Chest CT features are associated with poorer quality of life in acute lung injury survivors

Early nintedanib deployment in COVID-19 interstitial lung disease (ENDCOV-I): study protocol of a randomised, double-blind, placebo-controlled trial

INTRODUCTION

In December 2019, the novel SARS-CoV-2 triggered a global pneumonia outbreak, leading to millions of deaths worldwide. A subset of survivors faces increased morbidity and mortality, particularly due to subacute lung injury evolving to chronic fibrosing interstitial lung disease. While nintedanib, a tyrosine-kinase inhibitor, shows promise in treating progressive fibrotic lung disease, limited randomised trial data exists for post-COVID-19-induced lung injury. We hypothesise that treatment with nintedanib may attenuate advancement to the fibrotic stages, offering a potential avenue for improving outcomes in this specific patient subset.

METHODS AND ANALYSIS

We describe the design of a multicentre, randomised, double-blind, placebo-controlled trial involving approximately 170 patients with subacute lung injury secondary to COVID-19, who required respiratory support with oxygen supplementation. Patients are randomised by site and disease phenotype (fibrotic vs non-fibrotic) in a 1:1 ratio to either oral nintedanib or placebo. Patients will be followed for 180 days. The primary endpoint is to assess change from baseline in forced vital capacity (FVC, mL) at 180 days. Secondary objectives include change in FVC (mL) at 90 days; diffusing capacity of carbon monoxide (% of predicted) and 6-min walk test (feet) at 180 days; and mortality at 90 and 180 days. Qualitative and quantitative changes in high-resolution computerised tomography (HRCT), change in patient-reported outcome measures (PROMs) and safety endpoints will also be assessed. Analysis will be performed according to the intention-to-treat principle.

ETHICS AND DISSEMINATION

The study is conducted in accordance with the Good Clinical Practices as outlined by the Food and Drug Administration and the Declaration of Helsinki 2008. This study received approval from participating sites' Institutional Review Boards and committees, including The Ethics Committee of the Medical Board at the Mount Sinai Hospital (ID: HS#20-01166). The Independent Oversight Committee oversees study conduct, data and patient safety for the duration of the study investigation. The trial details presented align with the trial protocol V.8. (April 2022). Results will be presented at national and international conferences, published in a peer-reviewed journal and disseminated to patients, funders and researchers on data analysis completion.

TRIAL REGISTRATION NUMBER

NCT04619680. First posted 6 November 2020.

Gpnmb and Spp1 mark a conserved macrophage injury response masking fibrosis-specific programming in the lung

Macrophages are required for healthy repair of the lungs following injury, but they are also implicated in driving dysregulated repair with fibrosis. How these 2 distinct outcomes of lung injury are mediated by different macrophage subsets is unknown. To assess this, single-cell RNA-Seq was performed on lung macrophages isolated from mice treated with LPS or bleomycin. Macrophages were categorized based on anatomic location (airspace versus interstitium), developmental origin (embryonic versus recruited monocyte derived), time after inflammatory challenge, and injury model. Analysis of the integrated dataset revealed that macrophage subset clustering was driven by macrophage origin and tissue compartment rather than injury model. Gpnmb-expressing recruited macrophages that were enriched for genes typically associated with fibrosis were present in both injury models. Analogous GPNMB-expressing macrophages were identified in datasets from both fibrotic and nonfibrotic lung disease in humans. We conclude that this subset represents a conserved response to tissue injury and is not sufficient to drive fibrosis. Beyond this conserved response, we identified that recruited macrophages failed to gain resident-like programming during fibrotic repair. Overall, fibrotic versus nonfibrotic tissue repair is dictated by dynamic shifts in macrophage subset programming and persistence of recruited macrophages.

Postinfectious Pulmonary Complications: Establishing Research Priorities to Advance the Field: An Official American Thoracic Society Workshop Report

Continued improvements in the treatment of pulmonary infections have paradoxically resulted in a growing challenge of individuals with postinfectious pulmonary complications (PIPCs). PIPCs have been long recognized after tuberculosis, but recent experiences such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic have underscored the importance of PIPCs following other lower respiratory tract infections. Independent of the causative pathogen, most available studies of pulmonary infections focus on short-term outcomes rather than long-term morbidity among survivors. In this document, we establish a conceptual scope for PIPCs with discussion of globally significant pulmonary pathogens and an examination of how these pathogens can damage different components of the lung, resulting in a spectrum of PIPCs. We also review potential mechanisms for the transition from acute infection to PIPC, including the interplay between pathogen-mediated injury and aberrant host responses, which together result in PIPCs. Finally, we identify cross-cutting research priorities for the field to facilitate future studies to establish the incidence of PIPCs, define common mechanisms, identify therapeutic strategies, and ultimately reduce the burden of morbidity in survivors of pulmonary infections.

COVID-19's Radiologic, Functional, and Serologic Consequences at 6-Month and 18-Month Follow-up: A Prospective Cohort Study

BACKGROUND

We evaluated the radiologic, pulmonary functional, and antibody statuses of coronavirus disease 2019 (COVID-19) patients 6 and 18 months after discharge, comparing changes in status and focusing on risk factors for residual computed tomography (CT) abnormalities.

METHODS

This prospective cohort study was conducted on COVID-19 patients discharged between April 2020 and January 2021. Chest CT, pulmonary function testing (PFT), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) measurements were performed 6 and 18 months after discharge. We evaluated factors associated with residual CT abnormalities and the correlation between lesion volume in CT (lesionvolume), PFT, and IgG levels.

RESULTS

This study included 68 and 42 participants evaluated 6 and 18 months, respectively, after hospitalizations for COVID-19. CT abnormalities were noted in 22 participants (32.4%) at 6 months and 13 participants (31.0%) at 18 months. Lesionvolume was significantly lower at 18 months than 6 months (P < 0.001). Patients with CT abnormalities at 6 months showed lower forced expiratory volume in 1 second (FEV1) and FEV1/forced vital capacity (FVC), and patients with CT abnormalities at 18 months exhibited lower FVC. FVC significantly improved between 6 and 18 months of follow-up (all P < 0.0001). SARS-CoV-2 IgG levels were significantly higher in patients with CT abnormalities at 6 and 18 months (P < 0.001). At 18-month follow-up assessments, age was associated with CT abnormalities (odds ratio, 1.17; 95% confidence interval, 1.03-1.32; P = 0.01), and lesionvolume showed a positive correlation with IgG level (r = 0.643, P < 0.001).

CONCLUSION

At 18-month follow-up assessments, 31.0% of participants exhibited residual CT abnormalities. Age and higher SARS-CoV-2 IgG levels were significant predictors, and FVC was related to abnormal CT findings at 18 months. Lesionvolume and FVC improved between 6 and 18 months.

TRIAL REGISTRATION

Clinical Research Information Service Identifier: KCT0008573.

Mediators of monocyte chemotaxis and matrix remodeling are associated with mortality and pulmonary fibroproliferation in patients with severe COVID-19

Acute respiratory distress syndrome (ARDS) has a fibroproliferative phase that may be followed by pulmonary fibrosis. Pulmonary fibrosis following COVID-19 pneumonia has been described at autopsy and following lung transplantation. We hypothesized that protein mediators of tissue remodeling and monocyte chemotaxis are elevated in the plasma and endotracheal aspirates of critically ill patients with COVID-19 who subsequently develop features of pulmonary fibroproliferation. We enrolled COVID-19 patients admitted to the ICU with hypoxemic respiratory failure. (n = 195). Plasma was collected within 24h of ICU admission and at 7d. In mechanically ventilated patients, endotracheal aspirates (ETA) were collected. Protein concentrations were measured by immunoassay. We tested for associations between protein concentrations and respiratory outcomes using logistic regression adjusting for age, sex, treatment with steroids, and APACHE III score. In a subset of patients who had CT scans during hospitalization (n = 75), we tested for associations between protein concentrations and radiographic features of fibroproliferation. Among the entire cohort, plasma IL-6, TNF-α, CCL2, and Amphiregulin levels were significantly associated with in-hospital mortality. In addition, higher plasma concentrations of CCL2, IL-6, TNF-α, Amphiregulin, and CXCL12 were associated with fewer ventilator-free days. We identified 20/75 patients (26%) with features of fibroproliferation. Within 24h of ICU admission, no measured plasma proteins were associated with a fibroproliferative response. However, when measured 96h-128h after admission, Amphiregulin was elevated in those that developed fibroproliferation. ETAs were not correlated with plasma measurements and did not show any association with mortality, ventilator-free days (VFDs), or fibroproliferative response. This cohort study identifies proteins of tissue remodeling and monocyte recruitment are associated with in-hospital mortality, fewer VFDs, and radiographic fibroproliferative response. Measuring changes in these proteins over time may allow for early identification of patients with severe COVID-19 at risk for fibroproliferation.

Hydrochloric Acid-Induced Acute Lung Injury Models: Dynamic Change and Quantitative Analysis of Modified Lung Ultrasound Scoring System and High-Resolution Computed Tomography

OBJECTIVE

Acute lung injury (ALI) has become a research hotspot due to its significant public health impact. To explore the value of the use of modified lung ultrasound (MLUS) scoring system for evaluating ALI using a rabbit model of ALI induced by hydrochloric acid (HCl) and investigate its correlation with high-resolution computed tomography (HRCT) and histopathological scores.

METHODS

Twenty New Zealand laboratory rabbits were randomly assigned to control group (N = 5) and 3 experimental groups (N = 5 each). The control group received instillation of physiological saline, while the 3 experimental groups received 2 mL/kg of different doses of HCl instillation (mild group: pH 1.5, moderate group: pH 1.2, and severe group: pH 1.0) through the trachea under ultrasound guidance. Pulmonary ultrasound (using Mindray Reason9 linear array probes with frequency of 6-15 mHz) and HRCT examinations were performed before modeling (0H) and at 1H, 2H, 4H, 8H, 12H after modeling. The experimental rabbits were sacrificed at 12H for examination of gross lung morphology and hematoxylin-eosin-stained histopathological sections. The correlation of MLUS scores with HRCT/histopathological scores was assessed.

RESULTS

All rabbits in the experimental groups showed oxygenation index PaO₂/FiO₂<300. Successful establishment of ALI model was proven by autopsy (successful modeling rate: 100%). The pathological damage increased with increase in HCl dosage. MLUS scores showed a positive correlation with HRCT scores/pathological severity. There was a strong positive correlation between MLUS scores and histopathological scores (r = 0.963, p < 0.05) as well as between HRCT scores and histopathological scores (r = 0.932, p < 0.05).

CONCLUSION

Transtracheal injection of different dosages of HCl under ultrasound guidance induced different degrees of ALI. The MLUS scoring system can be used for semiquantitative evaluation of ALI, and is suitable as a screening tool.

Effects of pulmonary rehabilitation on functional and psychological parameters in post-acute sequelae of SARS-CoV-2 infection (PASC) patients

BACKGROUND

COVID-19 survivors may develop long-term symptoms of fatigue, dyspnea, mental health issues, and functional limitations: a condition termed post-acute sequelae of COVID-19 (PASC). Pulmonary rehabilitation (PR) is a recommended treatment for PASC; however, there is a lack of data regarding PR's effect on multiple health indices and the factors that influence patient outcomes. The aim of our study is to evaluate the impact of pulmonary rehabilitation on functional and psychological parameters in patients diagnosed with Post-Acute Sequelae of SARS-CoV-2 Infection (PASC), thereby offering insights into the efficacy of such interventions in improving the quality of life and clinical outcomes for these individuals.

METHODS

We extracted patient demographic, comorbidity, and outcome data from Allegheny Health Network's electronic medical records. Functionality test results were compared before and after PR, including 6-minute walk test (6MWT), chair rise repetitions (CR reps), timed up and go test (TUG), gait speed (Rehab gait), modified medical research council scale (MMRC), shortness of breath questionnaire (SOBQ), hospital anxiety and depression scale (HADS) and chronic obstructive pulmonary disease assessment test (CAT) scores. Multiple regression analysis was done to evaluate the effect of comorbidities and patient factors on patient responses to PR.

RESULTS

The 55 patients included in this study had a mean time of 4 months between the initial COVID-19 diagnosis and the subsequent PASC diagnosis. Following pulmonary rehabilitation (PR), significant improvements were observed across various metrics. The distance covered in the 6-minute walk test (6MWT) increased markedly from a pre-rehabilitation average of 895 feet (SD 290) to 1,300 feet (SD 335) post-rehabilitation, with a mean change of 405 feet (95% CI [333, 477]). Chair rise repetitions (CR reps) saw an increase from 9 (SD 3) reps to 13 (SD 3) reps, with a change of 4 reps (95% CI [3.7, 4.9]). The timed up and go test (TUG) time decreased significantly from 13 s (SD 5) to 10 s (SD 2), reflecting a mean reduction of 3 s (95% CI [-4.5, -2.5]). Rehabilitation gait speed improved from 1.0 m/s to 1.3 m/s, changing by 0.3 m/s (95% CI [0.2, 0.3]). The Modified Medical Research Council (MMRC) dyspnea scale showed a notable decrease from a mean of 2 (SD 1) to 1 (SD 1), a change of -1 (95% CI [-1.5, -1]). The Shortness of Breath Questionnaire (SOBQ) scores reduced significantly from 51 (SD 21) to 22 (SD 18), with a change of -29 (95% CI [-34, -23]). The Hospital Anxiety and Depression Scale (HADS) scores decreased from 11 (SD 7) to 8 (SD 7), a reduction of -4 (95% CI [-5, -2]). Lastly, the Chronic Obstructive Pulmonary Disease (COPD) Assessment Test (CAT) scores significantly dropped from 18 (SD 7) to 9 (SD 7), changing by -10 (95% CI [-11, -8]). However, the presence of hypertension, diabetes, chronic lung diseases, outpatient status, and receipt of specific pharmacologic treatments (decadron, decadron + remdesivir, and decadron + remdesivir + tocilizumab) were identified as factors associated with a poor response to PR.

CONCLUSION

Our study supports PR as an integrated model of care for PASC patients to improve several physical and mental health indices. The long-term effects of PR on patients' functional status should be investigated in the future.

IL-22 Binding Protein Controls IL-22-Driven Bleomycin-Induced Lung Injury

The high mortality rates of acute lung injury and acute respiratory distress syndrome challenge the field to identify biomarkers and factors that can be exploited for therapeutic approaches. IL-22 is a cytokine that has antibacterial and reparative properties in the lung. However, it also can exacerbate inflammation and requires tight control by the extracellular inhibitory protein known as IL-22 binding protein (IL-22BP) (Il22ra2). This study showed the necessity of IL-22BP in controlling and preventing acute lung injury using IL-22BP knockout mice (Il22ra2-/-) in the bleomycin model of acute lung injury/acute respiratory distress syndrome. Il22ra2-/- mice had greater sensitivity (weight loss and death) and pulmonary inflammation in the acute phase (first 7 days) of the injury compared with wild-type C57Bl/6 controls. The inflammation was driven by excess IL-22 production, inducing the influx of pathogenic IL-17A+ γδ T cells to the lung. Interestingly, this inflammation was initiated in part by the noncanonical IL-22 signaling to macrophages, which express the IL-22 receptor (Il22ra1) in vivo after bleomycin challenge. This study further showed that IL-22 receptor alpha-1+ macrophages can be stimulated by IL-22 to produce a number of IL-17-inducing cytokines such as IL-1β, IL-6, and transforming growth factor-β1. Together, the results suggest that IL-22BP prevents IL-22 signaling to macrophages and reduces bleomycin-mediated lung injury.

Fibrotic-Like Pulmonary Radiographic Patterns Are Not Associated With Adverse Outcomes in COVID-19 Chronic Critical Illness

OBJECTIVES

Pulmonary fibrosis is a feared complication of COVID-19. To characterize the risks and outcomes associated with fibrotic-like radiographic abnormalities in patients with COVID-19-related acute respiratory distress syndrome (ARDS) and chronic critical illness.

DESIGN

Single-center prospective cohort study.

SETTING

We examined chest CT scans performed between ICU discharge and 30 days after hospital discharge using established methods to quantify nonfibrotic and fibrotic-like patterns.

PATIENTS

Adults hospitalized with COVID-19-related ARDS and chronic critical illness (> 21 d of mechanical ventilation, tracheostomy, and survival to ICU discharge) between March 2020 and May 2020.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We tested associations of fibrotic-like patterns with clinical characteristics and biomarkers, and with time to mechanical ventilator liberation and 6-month survival, controlling for demographics, comorbidities, and COVID-19 therapies. A total of 141 of 616 adults (23%) with COVID-19-related ARDS developed chronic critical illness, and 64 of 141 (46%) had a chest CT a median (interquartile range) 66 days (42-82 d) after intubation. Fifty-five percent had fibrotic-like patterns characterized by reticulations and/or traction bronchiectasis. In adjusted analyses, interleukin-6 level on the day of intubation was associated with fibrotic-like patterns (odds ratio, 4.40 per quartile change; 95% CI, 1.90-10.1 per quartile change). Other inflammatory biomarkers, Sequential Organ Failure Assessment score, age, tidal volume, driving pressure, and ventilator days were not. Fibrotic-like patterns were not associated with longer time to mechanical ventilator liberation or worse 6-month survival.

CONCLUSIONS

Approximately half of adults with COVID-19-associated chronic critical illness have fibrotic-like patterns that are associated with higher interleukin-6 levels at intubation. Fibrotic-like patterns are not associated with longer time to liberation from mechanical ventilation or worse 6-month survival.

Pulmonary Sequelae of COVID-19: Focus on Interstitial Lung Disease

As the world transitions from the acute phase of the COVID-19 pandemic, a novel concern has arisen-interstitial lung disease (ILD) as a consequence of SARS-CoV-2 infection. This review discusses what we have learned about its epidemiology, radiological, and pulmonary function findings, risk factors, and possible management strategies. Notably, the prevailing radiological pattern observed is organising pneumonia, with ground-glass opacities and reticulation frequently reported. Longitudinal studies reveal a complex trajectory, with some demonstrating improvement in lung function and radiographic abnormalities over time, whereas others show more static fibrotic changes. Age, disease severity, and male sex are emerging as risk factors for residual lung abnormalities. The intricate relationship between post-COVID ILD and idiopathic pulmonary fibrosis (IPF) genetics underscores the need for further research and elucidation of shared pathways. As this new disease entity unfolds, continued research is vital to guide clinical decision making and improve outcomes for patients with post-COVID ILD.

Dissecting pulmonary fibroblasts heterogeneity in lung development, health and diseases

Lung fibroblasts are the major components in the connective tissue of the pulmonary interstitium and play essential roles in the developing of postnatal lung, synthesizing the extracellular matrix and maintaining the integrity of the lung architecture. Fibroblasts are activated in various disease conditions and exhibit functional heterogeneities according to their origin, spatial location, activated state and microenvironment. In recent years, advances in technology have enabled researchers to identify fibroblast subpopulations in both mouse and human. Here, we discuss pulmonary fibroblast heterogeneity, focusing on the developing, healthy and pathological lung conditions. We firstly review the expression profiles of fibroblasts during lung development, and then consider fibroblast diversity according to different anatomical sites of lung architecture. Subsequently, we discuss fibroblast heterogeneity in genetic lineage. Finally, we focus on how fibroblast heterogeneity may shed light on different pathological lung conditions such as fibrotic diseases, infectious diseases including COVID-19, and lung cancers. We emphasize the importance of comparative studies to illuminate the overlapping characteristics, expression profiles and signaling pathways of the fibroblast subpopulations across disease conditions, a better characterization of the functional complexity rather than the expression of a particular gene may have important therapeutic applications.

Radiological appearance and lung function six months after invasive ventilation in ICU for COVID-19 pneumonia: An observational follow-up study

BACKGROUND

Respiratory functional sequelae in COVID-19 patients admitted to the intensive care unit for invasive ventilation are sparsely reported. The aim of this study was to investigate the radiological lung appearance, lung function and their association at 6 months after hospital discharge. It was hypothesized that the degree of pathological morphology on CT scans would correlate with lung function at the time of follow-up.

METHODS AND FINDINGS

In this single-centre prospective observational study, 86 from 154 patients admitted to ICU due to COVID-19 between March 2020 and May 2021 were followed up at 6 months post discharge with computed tomography (CT) of the chest and pulmonary function tests (PFTs). The PFT results were expressed as z-scores calculated as the difference between the measured and predicted values divided by the standard deviation obtained from a reference population. Correlations were evaluated by Spearman's rho including the 95% confidence interval. Pathological changes on CT were found in 78/85 participants with fibrous parenchymal bands being the most prevalent finding (91%) followed by traction bronchiectasis (64%) and ground glass opacities (41%). Sixty-five participants performed PFTs, and a restrictive pattern was the most prevalent abnormality (34%). Diffusing capacity of the lung for carbon monoxide (DLCO) was reduced in 66% of participants. The CT severity score weakly correlated with forced vital capacity (FVC) z-score (0.295, p = 0.006), DLCO z-score (-0.231, p = 0.032) and alveolar volume (VA) z-score (0.253, p = 0.019).

CONCLUSIONS

Most patients showed persistent radiological abnormalities on CT and reduced lung volumes, impaired diffusion capacity and patterns of restrictive lung function at 6 months post discharge from the ICU. The correlations between abnormalities on CT and lung function tests were weak. Further, studies with a long-term follow-up of lung function in this group of patients are needed.

CT Approach to Lung Injury

Diffuse alveolar damage (DAD), which represents the pathologic changes seen after acute lung injury, is caused by damage to all three layers of the alveolar wall and can ultimately result in alveolar collapse with loss of the normal pulmonary architecture. DAD has an acute phase that predominantly manifests as airspace disease at CT owing to filling of the alveoli with cells, plasma fluids, and hyaline membranes. DAD then evolves into a heterogeneous organizing phase, with mixed airspace and interstitial disease characterized by volume loss, architectural distortion, fibrosis, and parenchymal loss. Patients with DAD have a severe clinical course and typically require prolonged mechanical ventilation, which may result in ventilator-induced lung injury. In those patients who survive DAD, the lungs will remodel over time, but most will have residual findings at chest CT. Organizing pneumonia (OP) is a descriptive term for a histologic pattern characterized by intra-alveolar fibroblast plugs. The significance and pathogenesis of OP are controversial. Some authors regard it as part of a spectrum of acute lung injury, while others consider it a marker of acute or subacute lung injury. At CT, OP manifests with various forms of airspace disease that are most commonly bilateral and relatively homogeneous in appearance at individual time points. Patients with OP most often have a mild clinical course, although some may have residual findings at CT. In patients with DAD and OP, imaging findings can be combined with clinical information to suggest the diagnosis in many cases, with biopsy reserved for difficult cases with atypical findings or clinical manifestations. To best participate in the multidisciplinary approach to patients with lung injury, radiologists must not only recognize these entities but also describe them with consistent and meaningful terminology, examples of which are emphasized in the article. © RSNA, 2023 See the invited commentary by Kligerman et al in this issue. Quiz questions for this article are available in the supplemental material.

Mediators of monocyte chemotaxis and matrix remodeling are associated with the development of fibrosis in patients with COVID-19

Acute respiratory distress syndrome (ARDS) has a fibroproliferative phase that may be followed by pulmonary fibrosis. This has been described in patients with COVID-19 pneumonia, but the underlying mechanisms have not been completely defined. We hypothesized that protein mediators of tissue remodeling and monocyte chemotaxis are elevated in the plasma and endotracheal aspirates of critically ill patients with COVID-19 who subsequently develop radiographic fibrosis. We enrolled COVID-19 patients admitted to the ICU who had hypoxemic respiratory failure, were hospitalized and alive for at least 10 days, and had chest imaging done during hospitalization ( n = 119). Plasma was collected within 24h of ICU admission and at 7d. In mechanically ventilated patients, endotracheal aspirates (ETA) were collected at 24h and 48-96h. Protein concentrations were measured by immunoassay. We tested for associations between protein concentrations and radiographic evidence of fibrosis using logistic regression adjusting for age, sex, and APACHE score. We identified 39 patients (33%) with features of fibrosis. Within 24h of ICU admission, plasma proteins related to tissue remodeling (MMP-9, Amphiregulin) and monocyte chemotaxis (CCL-2/MCP-1, CCL-13/MCP-4) were associated with the subsequent development of fibrosis whereas markers of inflammation (IL-6, TNF-α) were not. After 1 week, plasma MMP-9 increased in patients without fibrosis. In ETAs, only CCL-2/MCP-1 was associated with fibrosis at the later timepoint. This cohort study identifies proteins of tissue remodeling and monocyte recruitment that may identify early fibrotic remodeling following COVID-19. Measuring changes in these proteins over time may allow for early detection of fibrosis in patients with COVID-19.

Quantitative image analysis in COVID-19 acute respiratory distress syndrome: a cohort observational study

Background Acute respiratory distress syndrome (ARDS) is a severe form of acute lung injury commonly associated with pneumonia, including coronavirus disease-19 (COVID-19). The resultant effect can be persistent lung damage, but its extent is not known. We used quantitative high resolution computed tomography (QHR-CT) lung scans to radiographically characterize the lung damage in COVID-19 ARDS (CARDS) survivors. Methods Patients with CARDS (N=20) underwent QHR-CT lung scans 60 to 90 days after initial diagnosis, while hospitalized at a long-term acute care hospital (LTACH). QHR-CT assessed for mixed disease (QMD), ground glass opacities (QGGO), consolidation (QCON) and normal lung tissue (QNL). QMD was correlated with respiratory support on admission, tracheostomy decannulation and supplementary oxygen need on discharge. Results Sixteen patients arrived with tracheostomy requiring invasive mechanical ventilation. Four patients arrived on nasal oxygen support. Of the patients included in this study 10 had the tracheostomy cannula removed, four remained on invasive ventilation, and two died. QHR-CT showed 45% QMD, 28.1% QGGO, 3.0% QCON and QNL=23.9%. Patients with mandatory mechanical ventilation had the highest proportion of QMD when compared to no mechanical ventilation. There was no correlation between QMD and tracheostomy decannulation or need for supplementary oxygen at discharge. Conclusions Our data shows severe ongoing lung injury in patients with CARDS, beyond what is usually expected in ARDS. In this severely ill population, the extent of mixed disease correlates with mechanical ventilation, signaling formation of interstitial lung disease. QHR-CT analysis can be useful in the post-acute setting to evaluate for interstitial changes in ARDS.

Quantitative image analysis in COVID-19 acute respiratory distress syndrome: a cohort observational study

Background Acute respiratory distress syndrome (ARDS) is a severe form of acute lung injury commonly associated with pneumonia, including coronavirus disease-19 (COVID-19). The resultant effect can be persistent lung damage, but its extent is not known. We used quantitative high resolution computed tomography (QHR-CT) lung scans to radiographically characterize the lung damage in COVID-19 ARDS (CARDS) survivors. Methods Patients with CARDS (N=20) underwent QHR-CT lung scans 60 to 90 days after initial diagnosis, while hospitalized at a long-term acute care hospital (LTACH). QHR-CT assessed for mixed disease (QMD), ground glass opacities (QGGO), consolidation (QCON) and normal lung tissue (QNL). QMD was correlated with respiratory support on admission, tracheostomy decannulation and supplementary oxygen need on discharge. Results Sixteen patients arrived with tracheostomy requiring invasive mechanical ventilation. Four patients arrived on nasal oxygen support. Of the patients included in this study 10 had the tracheostomy cannula removed, four remained on invasive ventilation, and two died. QHR-CT showed 45% QMD, 28.1% QGGO, 3.0% QCON and QNL=23.9%. Patients with mandatory mechanical ventilation had the highest proportion of QMD when compared to no mechanical ventilation. There was no correlation between QMD and tracheostomy decannulation or need for supplementary oxygen at discharge. Conclusions Our data shows severe ongoing lung injury in patients with CARDS, beyond what is usually expected in ARDS. In this severely ill population, the extent of mixed disease correlates with mechanical ventilation, signaling formation of interstitial lung disease. QHR-CT analysis can be useful in the post-acute setting to evaluate for interstitial changes in ARDS.

Functional, imaging, and respiratory evaluation (FIRE) of patients post-hospitalization for COVID-19: protocol for a pilot observational study

Introduction

We describe a protocol for FIRE CORAL, an observational cohort study that examines the recovery from COVID-19 disease following acute hospitalization with an emphasis on functional, imaging, and respiratory evaluation.

Methods and analysis

FIRE CORAL is a multicenter prospective cohort study of participants recovering from COVID-19 disease with in-person follow-up for functional and pulmonary phenotyping conducted by the National Heart, Lung and Blood Institute (NHLBI) Prevention and Early Treatment of Acute Lung Injury (PETAL) Network. FIRE CORAL will include a subset of participants enrolled in Biology and Longitudinal Epidemiology of PETAL COVID-19 Observational Study (BLUE CORAL), an NHLBI-funded prospective cohort study describing the clinical characteristics, treatments, biology, and outcomes of hospitalized patients with COVID-19 across the PETAL Network. FIRE CORAL consists of a battery of in-person assessments objectively measuring pulmonary function, abnormalities on lung imaging, physical functional status, and biospecimen analyses. Participants will attend and perform initial in-person testing at 3 to 9 months after hospitalization. The primary objective of the study is to determine the feasibility of longitudinal assessments investigating multiple domains of recovery from COVID-19. Secondarily, we will perform descriptive statistics, including the prevalence and characterization of abnormalities on pulmonary function, chest imaging, and functional status. We will also identify potential clinical and biologic factors that predict recovery or the occurrence of persistent impairment of pulmonary function, chest imaging, and functional status.

Ethics and dissemination

FIRE CORAL is approved via the Vanderbilt University central institutional review board (IRB) and via reliance agreement with the site IRBs. Results will be disseminated via the writing group for the protocol committee and reviewed by the PETAL Network publications committee prior to publication. Data obtained via the study will subsequently be made publicly available via NHLBI’s biorepository.

Strengths and limitations of the study

Strengths:

First US-based multicenter cohort of pulmonary and functional outcomes in patients previously hospitalized for COVID-19 infection

Longitudinal biospecimen measurement allowing for biologic phenotyping of abnormalities

Geographically diverse cohort allowing for a more generalizable understanding of post-COVID pulmonary sequela

Limitations:

Selected cohort given proximity to a participating center

Small cohort which may be underpowered to identify small changes in pulmonary function

Lung function and radiological findings 1 year after COVID-19: a prospective follow-up

BACKGROUND

The coronavirus disease (COVID-19) pandemic has already affected more than 400 million people, with increasing numbers of survivors. These data indicate that a myriad of people may be affected by pulmonary sequelae of the infection. The aim of this study was to evaluate pulmonary sequelae in patients with bilateral COVID-19 pneumonia according to severity 1 year after hospital discharge.

METHODS

COVID-FIBROTIC is a multicenter prospective observational cohort study for admitted patients with bilateral COVID-19 pneumonia. Pulmonary functional outcomes and chest computed tomography sequelae were analyzed 12 months after hospital discharge and we classified patients into three groups according to severity. A post hoc analysis model was designed to establish how functional test changed between groups and over time. A multivariable logistic regression model was created to study prognostic factors for lung diffusion impairment and radiological fibrotic-like changes at 12 months.

RESULTS

Among 488 hospitalized patients with COVID-19 pneumonia, 284 patients had completed the entire evaluation at 12 months. Median age was 60.5 ± 11.9 and 55.3% were men. We found between-group differences in male sex, length of hospital stay, radiological involvement and inflammatory laboratory parameters. The functional evaluation of pulmonary sequelae showed that severe patients had statistically worse levels of lung diffusion at 2 months but no between group differences were found in subsequent controls. At 12-month follow up, however, we found impaired lung diffusion in 39.8% unrelated to severity. Radiological fibrotic-like changes at 12 months were reported in 22.7% of patients (102/448), only associated with radiological involvement at admission (OR: 1.55, 95% CI 1.06-2.38; p = 0.02) and LDH (OR: 0.99, 95% CI 0.98-0.99; p = 0.046).

CONCLUSION

Our data suggest that a significant percentage of individuals would develop pulmonary sequelae after COVID 19 pneumonia, regardless of severity of the acute process. Trial registration clinicaltrials.gov NCT04409275 (June 1, 2020).

Exposure modality influences viral kinetics but not respiratory outcome of COVID-19 in multiple nonhuman primate species

The novel coronavirus SARS-CoV-2 emerged in late 2019, rapidly reached pandemic status, and has maintained global ubiquity through the emergence of variants of concern. Efforts to develop animal models have mostly fallen short of recapitulating severe disease, diminishing their utility for research focusing on severe disease pathogenesis and life-saving medical countermeasures. We tested whether route of experimental infection substantially changes COVID-19 disease characteristics in two species of nonhuman primates (Macaca mulatta; rhesus macaques; RM, Chlorocebus atheiops; African green monkeys; AGM). Species-specific cohorts were experimentally infected with SARS-CoV-2 by either direct mucosal (intratracheal + intranasal) instillation or small particle aerosol in route-discrete subcohorts. Both species demonstrated analogous viral loads in all compartments by either exposure route although the magnitude and duration of viral loading was marginally greater in AGMs than RMs. Clinical onset was nearly immediate (+1dpi) in the mucosal exposure cohort whereas clinical signs and cytokine responses in aerosol exposure animals began +7dpi. Pathologies conserved in both species and both exposure modalities include pulmonary myeloid cell influx, development of pleuritis, and extended lack of regenerative capacity in the pulmonary compartment. Demonstration of conserved pulmonary pathology regardless of species and exposure route expands our understanding of how SARS-CoV-2 infection may lead to ARDS and/or functional lung damage and demonstrates the near clinical response of the nonhuman primate model for anti-fibrotic therapeutic evaluation studies.

The Effect of Exercise-Based Pulmonary Rehabilitation on Quality of Life in Recovered COVID-19 Patients; a Quasi-Experimental Study

Introduction

The coronavirus disease 2019 (COVID-19) is associated with a variety of physical and emotional disorders, and subsequently lower Quality of Life (QOL). This study aimed to investigate the effect of a 2-week exercise-based pulmonary rehabilitation on clinical characteristics and QOL of severe COVID-19 patients after discharge from intensive care unit (ICU).

Methods

In this quasi-experimental study, eligible severe COVID-19 cases, who had survived and were discharged from ICU were selected using convenience sampling method. O2 saturation (SpO2), pulse rate, dyspnea, and QOL were evaluated and compared before and after two weeks of exercise-based pulmonary rehabilitation (PR).

Results

35 cases with the mean age of 57.86 ± 11.73 (18-75) years were studied (51.4% female). The mean SpO2 increased from 90.41 ± 3.97 to 95.11 ± 1.96% after two weeks of pulmonary rehabilitation (p<0.0001). In addition, the mean pulse rate (98.97±16.23 to 88.91±14.03 pulse/minute; p<0.001) and the mean dyspnea severity (5.6±1.97 to 3.45±1.97; p<0.0001) decreased after two weeks of intervention. Besides, the mean total QOL and its dimensions, including general health (p<0.0001), physical status (p<0.0001), emotional status (p = 0.036), and social function (p<0.0001) of patients, had significantly increased after intervention.

Conclusion

Based on the findings of this study, it seems that two-week exercise-based pulmonary rehabilitation could be effective in increasing the SpO2, decreasing dyspnea and pulse rate, and improving the QOL of patients with severe COVID-19 after discharge from ICU.

PTPα Promotes Fibroproliferative Responses After Acute Lung Injury

The Acute Respiratory Distress Syndrome (ARDS) is a major healthcare problem, accounting for significant mortality and long-term disability. Approximately 25% of patients with ARDS will develop an over-exuberant fibrotic response, termed fibroproliferative ARDS (FP-ARDS) that portends a poor prognosis and increased mortality. The cellular pathologic processes that drive FP-ARDS remain incompletely understood. We have previously shown that the transmembrane receptor-type tyrosine phosphatase Protein Tyrosine Phosphatase-a (PTPa) promotes pulmonary fibrosis in preclinical murine models through regulation of TGF-b signaling. In this study, we examine the role of PTPa in the pathogenesis of FP-ARDS in a preclinical murine model of acid (HCl)-induced acute lung injury. We demonstrate that while mice genetically deficient in PTPa (Ptpra^-/-) are susceptible to early HCl-induced lung injury, they exhibit markedly attenuated fibroproliferative responses. Additionally, early pro-fibrotic gene expression is reduced in lung tissue after acute lung injury in Ptpra^-/- mice, and stimulation of naïve lung fibroblasts with the BAL fluid from these mice results in attenuated fibrotic outcomes compared to wild type littermate controls. Transcriptomic analyses demonstrates reduced Extracellular Matrix (ECM) deposition and remodeling in mice genetically deficient in PTPa. Importantly, human lung fibroblasts modified with a CRISPR-targeted deletion of PTPRA exhibit reduced expression of profibrotic genes in response to TGF-β stimulation, demonstrating the importance of PTPa in human lung fibroblasts. Together, these findings demonstrate that PTPa is a key regulator of fibroproliferative processes following acute lung injury and could serve as a therapeutic target for patients at risk for poor long-term outcomes in ARDS.

Landscape of Peripheral Blood Mononuclear Cells and Soluble Factors in Severe COVID-19 Patients With Pulmonary Fibrosis Development

Resulting from severe inflammation and cell destruction, COVID-19 patients could develop pulmonary fibrosis (PF), which remains in the convalescent stage. Nevertheless, how immune response participates in the pathogenesis of PF progression is not well defined. To investigate that question, 12 patients with severe COVID-19 were included in the study. Peripheral mononuclear cell (PBMC) samples were collected shortly after their admission and proceeded for single-cell RNA sequencing (scRNA-seq). After 14 days of discharge, the patients were revisited for chest CT scan. PF index (FI) was computed by AI-assisted CT images. Patients were categorized into FI^hi and FI^lo based on median of FI. By scRNA-seq analysis, our data demonstrated that frequency of CD4+ activated T cells and Treg cells were approximately 3-fold higher in FI^hi patients compared with FI^lo ones (p < 0.034 for all). By dissecting the differentially expressed genes, we found an overall downregulation of IFN-responsive genes (STAT1, IRF7, ISG15, ISG20, IFIs, and IFITMs) and S100s alarmins (S100A8, S100A9, S100A12, etc.) in all T-cell clusters, and cytotoxicity-related genes (GZMB, PRF1, and GNLY) in CTLs and γδ T cells in the FI^hi cohort, compared with FI^lo subjects. The GSEA analysis illustrated decreased expression of genes enriched in IFN signaling, innate immune response, adaptive immune response in T cells, NK cells, and monocytes in FI^hi patients compared with FI^lo ones. In conclusion, these data indicated that the attenuated IFN-responsive genes and their related signaling pathways could be critical for PF progression in COVID-19 patients.

Prognosis and antibody profiles in survivors of critical illness from COVID-19: a prospective multicentre cohort study

BACKGROUND

There is a need to assess the long-term outcomes of survivors of critical illness from COVID-19.

METHODS

Ninety-two survivors of critical illness from COVID-19 from four hospitals in Hubei Province, China participated in this prospective cohort study. Multiple characteristics, including lung function (lung volumes, diffusing capacity for carbon monoxide, chest computed tomography scores, and walking capacity); immune status (SARS-CoV-2-neutralising antibody and all subtypes of immunoglobulin (Ig) G against SARS-CoV-2, immune cells in response to ex vivo antigen peptide stimuli, and lymphocyte count and its subtypes); liver, coagulation, and kidney functions; quality of life; cognitive function; and mental status, were assessed after 3, 6, and 12 months of follow-up.

RESULTS

Amongst the 92 enrolled survivors, 72 (78%) patients required mechanical ventilation. At 12 months, the predicted percentage diffusing capacity of lung for carbon monoxide was 82% (inter-quartile range [IQR]: 76-97%) with a residual volume of 77 (64-88)%. Other lung function parameters and the 6-min walk test improved gradually over time and were almost back to normal by 12 months. The titres of IgG and neutralising antibody to COVID-19 remained high at 12 months compared with those of controls who were not infected with COVID-19, although IgG titres decreased significantly from 34.0 (IQR: 23.8-74.3) to 15.0 (5.8-24.3) AU ml-1 (P<0.001), whereas neutralising antibodies decreased from 29.99 (IQR: 19.43-53.93) AU ml-1 at 6 months to 19.75 (13.1-29.8) AU ml-1 (P<0.001) at 12 months. In general, liver, kidney, physical, and mental functions also improved over time.

CONCLUSIONS

Survivors of critical illness from COVID-19 show some persistent long-term impairments in lung function. However, a majority of these tests were normal by 12 months. These patients still had detectable levels of neutralising antibodies against SARS-CoV-2 and all types of IgG at 12 months, but the levels had declined over this time period.

CLINICAL TRIAL REGISTRATION

None.

From ARDS to pulmonary fibrosis: the next phase of the COVID-19 pandemic?

While the coronavirus disease 19 (COVID-19) pandemic has transformed the medical and scientific communites since it was first reported in late 2019, we are only beginning to understand the chronic health burdens associated with this disease. Although COVID-19 is a multi-systemic disease, the lungs are the primary source of infection and injury, resulting in pneumonia and, in severe cases, acute respiratory distress syndrome (ARDS). Given that pulmonary fibrosis is a well-recognized sequela of ARDS, many have questioned whether COVID-19 survivors will face long-term pulmonary consequences. This review is aimed at integrating our understanding of the pathophysiologic mechanisms underlying fibroproliferative ARDS with our current knowledge of the pulmonary consequences of COVID-19 disease.

Outpatient Pulmonary Rehabilitation in Patients with Long COVID Improves Exercise Capacity, Functional Status, Dyspnea, Fatigue, and Quality of Life

BACKGROUND

COVID-19 survivors face the risk of long-term sequelae including fatigue, breathlessness, and functional limitations. Pulmonary rehabilitation has been recommended, although formal studies quantifying the effect of rehabilitation in COVID-19 patients are lacking.

METHODS

We conducted a prospective observational cohort study including consecutive patients admitted to an outpatient pulmonary rehabilitation center due to persistent symptoms after COVID-19. The primary endpoint was change in 6-min walk distance (6MWD) after undergoing a 6-week interdisciplinary individualized pulmonary rehabilitation program. Secondary endpoints included change in the post-COVID-19 functional status (PCFS) scale, Borg dyspnea scale, Fatigue Assessment Scale, and quality of life. Further, changes in pulmonary function tests were explored.

RESULTS

Of 64 patients undergoing rehabilitation, 58 patients (mean age 47 years, 43% women, 38% severe/critical COVID-19) were included in the per-protocol-analysis. At baseline (i.e., in mean 4.4 months after infection onset), mean 6MWD was 584.1 m (±95.0), and functional impairment was graded in median at 2 (IQR, 2-3) on the PCFS. On average, patients improved their 6MWD by 62.9 m (±48.2, p < 0.001) and reported an improvement of 1 grade on the PCFS scale. Accordingly, we observed significant improvements across secondary endpoints including presence of dyspnea (p < 0.001), fatigue (p < 0.001), and quality of life (p < 0.001). Also, pulmonary function parameters (forced expiratory volume in 1 s, lung diffusion capacity, inspiratory muscle pressure) significantly increased during rehabilitation.

CONCLUSION

In patients with long COVID, exercise capacity, functional status, dyspnea, fatigue, and quality of life improved after 6 weeks of personalized interdisciplinary pulmonary rehabilitation. Future studies are needed to establish the optimal protocol, duration, and long-term benefits as well as cost-effectiveness of rehabilitation.

The Impact of Sociodemographic, Nutritional, and Health Factors on the Incidence and Complications of COVID-19 in Egypt: A Cross-Sectional Study

This study was intended to explore sociodemographic, nutritional, and health-related factors on the incidence of COVID-19 infection within the Egyptian population by assessing the frequency and determinants of post-COVID-19 symptoms and complications. A cross-sectional study using a structured survey on 15,166 participants was adopted. The results revealed common symptoms including fever (79.1%), cough (74.5%), anosmia& ageusia (68.4%), and dyspnea (66.9%). The patients were nonsmokers (83.9%), while 9.7% were mild smokers. The percentage of infected patients with comorbidities versus those without comorbidities were 29%, 71%, respectively. The highest incidence of infection was in those patients with hypertension (14.8%) and diabetes (10.9%), especially females with age >50 years and obesity (BMI; 30−39.9). The highest risks were observed for anticoagulants in the age above 50 years, morbid obesity, presence of comorbidities, and being a healthcare worker. The predictors of clot risk were in the age above 50 years, non-educated, and eating meat and eggs. Nonetheless, the highest risk of using antidepressants was in patients >50 years and those who traveled abroad. These findings and similarities within the surrounding region, the Middle East, North Africa, and South Europe, indicate the possibility of sharing the same viral strain and characteristics that may predict a similar vaccine efficacy and response.

Clinical characteristics and outcomes of post-COVID-19 pulmonary fibrosis: A case-control study

The development of pulmonary fibrosis is a rare complication of the novel coronavirus disease 2019 (COVID-19). Limited information is available in the literature about that, and the present study aimed to address this gap.This case-control study included 64 patients with post-COVID-19 pulmonary fibrosis who were hospitalized for COVID-19.The percentage of patients aged ≥65 years (44%) who demised was higher than those who survived (25%). Male patients (62%) had higher mortality than female patients (37%). The most frequently reported clinical symptoms were shortness of breath (98%), cough (91%), and fever (70%). Most COVID-19 patients with pulmonary fibrosis (81%) were admitted to an intensive care unit (ICU), and 63% required mechanical ventilation. Bilateral lung infiltrates (94%), "ground glass" opacity (91%), "honeycomb" lung (25%), and pulmonary consolidation (9%) were commonly identified in COVID-19 patients with pulmonary fibrosis who survived. The findings for computed tomography and dyspnea scale were significantly higher in severe cases admitted to the ICU who required mechanical ventilation. A higher computerized tomography score also correlated significantly with a longer duration of stay in hospital and a higher degree of dyspnea. Half of the COVID-19 patients with pulmonary fibrosis (50%) who survived required oxygen therapy, and those with "honeycomb" lung required long-term oxygen therapy to a far greater extent than others. Cox regression revealed that smoking and asthma were significantly associated with ICU admission and the risk of mortality.Post-COVID-19 pulmonary fibrosis is a severe complication that leads to permanent lung damage or death.

Recovering from a pandemic: pulmonary fibrosis after SARS-CoV-2 infection

Acute manifestations of SARS-CoV-2 infection continue to impact the lives of many across the world. Post-acute sequelae of coronavirus disease 2019 (COVID-19) may affect 10–30% of survivors of COVID-19, and post-acute sequelae of COVID-19 (PASC)-pulmonary fibrosis is a long-term outcome associated with major morbidity. Data from prior coronavirus outbreaks (severe acute respiratory syndrome and Middle East respiratory syndrome) suggest that pulmonary fibrosis will contribute to long-term respiratory morbidity, suggesting that PASC-pulmonary fibrosis should be thoroughly screened for through pulmonary function testing and cross-sectional imaging. As data accumulates on the unique pathobiologic mechanisms underlying critical COVID-19, a focus on corollaries to the subacute and chronic profibrotic phenotype must be sought as well. Key aspects of acute COVID-19 pathobiology that may account for increased rates of pulmonary fibrosis include monocyte/macrophage–T-cell circuits, profibrotic RNA transcriptomics, protracted elevated levels of inflammatory cytokines, and duration of illness and ventilation. Mechanistic understanding of PASC-pulmonary fibrosis will be central in determining therapeutic options and will ultimately play a role in transplant considerations. Well-designed cohort studies and prospective clinical registries are needed. Clinicians, researchers and healthcare systems must actively address this complication of PASC to minimise disability, maximise quality of life and confront a post-COVID-19 global health crisis.

A complication of COVID-19, PASC-pulmonary fibrosis, has the potential to become a global respiratory health crisis. Dedicated surveillance, mechanistic understanding and clinical and research efforts are needed to confront this emerging sequela of COVID-19.https://bit.ly/3GEyB04

Reversible Bronchiectasis in COVID-19 Survivors With Acute Respiratory Distress Syndrome: Pseudobronchiectasis

To retrospectively analyze whether traction bronchiectasis was reversible in coronavirus disease 2019 (COVID-19) survivors with acute respiratory distress syndrome (ARDS), and whether computed tomography (CT) findings were associated with the reversibility, 41 COVID-19 survivors with ARDS were followed-up for more than 4 months. Demographics, clinical data, and all chest CT images were collected. The follow-up CT images were compared with the previous CT scans. There were 28 (68%) patients with traction bronchiectasis (Group I) and 13 (32%) patients without traction bronchiectasis (Group II) on CT images. Traction bronchiectasis disappeared completely in 21 of the 28 (75%) patients (Group IA), but did not completely disappear in seven of the 28 (25%) patients (Group IB). In the second week after onset, the evaluation score on CT images in Group I was significantly higher than that in Group II (p = 0.001). The proportion of reticulation on the last CT images in Group IB was found higher than that in Group IA (p < 0.05). COVID-19 survivors with ARDS might develop traction bronchiectasis, which can be absorbed completely in most patients. Traction bronchiectasis in a few patients did not disappear completely, but bronchiectasis was significantly relieved. The long-term follow-up is necessary to further assess whether traction bronchiectasis represents irreversible fibrosis.

Pulmonary fibrosis 4 months after COVID-19 is associated with severity of illness and blood leucocyte telomere length

The risk factors for development of fibrotic-like radiographic abnormalities after severe COVID-19 are incompletely described and the extent to which CT findings correlate with symptoms and physical function after hospitalisation remains unclear. At 4 months after hospitalisation, fibrotic-like patterns were more common in those who underwent mechanical ventilation (72%) than in those who did not (20%). We demonstrate that severity of initial illness, duration of mechanical ventilation, lactate dehydrogenase on admission and leucocyte telomere length are independent risk factors for fibrotic-like radiographic abnormalities. These fibrotic-like changes correlate with lung function, cough and measures of frailty, but not with dyspnoea.

Compression depth of 30 mm has similar efficacy and fewer complications versus 50 mm during mechanical chest compression with miniaturized chest compressor in a porcine model of cardiac arrest

Background

Current guidelines recommend a 50 mm or greater compression depth for manual chest compression in adults. However, whether this uniform compression depth is a suitable requirement for mechanical CPR remains to be determined. We hypothesized that a relatively shallow compression depth (30 mm) would have similar hemodynamic efficacy but fewer complications versus the standard compression depth (50 mm) during mechanical cardiopulmonary resuscitation (CPR) with the miniaturized chest compressor (MCC) in a porcine model.

Methods

In the current study, we used a total of 16 domestic male pigs (38±2 kg). All pigs were exposed to 7 min of ventricular fibrillation (VF) followed by 5 min of CPR. Then the animals were randomly assigned to the shallow (30 mm) group and the standard (50 mm) group. At the second min of CPR, every pig was given epinephrine (20 µg/kg) through the femoral vein and repeated every 3 min. First defibrillation was delivered with a single 120 J shock at 5 min of CPR. Hemodynamics, carotid blood flow (CBF), end-tidal carbon dioxide (ETCO₂), coronary perfusion pressure (CPP), intrathoracic pressure (ITP) and arterial blood gas were measured. Rib fractures and lung injuries, as indicated by ground-glass opacification (GGO), as well as intense parenchymal opacification (IPO), were assessed and calculated by quantitative computed tomography (QCT) scan.

Results

We found no significant differences in CPP, CBF, or ETCO₂ between the both groups throughout the CPR period. After administration of epinephrine, the CPP of all animals increased while ETCO₂ and CBF decreased during CPR. A significantly lower intrathoracic positive pressure (ITPP) and systolic artery pressure (SAP) were measured in the shallow group at the first min of CPR. However, we didn’t find remarkable differences in these values between the both groups for the next 4 min of CPR. All animals were successfully resuscitated. The shallow group had significantly lower IPO QCT scores compared with the standard group. We found no significant differences in GGO QCT scores after resuscitation between both groups.

Conclusions

Relatively shallow compression depth has similar hemodynamic efficacy but fewer complications versus the standard compression depth.

CT of Post-Acute Lung Complications of COVID-19

The acute course of COVID-19 is variable and ranges from asymptomatic infection to fulminant respiratory failure. Patients recovering from COVID-19 can have persistent symptoms and CT abnormalities of variable severity. At 3 months after acute infection, a subset of patients will have CT abnormalities that include ground-glass opacity (GGO) and subpleural bands with concomitant pulmonary function abnormalities. At 6 months after acute infection, some patients have persistent CT changes to include the resolution of GGOs seen in the early recovery phase and the persistence or development of changes suggestive of fibrosis, such as reticulation with or without parenchymal distortion. The etiology of lung disease after COVID-19 may be a sequela of prolonged mechanical ventilation, COVID-19-induced acute respiratory distress syndrome (ARDS), or direct injury from the virus. Predictors of lung disease after COVID-19 include need for intensive care unit admission, mechanical ventilation, higher inflammatory markers, longer hospital stay, and a diagnosis of ARDS. Treatments of lung disease after COVID-19 are being investigated, including the potential of antifibrotic agents for prevention of lung fibrosis after COVID-19. Future research is needed to determine the long-term persistence of lung disease after COVID-19, its impact on patients, and methods to either prevent or treat it. © RSNA, 2021.

Post-COVID-19 Pulmonary Fibrosis: Novel Sequelae of the Current Pandemic

Since the initial identification of the novel coronavirus SARS-CoV-2 in December 2019, the COVID-19 pandemic has become a leading cause of morbidity and mortality worldwide. As effective vaccines and treatments begin to emerge, it will become increasingly important to identify and proactively manage the long-term respiratory complications of severe disease. The patterns of imaging abnormalities coupled with data from prior coronavirus outbreaks suggest that patients with severe COVID-19 pneumonia are likely at an increased risk of progression to interstitial lung disease (ILD) and chronic pulmonary vascular disease. In this paper, we briefly review the definition, classification, and underlying pathophysiology of interstitial lung disease (ILD). We then review the current literature on the proposed mechanisms of lung injury in severe COVID-19 infection, and outline potential viral- and immune-mediated processes implicated in the development of post-COVID-19 pulmonary fibrosis (PCPF). Finally, we address patient-specific and iatrogenic risk factors that could lead to PCPF and discuss strategies for reducing risk of pulmonary complications/sequelae.

Management of patients with digestive diseases during the COVID-19 pandemic. Clinical Practice Guidelines by the Russian scientific medical society of internal medicine (RSMSIM) and the Gastroenterological Scientific Society of Russia (2nd edition)

The presented clinical practice guidelines of the Gastroenterological Scientific Society of Russia (GSSR), diagnostic, and therapeutic approaches for patients with digestive diseases during the COVID-19 pandemic. The guidelines were approved by the XXIII Congress of the GSSR and the 22nd International Slavonic-Baltic Scientifi c Forum “St. Petersburg - Gastro-2020 ON-LINE” (St. Petersburg, June 11, 2020). The presented clinical practice guidelines of the Russian Scientific Medical Society of Internal Medicine (RSMSIM) and the Gastroenterological Scientific Society of Russia (GSSR), diagnostic, and therapeutic approaches for patients with digestive diseases during the COVID-19 pandemic. The recommendations were approved at the XV National Congress of Internal Medicine, XXIII Congress of NOGR on the basis of the 1st edition, adopted at the 22nd International Slavic- Baltic Scientific Forum “St. Petersburg - Gastro-2020 ON-LINE”.

Mesenchymal Stromal Cell Secretome for Post-COVID-19 Pulmonary Fibrosis: A New Therapy to Treat the Long-Term Lung Sequelae?

To date, more than 100 million people worldwide have recovered from COVID-19. Unfortunately, although the virus is eradicated in such patients, fibrotic irreversible interstitial lung disease (pulmonary fibrosis, PF) is clinically evident. Given the vast numbers of individuals affected, it is urgent to design a strategy to prevent a second wave of late mortality associated with COVID-19 PF as a long-term consequence of such a devastating pandemic. Available antifibrotic therapies, namely nintedanib and pirfenidone, might have a role in attenuating profibrotic pathways in SARS-CoV-2 infection but are not economically sustainable by national health systems and have critical adverse effects. It is our opinion that the mesenchymal stem cell secretome could offer a new therapeutic approach in treating COVID-19 fibrotic lungs through its anti-inflammatory and antifibrotic factors.

COVID-19: Direct and Indirect Mechanisms of Statins

The virus responsible for the current COVID-19 pandemic is severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): a new virus with high infectivity and moderate mortality. The major clinical manifestation of COVID-19 is interstitial pneumonia, which may progress to acute respiratory distress syndrome (ARDS). However, the disease causes a potent systemic hyperin-flammatory response, i.e., a cytokine storm or macrophage activation syndrome (MAS), which is associated with thrombotic complications. The complexity of the disease requires appropriate intensive treatment. One of promising treatment is statin administration, these being 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors that exert pleiotropic anti-inflammatory effects. Recent studies indicate that statin therapy is associated with decreased mortality in COVID-19, which may be caused by direct and indirect mechanisms. According to literature data, statins can limit SARS-CoV-2 cell entry and replication by inhibiting the main protease (Mpro) and RNA-dependent RNA polymerase (RdRp). The cytokine storm can be ameliorated by lowering serum IL-6 levels; this can be achieved by inhibiting Toll-like receptor 4 (TLR4) and modulating macrophage activity. Statins can also reduce the complications of COVID-19, such as thrombosis and pulmonary fibrosis, by reducing serum PAI-1 levels, attenuating TGF-β and VEGF in lung tissue, and improving endothelial function. Despite these benefits, statin therapy may have side effects that should be considered, such as elevated creatinine kinase (CK), liver enzyme and serum glucose levels, which are already elevated in severe COVID-19 infection. The present study analyzes the latest findings regarding the benefits and limitations of statin therapy in patients with COVID-19.

Post-acute COVID-19 syndrome

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the pathogen responsible for the coronavirus disease 2019 (COVID-19) pandemic, which has resulted in global healthcare crises and strained health resources. As the population of patients recovering from COVID-19 grows, it is paramount to establish an understanding of the healthcare issues surrounding them. COVID-19 is now recognized as a multi-organ disease with a broad spectrum of manifestations. Similarly to post-acute viral syndromes described in survivors of other virulent coronavirus epidemics, there are increasing reports of persistent and prolonged effects after acute COVID-19. Patient advocacy groups, many members of which identify themselves as long haulers, have helped contribute to the recognition of post-acute COVID-19, a syndrome characterized by persistent symptoms and/or delayed or long-term complications beyond 4 weeks from the onset of symptoms. Here, we provide a comprehensive review of the current literature on post-acute COVID-19, its pathophysiology and its organ-specific sequelae. Finally, we discuss relevant considerations for the multidisciplinary care of COVID-19 survivors and propose a framework for the identification of those at high risk for post-acute COVID-19 and their coordinated management through dedicated COVID-19 clinics.

Determinants of persistent post-COVID-19 symptoms: value of a novel COVID-19 symptom score

Background

Being a newly emerging disease, little is known about its long-lasting post-COVID-19 consequences. The aim of this work is to assess the frequency, patterns, and determinants of persistent post-COVID-19 symptoms and to evaluate the value of a proposed novel COVID-19 symptom score. Patients with confirmed COVID-19 in a hospital-based registry were included in a cross-sectional study (the hospitals including Assiut University Hospital, Assiut Chest Hospital, Aswan University Hospital, and Aswan Specialized Hospital). The patient demographics, comorbid disorders, the mean duration since the onset of the symptoms, history of hospital or ICU admittance, and the treatment taken during the acute state, as well as symptom score before and after convalescence, were recorded.

Results

The most frequent constitutional and neurological symptoms were myalgia (60.0%), arthralgia (57.2%), restriction of daily activities (57.0%), and sleeping troubles (50.9%), followed by anorexia (42.6%), chest pain (32.6%), gastritis (32.3%), cough (29.3%), and dyspnea (29.1%). The mean total score of acute stage symptoms was 31.0 ± 16.3 while post-COVID 19 symptom score was 13.1 ± 12.6 (P < 0.001). The main determinants of the persistent post-COVID-19 symptoms were the need for oxygen therapy (P < 0.001), pre-existing hypertension (P = 0.039), chronic pulmonary disorders (P = 0.012), and any chronic comorbidity (P = 0.004). There was a correlation between the symptom score during the acute attack and post-COVID-19 stage (P < 0.001, r = 0.67). The acute phase score had 83.5% sensitivity and 73.3% specificity for the cutoff point > 18 to predict occurrence of post-COVID-19 symptoms.

Conclusions

COVID-19 can present with a diverse spectrum of long-term post-COVID-19 symptoms. Increased acute phase symptom severity and COVID-19 symptom score > 18 together with the presence of any comorbid diseases increase the risk for persistent post-COVID-19 manifestations and severity.

[Is there a post-COVID syndrome?]

Für kritisch kranke COVID-19-Patienten könnte das Überleben der Akutphase evtl. nur die Bewältigung der ersten Etappe eines insgesamt langen und herausfordernden Weges sein. Körperliche, kognitive und psychologische Folgen sind realistisch. Aber stellen residuale Symptome bei Patienten mit mikrobiologischer Normalisierung tatsächlich ein „Post-COVID-Syndrom“ dar, und welche Symptome sind in diesem Zusammenhang prinzipiell denkbar und in der Lage, dieses zu begründen? Dass kritisch kranke Patienten oftmals über einen längeren Zeitraum nach ihrer Krankenhausentlassung noch funktionelle Einschränkungen erleben, ist nicht neu. Für die Diagnose eines Post-COVID-Syndroms ist es aber in den meisten Fällen bei COVID-19 jetzt noch zu früh. Dafür müssen die Symptome mindestens 6 Monate anhalten. Aktuell kann man daher wohl nur von postinfektiöser Fatigue sprechen. Und selbst wenn sich Betroffene körperlich wieder erholen, so sind sie evtl. besonders gefährdet, an lang anhaltenden mentalen Gesundheitsproblemen zu leiden bzw. eine reduzierte Lebensqualität zu empfinden. Solche Beobachtungen gibt es jedoch nicht nur nach einem ARDS („acute respiratory distress syndrome“), viele Intensivpatienten verzeichnen lange anhaltende Beschwerden, die auch als „post-intensive care syndrome“ (PICS) bezeichnet werden. In Summe bestehen jedenfalls ausreichend Hinweise für die mögliche Existenz eines „Post-COVID-Syndroms“ bzw. für die Berechtigung, die denkbaren Folgeerscheinungen mit persistierenden Symptomen so zu bezeichnen. Es sind alle Anstrengungen gerechtfertigt, die eine vollständige funktionelle Wiederherstellung und eine Rückkehr in ein Leben nach Corona ermöglichen.

An integrated multidisciplinary model of COVID-19 recovery care

Background

In January 2020, the WHO declared the SARS-CoV-2 outbreak a public health emergency; by March 11, a pandemic was declared. To date in Ireland, over 3300 patients have been admitted to acute hospitals as a result of infection with COVID-19.

Aims

This article aims to describe the establishment of a COVID Recovery Service, a multidisciplinary service for comprehensive follow-up of patients with a hospital diagnosis of COVID-19 pneumonia.

Methods

A hybrid model of virtual and in-person clinics was established, supported by a multidisciplinary team consisting of respiratory, critical care, infectious diseases, psychiatry, and psychology services. This model identifies patients who need enhanced follow-up following COVID-19 pneumonia and aims to support patients with complications of COVID-19 and those who require integrated community care.

Results

We describe a post-COVID-19 service structure together with detailed protocols for multidisciplinary follow-up. One hundred seventy-four patients were discharged from Beaumont Hospital after COVID-19 pneumonia. Sixty-seven percent were male with a median age (IQR) of 66.5 (51–97). Twenty-two percent were admitted to the ICU for mechanical ventilation, 11% had non-invasive ventilation or high flow oxygen, and 67% did not have specialist respiratory support. Early data suggests that 48% of these patients will require medium to long-term specialist follow-up.

Conclusions

We demonstrate the implementation of an integrated multidisciplinary approach to patients with COVID-19, identifying those with increased physical and mental healthcare needs. Our initial experience suggests that significant physical, psychological, and cognitive impairments may persist despite clinical resolution of the infection.

Participant Retention in Follow-Up Studies of Acute Respiratory Failure Survivors

BACKGROUND

With an increasing number of follow-up studies of acute respiratory failure survivors, there is need for a better understanding of participant retention and its reporting in this field of research. Hence, our objective was to synthesize participant retention data and associated reporting for this field.

METHODS

Two screeners independently searched for acute respiratory failure survivorship studies within a published scoping review to evaluate subject outcomes after hospital discharge in critical illness survivors.

RESULTS

There were 21 acute respiratory failure studies (n = 4,342 survivors) over 47 follow-up time points. Six-month follow-up (range: 2-60 months) was the most frequently reported time point, in 81% of studies. Only 1 study (5%) reported accounting for loss to follow-up in sample-size calculation. Retention rates could not be calculated for 5 (24%) studies. In 16 studies reporting on retention across all time points, retention ranged from 32% to 100%. Pooled retention rates at 3, 6, 12, and 24 months were 85%, 89%, 82%, and 88%, respectively. Retention rates did not significantly differ by publication year, participant mean age, or when comparing earlier (3 months) versus each later follow-up time point (6, 12, or 24 months).

CONCLUSIONS

Participant retention was generally high but varied greatly across individual studies and time points, with 24% of studies reporting inadequate data to calculate retention rate. High participant retention is possible, but resources for optimizing retention may help studies retain participants. Improved reporting guidelines with greater adherence would be beneficial.

Pulmonary fibrosis and COVID-19: the potential role for antifibrotic therapy

In December, 2019, reports emerged from Wuhan, China, of a severe acute respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). By the end of April, 2020, over 3 million people had been confirmed infected, with over 1 million in the USA alone, and over 215 000 deaths. The symptoms associated with COVID-19 are diverse, ranging from mild upper respiratory tract symptoms to severe acute respiratory distress syndrome. The major risk factors for severe COVID-19 are shared with idiopathic pulmonary fibrosis (IPF), namely increasing age, male sex, and comorbidities such as hypertension and diabetes. However, the role of antifibrotic therapy in patients with IPF who contract SARS-CoV-2 infection, and the scientific rationale for their continuation or cessation, is poorly defined. Furthermore, several licensed and potential antifibrotic compounds have been assessed in models of acute lung injury and viral pneumonia. Data from previous coronavirus infections such as severe acute respiratory syndrome and Middle East respiratory syndrome, as well as emerging data from the COVID-19 pandemic, suggest there could be substantial fibrotic consequences following SARS-CoV-2 infection. Antifibrotic therapies that are available or in development could have value in preventing severe COVID-19 in patients with IPF, have the potential to treat severe COVID-19 in patients without IPF, and might have a role in preventing fibrosis after SARS-CoV-2 infection.

Pulmonary fibrosis in the aftermath of the COVID-19 era (Review)

The year 2020 is characterized by the COVID-19 pandemic that has resulted in more than half a million deaths in recent months. The high mortality is associated with acute severe respiratory failure that results in ICU admission and intubation. While facing this fatal disease, research and clinical observations need to be carried out in order to evaluate the long-term effects of the COVID-19 acute respiratory distress syndrome (ARDS). Potent clinical and laboratory biomarkers should be studied to be able to predict the subgroup of patients that are going to deteriorate or develop lung fibrosis. The opportunity of personalized medicine is a good way to consider for these patients.

Circulating fibrocytes traffic to the lung in murine acute lung injury and predict outcomes in human acute respiratory distress syndrome: a pilot study

Background

Fibrosis is an integral component of the pathogenesis of acute lung injury and is associated with poor outcomes in patients with acute respiratory distress syndrome (ARDS). Fibrocytes are bone marrow-derived cells that traffic to injured tissues and contribute to fibrosis; hence their concentration in the peripheral blood has the potential to serve as a biomarker of lung fibrogenesis. We therefore sought to test the hypothesis that the concentration and phenotype of circulating fibrocytes in patients with ARDS predicts clinical outcomes.

Methods

For the animal studies, C57Bl/6 mice were infected with experimental Klebsiella pneumoniae in a model of acute lung injury; one-way ANOVA was used to compare multiple groups and two-way ANOVA was used to compare two groups over time. For the human study, 42 subjects with ARDS and 12 subjects with pneumonia (without ARDS) were compared to healthy controls. Chi-squared or Fisher’s exact test were used to compare binary outcomes. Survival data was expressed using a Kaplan-Meier curve and compared by log-rank test. Univariable and multivariable logistic regression were used to predict death.

Results

In mice with acute lung injury caused by Klebsiella pneumonia, there was a time-dependent increase in lung soluble collagen that correlated with sequential expansion of fibrocytes in the bone marrow, blood, and then lung compartments. Correspondingly, when compared via cross-sectional analysis, the initial concentration of blood fibrocytes was elevated in human subjects with ARDS or pneumonia as compared to healthy controls. In addition, fibrocytes from subjects with ARDS displayed an activated phenotype and on serial measurements, exhibited intermittent episodes of markedly elevated concentration over a median of 1 week. A peak concentration of circulating fibrocytes above a threshold of > 4.8 × 10⁶ cells/mL cells correlated with mortality that was independent of age, ratio of arterial oxygen concentration to the fraction of inspired oxygen, and vasopressor requirement.

Conclusions

Circulating fibrocytes increase in a murine model of acute lung injury and elevation in the number of these cells above a certain threshold is correlated with mortality in human ARDS. Therefore, these cells may provide a useful and easily measured biomarker to predict outcomes in these patients.

Alterations in Respiratory Mechanics and Neural Respiratory Drive After Restoration of Spontaneous Circulation in a Porcine Model Subjected to Different Downtimes of Cardiac Arrest

Background

The potential alterations of respiratory pathophysiology after cardiopulmonary resuscitation (CPR) are relatively undefined. While untreated arrest is known to affect post–cardiopulmonary resuscitation circulation, whether it affects respiratory pathophysiology remains unclear. We aimed to investigate the post–cardiopulmonary resuscitation changes in respiratory mechanics and neural respiratory drive with varying delays (5 or 10 minutes) in the treatment of ventricular fibrillation (VF).

Methods and Results

Twenty‐six male Yorkshire pigs were used. Anesthetized pigs weighing 38±5 kg were randomized into 3 groups (n=10 each in the VF5 and VF10 groups, with VF kept untreated for 5 and 10 minutes, respectively, and n=6 in the sham group without VF). Defibrillation was attempted after 6 minutes of cardiopulmonary resuscitation. Pulse‐induced contour cardiac output, respiratory mechanics, diaphragmatic electromyogram, blood gas, lung imaging, and histopathology were evaluated for 12 hours. Significantly elevated mean root mean square of diaphragmatic electromyogram, transdiaphragmatic pressure, and minute ventilation were observed, but reduced minute ventilation/mean root mean square, dynamic pulmonary compliance, and Pao₂ were noted in both VF groups. Despite recovery of spontaneous breathing, the abnormalities in respiratory mechanics and neural respiratory drive, Pao₂, and extravascular lung water continued to last for >12 hours. The changes in imaging (P=0.027) and histopathology (P=0.012) were more severe in the VF10 group compared with the VF5 group.

Conclusions

There is an uncoupling between the respiratory center and ventilation after restoration of spontaneous circulation. Prolonged untreated arrest from cardiac arrest contributes to more serious alterations in lung pathophysiology.

ERS statement on chest imaging in acute respiratory failure

Chest imaging in patients with acute respiratory failure plays an important role in diagnosing, monitoring and assessing the underlying disease. The available modalities range from plain chest X-ray to computed tomography, lung ultrasound, electrical impedance tomography and positron emission tomography. Surprisingly, there are presently no clear-cut recommendations for critical care physicians regarding indications for and limitations of these different techniques.The purpose of the present European Respiratory Society (ERS) statement is to provide physicians with a comprehensive clinical review of chest imaging techniques for the assessment of patients with acute respiratory failure, based on the scientific evidence as identified by systematic searches. For each of these imaging techniques, the panel evaluated the following items: possible indications, technical aspects, qualitative and quantitative analysis of lung morphology and the potential interplay with mechanical ventilation. A systematic search of the literature was performed from inception to September 2018. A first search provided 1833 references. After evaluating the full text and discussion among the committee, 135 references were used to prepare the current statement.These chest imaging techniques allow a better assessment and understanding of the pathogenesis and pathophysiology of patients with acute respiratory failure, but have different indications and can provide additional information to each other.

Optimizing Post-Intensive Care Unit Rehabilitation

Survivors of intensive care unit (ICU) admission face unique challenges after hospital discharge. In addition to an increased overall mortality and rates of hospital readmission, patients often experience difficulties in physical functioning, cognition, and mental health, which are collectively termed post-intensive care syndrome. To this date, there are no established strategies to address these deleterious outcomes. A number of studies have examined various unique methods to prevent and treat PICS symptoms, including early physical and occupational therapy, providing post-discharge education, or facilitating routine follow up in post-ICU clinics. These trials have yet to demonstrate any substantial or meaningful effect in post-ICU patients and collectively reinforce the need for further research to identify effective intervention for patients who survive critical illness.