Eur Respir J 2000; 15: 1009-1013
Copyright © ERS Journals Ltd 2000
The current single exhalation method of measuring exhales nitric oxide is affected by airway calibre
LP Ho,
FT Wood,
A Robson,
JA Innes,
and
AP Greening
The authors have observed that some patients with acute exacerbations of asthma do not have substantially higher levels of exhaled nitric oxide (NO). The study examined whether this could be explained by the effect of airway calibre on exhaled NO. Exhaled NO, height and forced expiratory volume in one second (FEV1) were measured in 12 steroid-naive asthmatics and 17 normal subjects. For comparison, another group of patients with airways disease (34 cystic fibrosis patients) were also studied. In 20 asthmatics (on various doses of inhaled steroids, 0-3,200 microg x day-1), exhaled NO was measured before and after histamine challenge (immediately after reaching the provocative concentration causing a 20% fall in FEV1) and in 12 of these patients, also after nebulized salbutamol to restore FEV1 to baseline. Studies were also conducted to examine possible confounding effects of repeated spirometry (as would occur in histamine challenge) and nebulized salbutamol alone in exhaled NO levels. Exhaled NO was measured using a single exhalation method with a chemiluminescence analyser at a constant flow rate and mouth pressure. There was a significant correlation between FEV1 and exhaled NO in steroid naive asthmatics (r=0.9, p<0.001) and cystic fibrosis patients (r=-0.48, p<0.05) but not in normal subjects (r=-0.13, p=0.61). Exhaled NO decreased significantly after histamine challenge and returned to baseline after bronchodilation by nebulized salbutamol (mean+/-SEM: 23.6+/-3.6 parts per billion (ppb) (prehistamine), 18.2+/-2.7 ppb (posthistamine) and 23.6+/-3.8 ppb (postsalbutamol) p=0.001). Repeated spirometry and nebulized salbutamol did not affect exhaled NO measurements significantly. Exhaled nitric oxide levels appear to be lower in circumstances of smaller airway diameter. Hence, within a subject nitric oxide levels may be artefactually decreased during bronchoconstriction. This may be caused by increased airflow velocity in constricted airways when the exhalation rate is kept constant.
This article has been cited by other articles:

|
 |

|
 |
 
D. Hubert, F. Aubourg, B. Fauroux, L. Trinquart, I. Sermet, G. Lenoir, A. Clement, A. T. Dinh-Xuan, B. Louis, B. Mahut, et al.
Exhaled nitric oxide in cystic fibrosis: relationships with airway and lung vascular impairments
Eur. Respir. J.,
July 1, 2009;
34(1):
117 - 124.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. F. Folino, M. L. Scapellato, C. Canova, P. Maestrelli, G. Bertorelli, L. Simonato, S. Iliceto, and M. Lotti
Individual exposure to particulate matter and the short-term arrhythmic and autonomic profiles in patients with myocardial infarction
Eur. Heart J.,
July 1, 2009;
30(13):
1614 - 1620.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. Ferrazzoni, M. C. Scarpa, G. Guarnieri, M. Corradi, A. Mutti, and P. Maestrelli
Exhaled Nitric Oxide and Breath Condensate pH in Asthmatic Reactions Induced by Isocyanates
Chest,
July 1, 2009;
136(1):
155 - 162.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. Verbanck, Y. Kerckx, D. Schuermans, W. Vincken, M. Paiva, and A. Van Muylem
Effect of airways constriction on exhaled nitric oxide
J Appl Physiol,
April 1, 2008;
104(4):
925 - 930.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Y. Kerckx, A. Michils, and A. Van Muylem
Airway contribution to alveolar nitric oxide in healthy subjects and stable asthma patients
J Appl Physiol,
April 1, 2008;
104(4):
918 - 924.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
P. E. Silkoff, F. A. Romero, N. Gupta, R. G. Townley, and H. Milgrom
Exhaled Nitric Oxide in Children With Asthma Receiving Xolair (Omalizumab), a Monoclonal Anti-Immunoglobulin E Antibody
Pediatrics,
April 1, 2004;
113(4):
e308 - e312.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
F L M Ricciardolo, M C Timmers, J K Sont, G Folkerts, and P J Sterk
Effect of bradykinin on allergen induced increase in exhaled nitric oxide in asthma
Thorax,
October 1, 2003;
58(10):
840 - 845.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. A. KHARITONOV and P. J. BARNES
Exhaled Markers of Pulmonary Disease
Am. J. Respir. Crit. Care Med.,
June 1, 2001;
163(7):
1693 - 1722.
[Full Text]
[PDF]
|
 |
|
Copyright © 2000 by the European Respiratory Society.
|