title: Measurement of eNO with portable analyser might improve the management of persistent cough at primary care practice in Japan.
abstract: OBJECTIVE
  There are some controversial reports that investigated the usefulness of exhaled nitric oxide (eNO) to predict the efficacy of inhaled corticosteroids (ICS) in chronic cough patients. Therefore, we retrospectively analysed the usefulness of eNO measurement with portable analyser to predict the requirement of ICS therapy in persistent cough (defined as lasting for 3 weeks or more) patients in Japan and investigated whether it might improve the management of persistent cough at primary care practice.
  
  
  METHODS
  We retrospectively reviewed the clinical records of adult patients who had been referred to our hospital for persistent cough from 1 June 2009 to 30 April 2011.
  
  
  RESULTS
  Forty-two patients had the requirement of ICS (group S) and 35 patients had no requirement of ICS (group N). Forty-three per cent of the patients who required ICS had not received ICS, and 29% of the patients who did not required ICS had received ICS. In the steroid-naive patients without current smoking, mean eNO level was significantly higher in group S [60.6 ± 14.1 parts per billion (ppb) vs 22.2 ± 2.3 ppb, P = 0.001] and the sensitivity and the specificity of eNO for predicting the requirement of ICS were 78.6% and 80.0%, respectively. The rate of the patients who received inappropriate treatment about ICS tended to be reduced from 41% to 21% if the eNO was used to predict the requirement of ICS with cut-off value of eNO 26.5 ppb (P = 0.118).
  
  
  CONCLUSIONS
  Measurement of eNO could be one of the management tools for persistent cough at primary care practice.
authors.affiliation: Respiratory Disease Center, Yokohama City University Medical Center, Yokohama, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Respiratory Disease Center, Yokohama City University Medical Center, Yokohama, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Shinkai
authors.affiliation: Respiratory Disease Center, Yokohama City University Medical Center, Yokohama, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Shinoda
authors.affiliation: Respiratory Disease Center, Yokohama City University Medical Center, Yokohama, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Hara
authors.affiliation: Respiratory Disease Center, Yokohama City University Medical Center, Yokohama, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Yamaguchi
authors.affiliation: Department of Pediatrics, Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: Bruce K
authors.initials: BK
authors.lastname: Rubin
authors.affiliation: Department of Internal Medicine and Clinical Immunology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ishigatsubo
authors.affiliation: Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kaneko
mesh_terms: D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage*; D000328:Adult; D003371:Cough / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis* / Q000378:metabolism; D011320:Primary Health Care; D012189:Retrospective Studies
chemical_list: D000305:Adrenal Cortex Hormones; D009569:Nitric Oxide
keywords: cough; exhaled nitric oxide; inhaled corticosteroids; primary care practice