The purpose of this presentation is to examine the utility of exhaled nitrous oxide (eNO) as a measure of asthma control.
The data presented here are baseline assessments from a prospective treatment study of children with moderate persistent asthma who by history were well controlled. On enrollment into the study we collected baseline data on the children’s medical history, conducted a brief physical examination and collected standard pulmonary function measures. Enrollment criteria were: between the ages of 8 to 14, moderate persistent but stable asthma, no respiratory tract infections or hospitalizations for the last two months, and no use of oral steroids for the previous 3 months.
We present baseline data on 35 children in this ongoing study. Sixty percent of the children were male, their average age was 10.3 (SD=1.7). Two-thirds of the children were Caucasian, one third were Hispanic. At baseline their FVC% predicted was 104% (SD=12.4), FEV1 % predicted was 81.98% (SD 7.17), and FEV25-75% predicted was 88.26% (SD = 29.29). Forty-three percent had been admitted to a hospital at least once overnight for asthma, and 17% had been admitted to intensive care for asthma symptoms. Their average eNO was 9.98 (range 3.2 to 27.2, SD=6.30). eNO values significantly correlated only with recent cold, FEV1 and, by history, number of times admitted overnight to a hospital for asthma symptoms.CONCLUSIONS: In this sample of children with moderate persistent asthma, eNO did not correlate to asthma control as measured by pulmonary function, other than FEV1. eNO was also not correlated to physical exam findings or use of inhaled steroids.
eNO may be useful as a broader screening tool for asthma control, rather than as a clinical indicator of asthma severity in children with moderate controlled asthma.
J. Mark, None.