Fractional Exhaled Nitric Oxide Testing: Change in Clinical Management of Asthma, or Chronic Obstructive Pulmonary

Asthma and chronic obstructive pulmonary disease (COPD) are common airway inflammatory conditions that can present in isolation or a combination known as asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS). Due to similarities in clinical presentation, differentiating these conditions can be challenging. Fractional exhaled nitric oxide (FeNO) is an endogenous molecule that can be elevated in patients with airway inflammation, particularly asthma. The purpose of this study was to determine if FeNO levels can be used to change pharmacologic management (addition, in patients presenting with asthma, COPD, and ACOS. A retrospective chart review of 250 patients underwent FeNO testing; 93 patients were included in the final analysis with their FeNO levels and medications. Out of 76 patients, 34 were prescribed medications of interest (inhaled corticosteroids (ICS), Inhaled corticosteroids - long-acting beta-agonists (ICS-LABA), anticholinergics (AC) monotherapy or combination therapy). After the FeNO testing, the number of patients on ICS therapy doubled (8 to 16), and the number of patients on ICS -LABA increased by 69.2%. Lastly, the number of patients not on medication of interest, 57.1%, ended up on one after FeNO testing. Our results support the utility of FeNO as a viable test to manage patients with obstructive lung disease.