2) was related with lung recruitability (R(2) 0.19; P = 0.01). Patients who decreased their PaCO(2) more than the median value (-0.9 mmHg) had a greater lung recruitability (19 +/- 16 vs. 8 +/- 6%; P = 0.02), higher baseline PaCO(2) (48 +/- 8 vs. 41 +/- 11 mmHg; P = 0.07), heavier lungs (1,968 +/- 829 vs. 1,521 +/- 342 g; P = 0.06) and more non-aerated tissue (1,009 +/- 704 vs. 536 +/- 188 g; P = 0.02) than those who did not.
  
  
  CONCLUSIONS
  During prone position, changes in PaCO(2), but not in oxygenation, are associated with lung recruitability which, in turn, is associated with the severity of lung injury.
authors.affiliation: Dipartimento di Anestesiologia, Terapia Intensiva e Scienze Dermatologiche, Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena di Milano, Università degli Studi di Milano, Via F. Sforza 35, 20122 Milan, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Protti
authors.forename: Davide
authors.initials: D
authors.lastname: Chiumello
authors.forename: Massimo
authors.initials: M
authors.lastname: Cressoni
authors.forename: Eleonora
authors.initials: E
authors.lastname: Carlesso
authors.forename: Cristina
authors.initials: C
authors.lastname: Mietto
authors.forename: Virna
authors.initials: V
authors.lastname: Berto
authors.forename: Marco
authors.initials: M
authors.lastname: Lazzerini
authors.forename: Michael
authors.initials: M
authors.lastname: Quintel
authors.forename: Luciano
authors.initials: L
authors.lastname: Gattinoni
mesh_terms: D055371:Acute Lung Injury / Q000503:physiopathology*; D000328:Adult; D000368:Aged; D002245:Carbon Dioxide; D005260:Female; D006801:Humans; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D016684:Prone Position / Q000502:physiology; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D015656:Respiratory Mechanics / Q000502:physiology*; D014057:Tomography, X-Ray Computed
chemical_list: D002245:Carbon Dioxide