Frank is 65 and has been diagnosed with COPD.
He has a previous smoking history of 25 pack-years. He has no allergies, and reports that his breathing difficulties began 5 years ago. Frank has been on inhaled corticosteroid (ICS) therapy with fluticasone (100μg twice daily).
Frank is generally compliant with his ICS regimen. He describes his condition as relatively constant, with periods of worsening during airway infections.
• FEV1 is 42% of expected, with 6% reversibility.
• FENO is 10 ppb.
• Is Frank’s COPD becoming more severe?
• Should he continue taking ICS?
Current treatment guidelines for COPD entail two separate, lengthy processes for administering ICS: a “trial of steroid”, whereby spirometric improvement is measured at a later date; or an observation of repeated exacerbations over a period of years. The situation can be complicated by the fact that patients with COPD may have been previously prescribed ICS according to unknown criteria, and the relevance of those criteria may not be clear to the treating physician. Although FENO is not routinely measured in patients with COPD, evidence suggests it can provide additional information about disease severity, prognosis, and possible response to anti-inflammatory therapy, and may help to determine whether ICS treatment is necessary.
Frank’s doctor tells him to stop taking his ICS medication.
After initially dropping, Frank’s FENO value rises to 15 ppb over the course of 7 weeks. He reports no worsening of symptoms.
The modest increase in Frank’s FENO value, coupled with his stable symptoms, suggests that his COPD is well-controlled, and is not severe enough to warrant continuation of ICS therapy.