HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Supplementary data Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Michils, A. Articles by Van Muylem, A. PubMed PubMed Citation Articles by Michils, A. Articles by Van Muylem, A.

Exhaled nitric oxide and asthma control: a longitudinal study in unselected patients

Chest Dept, Erasme University Hospital, Brussels, Belgium.

CORRESPONDENCE: A. Van Muylem, Chest Dept, CUB Erasme, 808 Route de Lennik, B-1070 Brussels, Belgium. Fax: 32 25554411. E-mail: avmuylem{at}ulb.ac.be

Keywords: Asthma control, exhaled nitric oxide, lung function

Received: February 19, 2007
Accepted October 31, 2007

Controlled studies have shown that monitoring of the exhaled nitric oxide fraction (F_eNO) improves asthma management. However, the studies seldom consider the full range of patients seen in clinical practise. In the present study, the ability of F_eNO to reflect asthma control over time is investigated in a regular clinical setting, and meaningful F_eNO cut-off points and changes are identified.

Answers to the Asthma Control Questionnaire and F_eNO were recorded at least once in 341 unselected asthma patients. The whole population and subgroups were considered, i.e. both inhaled corticosteroid (ICS)-naïve and low or high-to-medium ( or >500 µg beclomethasone dipropionate equivalents·day^–1) ICS-dose groups.

An F_eNO decrease <40% or increase <30% precludes asthma control optimisation or deterioration, respectively (negative predictive value 79 and 82%, respectively). In the present study’s low-dose group, a decrease >40% indicated asthma control optimisation (positive predictive value (PPV) 83%). In ICS-naïve patients, F_eNO >35 ppb predicted asthma control improvement in response to ICS (PPV 68%). In most cases, forced expiratory volume in one second assessments were not useful.

In conclusion, in a given patient, exhaled nitric oxide fraction was found to be significantly related to asthma control over time. The overall ability of exhaled nitric oxide fraction to reflect asthma control was reduced in patients using high doses of inhaled corticosteroids. Forced expiratory volume in one second had little additional value in assessing asthma control.