Comparison of Predicted Total Lung Capacity and Total Lung Capacity by Computed Tomography in Lung Transplantation Candidates

In patients with mild chronic obstructive pulmonary disease (COPD), the effect of deep inspirations (DIs) to reverse methacholine-induced bronchoconstriction is largely attenuated. In this study, we tested the hypothesis that the effectiveness of DI is reduced with increasing disease severity and that this is associated with a reduction in the ability of DI to distend the airways. Fifteen subjects [Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage I–II: n = 7; GOLD stage III–IV: n = 8] underwent methacholine bronchoprovocation in the absence of DI, followed by DI. The effectiveness of DI was assessed by their ability to improve inspiratory vital capacity and forced expiratory volume in 1 s (FEV1). To evaluate airway distensibility, two sets of high-resolution computed tomography scans [at residual volume (RV) and at total lung capacity] were obtained before the challenge. In addition, mean parenchymal density was calculated on the high-resolution computed tomography scans. We found a strong correlation between the response to DI and baseline FEV1 %predicted ( r2 = 0.70, P < 0.0001) or baseline FEV1/forced vital capacity ( r2 = 0.57, P = 0.001). RV %predicted and functional residual capacity %predicted correlated inversely ( r2 = 0.33, P = 0.02 and r2 = 0.32, P = 0.03, respectively), and parenchymal density at RV correlated directly ( r2 = 0.30, P = 0.03), with the response to DI. Finally, the effect of DI correlated to the change in large airway area from RV to total lung capacity ( r2 = 0.44, P = 0.01). We conclude that loss of the effects of DI is strongly associated with COPD severity and speculate that the reduction in the effectiveness of DI is due to the failure to expand the lungs because of the hyperinflated state and/or the parenchymal damage that prevents distension of the airways with lung inflation.

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Predicted Total Lung Capacity Ratio between Donors and Recipients Does Not Predict Outcomes in Non-Volume Reduced Lung Transplantation

The Journal of Heart and Lung Transplantation ◽

10.1016/j.healun.2019.01.461 ◽

2019 ◽

Vol 38 (4) ◽

pp. S191

Author(s):

R. Poyanmehr ◽

W. Sommer ◽

F. Ius ◽

J. Salman ◽

T. Siemeni ◽

...

Keyword(s):

Lung Transplantation ◽

Total Lung Capacity ◽

Lung Capacity ◽

Capacity Ratio

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Respiratory symptoms and radiologic findings in post-acute COVID-19 syndrome

ERJ Open Research ◽

10.1183/23120541.00479-2021 ◽

2021 ◽

pp. 00479-2021

Author(s):

Etienne-Marie Jutant ◽

Olivier Meyrignac ◽

Antoine Beurnier ◽

Xavier Jaïs ◽

Tai Pham ◽

...

Keyword(s):

Computed Tomography ◽

Respiratory Symptoms ◽

Total Lung Capacity ◽

Pulmonary Function Tests ◽

High Resolution Computed Tomography ◽

Lung Capacity ◽

Radiologic Findings ◽

Care Visit ◽

Respiratory Complaints ◽

New Onset

RationaleThe characteristics of patients with respiratory complaints and/or lung radiologic abnormalities after hospitalisation for COVID-19 are unknown. The objectives were to determine their characteristics and the relationships between dyspnoea, radiologic abnormalities and functional impairment.MethodsIn the COMEBAC cohort study, 478 hospital survivors were evaluated by telephone 4 months after hospital discharge, and 177 who had been hospitalised in an intensive care unit (ICU) or presented relevant symptoms underwent an ambulatory evaluation. New-onset dyspnoea and cough were evaluated, and the results of pulmonary function tests, high-resolution computed tomography of the chest were collected.ResultsAmong the 478 patients, 78 (16.3%) reported new-onset dyspnoea, and 23 (4.8%) new-onset cough. The patients with new-onset dyspnoea were younger (56.1±12.3 versus 61.9±16.6 years), had more severe COVID-19 (ICU admission 56.4% versus 24.5%) and more frequent pulmonary embolism (18.0% versus 6.8%) (all p≤0.001) than patients without dyspnoea. Among the patients reassessed at the ambulatory care visit, the prevalence of fibrotic lung lesions was 19.3%, with extent <25% in 97% of the patients. The patients with fibrotic lesions were older (61±11 versus 56±14 years, p=0.03), more frequently managed in ICU (87.9 versus 47.4%, p<0.001), had lower total lung capacity (74.1±13.7 versus 84.9±14.8%pred, p<0.001) and diffusing lung capacity for carbon monoxide (DLCO) (73.3±17.9 versus 89.7±22.8%pred, p<0.001). The combination of new-onset dyspnoea, fibrotic lesions and DLCO <70%pred was observed in 8/478 patients.ConclusionsNew-onset dyspnoea and mild fibrotic lesions were frequent at 4 months, but the association of new-onset dyspnoea, fibrotic lesions and low DLCO was rare.

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