Exhaled Nitric Oxide (FeNO) in Patients Hospitalized for an Exacerbation of Bronchiectasis and/or COPD

Exhaled nitric oxide (FeNO) represents an important marker of airway inflammation, yet its role in chronic obstructive pulmonary disease (COPD) and/or bronchiectasis is not well studied. We aimed to measure FeNO in patients with COPD, bronchiectasis, and combination of COPD/bronchiectasis during an acute exacerbation (AE) of the underlying disease as well as to describe the characteristics of patients with COPD/bronchiectasis overlap in patients hospitalized for an acute exacerbation (AE). Seventy-nine patients were enrolled in the study as follows: COPD n = 45, bronchiectasis n = 18, and COPD and bronchiectasis n = 16. FeNO was measured with a commercially available analyzer within 24 hours of admission and at discharge. FeNO differed significantly on admission when compared at discharge in the whole group (16.91 ± 16.14 vs 12.48 ± 10.67, p = 0.008, respectively). On admission, FeNO was 17.80 ± 18.77 ppb in COPD patients, 17.12 ± 6.59 in bronchiectasis patients, and 11.55 ± 2.42 in patients with COPD/bronchiectasis overlap. At discharge, FeNO was 12.40 ± 12.11 ppb in COPD patients, 15.50 ± 6.39 in bronchiectasis patients, and 9.00 ± 3.22 in patients with combination. FeNO differed significantly in bronchiectasis patients versus patients with COPD/bronchiectasis overlap at admission (p = 0.043) and at discharge (p = 0.020) and versus COPD patients at discharge (p = 0.043). FeNO decreased significantly during the AE in all groups (p = 0.001 for COPD, p = 0.021 for bronchiectasis, and p = 0.026 for combination). FeNO levels in patients with COPD and/or bronchiectasis exacerbation are possibly increased at admission and decrease at discharge. The differences in FeNO levels between groups may reflect different underlying inflammatory mechanisms.