Published in

Karger Publishers, International Archives of Allergy and Immunology, 1(183), p. 105-115, 2021

DOI: 10.1159/000518320

Links

Tools

Export citation

Search in Google Scholar

Alveolar Nitric Oxide and Peripheral Oxygen Saturation in Frequent Exacerbators with Asthma: A Pilot Study

This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Green circle
Preprint: archiving allowed
Green circle
Postprint: archiving allowed
Red circle
Published version: archiving forbidden
Data provided by SHERPA/RoMEO

Abstract

<b><i>Introduction</i></b>: Asthmatics can experience recurrent exacerbations (AEs), irrespectively of asthma severity. Airway inflammatory monitoring could be fundamental to optimize the asthma management. The present study evaluated whether exhaled NO concentrations in proximal and distal respiratory compartments are different in AE-prone patients in combination with T2 blood biomarkers and resting oxygen saturation (SpO<sub>2</sub>). <b><i>Methods</i></b>: In this observational cross-sectional study, 91 mild-to-severe asthmatics were enrolled. Clinical characteristics, blood and lung function parameters including SpO<sub>2</sub>, and F<sub>E</sub>NO were evaluated. On 50 randomly selected patients, C<sub>A</sub>NO and J<sub>aw</sub>NO were also analyzed. Then, patients were stratified in frequent exacerbators (FEs) or non-frequent exacerbators (nFEs), according to AE frequency in the previous year (phase I). Chart data were re-evaluated through a 12-month follow-up period post exhaled NO measurement to detect occurrence of novel AE (phase II). <b><i>Results</i></b>: FE asthmatics had poorer asthma control and required higher therapeutic intensity (<i>p</i> &#x3c; 0.05). F<sub>E</sub>NO, C<sub>A</sub>NO, and J<sub>aw</sub>NO were similar between FE and nFE. FE exhibited higher total serum IgE levels and residual volume values but reduced SpO<sub>2</sub> than nFE (<i>p</i> &#x3c; 0.05); SpO<sub>2</sub>&#x3c;96.5% characterized the FE patient (odds ratio = 2.94). In phase II, C<sub>A</sub>NO was higher in the group with novel AE at 1-month post-NO measurement (<i>p</i> &#x3c; 0.05), but not afterward. A higher prevalence of C<sub>A</sub>NO &#x3e;6 ppb was detected in asthmatics who developed AE within 1 month, suggesting its potential clinical use as biomarker in predicting near-future AE (RR = 11.20). <b><i>Conclusion</i></b>: AE-susceptible asthmatics are characterized by air trapping and distal airway inflammation in conjunction with lower oxygen saturation. C<sub>A</sub>NO and SpO<sub>2</sub> could exert specific roles, respectively, in predicting AE and monitoring FE asthmatics.