title: The effects of ventilatory mode on lung aeration assessed with computer tomography: a randomized controlled study.
abstract: Maintenance of spontaneous breathing superimposed on mechanical ventilation is suggested to improve gas exchange in patients with acute lung injury. The aim of this study was to evaluate the long-term effects of airway pressure release ventilation with maintained unsupported spontaneous breathing (APRV) and synchronized intermittent mandatory ventilation with pressure support (SIMV) on the amount of lung collapse in acute lung injury patients. Thirty-seven patients with acute lung injury were studied in a trial comparing APRV or SIMV. Computer-assisted tomography scannings (CT) were performed before randomization and at day 7. The change in the amount of nonaerated lung was comparable between groups; 14.7% (3.8-17.4) in APRV group (n = 13) and 9.6% (-1.4 to 18.62) in the SIMV group (n = 10), (P = .65, difference in mean 4.9%, 95% confidence interval -9.0% to 19.0%). The effects of APRV and SIMV on lung aeration are similar after 7 days of mechanical ventilation.
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Helsinki University Hospital, Hospital District of Helsinki and Uusimaa, Finland, tero.varpula@hus.fi
authors.forename: Tero
authors.initials: T
authors.lastname: Varpula
authors.forename: Päivi
authors.initials: P
authors.lastname: Valta
authors.forename: Antti
authors.initials: A
authors.lastname: Markkola
authors.forename: Katriina
authors.initials: K
authors.lastname: Pohjanen
authors.forename: Juha
authors.initials: J
authors.lastname: Halavaara
authors.forename: Markku
authors.initials: M
authors.lastname: Hynynen
authors.forename: Ville
authors.initials: V
authors.lastname: Pettilä
mesh_terms: D055371:Acute Lung Injury / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy*; D000328:Adult; D016001:Confidence Intervals; D045422:Continuous Positive Airway Pressure; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D001261:Pulmonary Atelectasis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000517:prevention & control; D012121:Respiration, Artificial / Q000379:methods*; D012131:Respiratory Insufficiency / Q000628:therapy*; D013997:Time Factors; D014057:Tomography, X-Ray Computed