1. Department of Emergency and Intensive Care Medicine, Centro Hospitalar S.João, Porto, Portugal
2. Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine of Porto, Porto, Portugal
3. Department of Internal Medicine, Centro Hospitalar Póvoa de Varzim, Vila do Conde, Póvoa de Varzim, Portugal
4. Department of Internal Medicine, Centro Hospitalar S.João, Porto, Portugal
5. Department of Medicine, Faculty of Medicine of Porto, Porto, Portugal