Plain English Summary
Background and study aims
Despite several effective treatment approaches including prone positioning and low tidal volume, acute respiratory distress syndrome (ARDS, an acute lung impairment) still carries a high mortality. Therefore, extracorporeal lung membrane oxygenation (ECMO, a way of getting blood oxygenated outside the body) is also used. Despite more than 40 years of clinical use of ECMO, it remains controversial. This might be related to its use as a rescue treatment in the first clinical studies. Analysis of previous studies suggests that starting ECMO earlier might be beneficial. However, there is still controversy regarding which patients should be treated with ECMO according to which criteria, and also which interval after the start of mechanical ventilation (breathing support) provides the best effect size of ECMO compared with conventional treatment.
Most of the recent and ongoing studies include patients based on the recent ARDS definitions (Berlin; American European Consensus Conference AECC) and on scoring systems like the lung injury score (LIS). However, there is a lack of studies with systematic repeated comparison of the predictive capabilities of these scores over time. In addition to the traditional definitions and scores, other parameters such as the oxygenation index (OI, an index which is calculated using airway pressure, fraction of inspired oxygen and arterial partial pressure of oxygen) or the extravascular lung water index (EVLWI, an index which is used to quantify the amount of fluid outside the pulmonary vessels) might predict the outcome even better than the definitions and scoring systems used to date.
Therefore, the aim of this study is to compare the predictive capabilities of the oxygenation index, AECC and Berlin definitions of ARDS (definitions of ARDS that were suggested from expert consensus conferences), the Murray score and its total score without radiological points (Murray-WRP) as well as EVLWI, regarding 28-days mortality.
Who can participate?
Patients aged 18 or older with ARDS according to the Berlin definition
What does the study involve?
Daily measurement of AECC- and Berlin-definition of ARDS, modified Murray score without radiological points (Murray_mod) and oxygenation index (OI) for four days after intubation. Documentation of haemodynamic (blood flow) parameters derived from transpulmonary thermodilution (TPTD, a way of measuring different parameters for lung and heart function) and pulse contour analysis (PCA, a way of measuring cardiac output; PiCCO; Pulsion Medical Systems; Feldkirchen, Germany), if PiCCO monitoring (a medical device used for haemodynamic observations) is available irrespective of the study.
What are the possible benefits and risks of participating in the study?
The possible benefit is a very thorough analysis and monitoring of pulmonary and haemodynamic parameters. There are no additional risks to participants due to the observational design of the study.
Where is the study run from?
General Intensive Care Unit R3a (2/11) of the university hospital Klinikum rechts der Isar, Technical University of Munich (Germany)
When is the study starting and how long is it expected to run for?
May 2015 to September 2016
Who is funding the study?
Technical University of Munich (Germany)
Who is the main contact?
Prof. Wolfgang Huber
Prediction of outcome in patients with ARDS: a prospective comparison of ARDS-definitions and other ARDS-associated parameters, ratios and scores at intubation and over time
The aim of this observational study was to compare the predictive capabilities of the oxygenation-index OI (mean airway pressure*FiO2/pO2), AECC- and Berlin-definitions of ARDS, single components of Murray-score and its total score without radiological points (Murray-WRP) as well as the EVLWI regarding ICU-, 28-days- and hospital mortality.
Main questions addressed by the study:
1. Which day among days 1-4 provides the best prediction of 28-day mortality?
2. Which score or parameter provides the best prediction of 28-day mortality in general?
3. In patients with PiCCO-monitoring available: Does measurement of extravascular lung water index (EVLWI) provide additional prognostic information?
4. Are there hints that advanced haemodynamic monitoring “per se” might improve the prognosis of patients with ARDS?
5. Are there hints that the inclusion criteria of the EXODUS trial should be modified?
Approved 20/08/2018, Ethikkommission der Technischen Universität München (Prof. Dr. Georg Schmidt, Ismaninger Straße 22, 81675 München, Germany, Tel: +49 (0)89 4140 4371; Email: firstname.lastname@example.org), ref: 343/18 S
Single-center observational cohort study
Primary study design
Secondary study design
Patient information sheet
Acute respiratory distress syndrome (ARDS)
Due to the observational design of the study no specific intervention related to the study was performed. Routine data of patients with ARDS and (if available irrespectively of the study) data from PiCCO monitoring were documented for up to 10 days after intubation. All measurements were repeated at least once per day.
Daily measurement of AECC- and Berlin-definition of ARDS, modified Murray-score without radiological points (Murray_mod) and oxygenation index (OI) for four days after intubation. Documentation of haemodynamic parameters derived from transpulmonary thermodilution (TPTD) and pulse contour analysis (PCA; PiCCO; Pulsion Medical Systems; Feldkirchen, Germany), if the PiCCO-monitoring is available irrespectively of the study.
All patients received normal routine care and there was no follow-up period beyond 28-day mortality.
Primary outcome measure
28-day mortality measured using medical records
Secondary outcome measures
There are no secondary outcome measures
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Aged 18 or older
2. Critically ill
3. Acute respiratory distress syndrome (ARDS) according to Berlin Definition
Target number of participants
Participant exclusion criteria
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Technische Universität München
Medizinische Klinik und Poliklinik II Klinikum rechts der Isar Ismaningerstr. 22
Technische Universität München
Medizinische Klinik und Poliklinik II
Klinikum rechts der Isar
Ismaninger Straße 22
Technische Universität München
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Planned publication in a peer-reviewed journal.
IPD sharing statement:
The datasets generated during the current study are available upon request from Paul Schmidle (email@example.com) and Wolfgang Huber (firstname.lastname@example.org). The data will be available following permission from the Institutional Review Board.
Intention to publish date
Participant level data
Available on request
Basic results (scientific)