title: Correlation of exhaled breath temperature with bronchial blood flow in asthma.
abstract: In asthma elevated rates of exhaled breath temperature changes (Deltae degrees T) and bronchial blood flow (Qaw) may be due to increased vascularity of the airway mucosa as a result of inflammation.We investigated the relationship of Deltae degrees T with Qaw and airway inflammation as assessed by exhaled nitric oxide (NO). We also studied the anti-inflammatory and vasoactive effects of inhaled corticosteroid and beta2-agonist.Deltae degrees T was confirmed to be elevated (7.27 +/- 0.6 Delta degrees C/s) in 19 asthmatic subjects (mean age +/- SEM, 40 +/- 6 yr; 6 male, FEV1 74 +/- 6 % predicted) compared to 16 normal volunteers (4.23 +/- 0.41 Delta degrees C/s, p < 0.01) (30 +/- 2 yr) and was significantly increased after salbutamol inhalation in normal subjects (7.8 +/- 0.6 Delta degrees C/ s, p < 0.05) but not in asthmatic patients. Qaw, measured using an acetylene dilution method was also elevated in patients with asthma compared to normal subjects (49.47 +/- 2.06 and 31.56 +/- 1.6 mul/ml/min p < 0.01) and correlated with exhaled NO (r = 0.57, p < 0.05) and Deltae degrees T (r = 0.525, p < 0.05). In asthma patients, Qaw was reduced 30 minutes after the inhalation of budesonide 400 mug (21.0 +/- 2.3 mul/ml/min, p < 0.05) but was not affected by salbutamol.Deltae degrees T correlates with Qaw and exhaled NO in asthmatic patients and therefore may reflect airway inflammation, as confirmed by the rapid response to steroids.
authors.affiliation: Department of Thoracic Medicine, National Heart and Lung Institute, Faculty of Medicine, Imperial College, London, UK. p.paredi@imperial.ac.uk
authors.forename: Paolo
authors.initials: P
authors.lastname: Paredi
authors.forename: Sergei A
authors.initials: SA
authors.lastname: Kharitonov
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Barnes
mesh_terms: D000328:Adult; D001249:Asthma / Q000503:physiopathology*; D001783:Blood Flow Velocity; D001944:Breath Tests; D001980:Bronchi / Q000098:blood supply* / Q000503:physiopathology*; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D013223:Statistics as Topic; D013696:Temperature