1 Department of Intensive Care Medicine, Hospital Universitario La Paz, Paseo de la Castellana 264, 28046 Madrid, Spain. Electronic address: alexander_agrifoglio@yahoo.es.
2 Department of Intensive Care Medicine, Hospital Universitario La Paz, Paseo de la Castellana 264, 28046 Madrid, Spain. Electronic address: luciacachafeiro@yahoo.es.
3 Department of Intensive Care Medicine, Hospital Universitario La Paz, Paseo de la Castellana 264, 28046 Madrid, Spain. Electronic address: luarnaria@yahoo.es.
4 Department of Intensive Care Medicine, Hospital Universitario La Paz, Paseo de la Castellana 264, 28046 Madrid, Spain. Electronic address: jmaelizalde@gmail.com.
5 Department of Intensive Care Medicine, Hospital Universitario La Paz, Paseo de la Castellana 264, 28046 Madrid, Spain. Electronic address: agdl@telefonica.net.