title: Bedside ultrasound assessment of positive end-expiratory pressure-induced lung recruitment.
abstract: BACKGROUND
  In the critically ill patients, lung ultrasound (LUS) is increasingly being used at the bedside for assessing alveolar-interstitial syndrome, lung consolidation, pneumonia, pneumothorax, and pleural effusion. It could be an easily repeatable noninvasive tool for assessing lung recruitment.
  
  
  OBJECTIVE
  Our goal was to compare the pressure-volume (PV) curve method with LUS for assessing positive end-expiratory pressure (PEEP)-induced lung recruitment in patients with acute respiratory distress syndrome/acute lung injury (ARDS/ALI).
  
  
  METHODS
  Thirty patients with ARDS and 10 patients with ALI were prospectively studied. PV curves and LUS were performed in PEEP 0 and PEEP 15 cm H₂O₂. PEEP-induced lung recruitment was measured using the PV curve method.
  
  
  RESULTS
  Four LUS entities were defined: consolidation; multiple, irregularly spaced B lines; multiple coalescent B lines; and normal aeration. For each of the 12 lung regions examined, PEEP-induced ultrasound changes were measured, and an ultrasound reaeration score was calculated. A highly significant correlation was found between PEEP-induced lung recruitment measured by PV curves and ultrasound reaeration score (Rho = 0.88; P < 0.0001). An ultrasound reaeration score of +8 or higher was associated with a PEEP-induced lung recruitment greater than 600 ml. An ultrasound lung reaeration score of +4 or less was associated with a PEEP-induced lung recruitment ranging from 75 to 450 ml. A statistically significant correlation was found between LUS reaeration score and PEEP-induced increase in Pa(O₂) (Rho = 0.63; P < 0.05).
  
  
  CONCLUSIONS
  PEEP-induced lung recruitment can be adequately estimated with bedside LUS. Because LUS cannot assess PEEP-induced lung hyperinflation, it should not be the sole method for PEEP titration.
authors.affiliation: Multidisciplinary Intensive Care Unit Pierre Viars, Assistance Publique Hôpitaux de Paris. jjrouby@invivo.edu
authors.forename: Belaïd
authors.initials: B
authors.lastname: Bouhemad
authors.forename: Hélène
authors.initials: H
authors.lastname: Brisson
authors.forename: Morgan
authors.initials: M
authors.lastname: Le-Guen
authors.forename: Charlotte
authors.initials: C
authors.lastname: Arbelot
authors.forename: Qin
authors.initials: Q
authors.lastname: Lu
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Rouby
mesh_terms: D055371:Acute Lung Injury / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000502:physiology; D008875:Middle Aged; D019095:Point-of-Care Systems; D011175:Positive-Pressure Respiration; D012128:Respiratory Distress Syndrome / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy; D012129:Respiratory Function Tests; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014463:Ultrasonography