Prevalence, risk factors and treatments for post-COVID-19 breathlessness: a systematic review and meta-analysis

Analysis of risk factors for long COVID after mild COVID-19 during the Omicron wave in Japan

BACKGROUND

Post-COVID-19 syndrome, referred to as "long COVID," is characterized by persistent symptoms that develop during or after SRAS-CoV-2 infection lasting for ≥12 weeks, which cannot be explained by factors other than COVID-19. Previous studies before the Omicron pandemic have identified female sex, older age (≥50 years), severity of illness, obesity, diabetes, and smoking as risk factors for long COVID. However, data on long COVID following the emergence of the Omicron variants are limited.

METHODS

An online survey was conducted among outpatients diagnosed with mild COVID-19 at 14 participating institutions in Japan between July 30, 2022, and December 31, 2023.

RESULTS

Of the included 246 cases, 76 (35.5%) experienced at least one long COVID symptom 12 weeks after onset. Logistic regression analysis revealed that age ≥40 years was significantly associated with an increased risk of respiratory (odds ratio [OR]: 3.80, 95% confidence interval [CI]: 1.67-8.65) and neurologic symptoms (OR: 4.53, 95% CI: 1.84-11.13). Conversely, antiviral drug use was associated with a decreased risk of respiratory symptoms (OR: 0.31, 95% CI: 0.11-0.93).

CONCLUSION

Caution is warranted when treating patients over 40 years of age with mild COVID-19 due to their higher susceptibility to developing long COVID. Antiviral drugs may be beneficial in managing respiratory symptoms and mitigating disease severity.

Dyspnea, dysfunctional breathing disorders, and the Bayesian brain hypothesis

Clinicians frequently evaluate patients who present with dyspnea. This term describes uncomfortable breathing during physical activity, and the intensity or degree of dyspnea can vary in an individual depending on circumstances and between individuals. In some cases, the level of dyspnea appears out of proportion to other information relevant to the cardiorespiratory system, and this situation has been described as dysfunctional breathing. The Bayesian brain hypothesis helps clinicians understand this symptom in these patients. This hypothesis suggests that prior experiences with dyspnea during physical activity or a respiratory disorder provide the background that is used to interpret current symptoms. This review outlines problems associated with the use of the term "dyspnea" and briefly describes how the Bayesian brain hypothesis might help clinicians understand this symptom better.

Therapeutic Potential of Propolis Extract in Managing Hyperinflammation and Long COVID-19: A Bioinformatics Study

Hyperinflammation is a significant factor in long COVID, impacting over 65 million post-COVID-19 individuals globally. Herbal remedies, including propolis, show promise in reducing severity and pro-inflammatory cytokines. However, the natural pharmacological role of propolis in COVID-19 management remains underexplored. Employing network pharmacology and in silico techniques, we assessed propolis extract's potential in countering SARS-CoV-2-induced inflammation. We identified 80 flavonoids via LC-MS/MS QTOF and employed 11 anti-inflammatory drugs as references for inflammation target fishing. Utilizing in silico techniques encompassing target fishing, molecular docking, and dynamics, we examined propolis' effects. We identified 1105 gene targets connected to inflammation through multiple validated target predictors. By integrating SARS-CoV-2 DEGs from GSE147507 with these targets, we identify 25 inflammation-COVID-19-associated propolis targets, including STAT1, NOS2, CFB, EIF2K2, NPY5R, and BTK. Enrichment analyses highlighted primary pharmacological pathways related to Epstein-Barr virus infection and COVID-19. Molecular docking validated isokaempferide, iristectorigenin B, 3'-methoxypuerarin, cosmosiin, and baicalein-7-O-β-d-glucopyranoside, which exhibited strong binding affinity and stability with relevant genes. Moreover, our findings indicate that propolis ligands could potentially suppress reactivation of Epstein-Barr Virus infections in post-COVID-19 cases. However, this study has a limitation in that the concentration of each propolis compound has not been quantified. Therefore, further exploration of propolis compounds quantification and experimental validation are needed to support these findings.

Neuroleptics used in critical COVID associated with moderate-severe dyspnea after hospital discharge

Dyspnea is a prominent symptom in patients with long COVID due to its high prevalence and significant clinical impact. However, the influence of commonly used medications in critically ill patients on long-term dyspnea remains unclear. This study aimed to identify risk factors and assess the impacts associated with moderate to severe dyspnea in COVID-19 survivors. This study evaluated patients admitted to a university hospital between April 2020 and April 2021. Data were collected on clinical preconditions, hospital and ICU stays, and the use of corticosteroids, neuroleptics, neuromuscular blockers, midazolam, fentanyl, and noradrenaline. Post-discharge evaluations were conducted at 1 and 12 months, assessing dyspnea, frailty, quality of life, functional capacity, anxiety, and depression. Descriptive statistics, including frequencies and percentages, were used, and logistic regression analysis was performed to identify factors associated with moderate to severe dyspnea at 1 and 12 months post-discharge. Statistical significance was defined as P < 0.05. A total of 100 patients were prospectively included in the study; all underwent the 1-month evaluation, and 63 completed the 12-month evaluation. Limiting dyspnea, defined as an mMRC score > 1, was observed in 56.6% of patients at 1 month and 33.9% at 12 months post-discharge. Independent factors associated with limiting dyspnea at 1 month included the total dose of neuroleptics administered during hospitalization and the presence of pre-existing comorbidities. The use of corticosteroids, neuromuscular blockers, midazolam, fentanyl, and noradrenaline showed no significant association with limiting dyspnea. Dyspnea at 1 month post-discharge was an independent risk factor for the persistence of limiting dyspnea at 12 months. Patients with limiting dyspnea at 12 months exhibited higher levels of depression, anxiety, and frailty, alongside reduced quality of life and functionality. Patients with severe COVID-19 exhibit a high prevalence of limiting dyspnea in the long term. The total dose of neuroleptics administered during hospitalization and the presence of comorbidities were independently associated with limiting dyspnea after discharge. At 12 months post-discharge, individuals with persistent limiting dyspnea frequently demonstrated additional physical and mental health impairments, underscoring the need for comprehensive evaluation and management to mitigate the burden of long-term disabilities.

Risk Factors and Predictors for Persistent Dyspnea Post-COVID-19: A Systematic Review

The most frequently reported post-coronavirus disease of 2019 (COVID-19) symptoms include shortness of breath, fatigue, and cognitive disturbances, with reports of persistent dyspnea ranging between 26% and 41%. There is an urgent need to understand the risk factors and predictors for persistent COVID-19 dyspnea in individuals at all levels of COVID-19 illness severity, to enable the implementation of targeted interventions for those likely to be most affected with persistent dyspnea. Thus, the purpose of this systematic review is to explore the risk factors and predictors that are associated with persistent dyspnea in the post-COVID-19 population. This review was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines and registered prospectively in PROSPERO as CRD42023466713. A search strategy was conducted across PubMed, CINAHL, Web of Science, and EMBASE databases, that included studies conducted from 2020 to March 2024. The Covidence platform was used for screening studies, scoring methodologic quality, and performing data extraction using a two-step independent review process. This review included 33 studies, addressing 83,920 participants across 20 countries. The strongest predictive risk factors for persistent dyspnea included the following: female sex, elevated body mass index, pulmonary comorbidities, pre-existing anxiety and depression, pre-COVID-19 physical limitations, the severity of the COVID-19 illness, and socioeconomic differences. Potential risk factors included increased age, smoking history, and COVID-19 variant type. The presence of biomarkers for persistent dyspnea in the post-COVID-19 population can be used by clinicians to prospectively identify those individuals who should be flagged. Early identification may then be leveraged for timely referral for prophylactic and rehabilitative interventions for dyspnea. A personalized plan to target those risk factors that are modifiable should follow.

Self-Reported Dyspnea Is Associated with Reduced Health-Related Quality of Life in Quaternary Hospital Workers 1 Year Post Mild COVID-19 Infection

BACKGROUND/OBJECTIVES

The COVID-19 pandemic had significant implications for healthcare workers (HWs), especially those that work in hospitals. This study evaluated health related quality of life (HRQOL) and its relationship with dyspnea approximately one year after COVID-19 infection in HWs.

METHODS

HWs with previous COVID-19 infections were interviewed, and the EuroQol five-dimensional three-level questionnaire (EQ-5D-3L) with a visual analog scale (VAS) was used to evaluate HRQOL. Self-reported clinical and sociodemographic data were also obtained. Data were stratified by the presence of self-reported dyspnea in the moment of the study interview. The association between self-reported dyspnea and HRQOL was evaluated by regression models, either unadjusted or adjusted for potential confounders (for age and sex, marital status, work category, number of comorbidities, and number of days between diagnosis and evaluation).

RESULTS

A total of 109 HWs were interviewed; the median number of days post COVID-19 diagnosis for this group was 400 (IIQ 25-75% 321-428). The majority were women (67.9%); the median age was 44 (IIQ 25-75% 38-52) years. Overall, the median EQ-5D-3L score was 0.79 (IIQ 25-75% 0.74-0.85), and the median VAS score was 80 (IIQ 25-75% 70-90). Self-reported dyspnea was indicated by 22 individuals (20.2%). Self-reported dyspnea was associated with lower EQ-5D-3L and VAS scores, both in adjusted and non-adjusted models. In addition, self-reported dyspnea was associated with more problems in carrying out usual activities in both the non-adjusted and adjusted models (p < 0.01).

CONCLUSIONS

Our results underscore the long-term implications of COVID-19, based on persistent perceptions of self-reported dyspnea and its relationship with HRQOL in HWs. Future studies, with extended follow-up and the employment of cardiopulmonary and mental health testing, may help to elucidate the nature and extent of COVID-19 sequelae.

Post-COVID breathlessness: a mathematical model of respiratory processing in the brain

Breathlessness is among the most common post-COVID symptoms. In a considerable number of patients, severe breathlessness cannot be explained by peripheral organ impairment. Recent concepts have described how such persistent breathlessness could arise from dysfunctional processing of respiratory information in the brain. In this paper, we present a first quantitative and testable mathematical model of how processing of respiratory-related signals could lead to breathlessness perception. The model is based on recent theories that the brain holds an adaptive and dynamic internal representation of a respiratory state that is based on previous experiences and comprises gas exchange between environment, lung and tissue cells. Perceived breathlessness reflects the brain's estimate of this respiratory state signaling a potentially hazardous disequilibrium in gas exchange. The internal respiratory state evolves from the respiratory state of the last breath, is updated by a sensory measurement of CO2 concentration, and is dependent on the current activity context. To evaluate our model and thus test the assumed mechanism, we used data from an ongoing rebreathing experiment investigating breathlessness in patients with post-COVID without peripheral organ dysfunction (N = 5) and healthy control participants without complaints after COVID-19 (N = 5). Although the observed breathlessness patterns varied extensively between individual participants in the rebreathing experiment, our model shows good performance in replicating these individual, heterogeneous time courses. The model assumes the same underlying processes in the central nervous system in all individuals, i.e., also between patients and healthy control participants, and we hypothesize that differences in breathlessness are explained by different weighting and thus influence of these processes on the final percept. Our model could thus be applied in future studies to provide insight into where in the processing cascade of respiratory signals a deficit is located that leads to (post-COVID) breathlessness. A potential clinical application could be, e.g., the monitoring of effects of pulmonary rehabilitation on respiratory processing in the brain to improve the therapeutic strategies.

A Narrative Review of Impact of Incentive Spirometer Respiratory Training in Long COVID

Long COVID refers to symptoms that appear 3 months after initial infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative virus of Coronavirus disease 2019 (COVID-19), and last for at least 2 months, not attributable to other diagnoses. This health issue significantly burdens patients' quality of life, the economy, and society. Improving the af-termath of COVID-19 is a crucial global health issue in the post-pandemic era. According to current results, it is evident that developing a simple, low-cost respiratory training method that can be easily used at home by themselves with long Coronavirus disease 2019 symptoms (long COVID) is an important and urgent issue. The incentive spirometer is widely used in physical, speech, and respiratory therapy, as well as in preventing postoperative pulmonary infections and improving sputum clearance. However, to date, the role of incentive spirometer respiratory training in long COVID symptoms is still limited. In this literature review is presented to explore the effectiveness of incentive spirometer respiratory training in alleviating symptoms among individuals recovering from long COVID. We also compile non-invasive assessment methods, with the aim to enable individuals to undergo training and assessments conveniently at home or in the community. In this review, a literature review approach was utilized to explore the effectiveness of incentive spirometer intervention in alleviating long-term COVID symptoms. This study is to synthesize the findings of articles published during January 2019 and December 2023 retrieved from PubMed/CINAHL/MEDLINE/ Google Scholar without re-strictions on study type. We ultimately identified seven articles and have summarized similar past studies. This review could contribute to improving symptoms related to long COVID by incentive spirometer respiratory training and serve as practical reference material for clinical medical staff and provide insights for healthcare policymakers in de-veloping guidelines for future research directions, clinical guidance, and educational strategies in the context of nursing care.

[Mechanisms of prolonged symptoms following acute COVID-19: Some pathophysiological pathways]

INTRODUCTION

Following the Omicron wave in early 2022, an estimated 60-70% of the French population was infected with the SARS-CoV-2 virus. One out of ten infected subjects could have persistent symptoms three months after infection, representing a public health challenge.

CURRENT STATE OF KNOWLEDGE

The persistent symptoms may be secondary to diverse entities with distinct mechanisms. While organic infection sequelae occur mainly after severe COVID-19, some symptoms appear to be essentially psychological in origin; in addition, many subjects present stereotyped symptoms of fluctuating intensity with no identified anatomical or psychic substratum, often in the aftermath of a benign infection. The most frequent complaints are fatigue, pain, dyspnea and difficulty concentrating.

PERSPECTIVES

The hypotheses explored to explain these symptoms include: persistent immune dysfunction, inducted autoimmunity, and microbiome disturbances. Persistent viral antigens may lie at the crossroads of these mechanisms. To date, these different etiological avenues have yet to lead to the development of diagnostic tests or specific therapeutic strategies.

CONCLUSION

Prolonged symptoms after COVID-19 correspond to heterogeneous nosological entities with poorly understood mechanisms.

Post‑recovery symptoms of infected cases after Omicron pandemic: a quick online cross-sectional study based on C19-YRSm in China

BACKGROUND

The post COVID-19 health condition of Chinese residents infected with Omicron is not clear after the change of epidemic prevention policies. This study aimed to clarify the epidemiology and associated factors about health status of rehabilitation patients.

METHODS

A quick questionnaire study based on C19-YRSm was conducted in mainland China through internet from May 1, 2023, to May 7, 2023. Chinese native speakers infected with Omicron variant agreed to participate were included. Persisting symptom and living habits were simultaneously inquired. Logistic regression analysis was used to identify the associated factors.

RESULTS

In this study 753 individuals were included. Of whom 57.90% were males, 89.38% did not seek medical service, 99.47% recovered within less than 120 days. Breathlessness (47.68%), cognitive impairment (44.89%), Anxiety/mood changes (33.20%), pain/discomfort (32.94%), fatigue or tiredness not improved by rest (32.27%) and post-exertional malaise (30.01%) were the top reported key symptoms. Less than 10% respondents reported functional limitations. The prevalence of fever was reported greater than that of other symptoms, with dry eyes at 14.87%, appetite change at 14.34%, and hair loss at 12.22%. Middle age (OR: 2.353, 95%CI: 1.171 ~ 4.729), underlying diseases (OR: 2.293, 95%CI: 1.216 ~ 4.324), severe key symptom (OR: 6.168, 95%CI: 1.376 ~ 27.642) and at least one other symptom (OR: 1.847, 95%CI: 1.225 ~ 2.718)during the recovery were the risk factors of poor overall health after infection (current overall health score <8; 74.10%), while daily exercise in recovery period (OR: 0.457, 95%CI: 0.229 ~ 0.913), a low-fat diet (OR: 0.600, 95%CI: 0.401 ~ 0.898) and the recovery time from 2 to 4 months (OR: 0.639, 95%CI: 0.445 ~ 0.918) were the protective factors.

CONCLUSION

This is the first time to use the C19-YRSm scale to evaluate the health status in China. The study revealed prevalence of persistent symptoms within 120 days after Omicron onset.

Short-term intermittent hypoxia exposure for dyspnea and fatigue in post-acute sequelae of COVID-19: A randomized controlled study

BACKGROUND

Post-acute sequelae of COVID-19 (PASC) is incurring a huge health and economic burden worldwide. There is currently no effective treatment or recommended drug for PASC.

METHODS

This prospective randomized controlled study was conducted in a hospital in China. The effect of intermittent hypoxia exposure (IHE; 5-min hypoxia alternating with 5-min normal air, repeated five times) on dyspnea and fatigue was investigated in patients meeting the NICE definition of PASC. Patients were computationally randomized to receive normoxia exposure (NE) and routine therapy or IHE and routine therapy. Six-minute walk distance (6MWD) and spirometry were tested before and after the interventions; the Borg Dyspnea Scale (Borg) and the modified Medical Research Council Dyspnea Scale (mMRC) were used to assess dyspnea; and the Fatigue Assessment Scale (FAS) and the Chalder Fatigue Scale-11 (CFQ-11) were used to assess fatigue. The study was registered in the Chinese Clinical Trial Registry (ChiCTR2300070565).

FINDINGS

Ninety-five participants (33 males and 62 females) were recruited between March 1, 2023 and December 30, 2023. Forty-seven patients in the IHE group received 10.0 (9.0, 15.0) days of IHE, and 48 patients in NE group received 10.0 (8.0, 12.0) days of NE. 6MWD, forced vital capacity (FVC), FVC %pred, forced expiratory volume in 1 s (FEV1), FEV1 %pred, tidal volume (VT), and dyspnea and fatigue scales markedly improved after IHE (p < 0.05), and improvements were greater than in the NE group (all p < 0.05). Furthermore, participants in IHE group had better subjective improvements in dyspnea and fatigue than those in the NE group (p < 0.05). Compared with <10 days of IHE, ≥10 days of IHE had a greater impact on 6MWD, FVC, FEV1, FEV1 %pred, VT, FAS, and CFQ-11. No severe adverse events were reported.

INTERPRETATION

IHE improved spirometry and 6MWD and relieved dyspnea and fatigue in PASC patients. Larger prospective studies are now needed to verify these findings.

Dyspnea and long COVID patients

Patients with prior COVID-19 infections often develop chronic post-COVID symptoms, such as fatigue and dyspnea. Some patients have residual pulmonary disorders with abnormal pulmonary function tests and/or chest radiographs to explain their dyspnea. However, other patients appear to have dyspnea that is out of proportion to any measurable change in lung function. Some of these patients have abnormal cardiopulmonary exercise testing with definite cardiac or respiratory limits. However, others have normal cardiopulmonary exercise testing based on VO2 measurement but pronounced dyspnea during this testing. These patients often have abnormal respiratory patterns, referred to as dysfunctional breathing, with irregular and variable respiratory rates and/or tidal volumes. Consequently, their control of breathing is impaired, and this may represent residual effects from prior COVID-19 infection involving the central nervous system. Alternatively, patients may have acquired "a memory" of respiratory symptoms during their infection which persists post-infection. These patients should participate in pulmonary rehabilitation and breathing retraining.

Correlating COVID-19 severity with biomarker profiles and patient prognosis

COVID-19's long-lasting and complex impacts have become a global concern, with diverse clinical outcomes. This study evaluated 226 participants to understand the clinical spectrum of COVID-19/Long COVID (LC), exploring how disease severity correlates with sociodemographic factors and biomarkers. Determinants related to COVID-19 severity included age (P < 0.001), lower education (P < 0.001), ethnicity (P = 0.003), overweight (P < 0.001), MTHFR gene rs1801133 (P = 0.035), cardiovascular diseases (P = 0.002), diabetes mellitus (DM) (P = 0.006), Factor VIII (FVIII) (P = 0.046), von Willebrand factor (VWF) (P = 0.002), and dimer D (DD) (P < 0.001). Six months later, in a portion of the monitored participants, a significant reduction in FVIII (P < 0.001), VWF (P = 0.002), and DD (P < 0.001) levels was observed, with only DD returning to normal values. Different systemic sequelae were identified, with higher incidences of joint pain and myalgia in participants with a clinical history of DM, chronic lung disease (CLD) and sustained high interleukin 6 values in the convalescent phase. CLD, COVID-19 severity and high DD levels increased the risk of developing dyspnea and palpitations. Women were more likely to develop lower limb phlebitis long-term, while sustained elevated FVIII in the convalescent phase was associated with an increased risk of swelling. Regular physical activity had a protective effect against swelling. This study highlights factors contributing to COVID-19 severity/LC, emphasizing endothelial cell activation as a potential mechanism.

Persistent disabilities 28 months after COVID-19 hospitalisation, a prospective cohort study

Background

Limited data are available on long-term respiratory disabilities in patients following acute COVID-19.

Patients and methods

This prospective, monocentric, observational cohort study included patients admitted to our hospital with acute COVID-19 between 12 March and 24 April 2020. Clinical, functional and radiological data were collected up to 28 months after hospital discharge.

Results

Among 715 patients hospitalised for COVID-19, 493 (69.0%) were discharged alive. We could access complete medical records for 268 out of 493 patients (54.4%); 138 out of 268 (51.5%) exhibited persistent respiratory symptoms and agreed with the data collection and follow-up. Patients were predominantly male (64.5%), with a mean±sd age of 58.9±15.3 years. At the last follow-up, the leading symptoms were asthenia (31.5%), dyspnoea (29.8%) and neuropsychological symptoms (17.7%). Lung function improved up to the last visit. Mean diffusing capacity of the lung for carbon monoxide (D LCO) was 77.8% of predicted value, total lung capacity (TLC) was 83.5% and O2 desaturation during exercise (O2 desaturation) was 2.3%. While D LCO improved over the entire period, TLC improved in the early phase and O2 desaturation in the late phase. Except for those with lung comorbidities, only one patient presented with minor functional and chest radiological alterations at 28 months.

Conclusion

Patients with acute COVID-19 discharged alive showed improved clinical symptoms, lung function parameters and radiological signs up to 28 months post-infection. Persistent symptoms consisted mainly of asthenia and dyspnoea, with lung function returning to normal. One patient without prior respiratory issues exhibited moderate pulmonary fibrosis.

A Systematic Review of Breathing Exercise Interventions: An Integrative Complementary Approach for Anxiety and Stress in Adult Populations

Aim: Nurses are well-qualified to deliver integrative complementary therapy interventions, a holistic approach to assist individuals experiencing anxiety and stress. Self-regulated, controlled breathing exercises (a clinical approach) are reported to decrease anxiety and increase stress tolerance. The aim of this systematic review was to evaluate the effectiveness of breathing exercise interventions on the psychological and physiologic outcomes of anxiety and stress among adults and assess the state of the science in the post-COVID-19 population. Methods: A systematic review was conducted, and four scientific databases were searched: PubMed, CINAHL, EMBASE, and Web of Science. Inclusion criteria included: (1) peer-reviewed studies, (2) adults over 18, (3) breathing exercise interventions, and (4) anxiety or stress as outcomes. Results: Out of 309 studies identified, 19 were included. Twelve reported significant improvements in anxiety and nine reported significant improvements in stress following varying breathing exercise interventions (p < .05). No adverse events were reported. Conclusions: Breathing exercises were found to be effective in reducing anxiety and stress in adults, however, there continues to be limited evidence that includes large randomized controlled trials. Breathing exercises are a holistic care approach that can be safely implemented by nurses to decrease symptomatology among adults, including the post-COVID population.

[Dyspnea in post-COVID-19 patients: A review]

New coronavirus infection may lead to long-term consequences, particularly to post-COVID syndrome, one of the most common manifestations of which is dyspnea. Post-COVID-19 shortness of breath may persist from one to several months and even years that results in low quality of life of patients. The review highlights possible risk factors and causes of dyspnea in post-COVID period such as lung damage, cardiovascular pathology, hyperventilation syndrome, dysfunction of the autonomic nervous system, detraining, anemia, etc. The authors present data about COVID-19-associated causes of dyspnea and severity of acute COVID-19. The review emphasizes the importance of a multidisciplinary approach to the diagnosis and treatment of patients with shortness of breath in post-COVID-19 period.

Quality of Sleep and Mental Symptoms Contribute to Health-Related Quality of Life after COVID-19 Pneumonia, a Follow-Up Study of More than 2 Years

A follow-up study was designed to assess correlations among physical signs, quality of sleep, common mental symptoms, and health-related quality of life after moderate to severe COVID-19 pneumonia. Daily changes in dyspnoea and pulse oximetry were recorded (200 days), and four evaluations (in >2 years) were performed on quality of sleep, mental symptoms, cognitive performance, and health-related quality of life. In a single center, 72 adults participated in the study (52.5 ± 13.7 years old), with no psychiatry/neurology/chronic lung/infectious diseases, chronic use of corticosteroids/immunosuppressive therapy, or pregnancy. Daily agendas showed delayed decreases in dyspnoea scores compared to pulse oximetry and heart rate recordings; however, changes in pulse oximetry were minimal. Slight changes in cognitive performance were related to the general characteristics of the participants (obesity and tobacco use) and with the severity of acute disease (MANCOVA, p < 0.001). Health-related quality of life gradually improved (MANCOVA, p < 0.004). During recovery, bad quality of sleep and mental symptoms (mainly attention/concentration) contributed to the subscores on health perception and vitality in the health-related quality of life assessment. Early mental support services including sleep hygiene could be beneficial during rehabilitation after acute COVID-19.

Effectiveness of telerehabilitation in patients with post-COVID-19: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To assess the effects of telerehabilitation on clinical symptoms, physical function, psychological function and quality of life (QoL) in patients with post-COVID-19.

DESIGN

Systematic review and meta-analysis of randomised controlled trials (RCTs).

DATA SOURCES

PubMed, Web of Science, Embase and Cochrane Library were searched for publications from 1 January 2020 to 17 April 2024.

ELIGIBILITY CRITERIA

RCTs investigating the effects of telerehabilitation in patients with post-COVID-19 were included. The outcomes of interest encompassed clinical symptoms, physical function, psychological function and QoL. Only studies reported in English were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted data and evaluated the risk of bias. Statistical analysis was conducted using Review Manager V.5.3, employing mean difference (MD) with a 95% CI, and the corresponding P value was used to ascertain the treatment effect between groups. Heterogeneity was quantified using the I2 statistic. The quality of evidence was assessed by GRADE.

RESULTS

16 RCTs (n=1129) were included in this systematic review, 15 of which (n=1095, 16 comparisons) were included in the meta-analysis. The primary pooled analysis demonstrated that, compared with no rehabilitation or usual care, telerehabilitation can improve physical function (measured by 30 s sit-to-stand test [6 RCTs, n=310, MD=1.58 stands, 95% CI 0.50 to 2.66; p=0.004]; 6 min walking distance [6 RCTs, n=324, MD=76.90 m, 95% CI 49.47 to 104.33; p<0.00001]; and physical function from the 36-item short-form health survey [5 RCTs, n=380, MD=6.12 units, 95% CI 2.85 to 9.38; p=0.0002]). However, the pooled results did not indicate significant improvements in clinical symptoms, pulmonary function, psychological function or QoL. The quality of the evidence was graded as low for physical function and Hospital Anxiety and Depression Scale-anxiety and very low for other assessed outcomes. The overall treatment completion rate was 78.26%, with no reports of severe adverse events in any included trials.

CONCLUSIONS

Despite the lack of significant improvements in certain variables, telerehabilitation could be an effective and safe option for enhancing physical function in patients with post-COVID-19. It is advisable to conduct further well-designed trials to continue in-depth exploration of this topic.

STUDY REGISTRATION

PROSPERO, CRD42023404647.

Body Mass Index and Thoracic Expansion in Post-COVID Dyspnea: A Secondary Analysis

Dyspnea secondary to lung impairment can persist following the acute phase of COVID-19. Thoracic expansion measurements have been used as a diagnostic tool to evaluate chest wall mobility, respiratory function, and the effects of respiratory muscle strength training. Changes in chest wall mobility may occur because of altered chest biomechanics in individuals with respiratory diseases and an elevated body mass index (BMI). The purpose of this secondary analysis was to evaluate whether BMI influences thoracic expansion or forced expiratory volume over 1 second (FEV1) in individuals with persistent dyspnea following COVID-19. This study assessed the relationship between BMI and thoracic expansion, pulmonary symptoms, and exercise capacity following a home-based pulmonary rehabilitation intervention. A secondary data analysis was conducted with a sample of 19 adults with persistent dyspnea following COVID-19 infection who participated in a 12-week, home-based pulmonary rehabilitation study. Participants received expiratory muscle strength training devices and were instructed to perform pulmonary rehabilitation exercises three times per week over the study period. Pulmonary function, pulmonary symptoms, exercise capacity, and BMI measurements were collected. For analysis, study participants were divided into obese (BMI > 30 kg/m2) or nonobese (BMI < 30 kg/m2) categories. Correlations using the change scores from baseline to 12 weeks between thoracic expansion, FEV1, pulmonary symptoms, and exercise capacity were assessed. In addition, the minimal detectable change (MDC) in thoracic expansion was explored. Thoracic expansion was significantly improved after 12 weeks of training (p = .012) in the nonobese group. There was a significant correlation between the change in walking distance and pulmonary symptoms (r = -.738, p < .001) and in thoracic expansion (r = .544, p = .020), and walking distance, when controlling for BMI, but no change in FEV1. Average MDC was 1.28 for inspiration and 0.91 for expiration. Measurements of thoracic expansion were significantly lower in post-COVID individuals with an increased BMI. Individuals with persistent dyspnea and a higher BMI may require additional measures to increase chest mobility or to detect pulmonary changes following COVID-19.

Long COVID syndrome: An unfolding enigma

Post-acute sequelae of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) disease (COVID-19), called as long COVID syndrome, is a major global public health issue after recovery from COVID-19. The disease occurs in symptomatic patients irrespective of illness severity. The symptoms continue after four wk of recovery from acute illness and persist beyond three months. Risk factors for long COVID include older age, female gender, multiple co-morbidities including diabetes mellitus, prior chronic respiratory illnesses, hospitalized patients with severe disease, especially receiving assisted ventilation, high viral load, reactivation of Epstein Barr (EB) virus and human herpes virus 6 (HH6), circulating auto antibodies against various organs and type I interferon. The prevalence varies from 10 to 20 per cent, and most data have been reported from high-income countries. Any system can get involved in long COVID. The symptoms include fatigue, cognition impairment, cough and dyspnoea, anosmia, hair loss and diarrhoea, among others. While there are no laboratory tests for confirmation of diagnosis, reduced complement C7 complexes at six months, and a two-gene biomarker including FYN and SARS-CoV-2 antisense ribonucleic acid (RNA) are emerging as potentially useful biomarkers for long COVID. There should be no alternative disease to explain various symptoms. Vaccination against SARS-CoV-2 and early use of oral antiviral nirmatrelvir within the first five days in patients with acute mild disease having various risk factors for progression to severe disease help in preventing long COVID. Several clinical trials are underway for the treatment of long COVID and the results of these are eagerly awaited. Physical and mental rehabilitation at home, at community level or in the hospital setting as appropriate is essential in patients with long COVID.

Special Issue "Latest Research in Post-COVID (Long COVID): Pathological and Treatment Studies of Sequelae and Complications"

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pathogen provoked the most unprecedented sanitary outbreak of the current century by causing coronavirus disease 2019 (COVID-19), which has led to approximately 775 million confirmed cases and more than 7 million deaths globally [...].

Lung function and quality of life one year after severe COVID-19 in Brazil

OBJECTIVE

To evaluate symptoms, lung function, and quality of life of a cohort of patients hospitalized for severe COVID-19 12 months after hospital admission.

METHODS

This was a cross-sectional study. We included severe COVID-19 survivors hospitalized in one of three tertiary referral hospitals for COVID-19 in the city of Belo Horizonte, Brazil. Participants were submitted to lung function and six-minute walk tests and completed the EQ-5D-3L questionnaire.

RESULTS

The whole sample comprised 189 COVID-19 survivors (mean age = 59.6 ± 13.4 years) who had been admitted to a ward only (n = 96; 50.8%) or to an ICU (n = 93; 49.2%). At 12 months of follow-up, 43% of patients presented with dyspnea, 27% of whom had a restrictive ventilatory disorder and 18% of whom presented with impaired DLCO. There were no significant differences in FVC, FEV1, and TLC between the survivors with or without dyspnea. However, those who still had dyspnea had significantly more impaired DLCO (14.9% vs. 22.4%; p < 0.020) and poorer quality of life.

CONCLUSIONS

After one year, survivors of severe COVID-19 in a middle-income country still present with high symptom burden, restrictive ventilatory changes, and loss of quality of life. Ongoing follow-up is needed to characterize long COVID-19 and identify strategies to mitigate its consequences.

Long COVID symptoms after 8-month recovery: persistent static lung hyperinflation associated with small airway dysfunction

BACKGROUND

Limited research has investigated the relationship between small airway dysfunction (SAD) and static lung hyperinflation (SLH) in patients with post-acute sequelae of COVID-19 (PASC) especially dyspnea and fatigue.

METHODS

64 patients with PASC were enrolled between July 2020 and December 2022 in a prospective observational cohort. Pulmonary function tests, impulse oscillometry (IOS), and symptom questionnaires were performed two, five and eight months after acute infection. Multivariable logistic regression models were used to test the association between SLH and patient-reported outcomes.

RESULTS

SLH prevalence was 53.1% (34/64), irrespective of COVID-19 severity. IOS parameters and circulating CD4/CD8 T-cell ratio were significantly correlated with residual volume to total lung capacity ratio (RV/TLC). Serum CD8 + T cell count was negatively correlated with forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) with statistical significance. Of the patients who had SLH at baseline, 57% continued to have persistent SLH after eight months of recovery, with these patients tending to be older and having dyspnea and fatigue. Post-COVID dyspnea was significantly associated with SLH and IOS parameters R5-R20, and AX with adjusted odds ratios 12.4, 12.8 and 7.6 respectively. SLH was also significantly associated with fatigue.

CONCLUSION

SAD and a decreased serum CD4/CD8 ratio were associated with SLH in patients with PASC. SLH may persist after recovery from infection in a substantial proportion of patients. SAD and dysregulated T-cell immune response correlated with SLH may contribute to the development of dyspnea and fatigue in patients with PASC.

Examining Well-Being and Cognitive Function in People with Long COVID and ME/CFS, and Age-Matched Healthy Controls: A Case-Case-Control Study

BACKGROUND

Well-being and cognitive function had not previously been compared between people with long COVID and people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Therefore, this study examined well-being and cognitive function in people with long COVID (∼16 months illness duration; n = 17) and ME/CFS (∼16 years illness duration; n = 24), versus age-matched healthy controls (n = 16).

METHODS

Well-being was examined using several questionnaires, namely the Health Visual Analogue Scale (VAS), Fatigue Severity Scale (FSS), post-exertional malaise (PEM), Pittsburgh Sleep Quality Index (PSQI), European Quality of Life-5 Domains (EQ-5D), MRC Dyspnoea, Self-Efficacy (SELTC), The Edinburgh Neurosymptoms Questionnaire (ENS), General Anxiety Disorder 7 (GAD-7) and Patient Health Questionnaire 9 (PHQ-9). Cognitive function was examined using Single Digit Modalities Test (SDMT), Stroop test and Trails A and B. These were delivered via a mobile application (app) built specifically for this remote data collection.

RESULTS

The main findings of the present investigation were that people with ME/CFS and people with long COVID were generally comparable on all well-being and cognitive function measures, but self-reported worse values for pain, fatigue, post-exertional malaise, sleep quality, general well-being in relation to mobility, usual activities, self-care, breathlessness, neurological symptoms, self-efficacy and other well-being such as anxiety and depression, compared to controls. There was no effect of group for cognitive function measures.

CONCLUSIONS

These data suggest that both people with long COVID and people with ME/CFS have similar impairment on well-being measures examined herein. Therefore, interventions that target well-being of people with ME/CFS and long COVID are required.

Can Galectin-3 be a reliable predictive biomarker for post-COVID syndrome development?

BACKGROUND AND OBJECTIVES

Reliable biomarkers able to predict post-COVID syndrome development are still lacking. The aim of the study was to evaluate the relationship between Galectin-3 blood concentrations and the development of post-COVID syndrome.

METHODS

We performed a single-center, prospective, observational study, enrolling 437 consecutive patients attending our outpatient clinic for the post-COVID assessment. For each patient, we recorded the main clinical, functional and radiological findings. We also dosed several blood biomarkers which have been related to COVID-19 disease, including Galectin-3. We performed Receiver Operating Characteristic (ROC) and multivariate regression analysis to evaluate the predictive performance of Galectin-3 for post-COVID syndrome development.

RESULTS

Among the blood biomarkers tested, Galectin-3 resulted the only one correlated with the outcome, although the insufficient performance of the Cox regression model from a statistical standpoint. Correlation coefficients and ROC curves analysis revealed the close relationship between Galectin-3 levels and the time passed from the acute phase of COVID-19 disease, suggesting a possible predictive role for this biomarker when dosed from 60 to 120 days after the infection.

CONCLUSIONS

Galectin-3 could play an important role as predictive biomarker for COVID-19 sequelae, but its evaluation must be carefully planned along the follow up to avoid misinterpretations.

Updated Clinical Practice Guidelines for the Diagnosis and Management of Long COVID

"Long COVID" is a term used to describe a condition when the symptoms and signs associated with coronavirus disease 2019 (COVID-19) persist for more than three months among patients infected with COVID-19; this condition has been reported globally and poses a serious public health issue. Long COVID can manifest in various forms, highlighting the need for appropriate evaluation and management by experts from various fields. However, due to the lack of clear clinical definitions, knowledge of pathophysiology, diagnostic methods, and treatment protocols, it is necessary to develop the best standard clinical guidelines based on the scientific evidence reported to date. We developed this clinical guideline for diagnosing and treating long COVID by analyzing the latest research data collected from the start of the COVID-19 pandemic until June 2023, along with the consensus of expert opinions. This guideline provides recommendations for diagnosis and treatment that can be applied in clinical practice, based on a total of 32 key questions related to patients with long COVID. The evaluation of patients with long COVID should be comprehensive, including medical history, physical examination, blood tests, imaging studies, and functional tests. To reduce the risk of developing long COVID, vaccination and antiviral treatment during the acute phase are recommended. This guideline will be revised when there is a reasonable need for updates based on the availability of new knowledge on the diagnosis and treatment of long COVID.

Pathophysiological, immunological, and inflammatory features of long COVID

The COVID-19 pandemic continues to cause severe global disruption, resulting in significant excess mortality, overwhelming healthcare systems, and imposing substantial social and economic burdens on nations. While most of the attention and therapeutic efforts have concentrated on the acute phase of the disease, a notable proportion of survivors experience persistent symptoms post-infection clearance. This diverse set of symptoms, loosely categorized as long COVID, presents a potential additional public health crisis. It is estimated that 1 in 5 COVID-19 survivors exhibit clinical manifestations consistent with long COVID. Despite this prevalence, the mechanisms and pathophysiology of long COVID remain poorly understood. Alarmingly, evidence suggests that a significant proportion of cases within this clinical condition develop debilitating or disabling symptoms. Hence, urgent priority should be given to further studies on this condition to equip global public health systems for its management. This review provides an overview of available information on this emerging clinical condition, focusing on the affected individuals' epidemiology, pathophysiological mechanisms, and immunological and inflammatory profiles.

Persistent Shortness of Breath in Post-COVID-19 Patients: Inducible Laryngeal Obstruction Can Be a Cause

BACKGROUND

Inducible laryngeal obstruction (ILO) is the adduction of the true vocal folds during inspiration or, less frequently, expiration. Its etiology is unknown.

PURPOSE

This study aimed to identify ILO as a possible cause of shortness of breath (SOB) in post-COVID-19 patients.

METHODS

A retrospective study was conducted on 59 post-COVID-19 adults complaining of SOB. We collected the cases' clinical and chest imaging data, including demographic data, pulmonary function test (PFT), CT chest, and laryngeal endoscopic examination. A visual score was used to assign the severity of the glottic obstruction. The grades of this score ranged from 0 (complete patency) to 3 (almost complete closure).

RESULTS

ILO was detected in 8 out of 59 cases (13.5%). Two cases out of eight had glottic closure grade 1, while five cases had glottic closure grade 2, and one had glottic closure grade 3. There was a positive correlation between ILO grades (the severity of glottic closure) and PFT results (the degree of upper airway restriction). PFTs in ILO have a specific pattern. It was typical for the expiratory loop to be normal and the inspiratory loop to be flattened.

CONCLUSION

ILO is a possible cause of SOB in post-COVID-19 adult cases. It should be considered during evaluation and management.

Post-COVID-19 condition in pregnant and postpartum women: a long-term follow-up, observational prospective study

Background

Post-COVID-19 condition has recently been defined as new or persistent common COVID-19 symptoms occurring three months after disease onset. The pathology of the disease is unclear, but immune and vascular factors seem to play a significant role. The incidence, severity, and implications of the disease after COVID-19 infection in pregnancy have not been established. We aimed to study the incidence and main risk factors for post-COVID-19 condition in an obstetric population and their implications for maternal and perinatal morbimortality.

Methods

This is a prospective observational cohort study undertaken including women during pregnancy or at admission for labour with acute COVID-19 infection from March 9th, 2020 to June 11th, 2022. The inclusion criteria were confirmed acute COVID-19 infection during the recruitment period, a lack of significant language barrier and consent for follow-up. Patients were clinically followed-up by telephone via semi structured questionnaires. The exclusion criteria were loss to follow-up, spontaneous miscarriage, and legal termination of pregnancy. Patients were classified into groups according to the severity of symptoms at onset. We included patients from the first six first waves of the pandemic according to national epidemiological data in Spain. We studied the incidence of post-COVID-19 condition and their main demographic, clinical and obstetric risk factors.

Findings

A total of 409 pregnant women were recruited at acute diagnosis, and 286 were followed-up. The mean time to follow-up was 92 weeks (standard deviation ± 28 weeks; median 100 weeks (Interquartile range: 76; 112)). A total of 140 patients had at least one post-COVID-19 symptom at least three months after acute infection. Neurological (60%) and cutaneous (55%) manifestations were the most frequent findings. The following profiles were identified as presenting a higher risk of post-COVID-19 condition: migrant women born in countries with lower Human Development Index; multiparous women; women with COVID-19 during pregnancy, mainly during the first and third trimesters, and in the first and second waves of the pandemic; women who had a higher number of symptoms; women who had a higher incidence of moderate and severe symptoms; women who required hospitalisation due to COVID-19 complications; and women who were not vaccinated before disease onset. We did not find any significant difference in perinatal results, such as gestational week at delivery, birthweight, the need for neonatal care or 5-min Apgar score, and newborns benefited from a high rate of breastfeeding at discharge. Women who were infected during successive waves of the pandemic had a significant and constant decrease in the risk of post-COVID-19 condition comparing to estimated risk in the first wave (OR: 0.70; 95% CI: 0.62, 0.92). Symptoms tended to resolve over time heterogeneously. Symptoms of myalgia and arthralgia took longer to resolve (mean of 60 weeks and 54 weeks, respectively). In a small but significant proportion of patients, neurological and psycho-emotional symptoms tended to become chronic after 90 weeks.

Interpretation

At least 34.2% of obstetric patients from our cohort with acute COVID-19 infection presented post-COVID-19 condition symptoms. Demographic and acute disease characteristics as well as specific pregnancy-related risk factors were identified. This is the first study to assess post-COVID-19 condition in pregnant women. Further analysis on the biological pathophysiology of post-COVID-19 is needed to explain the characteristics of the disease.

Funding

This study has been funded by Instituto de Salud Carlos III (ISCIII) through the project "PI21/01244" and co-funded by the European Union, as well as P2022/BMD-7321 (Comunidad de Madrid) and ProACapital, Halekulani S.L. and MJR.

Long COVID or Post-COVID-19 Condition: Past, Present and Future Research Directions

The presence of symptoms after an acute SARS-CoV-2 infection (long-COVID) has become a worldwide healthcare emergency but remains underestimated and undertreated due to a lack of recognition of the condition and knowledge of the underlying mechanisms. In fact, the prevalence of post-COVID symptoms ranges from 50% during the first months after the infection up to 20% two-years after. This perspective review aimed to map the existing literature on post-COVID symptoms and to identify gaps in the literature to guide the global effort toward an improved understanding of long-COVID and suggest future research directions. There is a plethora of symptomatology that can be due to COVID-19; however, today, there is no clear classification and definition of this condition, termed long-COVID or post-COVID-19 condition. The heterogeneity in the symptomatology has led to the presence of groups/clusters of patients, which could exhibit different risk factors and different mechanisms. Viral persistence, long-lasting inflammation, immune dysregulation, autoimmune reactions, reactivation of latent infections, endothelial dysfunction and alteration in gut microbiota have been proposed as potential mechanisms explaining the complexity of long-COVID. In such an equation, viral biology (e.g., re-infections, SARS-CoV-2 variants), host biology (e.g., genetics, epigenetics) and external factors (e.g., vaccination) should be also considered. These various factors will be discussed in the current perspective review and future directions suggested.

Treatable traits for long COVID

Long COVID, or post-acute COVID-19 sequelae, is experienced by an estimated one in eight adults following acute COVID-19. Long COVID is a new and complex chronic health condition that typically includes multiple symptoms that cross organ systems and fluctuate over time; a one-size-fits-all approach is, therefore, not likely to be appropriate nor relevant for long COVID treatment. 'Treatable Traits' is a personalized medicine approach, purpose-built to address the complexity and heterogeneity of complex chronic conditions. This comprehensive review aimed to understand how a treatable traits approach could be applied to long COVID, by first identifying the most prevalent long COVID treatable traits and then the available evidence for strategies to target these traits. An umbrella review of 22 systematic reviews identified 34 symptoms and complications common with long COVID, grouped into eight long COVID treatable trait clusters: neurological, chest, psychological, pain, fatigue, sleep impairment, functional impairment and other. A systematic review of randomized control trials identified 18 studies that explored different intervention approaches for long COVID prevention (k = 4) or management (k = 14). While a single study reported metformin as effective for long COVID prevention, the findings need to be replicated and consensus is required around how to define long COVID as a clinical trial endpoint. For long COVID management, current evidence supports exercise training or respiratory muscle training for long COVID treatable traits in the chest and functional limitation clusters. While there are studies exploring interventions targeting other long COVID treatable traits, further high-quality RCTs are needed, particularly targeting treatable traits in the clusters of fatigue, psychological, pain and sleep impairment.

Rehabilitation Interventions for Physical Capacity and Quality of Life in Adults With Post-COVID-19 Condition: A Systematic Review and Meta-Analysis

Importance

Current rehabilitation guidelines for patients with post-COVID-19 condition (PCC) are primarily based on expert opinions and observational data, and there is an urgent need for evidence-based rehabilitation interventions to support patients with PCC.

Objective

To synthesize the findings of existing studies that report on physical capacity (including functional exercise capacity, muscle function, dyspnea, and respiratory function) and quality of life outcomes following rehabilitation interventions in patients with PCC.

Data Sources

A systematic electronic search was performed from January 2020 until February 2023, in MEDLINE, Scopus, CINAHL, and the Clinical Trials Registry. Key terms that were used to identify potentially relevant studies included long-covid, post-covid, sequelae, exercise therapy, rehabilitation, physical activity, physical therapy, and randomized controlled trial.

Study Selection

This study included randomized clinical trials that compared respiratory training and exercise-based rehabilitation interventions with either placebo, usual care, waiting list, or control in patients with PCC.

Data Extraction and Synthesis

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A pairwise bayesian random-effects meta-analysis was performed using vague prior distributions. Risk of bias was assessed using the Cochrane risk of bias tool version 2, and the certainty of evidence was evaluated using the GRADE system by 2 independent researchers.

Main Outcomes and Measures

The primary outcome was functional exercise capacity, measured at the closest postintervention time point by the 6-minute walking test. Secondary outcomes were fatigue, lower limb muscle function, dyspnea, respiratory function, and quality of life. All outcomes were defined a priori. Continuous outcomes were reported as standardized mean differences (SMDs) with 95% credible intervals (CrIs) and binary outcomes were summarized as odds ratios with 95% CrIs. The between-trial heterogeneity was quantified using the between-study variance, τ2, and 95% CrIs.

Results

Of 1834 identified records, 1193 were screened, and 14 trials (1244 patients; 45% female participants; median [IQR] age, 50 [47 to 56] years) were included in the analyses. Rehabilitation interventions were associated with improvements in functional exercise capacity (SMD, -0.56; 95% CrI, -0.87 to -0.22) with moderate certainty in 7 trials (389 participants). These improvements had a 99% posterior probability of superiority when compared with current standard care. The value of τ2 (0.04; 95% CrI, 0.00 to 0.60) indicated low statistical heterogeneity. However, there was significant uncertainty and imprecision regarding the probability of experiencing exercise-induced adverse events (odds ratio, 1.68; 95% CrI, 0.32 to 9.94).

Conclusions and Relevance

The findings of this systematic review and meta-analysis suggest that rehabilitation interventions are associated with improvements in functional exercise capacity, dyspnea, and quality of life, with a high probability of improvement compared with the current standard care; the certainty of evidence was moderate for functional exercise capacity and quality of life and low for other outcomes. Given the uncertainty surrounding the safety outcomes, additional trials with enhanced monitoring of adverse events are necessary.

Respiratory sequelae of COVID-19: pulmonary and extrapulmonary origins, and approaches to clinical care and rehabilitation

Although the exact prevalence of post-COVID-19 condition (also known as long COVID) is unknown, more than a third of patients with COVID-19 develop symptoms that persist for more than 3 months after SARS-CoV-2 infection. These sequelae are highly heterogeneous in nature and adversely affect multiple biological systems, although breathlessness is a frequently cited symptom. Specific pulmonary sequelae, including pulmonary fibrosis and thromboembolic disease, need careful assessment and might require particular investigations and treatments. COVID-19 outcomes in people with pre-existing respiratory conditions vary according to the nature and severity of the respiratory disease and how well it is controlled. Extrapulmonary complications such as reduced exercise tolerance and frailty might contribute to breathlessness in post-COVID-19 condition. Non-pharmacological therapeutic options, including adapted pulmonary rehabilitation programmes and physiotherapy techniques for breathing management, might help to attenuate breathlessness in people with post-COVID-19 condition. Further research is needed to understand the origins and course of respiratory symptoms and to develop effective therapeutic and rehabilitative strategies.

Spontaneous physical functional recovery after hospitalization for COVID-19: insights from a 1 month follow-up and a model to predict poor trajectory

Background

Long COVID syndrome has emerged as a new global healthcare challenge, with impaired physical performance being a prominent debilitating factor. Cardiopulmonary rehabilitation is a mainstay of management of symptomatic post-COVID patients, and optimization of candidate selection might allow for more effective use of available resources.

Methods

In order to study the natural dynamics and to identify predictors of physical functional recovery following hospitalization for COVID-19, 6 min walk test was performed pre-discharge in 176 patients (40% hypertensive, 53% female, mean age 53.2 ± 13.5 years) with re-evaluation at 1 month.

Results

Six min walk distance and the reached percent of predicted distance (6MWD%) were suboptimal at both visits-396 ± 71 m (68.7 ± 12.4%) pre-discharge and 466 ± 65 m (81.8 ± 13.6%) at 1 month. Associated changes included significant oxygen desaturation (2.9 ± 2.5 and 2.3 ± 2.2%, respectively) and insufficient increment of heart rate during the test (24.9 ± 17.5 and 28.2 ± 12.0 bpm) that resulted in low reached percent of individual maximum heart rate (61.1 ± 8.1 and 64.3 ± 8.2%). Automatic clusterization of the study cohort by the 6MWD% changes has allowed to identify the subgroup of patients with poor "low base-low increment" trajectory of spontaneous post-discharge recovery that were characterized by younger age (38.2 ± 11.0 vs. 54.9 ± 12.1, p < 0.001) but more extensive pulmonary involvement by CT (43.7 ± 8.8 vs. 29.6 ± 19.4%, p = 0.029) and higher peak ESR values (36.5 ± 9.7 vs. 25.6 ± 12.8, p < 0.001). Predictors of poor recovery in multivariate logistic regression analysis included age, peak ESR, eGFR, percentage of pulmonary involvement by CT, need for in-hospital oxygen supplementation, SpO2 and mMRC dyspnea score pre-discharge, and history of hypertension.

Conclusion

COVID-19 survivors were characterized by decreased physical performance pre-discharge as assessed by the 6 min walk test and did not completely restore their functional status after 1 month of spontaneous recovery, with signs of altered blood oxygenation and dysautonomia contributing to the observed changes. Patients with poor "low base-low increment" trajectory of post-discharge recovery were characterized by younger age but more extensive pulmonary involvement and higher peak ESR values. Poor post-discharge recovery in the study cohort was predictable by the means of machine learning-based classification model that used age, history of hypertension, need for oxygen supplementation, and ESR as inputs.

Dyspnea in Post-Acute COVID-19: A Multi-Parametric Cardiopulmonary Evaluation

Post-acute COVID-19 is characterized by the persistence of dyspnea, but the pathophysiology is unclear. We evaluated the prevalence of dyspnea during follow-up and factors at admission and follow-up associated with dyspnea persistence. After five months from discharge, 225 consecutive patients hospitalized for moderate to severe COVID-19 pneumonia were assessed clinically and by laboratory tests, echocardiography, six-minute walking test (6MWT), and pulmonary function tests. Fifty-one patients reported persistent dyspnea. C-reactive protein (p = 0.025, OR 1.01 (95% CI 1.00-1.02)) at admission, longer duration of hospitalization (p = 0.005, OR 1.05 (95% CI 1.01-1.10)) and higher body mass index (p = 0.001, OR 1.15 (95% CI 1.06-1.28)) were independent predictors of dyspnea. Absolute drop in SpO₂ at 6MWT (p = 0.001, OR 1.37 (95% CI 1.13-1.69)), right ventricular (RV) global longitudinal strain (p = 0.016, OR 1.12 (95% CI 1.02-1.25)) and RV global longitudinal strain/systolic pulmonary artery pressure ratio (p = 0.034, OR 0.14 (95% CI 0.02-0.86)) were independently associated with post-acute COVID-19 dyspnea. In conclusion, dyspnea is present in many patients during follow-up after hospitalization for COVID-19 pneumonia. While higher body mass index, C-reactive protein at admission, and duration of hospitalization are predictors of persistent dyspnea, desaturation at 6MWT, and echocardiographic RV dysfunction are associated with this symptom during the follow-up period.

Trajectory of Post-COVID Self-Reported Fatigue and Dyspnoea in Individuals Who Had Been Hospitalized by COVID-19: The LONG-COVID-EXP Multicenter Study

Fatigue and dyspnoea are common post-COVID symptoms. The aim of this study was to apply Sankey plots and exponential bar plots for visualizing the evolution and trajectory of post-COVID fatigue and dyspnoea symptoms in a cohort of previously hospitalized COVID-19 survivors. A total of 1266 previously hospitalized patients due to COVID-19 participated in this multicentre study. They were assessed at hospital admission (T0), 8.4 months (T1), 13.2 months (T2) and 18.3 months (T3) after hospital discharge and were asked about the presence of self-reported fatigue or dyspnoea symptoms. Fatigue was defined as a self-perceived feeling of constant tiredness and/or weakness whereas dyspnoea was defined as a self-perceived feeling of shortness of breath at rest. We specifically asked for fatigue and dyspnoea that participants attributed to the infection. Clinical/hospitalization data were collected from hospital medical records. The prevalence of post-COVID fatigue was 56.94% (n = 721) at T1, 52.31% (n = 662) at T2 and 42.66% (n = 540) at T3. The prevalence of dyspnoea at rest decreased from 28.71% (n = 363) at hospital admission (T0), to 21.29% (n = 270) at T1, to 13.96% (n = 177) at T2 and 12.04% (n = 153) at T3. The Sankey plots revealed that 469 (37.08%) and 153 (12.04%) patients exhibited fatigue and dyspnoea at all follow-up periods. The recovery exponential curves show a decreased prevalence trend, showing that fatigue and dyspnoea recover the following three years after hospitalization. The regression models revealed that the female sex and experiencing the symptoms (e.g., fatigue, dyspnoea) at T1 were factors associated with the presence of post-COVID fatigue or dyspnoea at T2 and T3. The use of Sankey plots shows a fluctuating evolution of post-COVID fatigue and dyspnoea during the first two years after infection. In addition, exponential bar plots revealed a decreased prevalence of these symptoms during the first years after. The female sex is a risk factor for the development of post-COVID fatigue and dyspnoea.

[Post-COVID-19 syndrome]

In the aftermath of acute infection with the severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2), a large number of symptoms persist or appear, constituting a real syndrome called "long COVID-19" or "post-COVID- 19" or "post-acute COVID-19 syndrome". Its incidence is very high, half of patients showing at least one symptom at 4-6 months after Coronarovirus infectious disease 2019 (COVID-19). They can affect many organs. The most common symptom is persistent fatigue, similar to that seen after other viral infections. Radiological pulmonary sequelae are relatively rare and not extensive. On the other hand, functional respiratory symptoms, primarily dyspnoea, are much more frequent. Dysfunctional breathing is a significant cause of dyspnoea. Cognitive disorders and psychological symptoms are also very common, with anxiety, depression and post-traumatic stress symptoms being widely described. On the other hand, cardiac, endocrine, cutaneous, digestive or renal sequelae are rarer. The symptoms generally improve after several months, even if their prevalence at two years remains significant. Most of the symptoms are favored by the severity of the initial illness, and the psychic symptoms by the female sex. The pathophysiology of most symptoms is poorly understood. The influence of the treatments used in the acute phase is also important. Vaccination, on the other hand, seems to reduce their incidence. The sheer number of affected patients makes long-term COVID-19 syndrome a public health challenge.

Determinants of recovery from post-COVID-19 dyspnoea: analysis of UK prospective cohorts of hospitalised COVID-19 patients and community-based controls

Background

The risk factors for recovery from COVID-19 dyspnoea are poorly understood. We investigated determinants of recovery from dyspnoea in adults with COVID-19 and compared these to determinants of recovery from non-COVID-19 dyspnoea.

Methods

We used data from two prospective cohort studies: PHOSP-COVID (patients hospitalised between March 2020 and April 2021 with COVID-19) and COVIDENCE UK (community cohort studied over the same time period). PHOSP-COVID data were collected during hospitalisation and at 5-month and 1-year follow-up visits. COVIDENCE UK data were obtained through baseline and monthly online questionnaires. Dyspnoea was measured in both cohorts with the Medical Research Council Dyspnoea Scale. We used multivariable logistic regression to identify determinants associated with a reduction in dyspnoea between 5-month and 1-year follow-up.

Findings

We included 990 PHOSP-COVID and 3309 COVIDENCE UK participants. We observed higher odds of improvement between 5-month and 1-year follow-up among PHOSP-COVID participants who were younger (odds ratio 1.02 per year, 95% CI 1.01-1.03), male (1.54, 1.16-2.04), neither obese nor severely obese (1.82, 1.06-3.13 and 4.19, 2.14-8.19, respectively), had no pre-existing anxiety or depression (1.56, 1.09-2.22) or cardiovascular disease (1.33, 1.00-1.79), and shorter hospital admission (1.01 per day, 1.00-1.02). Similar associations were found in those recovering from non-COVID-19 dyspnoea, excluding age (and length of hospital admission).

Interpretation

Factors associated with dyspnoea recovery at 1-year post-discharge among patients hospitalised with COVID-19 were similar to those among community controls without COVID-19.

Funding

PHOSP-COVID is supported by a grant from the MRC-UK Research and Innovation and the Department of Health and Social Care through the National Institute for Health Research (NIHR) rapid response panel to tackle COVID-19. The views expressed in the publication are those of the author(s) and not necessarily those of the National Health Service (NHS), the NIHR or the Department of Health and Social Care.COVIDENCE UK is supported by the UK Research and Innovation, the National Institute for Health Research, and Barts Charity. The views expressed are those of the authors and not necessarily those of the funders.