Measurement of lung function in awake 2–4‐year‐old asthmatic children during methacholine challenge and acute asthma: A comparison of the impulse oscillation technique, the interrupter technique, and transcutaneous measurement of oxygen versus whole‐body plethysmography

Resistance and reactance in oscillation lung function reflect basal lung function and bronchial hyperresponsiveness respectively

“…10,12,17 However, other studies using bronchial challenge testing have suggested that X5 provides the best discrimination. 9,13 The present study demonstrated that baseline X5 (Pre) was significantly decreased in asthmatic compared with control subjects when predicted values were used. However, baseline R5 (Pre) showed a greater decrease than X5, using the predicted values; this finding implies that baseline lung function in patients with mild asthma is better reflected by R5 rather than X5.…”

“…25 However, many studies have recently used IOS to evaluate non-specific bronchial challenge tests in paediatric patients, because forced expiratory manoeuvres are usually difficult for these patients. 9,[13][14][15]26 Snashall et al 26 showed that IOS measures were more sensitive than FEV1, because positive reactions were observed following the administration of lower concentrations of histamine. Broeders et al 18 conducted a study in which FOT and FEV1 were compared in methacholine challenge tests; FOT showed positive reactions at lower concentrations of methacholine and had fewer complications.…”

Decreased lung function after preschool wheezing rhinovirus illnesses in children at risk to develop asthma

“…However, success rates for IOS and spirometry were similar in our study in contrast to other studies where children as young as 2 years were able to perform IOS. 10,24 This may be because in our study, spirometry and IOS were performed only once a year and with no further attempts at training the children between visits. Our findings suggest that both IOS and spirometry can be used in a complementary fashion in a clinical setting since 80% of children were able to successfully perform either IOS or spirometry by age 5 years, and the ability to complete one test was not associated with the ability to complete the other.…”

Study on small airway function in asthmatics with fractional exhaled nitric oxide and impulse oscillometry

“…28 IOS has been demonstrated that it is not complicated to assess small airway function in asthmatic patients. 29 Some parameters of IOS are available. The respiratory resistance at 5 Hz (R5) and 20 Hz (R20) are thought to be on behalf of the total and central airway resistance, respectively, and the difference between them (R5-R20) is considered to represent peripheral airway resistance.…”