Dysfunctional breathing diagnosed by cardiopulmonary exercise testing in 'long COVID' patients with persistent dyspnoea.

BACKGROUND: 'Long COVID'-associated dyspnoea may persist for months after SARS-CoV-2 infection. Among the causes of persistent dyspnoea, dysfunctional breathing (DB), defined as an erratic or inappropriate ventilation at rest or exercise, has been observed, but little is known about its occurrence and pathophysiology among individuals with 'long COVID'. We aimed to describe the occurrence and identify clinical predictors of DB among patients following SARS-CoV-2 infection. METHODS: Cardiopulmonary exercise testing (CPET) was performed in 51 SARS-CoV-2 patients (median age, 64 years (IQR, 15)); male, 66.7%) living with 'long COVID' and persistent dyspnoea. CPET was classified into three dominant patterns: respiratory limitation with gas exchange abnormalities (RL); normal CPET or O2 delivery/utilisation impairment (D); and DB. Non-parametric and χ2 tests were applied to analyse the association between CPET dominant patterns and demographics, pulmonary function tests and SARS-CoV-2 severity. RESULTS: Among 51 patients, DB mostly without hyperventilation was found in 29.4% (n=15), RL in 54.9% (n=28) and D in 15.7% (n=8). When compared with RL individuals, patients with DB were younger, had significantly less severe initial infection, a better transfer capacity for carbon monoxide (median 85% (IQR, 28)), higher oxygen consumption (22.9 mL/min/kg (IQR, 5.5)), a better ventilatory efficiency slope (31.6 (IQR, 12.8)), and a higher SpO2 (95% (IQR, 3)). CONCLUSIONS: Our findings suggest that DB without hyperventilation could be an important pathophysiological mechanism of disabling dyspnoea in younger outpatients following SARS-CoV-2 infection, which appears to be a feature of COVID-19 not described in other viral diseases.

Lung MRI assessment with high-frequency noninvasive ventilation at 3 T.

PURPOSE: To investigate three MR pulse sequences under high-frequency noninvasive ventilation (HF-NIV) at 3 T and determine which one is better-suited to visualize the lung parenchyma. METHODS: A 3D ultra-short echo time stack-of spirals Volumetric Interpolated Breath-hold Examination (UTE Spiral VIBE), without and with prospective gating, and a 3D double-echo UTE sequence with spiral phyllotaxis trajectory (3D radial UTE) were performed at 3 T in ten healthy volunteers under HF-NIV. Three experienced radiologists evaluated visibility and sharpness of normal anatomical structures, artifacts assessment, and signal and contrast ratio computation. The median of the three readers'scores was used for comparison, p < .05 was considered statistically significant. Incidental findings were recorded and reported. RESULTS: The 3D radial UTE resulted in less artifacts than the non-gated and gated UTE Spiral VIBE in inferior (score 3D radial UTE = 3, slight artifact without blurring vs. score UTE Spiral VIBE non-gated and gated = 2, moderate artifact with blurring of anatomical structure, p = .018 and p = .047, respectively) and superior lung regions (score 3D radial UTE = 3, vs. score UTE Spiral VIBE non-gated = 2.5, p = .48 and score UTE Spiral VIBE gated = 1, severe artifact with no normal structure recognizable, p = .014), and higher signal and contrast ratios (p = .002, p = .093). UTE Spiral VIBE sequences provided higher peripheral vasculature visibility than the 3D radial UTE (94.4% vs 80.6%, respectively, p < .001). The HF-NIV was well tolerated by healthy volunteers who reported on average minor discomfort. In three volunteers, 12 of 18 nodules confirmed with low-dose CT were identified with MRI (average size 2.6 ±â€¯1.2 mm). CONCLUSION: The 3D radial UTE provided higher image quality than the UTE Spiral VIBE. Nevertheless, a better nodule assessment was noticed with the UTE Spiral VIBE that might be due to better peripheral vasculature visibility, and requires confirmation in a larger cohort.

[Computer instruments for the management of isolated pulmonary nodule. Detectability and prediction of malignancy]. / Outils informatiques pour la prise en charge du nodule pulmonaire isolé - Détectabilité et prédiction de malignité.

Lung cancer remains the most common cause of cancer deaths in the world, but its mortality can be significantly reduced by diagnosis and early detection. Computerized resources were developed to assist radiologists in their management of the large volume of thoracic images to be analyzed. Their objective is the detection of pulmonary nodules with high sensitivity and a low rate of false-positives and the ability to differentiate benign and malignant nodules. The volume of a pulmonary nodule and its volume doubling time are essential to nodule management. Computer aided detection or diagnosis (CAD) software are not currently used in clinically settings on a routine basis . Significant advances are expected due to the implementation of the artificial intelligence systems who will probably be integrated into the multidisciplinary management of any pulmonary nodule.

Le cancer du poumon reste la principale cause de décès par cancer dans le monde. Sa mortalité peut être significativement réduite par un diagnostic et un dépistage précoce. Des outils informatiques ont été développés afin d'aider les radiologues à gérer la quantité d'images thoraciques à analyser. Ils ont pour objectif la détection des nodules pulmonaires avec une haute sensibilité et un taux faible de faux positifs, mais aussi la différenciation des nodules bénins et malins. Le volume d'un nodule pulmonaire et le temps de doublement déterminent la suite de la prise en charge de ce nodule. Ces deux paramètres sont inclus dans la plupart des recommandations actuelles. Les logiciels de détection assistés par ordinateur (CAD) ne sont pas utilisés en routine clinique actuellement. Des avancées dans ce domaine sont attendues en utilisant l'intelligence artificielle, notamment dans le cadre de la prise de décision multidisciplinaire.

[Bronchodilatation during spirometry : indications, realization and interpretation]. / Bronchodilatation lors de spirométrie : indications, réalisation et interprétation.

Spirometry with response to short-acting bronchodilators is a key element in the diagnostic work-up of patients with obstructive airways diseases and should be systematically assessed. Response to bronchodilators (RBD) is useful to differentiate asthma from COPD and to grade the severity of obstruction in COPD cases. RBD should not be used to decide for a bronchodilator therapy. An increase in Forced Expiratory Volume in 1 sec (FEV1) or Forced Vital Capacity (FVC) by > 200 ml and 12 % of baseline value is considered as criteria for significant bronchodilator response. With the exception of asthma diagnostic work-up, inhaled therapy should not be interrupted before spirometry. Paradoxical loss of lung function after administration of beta 2 agonists is rarely observed. When present, choice of an alternative bronchodilator agent should be considered.

La spirométrie avec mesure de la réponse aux bronchodilatateurs d'action rapide est un élément diagnostique clé dans le bilan des syndromes obstructifs et doit être systématiquement effectuée. Elle est utile pour distinguer l'asthme de la BPCO et permet de grader la sévérité de l'obstruction en cas de BPCO. On ne devrait pas l'utiliser pour décider du choix d'un bronchodilatateur. On retient comme critère de réversibilité une augmentation du volume expiré maximal en 1 seconde (VEMS) ou de la capacité vitale forcée (CVF) supérieure à 200 ml et 12 % de la valeur de base.Excepté pour le bilan initial d'un asthme, les traitements inhalés ne doivent pas être interrompus avant un bilan spirométrique. Une aggravation paradoxale après bêta-agonistes est une observation rare qui doit faire envisager une alternative à cette classe de bronchodilatateurs.

Mounier-Kuhn syndrome.

Mounier-Kuhn syndrome or congenital tracheobronchomegaly is a rare clinical and radiologic condition. It is characterized by a tracheal and bronchial dilation. Fewer than 100 cases have been reported in the medical literature since the original description in 1932. The first utilization of bronchoscopy for diagnosis of this condition was recorded by Lemoine only in 1949. The cause of this condition is not clearly understood; however, histopathologic findings of atrophy of smooth muscles and elastic tissue in the trachea and main bronchi have been observed. Tracheobronchomegaly can be associated with tracheal and bronchial diverticuli.