The following is a summary of “Fractional exhaled Nitric Oxide (FeNO)- test as add-on test in the diagnostic work-up of asthma: a study protocol,” published in the April 2024 issue of Pulmonology by Kaya et al.

Asthma, a prevalent condition characterized by chronic lower airway inflammation, bronchial hyperreactivity, and reversible airway obstruction, presents diagnostic challenges despite established guidelines. The Global Initiative of Asthma Guideline outlines a diagnostic flowchart, advocating for spirometry followed by bronchial challenge tests (BPT) with histamine or methacholine as a secondary step. 

However, BPTs are associated with significant drawbacks, including time-consuming procedures, potential side effects, and substantial financial costs, thereby imposing burdens on patients and healthcare providers and limiting lung function capacity. Notably, elevated Nitric Oxide (NO) levels correlate with airway eosinophilic inflammation in asthma. This offers a promising avenue for diagnostic refinement through the Fractional exhaled (Fe) NO-test, which measures NO levels in exhaled breath with minimal imposition. This prospective, multi-center study (Trial number: NCT06230458) seeks to evaluate the efficacy of integrating the FeNO-test into the diagnostic algorithm as an intermediary step between spirometry with reversibility and BPT. By comparing the traditional asthma diagnostic approach with this novel strategy, the study aims to assess the FeNO-based approach’s impact on reducing the need for BPTs, its cost-effectiveness, and its capacity to alleviate patient and healthcare burdens. 

Cost reductions associated with the FeNO-test will be quantified based on the potential reduction in the number of BPTs required. Additionally, the study will evaluate patient-reported outcomes, including changes in Visual Analogue Scale (VAS) scores and Asthma Quality of Life Questionnaire (AQLQ) scores following FeNO testing and BPTs, using independent T-tests. Furthermore, the FeNO-test’s diagnostic accuracy will be determined by comparing its outcomes with those of BPTs, gauging sensitivity and specificity. With an intended enrollment of 171 patients, this study offers valuable insights into optimizing asthma diagnostic protocols by integrating FeNO testing, streamlining procedures, and improving patient care.

Source: bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-024-02990-2