title: Positive end-expiratory pressure lung recruitment: comparison between lower inflection point and ultrasound assessment.
abstract: BACKGROUND
  Maintenance of the open lung alveoli in the expiration on mechanical ventilation in acute lung injury/acute respiratory distress syndrome (ALI/ARDS) remains challenging despite advances in lung imaging. The inspiratory lower inflection point (LIP) on the ventilator pressure-volume (P-V) curve estimates the required end-expiratory pressure for recruitment of alveolar consolidation. Alternatively, the end-expiratory pressure for recruitment of crater-like subpleural alveolar consolidation could be simply followed with ultrasound. These two methods for setting the ventilators positive end-expiratory pressure (PEEP) were compared.
  
  
  METHODS
  The observational study in surgical/neurosurgical intensive care between October 2009 and November 2011 included 17 deeply sedated or relaxed patients. LIP was measured with continuous low-flow method, as a pressure in cmH(2)O. Expiratory levelling between lower border of subpleural consolidation and adjacent pleural line, which means lung recruitment, was followed with linear ultrasound probe. PEEP in cmH(2)O at which the levelling occurs was compared with LIP pressure.
  
  
  RESULTS
  LIP pressure never exceeds the PEEP for recruitment of subpleural consolidations followed with ultrasound. A significant correlation (r = 0.839; p < 0.05) was found between two methods.
  
  
  CONCLUSIONS
  In this study, positive end-expiratory pressures for recruitment of subpleural consolidations followed by ultrasound always exceed the pressures measured with LIP. Respecting this, ultrasound method could be the guide for PEEP lung recruitment.
authors.affiliation: Department of Anaesthesiology and Intensive Care, University Hospital Center Sisters of Mercy, Vinogradska 29, 10000, Zagreb, Croatia. bojan.rode@zg.t-com.hr
authors.forename: Bojan
authors.initials: B
authors.lastname: Rode
authors.forename: Marinko
authors.initials: M
authors.lastname: Vučić
authors.forename: Mladen
authors.initials: M
authors.lastname: Siranović
authors.forename: Ana
authors.initials: A
authors.lastname: Horvat
authors.forename: Helena
authors.initials: H
authors.lastname: Krolo
authors.forename: Mijo
authors.initials: M
authors.lastname: Kelečić
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Gopčević
mesh_terms: D055371:Acute Lung Injury / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity / Q000502:physiology; D001810:Blood Volume / Q000502:physiology; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008168:Lung / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration / Q000379:methods*; D011650:Pulmonary Alveoli / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012128:Respiratory Distress Syndrome / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D013990:Tidal Volume / Q000502:physiology; D014463:Ultrasonography