title: End-tidal capnographic monitoring to detect apnea episodes during flexible bronchoscopy under sedation.
abstract: Apnea developing as a result of oversedation is a potential clinical problem in patients undergoing flexible bronchoscopy (FB) under sedation. However, there are no reports of evaluation using a standardized method of the frequency of occurrence of apnea episodes during FB under sedation. The aim of this study was to investigate the frequency of apnea episodes during FB under sedation in the clinical setting by end-tidal capnography.
  
  
  
  This study was a single-institution retrospective review of a prospectively maintained database and medical records, including capnographic data, from April 2015 to March 2016. We enrolled patients who were sedated with midazolam and underwent diagnostic FB under end-tidal capnographic monitoring. Apnea was defined as cessation of airflow for more than 10 s.
  
  
  
  Data from a total of 121 eligible patients were analyzed. A total of 131 apnea episodes (median duration 33 s) were recorded in 59 patients (48.8%). Prolonged apnea episodes lasting for more than 30 s occurred in 24 patients (19.8%). Furthermore, 55 apnea episodes (42.0%) were followed by a decline of the SpO2by ≥4% from the baseline.
  
  
  
  In this study, end-tidal capnography revealed the occurrence of apnea episodes at a high frequency in patients undergoing FB under sedation in the clinical setting.
authors.affiliation: Department of Respirology, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Ishiwata
authors.affiliation: Department of Respirology, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba, 260-8670, Japan. tsushimakenji@yahoo.co.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Tsushima
authors.affiliation: Medical Equipment Control Center, Chiba University Hospital, 1-8-1, Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Mai
authors.initials: M
authors.lastname: Fujie
authors.affiliation: Department of Respirology, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Department of Respirology, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Hirota
authors.affiliation: Department of Respirology, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Abe
authors.affiliation: Department of Respirology, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Kawata
authors.affiliation: Department of Respirology, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Terada
authors.affiliation: Department of Respirology, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Tatsumi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001049:Apnea / Q000453:epidemiology* / Q000209:etiology; D001999:Bronchoscopy; D019296:Capnography; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects*; D007564:Japan; D008297:Male; D008874:Midazolam / Q000009:adverse effects*; D008875:Middle Aged; D008991:Monitoring, Physiologic; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D006993:Hypnotics and Sedatives; D008874:Midazolam