Intrabreath oscillometry is a sensitive test for assessing disease control in adults with severe asthma

Chiabai, Joseane; Friedrich, Frederico; Fernandes, Morgana Thaís Carollo; Serpa, Faradiba Sarquis; Antunes, Marcos Otávio Brum; Neto, Firmino Braga; Makan, Gergely; Hantos, Zoltán; Sly, Peter D.; Jones, Marcus Herbert

doi:10.1016/j.anai.2021.06.005

Cited by 15 publications

(18 citation statements)

References 49 publications

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“…An unexpected finding in the present investigation was the fact that R eI was higher than R eE (i.e., ΔR was negative) in almost half of the subjects. This is in contrast to previous intra-breath studies where the typically positive ΔR values were attributed to the tidal dilatation of the pulmonary airways ( 7 , 20 , 21 ). One important specific factor in infancy is the large contribution of the extrathoracic pathways to Rrs, whose transmural pressures are dependent on V’ rather than V and are opposite to that of the pulmonary airways; this may lead to narrowing of the upper airways during inspiration and possibly some residual constriction at end inspiration.…”

Section: Discussioncontrasting

confidence: 99%

Respiratory Oscillometry in Newborn Infants: Conventional and Intra-Breath Approaches

et al. 2022

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BackgroundOscillometry has been employed widely as a non-invasive and standardized measurement of respiratory function in children and adults; however, limited information is available on infants.AimsTo establish the within-session variability of respiratory impedance (Zrs), to characterize the degree and profile of intra-breath changes in Zrs and to assess their impact on conventional oscillometry in newborns.Methods109 healthy newborns were enrolled in the study conducted in the first 5 postpartum days during natural sleep. A custom-made wave-tube oscillometry setup was used, with an 8–48 Hz pseudorandom and a 16 Hz sinusoidal signal used for spectral and intra-breath oscillometry, respectively. A resistance-compliance-inertance (R-C-L) model was fitted to average Zrs spectra obtained from successive 30-s recordings. Intra-breath measures, such as resistance (Rrs) and reactance (Xrs) at the end-expiratory, end-inspiratory and maximum-flow points were estimated from three 90-s recordings. All natural and artifact-free breaths were included in the analysis.ResultsWithin-session changes in the mean R, C and L values, respectively, were large (mean coefficients of variation: 10.3, 20.3, and 26.6%); the fluctuations of the intra-breath measures were of similar degree (20–24%). Intra-breath analysis also revealed large swings in Rrs and Xrs within the breathing cycle: the peak-to-peak changes amounted to 93% (range: 32–218%) and 41% (9–212%), respectively, of the zero-flow Zrs magnitude.DiscussionIntra-breath tracking of Zrs provides new insight into the determinants of the dynamics of respiratory system, and highlights the biasing effects of mechanical non-linearities on the average Zrs data obtained from the conventional spectral oscillometry.

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Section: Discussioncontrasting

confidence: 99%

Respiratory Oscillometry in Newborn Infants: Conventional and Intra-Breath Approaches

et al. 2022

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“…Standard (also known as spectral) oscillometry provides the mean values of Zrs at different frequencies over entire breath cycles. Intrabreath oscillometry is a novel modality that tracks changes in lung mechanics continuously during inspiration and expiration, and focuses on the zero-flow instants of breathing, such as end expiration and end inspiration, where the upper airway nonlinearities are minimal ( Gray et al, 2019 ; Chiabai et al, 2021 ; Hantos, 2021 ; Makan et al, 2022 ). Spectral oscillometry has been found to be more sensitive than spirometry in detecting chronic obstructive pulmonary disease (COPD) and asthma in the small airways, and is able to distinguish COPD from interstitial lung disease ( Dellacà et al, 2004 ; Fujii et al, 2015 ; Paredi et al, 2010 ; Sugiyama et al, 2013 ).…”

Section: Introductionmentioning

confidence: 99%

Characterization of chronic lung allograft dysfunction phenotypes using spectral and intrabreath oscillometry

Vasileva²,

Hanafi³

et al. 2022

Front. Physiol.

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Background: Chronic lung allograft dysfunction (CLAD) is the major cause of death beyond 2 years after lung transplantation and develops in 50% of all patients by 5 years post-transplant. CLAD is diagnosed on the basis of a sustained drop of 20% for at least 3 months in the forced expiratory volume (FEV1), compared to the best baseline value achieved post-transplant. CLAD presents as two main phenotypes: bronchiolitis obliterans syndrome (BOS) is more common and has better prognosis than restrictive allograft syndrome (RAS). Respiratory oscillometry is a different modality of lung function testing that is highly sensitive to lung mechanics. The current study investigated whether spectral and intrabreath oscillometry can differentiate between CLAD-free, BOS- and RAS-CLAD at CLAD onset, i.e., at the time of the initial 20% drop in the FEV1.Methods: A retrospective, cross-sectional analysis of 263 double lung transplant recipients who underwent paired testing with oscillometry and spirometry at the Toronto General Pulmonary Function Laboratory from 2017 to 2022 was conducted. All pulmonary function testing and CLAD diagnostics were performed following international guidelines. Statistical analysis was conducted using multiple comparisons.Findings: The RAS (n = 6) spectral oscillometry pattern differs from CLAD-free (n = 225) by right-ward shift of reactance curve similar to idiopathic pulmonary fibrosis whereas BOS (n = 32) has a pattern similar to obstructive lung disease. Significant differences were found in most spectral and intrabreath parameters between BOS, RAS, and time-matched CLAD-free patients. Post-hoc analysis revealed these differences were primarily driven by BOS instead of RAS. While no differences were found between CLAD-free and RAS patients with regards to spectral oscillometry, the intrabreath metric of reactance at end-inspiration (XeI) was significantly different (p < 0.05). BOS and RAS were differentiated by spectral oscillometry measure R5, and intrabreath resistance at end expiration, ReE (p < 0.05 for both).Conclusion: Both spectral and intrabreath oscillometry can differentiate BOS-CLAD from CLAD-free states while intrabreath oscillometry, specifically XeI, can uniquely distinguish RAS-CLAD from CLAD-free. Spectral and intrabreath oscillometry offer complementary information regarding lung mechanics in CLAD patients to help distinguish the two phenotypes and could prove useful in prognostication.

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“…A análise intra-breath mostra alta sensibilidade para detectar comprometimento da função pulmonar. (19,20) A oscilometria aplicada por meio da técnica do tubo de onda proporciona novos parâmetros para a análise da mecânica ventilatória. Por exigir apenas cooperação passiva do paciente, a técnica tem sido cada vez mais utilizada em crianças como complemento aos métodos clássicos de avaliação pulmonar.…”

Section: Introductionunclassified

“…Intra-breath analysis shows high sensitivity for detecting lung function impairment. 19 , 20 Oscillometry applied by the wave-tube technique provides new parameters for the analysis of ventilatory mechanics. Because it requires only passive cooperation from the patient, the technique has increasingly been used in children as a complement to the classic methods of pulmonary assessment.…”

Section: Introductionmentioning

confidence: 99%

Intra-breath oscillometry for the evaluation of lung function in children and adolescents with a history of preterm birth

et al. 2022

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Objective: To assess respiratory system impedance (Zrs) and spirometric parameters in children and adolescents with and without a history of preterm birth. Methods: We evaluated a sample of 51 subjects between 11 and 14 years of age: 35 who had a history of preterm birth (preterm group) and 16 who had been born at term (full-term group). Lung function was measured by spirometry, spectral oscillometry, and intra-breath oscillometry. Results: Neither spirometry nor spectral oscillometry revealed any statistically significant differences between the preterm and full-term groups. However, intra-breath oscillometry demonstrated significant differences between the two groups in terms of the change in resistance, reactance at end-inspiration, and the change in reactance (p < 0.05 for all). Conclusions: Our findings suggest that abnormalities in Zrs persist in children and adolescents with a history of preterm birth and that intra-breath oscillometry is more sensitive than is spectral oscillometry. Larger studies are needed in order to validate these findings and to explore the impact that birth weight and gestational age at birth have on Zrs later in life.

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Intrabreath oscillometry is a sensitive test for assessing disease control in adults with severe asthma

Cited by 15 publications

References 49 publications

Respiratory Oscillometry in Newborn Infants: Conventional and Intra-Breath Approaches

Respiratory Oscillometry in Newborn Infants: Conventional and Intra-Breath Approaches

Characterization of chronic lung allograft dysfunction phenotypes using spectral and intrabreath oscillometry

Intra-breath oscillometry for the evaluation of lung function in children and adolescents with a history of preterm birth

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