Differences Between Central Airway Obstruction and Chronic Obstructive Pulmonary Disease Detected with the Forced Oscillation Technique

Asthma and chronic obstructive pulmonary disease (COPD) in people with multiple sclerosis: A systematic review and meta-analysis

BACKGROUND

Studies have found that multiple sclerosis (MS) has an impact on the initiation or the course of asthma and chronic obstructive pulmonary disease (COPD). This review amied to investigate the prevalence and odds of asthma and COPD among people with MS (pwMS).

METHOD

PubMed, Embase, Scopus, and Web of Science were systemically searched from inception to May 2023. R version 4.3.2 and random-effect model were used to calculate the pooled prevalence and odds ratio (OR), with their 95 % confidence interval (CI), in pwMS.

RESULTS

A total of 40 studies consisting of 287,702 pwMS were included. 37 studies indicated that the pooled prevalences of asthma and COPD among pwMS were 5.97 % (95 % CI: 4.62 %-7.69 %, I2=99 %) and 3.03 % (95 % CI: 1.82 %-5.00 %, I2=99 %), respectively. 24 studies on 236,469 pwMS and 85,328,673 healthy controls revealed that the overall odds of asthma and COPD in MS were 1.14 (95 % CI: 0.76-1.71, p-value=0.53, I2=97 %) and 1.28 (95 % CI: 1.11-1.47, p-value<0.01, I2=70 %), respectively.

CONCLUSION

MS can increased the risk of developing COPD, while asthma does not exhibit a significant relationship with MS. Our study highlights the importance of identifying pwMS who face greater risks of respiratory issues to monitor efficiently and initiate suitable preventative actions.

Challenges in diagnosis and management of central airway obstruction: Case series

Central airway obstruction often presents with respiratory symptoms identical to those of common respiratory diseases. Diagnosis of central airway obstruction is challenging in clinical practice, especially misdiagnosed as asthma or chronic obstructive pulmonary disease in case of "normal" chest X-ray. Here, we reported five central airway obstruction cases: the first and fourth cases misdiagnosed as asthma, the second masquerading as chronic obstructive pulmonary disease exacerbation, the third diagnosed incorrectly with non-resolving pneumonia, and the fifth misdiagnosed as chronic obstructive pulmonary disease. We then analyzed diagnostic clues potentially useful to differentiate central airway obstruction from asthma/chronic obstructive pulmonary disease. A multidisciplinary approach to manage central airway obstruction is essential, particularly selecting judiciously the method of respiratory support due to the high risk of completed airway collapse or obstruction during interventional period.

Motor and respiratory functions are main challenges to patients with multiple sclerosis

Abstract Introduction People with multiple sclerosis (MS) present wide and varied symptoms. Objective To investigate the impact of MS on subjects’ motor and respiratory functions. Methods One hundred one participants were enrolled in this study. The subjects had previous diagnosis of relapsing-remittent MS (n = 48) or presented no neurologic diseases (n = 53, control group). Assess-ments involved mobility (Timed Get Up and Go) and balance (Berg Balance Scale) tests. A force platform was used to evaluate postural stabilometry. Respiratory functions were assessed with a portable spirometer and a digital manovacuometer. Data analyses were carried out with Student´s t-tests, chi-square, and Pearson correlation index. Significance was set at 5%. Results Compared to control peers, participants with MS showed higher motor dysfunctions affecting mobility, balance, and postural stability. Spirometry indicated normal parameters for pulmonary flows and lung capacities in both groups. The manovacuometer, differently, pointed to a respiratory muscle weakness in 48% of participants with MS. Correlation analyses highlighted that respiratory functions are more associated to dynamic than to static motor tests. Conclusion Pathological changes in MS lead to motor dysfunction on mobility, balance and postural stability. Respiratory tests showed normal pulmonary flows and lung capacities in patients with MS, but with commitment of respiratory muscle strength. Respiratory functions were more impacted by dynamic tasks rather than static motor tasks.

Lung disease burden assessment by oscillometry in a systematically disadvantaged urban population experiencing homelessness or at-risk for homelessness in Ottawa, Canada from a prospective observational study

Rationale

Oscillometry is an emerging technique that offers some advantages over spirometry as it does not require forced exhalation and may detect early changes in respiratory pathology. Obstructive lung disease disproportionately impacts people experiencing homelessness with a high symptoms burden, yet oscillometry is not studied in this population.

Objectives

To assess lung disease and symptom burden using oscillometry in people experiencing homelessness or at-risk of homelessness using a community-based participatory action research approach (The Bridge Model™).

Methods

Of 80 recruited, 55 completed baseline oscillometry, 64 completed spirometry, and all completed patient-reported outcomes with demographics, health, and respiratory symptom related questionnaires in the Participatory Research in Ottawa: Management and Point-of-Care for Tobacco Dependence project. Using a two-tail t-test, we compared mean oscillometry values for airway resistance (R_5–20), reactance area under the curve (A_x) and reactance at 5 Hz (X₅) amongst individuals with fixed-ratio method (FEV₁/FVC ratio < 0.70) and LLN (FEV₁/FVC ratio ≤ LLN) spirometry diagnosed chronic obstructive pulmonary disease (COPD). We compared mean oscillometry parameters based on participants’ COPD assessment test (CAT) scores using ANOVA test.

Results

There was no significant difference between the pre- and post- bronchodilator values of R_5–20 and A_x for the fixed ratio method (p = 0.63 and 0.43) and the LLN method (p = 0.45 and 0.36). There was a significant difference in all three of the oscillometry parameters, R_5–20, A_x and X₅, based on CAT score (p = 0.009, 0.007 and 0.05, respectively). There was a significant difference in R_5–20 and A_x based on the presence of phlegm (p = 0.03 and 0.02, respectively) and the presence of wheeze (p = 0.05 and 0.01, respectively). Oscillometry data did not correlate with spirometry data, but it was associated with CAT scores and correlated with the presence of self-reported symptoms of phlegm and wheeze in this population.

Conclusions

Oscillometry is associated with respiratory symptom burden and highlights the need for future studies to generate more robust data regarding the use of oscillometry in systematically disadvantaged populations where disease burden is disproportionately higher than the general population.

TrialRegistration: ClinicalTrails.gov—NCT03626064, Retrospective registered: August 2018, https://clinicaltrials.gov/ct2/show/NCT03626064

Evaluation of Impulse Oscillometry in Respiratory Airway Casts with Varying Obstruction Phenotypes, Locations, and Complexities

The use of impulse oscillometry (IOS) for lung function testing does not need patient cooperation and has gained increasing popularity among both young and senior populations, as well as in patients with breathing difficulties. However, studies of the IOS sensitivity to regional lung obstructions are limited and have shown mixed results. The objective of this study was to evaluate the performance of an IOS system in 3D-printed lung models with structural abnormalities at different locations and with different severities. Lung trees of two complexity levels were tested, with one extending to the sixth generation (G6) and the other to G12. The IOS responses to varying glottal apertures, carina ridge tumors, and segmental bronchial constrictions were quantified in the G6 lung geometry. Both the G6 and G12 lung casts were prepared using high-resolution 3D printers. Overall, IOS detected the progressive airway obstructions considered in this study. The resonant frequency dropped with increasing obstructions for all three disease phenotypes in the G6 lung models. R20Hz increased with the increase in airway obstructions. Specifically, R20Hz in the airway model with varying glottal apertures agreed reasonably well with complementary measurements using TSI VelociCalc. In contrast to the high-resistance (R) sensitivity to the frequency in G6 lung models, R was nearly independent of frequency in G12 lung models. IOS R20Hz demonstrated adequate sensitivity to the structural remodeling in the central airways. However, the changes of R5Hz and X5Hz vs. airway obstructions were inconclusive in this study, possibly due to the rigid lung casts and the difference of a container–syringe system from human lungs.