Published: 08-05-2014 10:29 | Updated: 08-05-2014 10:40

Breathing test improves asthma treatment

By measuring the levels of nitric oxide in exhaled air, it is possible to improve the care of asthma patients, according to a new doctoral thesis from Karolinska Institutet. A simple breathing test can quickly reveal any inflammation in the respiratory airways.

"As a result, anti-inflammatory treatment can be directed more adequately, keeping the asthma under better control as well as reducing the risk of the patient getting worse", says Dr. Jörgen Syk, a general practitioner affiliated to the Centre for Family Medicine in Stockholm, and author of the current thesis.

Approximately 8% of Swedish people suffer from asthma, and a majority are treated within the primary healthcare system. In spite of inflammation being regarded as the underlying cause of asthma, diagnosis and treatment are based mainly on symptoms and lung function. This new thesis, however, shows that by measuring the so-called fraction of exhaled nitric acid (expressed as FENO), it is possible to receive valuable information about the level of inflammation in the respiratory airways and thus adapt treatment to the patient’s individual needs.

More than 180 patients

"This is the first time a study has been conducted in primary care to evaluate the benefit of controlling the anti-inflammatory treatment with FENO", comments Dr. Syk. "The results are promising and indicate that we should use this method in general practice."

The study included a little more than 180 patients aged 18 to 64 years and suffering from allergic asthma. They were randomized into two separate groups. In the first group, anti-inflammatory treatment was controlled with FENO, and in the second group, treatment was conducted in the traditional way. Participants were monitored five times during a one-year period.

The results show that participants in the group treated with the use of FENO had fewer symptoms of asthma, for example shortness of breath wheezing, and fewer periods of disease exacerbation, than the second group. The effect was achieved without increasing the average use of inhaled cortisone or bronchodilators by adjusting the treatment, so that patients with a low FENO were prescribed lower doses of their medication, while those with higher levels of FENO received higher doses. Another interesting finding was that when anti-inflammatory treatment was intensified, the concentration of the so-called IgE anti-body, mediating the allergy, decreased.

Improve diagnosis

According to Dr. Syk using FENO measurement can improve diagnosis and the detection of noncompliance of recommended treatment, a significant problem among asthma sufferers:

"Many people don't take their medication regularly, because they don't understand the benefit or because they are afraid of side-effects", he says. "When it’s possible to show an actual measured result, the patient gets an increased understanding of the disease, which in turn increases the motivation to follow treatment recommendations."

In the studies of the current thesis, a NIOX MINO apparatus was used to measure FENO. This device is easy to use, and does not inflict any discomfort on the patient. Dr. Syk points out, however, that a certain level of basic knowledge is required to be able to draw the correct conclusions, as the FENO result can easily be compromised by for example smoking, if the patient has a cold or by exposure to an allergen.

This research was conducted in close collaboration with researchers at Uppsala University. The Centre for Family Medicine is a partnership between Karolinska Institutet and Stockholm County Council.

Doctoral thesis

Treatment of atopic asthma in primary health care guided by exhaled nitric oxide measurement
Jörgen Syk
Karolinska Institutet 2014, ISBN: 978-91-7549-459-3