title: Exhaled nitric oxide predicts control in patients with difficult-to-treat asthma.
abstract: We aimed to evaluate the accuracy of baseline exhaled nitric oxide fraction (F(eNO)) to recognise individuals with difficult-to-treat asthma who have the potential to achieve control with a guideline-based stepwise strategy. 102 consecutive patients with suboptimal asthma control underwent stepwise increase in the treatment with maximal fluticasone/salmeterol combination dose for 1 month. Then, those who remained uncontrolled received oral corticosteroids for an additional month. With this approach, 53 patients (52%) gained control. Those who achieved control were more likely to have positive skin results (60.4% versus 34%; p = 0.01), positive bronchodilator test (57.1% versus 35.8%; p = 0.02) and peak expiratory flow variability > or =20% (71.1% versus 49.1%; p = 0.04). Conversely, depression was more frequent in those who remained uncontrolled (18.4 % versus 43.4 %; p = 0.01). An F(eNO) value > or =30 ppb demonstrated a sensitivity of 87.5% (95% CI 73.9-94.5%) and a specificity of 90.6% (95% CI 79.7-95.9%) for the identification of responsive asthmatics. The current results suggest that F(eNO) can identify patients with difficult-to-treat asthma and the potential to respond to high doses of inhaled corticosteroids or systemic steroids.
authors.affiliation: Pneumology Service, Hospital Xeral-Calde, c/Dr Ochoa, s/n. 27004 Lugo, Spain. eremos26@hotmail.com
authors.forename: L A
authors.initials: LA
authors.lastname: Pérez-de-Llano
authors.forename: F
authors.initials: F
authors.lastname: Carballada
authors.forename: O
authors.initials: O
authors.lastname: Castro Añón
authors.forename: M
authors.initials: M
authors.lastname: Pizarro
authors.forename: R
authors.initials: R
authors.lastname: Golpe
authors.forename: A
authors.initials: A
authors.lastname: Baloira
authors.forename: M
authors.initials: M
authors.lastname: Vázquez Caruncho
authors.forename: M
authors.initials: M
authors.lastname: Boquete
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000420:Albuterol / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000730:Androstadienes / Q000627:therapeutic use*; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use*; D001007:Anxiety / Q000175:diagnosis; D001249:Asthma / Q000175:diagnosis* / Q000188:drug therapy* / Q000378:metabolism; D001944:Breath Tests / Q000379:methods*; D001993:Bronchodilator Agents; D003863:Depression / Q000175:diagnosis; D004338:Drug Combinations; D016903:Drug Monitoring / Q000379:methods; D004351:Drug Resistance; D004359:Drug Therapy, Combination; D005260:Female; D000068297:Fluticasone-Salmeterol Drug Combination; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism*; D010366:Peak Expiratory Flow Rate / Q000187:drug effects; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013147:Spirometry
chemical_list: D000305:Adrenal Cortex Hormones; D000730:Androstadienes; D018927:Anti-Asthmatic Agents; D001993:Bronchodilator Agents; D004338:Drug Combinations; D000068297:Fluticasone-Salmeterol Drug Combination; D009569:Nitric Oxide; D000420:Albuterol