Mesenchymal stromal cell extracellular vesicles as therapy for acute and chronic respiratory diseases: A meta-analysis.

Preclinical studies suggest mesenchymal stromal cell extracellular vesicles (MSC-EVs) reduce inflammation and improve organ function in lung diseases; however, an objective analysis of all available data is needed prior to translation. Using rigorous meta-research methods, we determined the effectiveness of MSC-EVs for preclinical respiratory diseases and identified experimental conditions that may further refine this therapy. A systematic search of MEDLINE/Embase identified 1167 records. After screening, 52 articles were included for data extraction and evaluated for risk of bias and quality of reporting in study design. A random effects meta-analysis was conducted for acute lung injury (ALI; N = 23), bronchopulmonary dysplasia (BPD; N = 8) and pulmonary arterial hypertension (PAH; N = 7). Subgroup analyses identified EV methods/characteristics that may be associated with improved efficacy. Data is presented as standardized mean differences (SMD) or risk ratios (RR) with 95% confidence intervals (CI). For ALI, MSC-EVs markedly reduced lung injury (SMD -4.33, CI -5.73 to -2.92), vascular permeability (SMD -2.43, CI -3.05 to -1.82), and mortality (RR 0.39, CI 0.22 to 0.68). Small EVs were more consistently effective than large EVs whereas no differences were observed between tissue sources, immunocompatibility or isolation techniques. For BPD, alveolarization was improved by MSC-EVs (SMD -1.45, CI -2.08 to -0.82) with small EVs more consistently beneficial then small/large EVs. In PAH, right ventricular systolic pressure (SMD -4.16, CI -5.68 to -2.64) and hypertrophy (SMD -2.80, CI -3.68 to -1.91) were significantly attenuated by EVs. In BPD and PAH, EVs isolated by ultracentrifugation demonstrated therapeutic benefit whereas tangential flow filtration (N = 2) displayed minimal efficacy. Lastly, risk of bias and quality of reporting for experimental design were consistently unclear across all studies. Our findings demonstrate clear potential of MSC-EVs to be developed as therapy for acute and chronic lung diseases. However, greater transparency in research design and direct comparisons of isolation technique and EV subtypes are needed to generate robust evidence to guide clinical translation. Protocol Registration: PROSPERO CRD42020145334.

Comparison of Mortality Rate and Severity of Pulmonary Involvement in Coronavirus Disease-2019 Adult Patients With and Without Type 2 Diabetes: A Cohort Study.

OBJECTIVES: Patients with diabetes are potentially at higher risk of mortality due to coronavirus disease-2019 (COVID-19). In this study, we aimed to compare the outcomes and severity of pulmonary involvement in COVID-19 patients with and without diabetes. METHODS: In this cohort study, we recruited patients with diabetes who were hospitalized due to COVID-19 during the period from February 2020 to May 2020. Hospitalized individuals without diabetes were enrolled as control subjects. All patients were followed for 90 days and clinical findings and patients' outcomes were reported. RESULTS: Over a period of 4 months, 127 patients with diabetes and 127 individuals without diabetes with a diagnosis of COVID-19 were recruited. Their mean age was 65.70±12.51 years. Mortality was higher in the group with diabetes (22.8% vs 15.0%; p=0.109), although not significantly. More severe pulmonary involvement (p=0.015), extended hospital stay (p<0.001) and greater need for invasive ventilation (p=0.029) were reported in this population. Stepwise logistic regression revealed that diabetes was not independently associated with mortality (p=0.092). Older age (odds ratio [OR], 1.054; p=0.003), aggravated pulmonary involvement on admission (OR, 1.149; p=0.001), presence of comorbidities (OR, 1.290; p=0.020) and hypothyroidism (OR, 6.576; p=0.021) were associated with mortality. Diabetic foot infection had a strong positive correlation with mortality (OR, 49.819; p=0.016), whereas insulin therapy had a negative correlation (OR, 0.242; p=0.045). CONCLUSIONS: The mortality rate due to COVID-19 did not differ significantly between patients with or without diabetes. Older age, macrovascular complications and presence of comorbidities could increase mortality in people with diabetes. Insulin therapy during hospitalization could attenuate the detrimental effects of hyperglycemia and improve prognosis of patients with COVID-19 and diabetes.

Preexisting respiratory diseases and clinical outcomes in COVID-19: a multihospital cohort study on predominantly African American population.

BACKGROUND: Comorbidities play a key role in severe disease outcomes in COVID-19 patients. However, the literature on preexisting respiratory diseases and COVID-19, accounting for other possible confounders, is limited. The primary objective of this study was to determine the association between preexisting respiratory diseases and severe disease outcomes among COVID-19 patients. Secondary aim was to investigate any correlation between smoking and clinical outcomes in COVID-19 patients. METHODS:  This is a multihospital retrospective cohort study on 1871 adult patients between March 10, 2020, and June 30, 2020, with laboratory confirmed COVID-19 diagnosis. The main outcomes of the study were severe disease outcomes i.e. mortality, need for mechanical ventilation, and intensive care unit (ICU) admission. During statistical analysis, possible confounders such as age, sex, race, BMI, and comorbidities including, hypertension, coronary artery disease, congestive heart failure, diabetes, any history of cancer and prior liver disease, chronic kidney disease, end-stage renal disease on dialysis, hyperlipidemia and history of prior stroke, were accounted for. RESULTS:  A total of 1871 patients (mean (SD) age, 64.11 (16) years; 965(51.6%) males; 1494 (79.9%) African Americans; 809 (43.2%) with ≥ 3 comorbidities) were included in the study. During their stay at the hospital, 613 patients (32.8%) died, 489 (26.1%) needed mechanical ventilation, and 592 (31.6%) required ICU admission. In fully adjusted models, patients with preexisting respiratory diseases had significantly higher mortality (adjusted Odds ratio (aOR), 1.36; 95% CI, 1.08-1.72; p = 0.01), higher rate of ICU admission (aOR, 1.34; 95% CI, 1.07-1.68; p = 0.009) and increased need for mechanical ventilation (aOR, 1.36; 95% CI, 1.07-1.72; p = 0.01). Additionally, patients with a history of smoking had significantly higher need for ICU admission (aOR, 1.25; 95% CI, 1.01-1.55; p = 0.03) in fully adjusted models. CONCLUSION:  Preexisting respiratory diseases are an important predictor for mortality and severe disease outcomes, in COVID-19 patients. These results can help facilitate efficient resource allocation for critical care services.

Respiratory follow-up of patients with COVID-19 pneumonia.

The COVID-19 pandemic has led to an unprecedented surge in hospitalised patients with viral pneumonia. The most severely affected patients are older men, individuals of black and Asian minority ethnicity and those with comorbidities. COVID-19 is also associated with an increased risk of hypercoagulability and venous thromboembolism. The overwhelming majority of patients admitted to hospital have respiratory failure and while most are managed on general wards, a sizeable proportion require intensive care support. The long-term complications of COVID-19 pneumonia are starting to emerge but data from previous coronavirus outbreaks such as severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) suggest that some patients will experience long-term respiratory complications of the infection. With the pattern of thoracic imaging abnormalities and growing clinical experience, it is envisaged that interstitial lung disease and pulmonary vascular disease are likely to be the most important respiratory complications. There is a need for a unified pathway for the respiratory follow-up of patients with COVID-19 balancing the delivery of high-quality clinical care with stretched National Health Service (NHS) resources. In this guidance document, we provide a suggested structure for the respiratory follow-up of patients with clinicoradiological confirmation of COVID-19 pneumonia. We define two separate algorithms integrating disease severity, likelihood of long-term respiratory complications and functional capacity on discharge. To mitigate NHS pressures, virtual solutions have been embedded within the pathway as has safety netting of patients whose clinical trajectory deviates from the pathway. For all patients, we suggest a holistic package of care to address breathlessness, anxiety, oxygen requirement, palliative care and rehabilitation.

Respiratory support in patients with COVID-19 (outside intensive care unit). A position paper of the Respiratory Support and Chronic Care Group of the French Society of Respiratory Diseases.

With first cases noted towards the end of 2019 in China, COVID-19 infection was rapidly become a devastating pandemic. Even if most patients present with a mild to moderate form of the disease, the estimated prevalence of COVID-19-related severe acute respiratory failure (ARF) is 15-20% and 2-12% needed intubation and mechanical ventilation. In addition to mechanical ventilation some other techniques of respiratory support could be used in some forms of COVID-19 related ARF. This position paper of the Respiratory Support and Chronic Care Group of the French Society of Respiratory Diseases is intended to help respiratory clinicians involved in care of COVID-19 pandemic in the rational use of non-invasive techniques such as oxygen therapy, CPAP, non-invasive ventilation and high flow oxygen therapy in managing patients outside intensive care unit (ICU). The aims are: (1) to focus both on the place of each technique and in describing practical tips (types of devices and circuit assemblies) aimed to limit the risk of caregivers when using those techniques at high risk spreading of viral particles; (2) to propose a step-by-step strategy to manage ARF outside ICU.

Position Paper for the State-of-the-Art Application of Respiratory Support in Patients with COVID-19.

Against the background of the pandemic caused by infection with the SARS-CoV-2 virus, the German Respiratory Society has appointed experts to develop therapy strategies for COVID-19 patients with acute respiratory failure (ARF). Here we present key position statements including observations about the pathophysiology of (ARF). In terms of the pathophysiology of pulmonary infection with SARS-CoV-2, COVID-19 can be divided into 3 phases. Pulmonary damage in advanced COVID-19 often differs from the known changes in acute respiratory distress syndrome (ARDS). Two types (type L and type H) are differentiated, corresponding to early- and late-stage lung damage. This differentiation should be taken into consideration in the respiratory support of ARF. The assessment of the extent of ARF should be based on arterial or capillary blood gas analysis under room air conditions, and it needs to include the calculation of oxygen supply (measured from the variables of oxygen saturation, hemoglobin level, the corrected values of Hüfner's factor, and cardiac output). Aerosols can cause transmission of infectious, virus-laden particles. Open systems or vented systems can increase the release of respirable particles. Procedures in which the invasive ventilation system must be opened and endotracheal intubation carried out are associated with an increased risk of infection. Personal protective equipment (PPE) should have top priority because fear of contagion should not be a primary reason for intubation. Based on the current knowledge, inhalation therapy, nasal high-flow therapy (NHF), continuous positive airway pressure (CPAP), or noninvasive ventilation (NIV) can be performed without an increased risk of infection to staff if PPE is provided. A significant proportion of patients with ARF present with relevant hypoxemia, which often cannot be fully corrected, even with a high inspired oxygen fraction (FiO2) under NHF. In this situation, the oxygen therapy can be escalated to CPAP or NIV when the criteria for endotracheal intubation are not met. In ARF, NIV should be carried out in an intensive care unit or a comparable setting by experienced staff. Under CPAP/NIV, a patient can deteriorate rapidly. For this reason, continuous monitoring and readiness for intubation are to be ensured at all times. If the ARF progresses under CPAP/NIV, intubation should be implemented without delay in patients who do not have a "do not intubate" order.

COVID-19 and diabetes mellitus: implications for prognosis and clinical management.

INTRODUCTION: COVID-19 is a novel coronavirus that emerged from Wuhan, China in December 2019, and within 3 months became a global pandemic. AREAS COVERED: PubMed search of published data on COVID-19, respiratory infections, and diabetes mellitus (DM). DM associates with impairments of both cellular and humoral immunity. Early emergent global data reveal that severity of clinical outcome from COVID-19 infection (including hospitalization and admission to Intensive Care Unit [ICU]), associate with co-morbidities, prominently DM. The key principles of management of COVID-19 in patients with DM include ongoing focused outpatient management (remotely where necessary) and maintenance of good glycemic control. EXPERT OPINION: We will remember the dawn of the third decade of the twenty-first century as a time when the world changed, the true scale and impact of which is hard for us to imagine. Like a phoenix from the ashes though, COVID-19 provides us with a great learning opportunity to renew insights into ourselves as individuals, our clinical teams, and the optimized provision of care for our patients. COVID-19 has re-shaped and re-focused our collective societal values, with a sea-changed shift from materialistic to human-centric, from self-centredness to altruism, ultimately for the betterment of patient care and the whole of society.

The Use of Non-invasive Vagus Nerve Stimulation to Treat Respiratory Symptoms Associated With COVID-19: A Theoretical Hypothesis and Early Clinical Experience.

OBJECTIVES: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a pandemic with no specific therapeutic agents and substantial mortality, and finding new treatments is critical. Most cases are mild, but a significant minority of patients develop moderate to severe respiratory symptoms, with the most severe cases requiring intensive care and/or ventilator support. This respiratory compromise appears to be due to a hyperimmune reaction, often called a cytokine storm. Vagus nerve stimulation has been demonstrated to block production of cytokines in sepsis and other medical conditions. We hypothesize that non-invasive vagus nerve stimulation (nVNS) might provide clinical benefits in patients with respiratory symptoms similar to those associated with COVID-19. MATERIALS AND METHODS: Information on two case reports was obtained via email correspondence and phone interviews with the patients. RESULTS: Both patients reported clinically meaningful benefits from nVNS therapy. In case 1, the patient used nVNS to expedite symptomatic recovery at home after hospital discharge and was able to discontinue use of opioid and cough suppressant medications. In case 2, the patient experienced immediate and consistent relief from symptoms of chest tightness and shortness of breath, as well as an improved ability to clear his lungs. CONCLUSIONS: Preliminary observations and a strong scientific foundation suggest that nVNS might provide clinical benefits in patients with COVID-19 via multiple mechanisms.

COVID-19-Related Severe Hypercoagulability in Patients Admitted to Intensive Care Unit for Acute Respiratory Failure.

In late December 2019 an outbreak of a novel coronavirus (SARS-CoV-2) causing severe pneumonia (COVID-19) was reported in Wuhan, Hubei Province, China. A common finding in most COVID-19 patients is high D-dimer levels which are associated with a worse prognosis. We aimed to evaluate coagulation abnormalities via traditional tests and whole blood thromboelastometry profiles in a group of 22 (mean age 67 ± 8 years, M:F 20:2) consecutive patients admitted to the Intensive Care Unit of Padova University Hospital for acute respiratory failure due to COVID-19. Cases showed significantly higher fibrinogen and D-dimer plasma levels versus healthy controls (p < 0.0001 in both comparisons). Interestingly enough, markedly hypercoagulable thromboelastometry profiles were observed in COVID-19 patients, as reflected by shorter Clot Formation Time (CFT) in INTEM (p = 0.0002) and EXTEM (p = 0.01) and higher Maximum Clot Firmness (MCF) in INTEM, EXTEM and FIBTEM (p < 0.001 in all comparisons). In conclusion, COVID-19 patients with acute respiratory failure present a severe hypercoagulability rather than consumptive coagulopathy. Fibrin formation and polymerization may predispose to thrombosis and correlate with a worse outcome.