Abstract
Introduction: Central airway nitric oxide flux (J′awNO) and peripheral airway/alveolar nitric oxide concentration (CANO) during asthma exacerbation has not been investigated after correction for axial NO back-diffusion. Methods: After measuring exhaled NO (fraction of exhaled nitric oxide (FENO); ppb) at 50, 100, 150 and 200 ml/s, J′awNO (nl/s) and CANO (ppb) were calculated using the two-compartment model and corrected for axial NO back-diffusion. Fifteen (8 males), non-smoking, patients with moderate-to-severe treated (inhaled corticosteroid (ICS) and inhaled long-acting β2-agonist (LABA)) asthma, age 57±13 years (mean±SD), were studied at baseline, during exacerbation prior to oral corticosteroid, and during recovery after an 8 day tapering prednisone course. Based on earlier asthma studies without correction, it was hypothesised that with correction for NO axial back-diffusion, the incidence of abnormal J′awNO and C ANO at baseline and after exacerbation would be ≥30% in 15 patients with asthma with 80% power. Results: At baseline when clinically stable, after 180 μg of albuterol, forced expiratory volume in 1 s (FEV 1; litres) was 78±26% predicted (p=0.009) with increased FENO at 50 ml/s (p=0.01) and J′awNO (p=0.02), but CANO was normal compared with the controls. During exacerbation FEV1 (litres) was 57±20% predicted (p=0.02), with increased FENO at 50 ml/s (p=0.01) and J′awNO (p=0.004), but CANO was normal. Recovery results were similar to baseline. Two of 15 patients with asthma always had normal exhaled NO gas exchange. Conclusions: The central airways were the major site of abnormal NO flux in 13 of 15 patients with moderate - severe asthma when stable and during exacerbation and could be easily detected with abnormal FENO at 50 ml/s. CANO was normal. Clinical trial number: NCT00576069.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 619-625 |
| Number of pages | 7 |
| Journal | Thorax |
| Volume | 65 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jan 1 2010 |
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ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
Cite this
Central and peripheral airway/alveolar sites of exhaled nitric oxide in acute asthma. / Gelb, Arthur F.; George, Steven; Silkoff, Philip E.; Krishnan, Anita; Fraser, Christine; Taylor, Colleen Flynn; Shinar, Chris M.; Maginot, Tamara.
In: Thorax, Vol. 65, No. 7, 01.01.2010, p. 619-625.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Central and peripheral airway/alveolar sites of exhaled nitric oxide in acute asthma
AU - Gelb, Arthur F.
AU - George, Steven
AU - Silkoff, Philip E.
AU - Krishnan, Anita
AU - Fraser, Christine
AU - Taylor, Colleen Flynn
AU - Shinar, Chris M.
AU - Maginot, Tamara
PY - 2010/1/1
Y1 - 2010/1/1
N2 - Introduction: Central airway nitric oxide flux (J′awNO) and peripheral airway/alveolar nitric oxide concentration (CANO) during asthma exacerbation has not been investigated after correction for axial NO back-diffusion. Methods: After measuring exhaled NO (fraction of exhaled nitric oxide (FENO); ppb) at 50, 100, 150 and 200 ml/s, J′awNO (nl/s) and CANO (ppb) were calculated using the two-compartment model and corrected for axial NO back-diffusion. Fifteen (8 males), non-smoking, patients with moderate-to-severe treated (inhaled corticosteroid (ICS) and inhaled long-acting β2-agonist (LABA)) asthma, age 57±13 years (mean±SD), were studied at baseline, during exacerbation prior to oral corticosteroid, and during recovery after an 8 day tapering prednisone course. Based on earlier asthma studies without correction, it was hypothesised that with correction for NO axial back-diffusion, the incidence of abnormal J′awNO and C ANO at baseline and after exacerbation would be ≥30% in 15 patients with asthma with 80% power. Results: At baseline when clinically stable, after 180 μg of albuterol, forced expiratory volume in 1 s (FEV 1; litres) was 78±26% predicted (p=0.009) with increased FENO at 50 ml/s (p=0.01) and J′awNO (p=0.02), but CANO was normal compared with the controls. During exacerbation FEV1 (litres) was 57±20% predicted (p=0.02), with increased FENO at 50 ml/s (p=0.01) and J′awNO (p=0.004), but CANO was normal. Recovery results were similar to baseline. Two of 15 patients with asthma always had normal exhaled NO gas exchange. Conclusions: The central airways were the major site of abnormal NO flux in 13 of 15 patients with moderate - severe asthma when stable and during exacerbation and could be easily detected with abnormal FENO at 50 ml/s. CANO was normal. Clinical trial number: NCT00576069.
AB - Introduction: Central airway nitric oxide flux (J′awNO) and peripheral airway/alveolar nitric oxide concentration (CANO) during asthma exacerbation has not been investigated after correction for axial NO back-diffusion. Methods: After measuring exhaled NO (fraction of exhaled nitric oxide (FENO); ppb) at 50, 100, 150 and 200 ml/s, J′awNO (nl/s) and CANO (ppb) were calculated using the two-compartment model and corrected for axial NO back-diffusion. Fifteen (8 males), non-smoking, patients with moderate-to-severe treated (inhaled corticosteroid (ICS) and inhaled long-acting β2-agonist (LABA)) asthma, age 57±13 years (mean±SD), were studied at baseline, during exacerbation prior to oral corticosteroid, and during recovery after an 8 day tapering prednisone course. Based on earlier asthma studies without correction, it was hypothesised that with correction for NO axial back-diffusion, the incidence of abnormal J′awNO and C ANO at baseline and after exacerbation would be ≥30% in 15 patients with asthma with 80% power. Results: At baseline when clinically stable, after 180 μg of albuterol, forced expiratory volume in 1 s (FEV 1; litres) was 78±26% predicted (p=0.009) with increased FENO at 50 ml/s (p=0.01) and J′awNO (p=0.02), but CANO was normal compared with the controls. During exacerbation FEV1 (litres) was 57±20% predicted (p=0.02), with increased FENO at 50 ml/s (p=0.01) and J′awNO (p=0.004), but CANO was normal. Recovery results were similar to baseline. Two of 15 patients with asthma always had normal exhaled NO gas exchange. Conclusions: The central airways were the major site of abnormal NO flux in 13 of 15 patients with moderate - severe asthma when stable and during exacerbation and could be easily detected with abnormal FENO at 50 ml/s. CANO was normal. Clinical trial number: NCT00576069.
UR - http://www.scopus.com/inward/record.url?scp=77955294728&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77955294728&partnerID=8YFLogxK
U2 - 10.1136/thx.2009.132696
DO - 10.1136/thx.2009.132696
M3 - Article
C2 - 20627920
AN - SCOPUS:77955294728
VL - 65
SP - 619
EP - 625
JO - Thorax
JF - Thorax
SN - 0040-6376
IS - 7
ER -