Sedation in colonoscopy by using three different propofol infusion methods and analysis of plasma concentration levels: a prospective comparative study - Carvalho, Paulo Henrique Boaventura de; Otoch, José Pinhata; Khan, Mohamad Ali; Sakai, Paulo; Guedes, Hugo Gonçalo; Artifon, Everson Luiz de Almeida (Arquivos Brasileiros de Cirurgia Digestiva, 2016)