The role of impulse oscillometry in the management of asthma when forced expiratory maneuvers are contraindicated: case series and literature review

Abstract

Objectives: The impulse oscillometry system (IOS) provides an alternative method of lung function testing for patients in whom forced expiratory manoeuvres are contraindicated, such as those with inherited vascular connective tissue disorders. Here we examine the role of IOS in the diagnosis and monitoring of asthma in such patients through a clinical case series and literature review. Methods: The clinical case series comprised of data from 12 patients with inherited connective tissue disorders representing 32 clinical encounters. Of these, 11 encounters were for asthma diagnosis and 21 were for asthma monitoring. Symptoms, exhaled nitric oxide (FeNO) and IOS were assessed at each encounter. Results: In the clinical case series, 5 of 6 patients with likely asthma (as determined by physician review and exhaled nitric oxide testing) had abnormal IOS parameters compared with 0 of 5 of those with unlikely asthma. In the monitoring group, 11 encounters resulted in treatment escalation (demonstrating suboptimal control), and 8 resulted in no change to treatment (good control). Six of 11 of those with suboptimal control had abnormalities in ≥3 IOS parameters, with R5 and R5-20 most frequently affected. Only 1 of 8 of those with good control had abnormalities in ≥3 IOS parameters. Conclusions: IOS can be used as an alternative to conventional lung function testing to support the diagnosis and monitoring of asthma when forced expiratory manoeuvres are contraindicated. Larger studies are required to establish severity and treatment escalation thresholds and provide clearer comparisons with spirometry values.

D-ROMs and PAT Tests Reveal a High Level of Oxidative Stress in Patients with Severe Well-Controlled Asthma, and D-ROMs Are Positively Correlated with R20 Values That Indicate Approximate Central Airway Resistance

“…For many years, IOS was promoted as an alternative measurement technique for airway resistance and obstruction in patients where maneuvers involved in plethysmography and spirometry prove difficult to perform, such as in the elderly, children, and obese patients [ 46 , 47 , 48 ]. IOS parameters are obtained more easily and effortlessly in comparison to FEV1.…”

Clinical application of oscillometry in respiratory diseases: an impulse oscillometry registry

“…These technical features allow oscillometry to provide additional information to the traditional PFTs. Coupled with its minimal demand for the co-operation of the patient, respiratory oscillometry is expected to be a potential complementary tool for traditional PFTs, especially for those who cannot perform spirometry [8] [9]. Despite its promising potential, oscillometry is currently more of a research tool than a routine test in practice, especially in adult clinical practice.…”

“…These technical features allow oscillometry to provide additional information to the traditional PFTs. Coupled with its minimal demand for the co-operation of the patient, respiratory oscillometry is expected to be a potential complementary tool to traditional PFTs, especially for those who cannot perform spirometry [ 8 , 9 ].…”

Understanding the fundamentals of oscillometry from a strip of lung tissue

“…Oscillometry is practical because it is effortless and requires very little cooperation, making it easy to perform for both the subject and the operator. This also means that, in contrast to spirometry, it can be performed in a reliable fashion on infants and children (Gray et al, 2019;Lavizzari et al, 2021;Ducharme et al, 2022), as well as on patients who are very sick (i.e., weak) or afflicted by disabilities (Veldhoen et al, 2022;Vielkind et al, 2022) or other conditions where forced expiratory maneuvers are contraindicated (Jordon et al, 2022). Oscillometry is also useful for many reasons.…”