1. Intensive Care Unit 4, Department of Intensive Care São Francisco Xavier Hospital, CHLO, Lisbon, 1449-005 Lisbon, Portugal
2. Nova Medical School, Clinical Medicine, CHRC, New University of Lisbon, 1169-056 Lisbon, Portugal
3. Instituto D’Or de Pesquisa e Ensino, Rio de Janeiro 22281-100, Brazil
4. Hospital Copa D´Or, Rio de Janeiro 22031-011, Brazil
5. Center for Clinical Epidemiology, Research Unit of Clinical Epidemiology, OUH Odense University Hospital, 5000 Odense C, Denmark