Outcomes using exhaled nitric oxide measurements as an adjunct to primary care asthma management.
BACKGROUND
Exhaled nitric oxide (FENO) measurements may help to highlight when inhaled corticosteroid (ICS) therapy should or should not be adjusted in asthma. This is often difficult to judge. Our aim was to evaluate a decision-support algorithm incorporating FENO measurements in a nurse-led asthma clinic.


METHODS
Asthma management was guided by an algorithm based on high (>45ppb), intermediate (30-45ppb), or low (<30ppb) FENO levels and asthma control status. This provided for one of eight possible treatment options, including diagnosis review and ICS dose adjustment.


RESULTS
Well controlled asthma increased from 41% at visit 1 to 68% at visit 5 (p=0.001). The mean fluticasone dose decreased from 312 mcg/day at visit 2 to 211mcg/day at visit 5 (p=0.022). There was a high level of protocol deviations (25%), often related to concerns about reducing the ICS dose. The % fall in FENO associated with a change in asthma status from poor control to good control was 35%.


CONCLUSIONS
An FENO-based algorithm provided for a reduction in ICS doses without compromising asthma control. However, the results may have been influenced by the education and support which patients received. Reluctance to reduce ICS dose was an issue which may have influenced the overall results.


BACKGROUND
Australian Clinical Trials Registry # 012605000354684.
Hewitt
Richard S
RS
Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
Modrich
Catherine M
CM
Cowan
Jan O
JO
Herbison
G Peter
GP
Taylor
D Robin
DR
D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000465:Algorithms; D000704:Analysis of Variance; D001249:Asthma / Q000188:drug therapy*; D015415:Biomarkers / Q000032:analysis; D002648:Child; D016903:Drug Monitoring; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D009569:Nitric Oxide / Q000032:analysis*; D017063:Outcome Assessment, Health Care; D011320:Primary Health Care; D016032:Randomized Controlled Trials as Topic
D000305:Adrenal Cortex Hormones; D015415:Biomarkers; D009569:Nitric Oxide