Increased alveolar nitric oxide by trumpet model in patients with obstructive sleep apnoea

Background We assessed distal/alveolar inflammation in patients with suggestive symptoms of obstructive sleep apnoea (OSA) and measured exhaled alveolar concentration of nitric oxide (CANO) using 2-compartment model (2-CM) and the trumpet model (with correction for axial NO back-diffusion). Methods Ninety five patients suspected for OSA without advanced cardio-respiratory disease underwent pulmonary function test, overnight polysomnography, and exhaled NO measurement using 2-CM model and the trumpet model. Patients with apnoea-hypopnoea index (AHI) Results CANO was significantly higher in OSA patients (n=71; 4.07±1.7ppb) as compared with controls (n=24; 2.24±1.06ppb; p 1%) was 0.855 (0.777-0.933) (p Conclusions Increased alveolar NO concentration was related to the severity of nocturnal oxygen desaturation in patients with OSA, linking the distal lung inflammation to intermittent hypoxia. CANO could be used to screen for severe OSA in suspected and symptomatic patients.