The sensitivity and specificity of the forced oscillation technique in the diagnosis of bronchoconstriction in children.

OBJECTIVE: The forced oscillation technique (FOT) is a useful diagnostic respiratory system for children. However, the final value of the FOT in the diagnosis of bronchoconstriction is still open. The aim of the study was to evaluate the sensitivity and specificity of the FOT vs. body plethysmography tests in the measure of bronchoconstriction in asthmatic children. MATERIALS AND METHODS: A total of 102 children aged 2 to 6 years diagnosed with early-onset asthma and 52 healthy controls were included in this prospective, randomized study. All asthmatic patients and healthy controls underwent a basic FOT as one measurement, according to the recommendation of the Resmon Pro FOT. Then, the reversibility test was performed 20 min after the administration of 200 mg salbutamol using the FOT and body plethysmography in all patients. RESULTS: The mean basic Rrs, Xrs and sRaw in asthmatic patients were, respectively, 11.13 ± 1.28 kPa sL-1, -4.6 ± 1.18 kPa sL-1 and 1.72 ± 0.58 kPa s. Similar parameters were significantly better in the control group (p < 0.05). A total of 73 (71.6%) asthmatic patients had a positive test using the FOT according to Calogero. In 4 (7.7%) patients in the control group, a positive test was obtained. In body plethysmography, similar results were reached, with a positive test in 76 (74.5%) study patients and 5 (9.6%) control patients. CONCLUSIONS: A bronchial reversibility test with the use of the FOT is useful for the diagnosis of bronchial asthma, especially with the use of an Rrs parameter, such as the body plethysmography test.

The Usefulness of the Forced Oscillation Technique in the Diagnosis of Bronchial Asthma in Children.

The forced oscillation technique (FOT) requires minimal patient cooperation and is useful for children. However, comprehensive values of respiratory impedance at baseline and after the reversibility test have not been definitively confirmed. The aim of this study was to evaluate the basic parameters of FOT reactance (Xrs) and resistance (Rrs) in groups of healthy children and children with controlled and uncontrolled asthma. The second aim was the assessment of the reversibility bronchial test using the forced oscillation method in children with bronchial asthma. Materials and Methods. One hundred and six children aged from 2 to 6 years diagnosed with early-onset controlled or uncontrolled asthma and healthy controls were included in this single-center, prospective, randomized study. All asthmatic patients and healthy controls underwent basic FOT as one measurement according to the recommendation of Resmon Pro FOT. The reversibility test was then performed 15 min after the administration of 200 mcg salbutamol by MDI in all patients. Results. Basic Rrs showed significantly higher mean values in patients with uncontrolled asthma compared to patients with controlled asthma, which were in turn higher than the values for patients in the control group (11.14 ± 1.29 versus 15.71 ± 2.6 versus 9.21 ± 0.98, resp.; p < 0.05). The data analysis showed similar relationships in terms of the Xrs between the studied groups (-4.76 ± 1.19 versus -7.31 ± 2.33 versus -2.11 ± 0.48, resp.; p < 0.05). According to the changes in the Rrs values, 35 (66%) positive bronchial reversibility tests were obtained in 53 subjects with controlled asthma and in 39 (74%) subjects with uncontrolled asthma. Conclusions. Rrs and Xrs obtained by FOT well-discriminate patients with asthma from healthy children. A bronchial reversibility test involving the use of FOT is valuable for the diagnosis of bronchial asthma.