title: Individual patient data analysis of tidal volumes used in three large randomized control trials involving patients with acute respiratory distress syndrome.
abstract: The acute respiratory distress syndrome (ARDS) is a condition with a high mortality and morbidity. Mechanical ventilation prevents immediate mortality but may further damage patients' lungs. Low tidal volume lung-protective strategies have been shown to increase survival by reducing this iatrogenic damage. Current guidelines recommend tidal volumes of 6-8 ml kg -1 of predicted body weight. We used data from three large randomized controlled trials of treatments for ARDS to determine compliance with these recommendations.
  We used the tidal volume recorded at randomization for all patients in the OSCAR, HARP-2, and BALTI-2 studies. In addition, we used the ventilation data for control arm patients in OSCAR and all patients in HARP-2 at days 1 and 7 after randomization.
  The three trials enrolled 1660 patients, with tidal volume data available at least at one time point in 1412 patients. Compliance with the 6-8 ml kg -1 recommendation for tidal volume ranged from 20 to 39% of patients across all time points in all three trials.
  Poor compliance with the guidelines for tidal volume in patients with ARDS has been demonstrated before in case series, but not in clinical trials where the patient population is specifically selected against standard ARDS diagnostic criteria and the investigators were encouraged to use low tidal volumes. This study may indicate a need to improve implementation and compliance with protective lung ventilation.
authors.affiliation: Department of Anaesthesia and Critical Care, John Radcliffe Hospital, Oxford, UK.
authors.forename: J
authors.initials: J
authors.lastname: Poole
authors.affiliation: Northern Ireland Clinical Trials Unit, Queen's University of Belfast, UK.
authors.forename: C
authors.initials: C
authors.lastname: McDowell
authors.affiliation: Clinical Trials Unit, University of Warwick, UK.
authors.forename: R
authors.initials: R
authors.lastname: Lall
authors.affiliation: Clinical Trials Unit, University of Warwick, UK.|Warwick Medical School, University of Warwick, UK.|Directorate of Anaesthetics, Heart of England NHS Foundation Trust, Birmingham, UK.
authors.forename: G
authors.initials: G
authors.lastname: Perkins
authors.affiliation: Centre for Experimental Medicine, Queen's University of Belfast, UK.|Regional Intensive Care Unit, Royal Victoria Hospital, Belfast, UK.
authors.forename: D
authors.initials: D
authors.lastname: McAuley
authors.affiliation: Directorate of Anaesthetics, Heart of England NHS Foundation Trust, Birmingham, UK.|Institute of Inflammation and Ageing, University of Birmingham, UK.
authors.forename: F
authors.initials: F
authors.lastname: Gao
authors.affiliation: Nuffield Department of Clinical Neurosciences, University of Oxford, UK.
authors.forename: D
authors.initials: D
authors.lastname: Young
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003627:Data Interpretation, Statistical; D005260:Female; D019983:Guideline Adherence; D006801:Humans; D008297:Male; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012128:Respiratory Distress Syndrome / Q000503:physiopathology*; D012129:Respiratory Function Tests; D013990:Tidal Volume; D055815:Young Adult
keywords: adult; critical care; respiratory distress syndrome; tidal volume