Measuring exhaled nitric oxide in COPD: from theoretical consideration to practical views.

Introduction: Chronic obstructive pulmonary disease (COPD) is traditionally perceived as Th1-inflammation, but some patients have Th2-inflammation. A high fraction of exhaled nitric oxide (FE) is seen in asthma with Th2-inflammation, justifying FE as a point-of-care biomarker. The use of FE in COPD is much less frequent.

Deciphering Alveolo-Capillary Gas Transfer Disturbances in Patients Recovering from COVID-19 Lung Disease.

Impaired lung gas exchange is commonly seen in patients with pulmonary involvement related to SARS-CoV-2 acute infection or post-acute COVID-19 syndrome (PACS). The primary aim of our study was to assess lung gas transfer, measuring the pulmonary diffusion capacity for nitric oxide (D) and carbon monoxide (D) in all COVID-19 patients. Our secondary aim was to decipher the respective roles of perturbed lung membrane conductance (D) and reduced pulmonary capillary volume (V) in patients with impaired lung gas exchange.