title: Selecting the 'right' positive end-expiratory pressure level.
abstract: OBJECTIVE
  To compare the positive end-expiratory pressure selection aiming either to oxygenation or to the full lung opening.
  
  
  RESULTS
  Increasing positive end-expiratory pressure in patients with severe hypoxemia is associated with better outcome if the oxygenation response is greater and positive end-expiratory pressure tests may be performed in a few minutes. The oxygenation response to recruitment maneuvers was associated with better outcome in patients with acute respiratory distress syndrome from influenza A (H1N1). If, after recruitment maneuver, the recruitment is not sustained by sufficient positive end-expiratory pressure, the lung will unavoidably collapse. Several papers investigated the positive end-expiratory pressure selection according to the deflation limb of the pressure-volume curve. It is still questionable whether to consider oxygenation or respiratory mechanics change as the best marker for adequate selection. A growing interest is paid to the estimate of transpulmonary pressure, although no consensus is available on which methodology is preferable. Finally, the positive end-expiratory pressure adequate for full lung opening may be computed combining the computed tomography scan variables and the chest wall elastance.
  
  
  CONCLUSIONS
  When compared, most of the methods give the same positive end-expiratory pressure values in patients with higher and lower recruitability. The positive end-expiratory pressure/inspiratory oxygen fraction tables are the only methods providing lower positive end-expiratory pressure in lower recruiters and higher positive end-expiratory pressure in higher recruiters.
authors.affiliation: aDipartimento di Anestesia, Rianimazione ed Emergenza Urgenza, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico bDipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milano, Milan, Italy.
authors.forename: Luciano
authors.initials: L
authors.lastname: Gattinoni
authors.forename: Eleonora
authors.initials: E
authors.lastname: Carlesso
authors.forename: Massimo
authors.initials: M
authors.lastname: Cressoni
mesh_terms: D000818:Animals; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000150:complications; D008176:Lung Volume Measurements; D011175:Positive-Pressure Respiration / Q000379:methods*; D018467:Positive-Pressure Respiration, Intrinsic; D012128:Respiratory Distress Syndrome / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D015656:Respiratory Mechanics; D013990:Tidal Volume; D014057:Tomography, X-Ray Computed