title: Use of Lung Ultrasound to Assess the Efficacy of an Alveolar Recruitment Maneuver in Rabbits With Acute Respiratory Distress Syndrome.
abstract: OBJECTIVE
  To investigate the application of lung ultrasound (US) in the evaluation and implementation of alveolar recruitment maneuvers in acute respiratory distress syndrome (ARDS).
  
  
  METHODS
  Twelve rabbits with saline lavage-induced lung injury were randomly divided into 2 groups: one with alveolar recruitment guided by lung US and the other with alveolar recruitment guided by maximal oxygenation. Recruitment maneuvers were applied according to a stepwise incremental positive end-expiratory pressure method in both groups. In the oxygenation group, a sum of the partial pressures of oxygen and carbon dioxide exceeding 400 mm Hg was used to define adequate recruitment. In the lung US group, a new protocol for reaeration in US-guided lung recruitment was used to guide treatment. Evaluation by lung US, respiratory mechanical parameters, the Smith pathologic score (Crit Care Med 1997; 25:1888-1897), and wet-to-dry ratio were compared between the groups.
  
  
  RESULTS
  Opening pressure was significantly higher in the lung US group (mean ± SD, 23.4 ± 3.4 cm H2O) than the oxygenation group (18.7 ± 2.1 cm H2O; P < .05). The reaeration score in the lung US group significantly increased during alveolar recruitment (6.5 ± 1.6 points at baseline versus 13.8 ± 3.0 points after completion; P < .05). Lung compliance, dead space shunts, the Smith pathologic score, and tissue wet-to-dry ratio, however, were not significantly different between the groups.
  
  
  CONCLUSIONS
  Lung US is an effective means of evaluating and guiding alveolar recruitment in ARDS. Compared with the maximal oxygenation-guided method, the protocol for reaeration in US-guided lung recruitment achieved a higher opening pressure, resulted in greater improvements in lung aeration, and substantially reduced lung heterogeneity in ARDS.
authors.affiliation: Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Dong-kai
authors.initials: DK
authors.lastname: Li
authors.affiliation: Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China. pumchicuky@163.com.
authors.forename: Da-wei
authors.initials: DW
authors.lastname: Liu
authors.affiliation: Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Long
authors.affiliation: Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Xiao-ting
authors.initials: XT
authors.lastname: Wang
mesh_terms: D000818:Animals; D008168:Lung / Q000000981:diagnostic imaging*; D011175:Positive-Pressure Respiration / Q000379:methods*; D011817:Rabbits; D015203:Reproducibility of Results; D012128:Respiratory Distress Syndrome / Q000000981:diagnostic imaging* / Q000628:therapy*; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014463:Ultrasonography / Q000379:methods*
keywords: acute respiratory distress syndrome; emergency medicine; lung recruitment; lung ultrasound; positive end-expiratory pressure