J C Duarte1, C R Cordeiro2, A J Ferreira2. 1. Pulmonology Unit, Hospitais da Universidade de Coimbra - Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal; University of Coimbra, Faculty of Medicine, Coimbra, Portugal. Electronic address: Joana_Duarte_17@hotmail.com. 2. Pulmonology Unit, Hospitais da Universidade de Coimbra - Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal; University of Coimbra, Faculty of Medicine, Coimbra, Portugal.