Practical assessment of asthma severity remains elusive

Recently, Rachael Zimlich, RN, reviewed a study published in Pediatric Pulmonology that discussed predicted FEV₁% and its correlation with more severe forms of asthma and as a predictor of poorer control of symptoms.¹ The premise of the study is that bronchodilator response can be both a diagnostic test and a test to asses severity. Change in lung function test has been used historically as confirmation of a diagnosis of asthma, but the idea of the amount of change in FEV₁% from baseline is novel.

The study measured both spirometry and fractional exhaled nitric oxide (FeNO) at baseline and then after bronchodilator administration. A change in over or equal to 12% in FEV₁ was considered a positive test. Patients with higher reversibility were found to have more severe forms of asthma. Increased FeNO and secondhand smoke also were found to be related to more severe forms of asthma. These numbers are interesting but probably of little help to primary pediatric providers with the possible exception of FeNO testing.

Study is helpful but difficult to replicate

Most primary care providers struggle to obtain baseline spirometry testing due to many factors including lack of staff training, lack of affordable equipment, and time constraints. Testing spirometry after bronchodilators is an even more time-consuming process that most primary pediatric providers do not have time in their schedules to perform. Fractional exhaled nitric oxide testing in the primary care office is quick and relatively easy and can show many of the same things discussed in the article. Spirometry without bronchodilators and nitric oxide testing seem to be the mainstay of asthma testing in most primary care practices.

Pediatric pulmonology practices may find the study more useful and be able to study reversibility with more accuracy and consistency. Both spirometry and FeNO testing have an age limit of 6 years and older in this study and usually in practical application. Patients aged younger than 6 years often struggle with spirometry testing. Exhaled nitric oxide testing seems to a little easier for younger patients but still can be a challenge to obtain.

Testing such as spirometry and the nitric oxide test are only part of diagnosing and managing asthma. Thorough history and use of proven questionnaires such as the Asthma Control Test are essential.

Younger patients often are a challenge to diagnosis. Parents can be skeptical of the diagnosis and adherence to medications is often poor. I hope that in the future we will be able to diagnose asthma sooner and increase compliance in all age groups. 

Mr. Smith, Member-at-Large and Board Member for SPAP, received his Bachelor of Science in Biology from Georgia Southwestern College in Americus, Georgia, next attending the University of Georgia for master’s work in education and later Emory University Physician Assistant school from which he obtained his Master of Medical Science.

In addition to membership in SPAP, Mr. Smith is also a member of the Georgia Association of Physician Assistants, American Academy of Physician Assistants, and the American Academy of Pediatrics. He is credentialed at Piedmont Columbus Regional Hospital where he chairs the Pediatric Preparedness Committee. He also is a Co-Trainer for the Pediatric Readiness Quality Collaborative, a national program through the Emergency Medical Services for Children.

In December of 2014, Mr. Smith earned a Certificate of Added Qualifications in Pediatrics from the National Commission on Certifications of Physician Assistants (NCCPA). This certification is in addition to his certification from the NCCPA and demonstrates knowledge and skills specific to pediatrics. He is married to Renee Smith, also a Physician Assistant, and they have one child, Emma.

References:

1. Zimlich R. Bronchodilators can help assess asthma severity. Contemp Pediatr. 2020;37(1):23,25.