1. Department of Intensive Care Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
2. Department of Epidemiology, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
3. Cardiovascular and Respiratory Physiology,TechMed Center,University of Twente, Enschede, the Netherlands
4. Department of Intensive Care Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
5. Department of Cardiology, Thorax Center, Erasmus, Rotterdam, The Netherlands