title: Effects of the open lung concept following ARDSnet ventilation in patients with early ARDS.
abstract: Ventilation with low tidal volume (VT) is well recognized as a protective approach to patients with acute respiratory distress syndrome (ARDS), but the optimal level of positive end-expiratory pressure (PEEP) remains uncertain. This study aims to evaluate two protective ventilatory strategies sequentially applied in patients with early ARDS.
  
  
  
  In this prospective cohort study, fifteen patients were ventilated during 24 h with positive end-expiratory pressure (PEEP) adjusted according to the ARDSnet low-PEEP table (ARDSnet-24 h). During the next 24 h, nine patients with PaO2/FIO2 ratio below 350 mmHg were ventilated with PEEP titrated according to the Open Lung Concept protocol (ARDSnet + OLC). In the other six patients, regardless of their PaO2/FIO2 ratio, the ARDSnet remained for a further 24 h (ARDSnet-48 h). Ventilatory variables, arterial blood-gas and cytokine were obtained at baseline, 24 and 48 h. Additionally, whole-lung-computed tomography was acquired at 24 and 48 h.
  
  
  
  A sustained improvement in PaO2/FIO2 ratio (P = 0.008) with a decrease in collapsed regions (P = 0.008) was observed in the ARDSnet + OLC group compared with the ARDSnet-24 h group. A reduction in IL-6 in plasma (P < 0.02) was observed throughout the protocol in the ARDSnet + OLC group. Compared with the ARDSnet-48 h group, the ARDSnet + OLC presented smaller amounts of collapsed areas (P = 0.018) without significant differences in hyperinflated regions and in driving and plateau pressures.
  
  
  
  In this set of patients with early ARDS, mechanical ventilation with an individually tailored PEEP sustained improved pulmonary function with better aeration, without significant increase in hyperinflated areas".
  
  
  
  Brazilian Clinical Trials Registry (ReBec). RBR-5zm9pr. 04th November 2015.
authors.affiliation: Internal Medicine Department, Federal University of Rio de Janeiro, Rua Reseda, 23/401, Rio de Janeiro, 22471-230, Brazil. vrotman@gmail.com.
authors.forename: Vivian
authors.initials: V
authors.lastname: Rotman
authors.affiliation: Laboratory of Respiration Physiology, Instituto de Biofísica Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Alysson Roncally
authors.initials: AR
authors.lastname: Carvalho
authors.affiliation: Department of Radiology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.|D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil.
authors.forename: Rosana Souza
authors.initials: RS
authors.lastname: Rodrigues
authors.affiliation: Instituto de Pesquisa Clínica Evandro Chagas (IPEC), Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
authors.forename: Denise Machado
authors.initials: DM
authors.lastname: Medeiros
authors.affiliation: ICU, Copa D'Or Hospital, Rio de Janeiro, Brazil.
authors.forename: Eduardo Costa
authors.initials: EC
authors.lastname: Pinto
authors.affiliation: D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil.|Instituto de Pesquisa Clínica Evandro Chagas (IPEC), Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
authors.forename: Fernando Augusto
authors.initials: FA
authors.lastname: Bozza
authors.affiliation: Respiratory ICU, InCor-Hospital das Clinicas, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Carlos Roberto Ribeiro
authors.initials: CRR
authors.lastname: Carvalho
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001784:Blood Gas Analysis; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D016209:Interleukin-8 / Q000097:blood; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration / Q000379:methods*; D011446:Prospective Studies; D065840:Protective Factors; D001261:Pulmonary Atelectasis / Q000150:complications / Q000000981:diagnostic imaging / Q000517:prevention & control*; D012128:Respiratory Distress Syndrome / Q000097:blood / Q000150:complications / Q000517:prevention & control*; D036542:Tomography, Spiral Computed; D055815:Young Adult
chemical_list: D015850:Interleukin-6; D016209:Interleukin-8
keywords: Lung -adult respiratory distress syndrome; Measurement techniques – tomography; Ventilation – effects