Ventilator-induced Lung Injury Vortex in Patients With SARS-CoV-2
ARDSMechanical Ventilation Complication1 moreThe concept of Ventilator-induced Lung Injury Vortex (VILI vortex) has recently been proposed as a progressive lung injury mechanism in which the alveolar stress/strain increases as the ventilable lung "shrinks" (1). This positive feedback inexorably leads to the acceleration of lung damage, with potentially irreversible results. Little is known about the clinical aspects of this condition. Understanding its behavior could contribute to changing its potential devastating impact. The objective of this study is to evaluate the incidence of VILI vortex in patients with acute respiratory syndrome (ARDS) secondary to COVID-19, to establish a connection between this phenomenon and mortality, and to identify the factors that have an impact on its development.
Mechanism of Delayed Neutrophil Apoptosis in Acute Lung Injury
Acute Lung Injury/Acute Respiratory Distress Syndrome (ARDS)Neutrophils3 moreLiterature basis Acute respiratory distress syndrome (ARDS) is a clinical syndrome characterized by respiratory distress and progressive hypoxemia, which is caused by diffuse alveolar and pulmonary interstitial edema caused by various pulmonary and extrapulmonary factors other than cardiogenic factors. ARDS incidence rate is as high as 75 /10 000 per year, and sepsis and pulmonary infection are the most common causes. In the past, it was generally believed that excessive immune activation is the core of the pathophysiology of ARDS, and neutrophils are recognized as the core driver of inflammatory hyperactivity and lung injury in ARDS. Although some progress has been made in the epidemiology, pathogenesis and pathophysiology of ARDS in the past 50 years, and the clinical outcomes of some patients with ARDS have been improved by optimizing the mode of mechanical ventilation and fluid treatment, as well as prone ventilation and the use of muscle relaxants, ARDS is still one of the most common causes of death and disability in intensive care units, The mortality rate of the disease is currently as high as 30-40%. There is still a lack of effective drugs for the treatment of ARDS in clinic, and even glucocorticoids applied for immune overactivation have not achieved good results. This is related to the unclear pathogenesis of ARDS. Therefore, it is still a hot and difficult point to further explore the pathogenesis and progression of ARDS and find new therapeutic targets. In the past, mature PMN in peripheral blood was generally considered as a functional cell in the end stage, but it is widely involved in different innate immune responses (including inflammation, infection, tumor, autoimmunity, etc.) and can adopt very different effector mechanisms. Therefore, with the deepening of research, neutrophil subtypes with different functions (such as immune regulation and repair) have been identified in recent years: cd16dimcd62lbrightpmn and cd16brightcd62ldimmpmn. In the steady state of healthy people, the classic mature neutrophils (cd16brightcd62lbright) in peripheral blood account for more than 98% of the total PMN, and the proportion of the two neutrophil subtypes is relatively low. In the inflammatory state, the proportion of cd16dimcd62lbright and cd16brightcd62ldim neutrophils increased significantly. Proteomic analysis showed that there were significant differences between the two subtypes of neutrophils. The nucleus of cd16dimcd62lbright neutrophil subgroup is banded, which is released from bone marrow after being stimulated by lipopolysaccharide (LPS). It accounts for 20% - 25% of PMN in whole blood in LPS infection model. The apoptosis rate is significantly reduced, and the bacteriostatic effects such as oxidative burst and phagocytosis are significantly enhanced; On the contrary, cd16brightcd62ldim neutrophil subgroup has reduced antibacterial ability and shows immunosuppressive phenotype. It is a newly discovered neutrophil subtype with immunosuppressive function in recent years, which can inhibit T cell proliferation, which is related to immunosuppression in the experimental human endotoxemia model. In our previous studies, we have successfully obtained a new amino acid derivative of ocotillol ginsenoside, which may have the pharmacological activities of ocotillol ginsenoside and glycine, and has a potential role in improving the delay of apoptosis and immunosuppression of ARDS neutrophil subtypes, and has the potential of new drug development for the treatment of ARDS. The experimental steps are as follows: Firstly, the peripheral blood of ARDS patients in ICU was collected, and neutrophils were isolated from the peripheral blood. The proportion of neutrophil subtypes and the degree of apoptosis were detected by flow cytometry. Co culture with human T lymphocytes in vitro to observe its ability to inhibit T cell proliferation. Then, the neutrophils of ARDS patients were cultured with different doses of ginsenoside glycine derivatives, and the detection of the above indexes was repeated again. Finally, the mechanism of neutrophils in the pathogenesis and progression of ARDS was discussed.
Biological Markers to Identify Early Sepsis and Acute Lung Injury
SepsisAcute Lung InjuryThere are no clear markers to identify sepsis and acute lung injury at early stage in clinical settings which would result in improved survival of the patients. In collaboration with the research team led by Dr. Zhang at St. Michael's Hospital, Toronto, we have initiated a pilot study looking for biological markers to detect severe sepsis and ARDS. We have found that human neutrophils peptides (a-defensins), certain coagulation variables and cytokine levels are very sensitive markers to differentiate severe sepsis, ARDS from cardiovascular diseases in ICU patients. These findings may provide valuable information for therapeutic guideline in clinical practice. The present study will focus on testing 'biological markers' to identify patients with sepsis and acute lung injury. We will examine the roles of three components of markers including inflammation, neutrophil activation and coagulation. We are hoping that this proposed translational research will help develop novel therapeutic strategy in sepsis and acute lung injury patients.
Respiratory Mechanics During One-lung Ventilation
Ventilator-Induced Lung InjuryLung Ventilator1 moreIntraoperative lung protective ventilatory strategy has been widely recognized to reduce postoperative pulmonary complications in laparotomy and laparoscopic surgeries. However, the clinical evidence and consensus for ventilatory strategy to protect the dependent lung segments during thoracic surgery that requires one-lung ventilation (OLV) is currently not available. Since lung compliance changes significantly during OLV, the levels of respiratory mechanics should be optimized to avoid barotrauma and volutrauma. This study aims to determine the optimal levels of volume-pressure dynamics during OLV and at the phase of recruitment of the independent lungs by achieving optimal lung compliance, gas exchange and hemodynamics.
A Central and Eastern European Survey On PEEP Titration and Alveolar Recruitment Manoeuvres During...
Ventilator-Induced Lung InjuryPositive End-Expiratory Pressure1 moreThe aim of this questionnaire-based survey is to evaluate the routine use of individual positive end-expiratory pressure (PEEP) and regular alveolar recruitment manoeuvres (ARM) of Central and Eastern European anaesthesiologists during general anaesthesia.
The ASTERS Study: Assessing the Role of Sphingolipids in AcuTE Respiratory Distress Syndrome (ARDS)...
Acute Lung InjuryAcute Respiratory Distress SyndromeAcute lung injury (ALI) and the more severe manifestation, acute respiratory distress syndrome (ARDS) describe syndromes of acute onset, bilateral, inflammatory pulmonary infiltrates and impaired oxygenation. ARDS/ALI are a continuum of disease which results in a life threatening, rapidly progressive illness and occurs in critically ill patients. Recent reports in the Journal of the American Medical Association (JAMA) highlight the significant public health impact ARDS/ALI has on the critically ill population in that despite robust research efforts, these illnesses continue to be under diagnosed, under treated, and continue to have a high mortality rate (≥ 40% of all confirmed diagnoses). The estimates for ARDS/ALI incidence vary due to inconsistencies with proper diagnosis and lack of valid biomarkers of disease; however, it is expected that anywhere from 20-50% of patients on mechanical ventilation will develop this disease. Previous work by our group has shown that sphingolipids play a multifaceted role in lung inflammation. Sphingolipid are a class of bioactive lipids that play a role in cellular processes such as apoptosis, cell migration, and adhesion. Ceramide is one species of sphingolipid the investigators have examined in both man and mouse. Our laboratory has shown that ceramide is up-regulated in pulmonary inflammation in mouse models of pneumonitis and is elevated in the exhaled breath condensate of mechanically ventilated patients at risk for ARDS/ALI. Our work coupled with the work of others highlighting a role for ceramide in chronic obstructive pulmonary disease (COPD), surfactant dysfunction, and infectious disease make ceramide a logical candidate biomarker that warrants further investigation. To our knowledge, there are no studies examining the role of ceramide as a biomarker in ARDS/ALI. Thus, our overarching hypothesis is that ceramide is elevated in the lungs of patients who develop ARDS/ALI. This lipid dysregulation accounts for the pathophysiology seen in this disease and may be a potential pharmacologic target for clinical treatment. Thus the purpose of this exploratory research is to maximize existing specimens to further evaluate ceramide as a biomarker for acute lung injury.
A New Ultrasonographic Tool to Assess Regional Pulmonary Strain
Ventilator-Induced Lung InjuryMechanical Ventilation ComplicationThis study is designed to assess the feasibility of the measurement of local pleural strain at 4 different anatomical sites. The secondary objectives of the study are: To assess intra- and inter-observer variability in the measurement of local pleural strain To identify the strain parameters demonstrating the most clinically relevant and the most significant correlation with a change in tidal volume Hypothesis: The analysis of lung ultrasonographic sequences using speckle-tracking allows the determination of local pleural strain in 4 predetermined pulmonary areas.
Ventilator-Associated Events: Prevalence, Outcome and Preventability
Ventilator-Associated Lung InjuryThe aim of this study is to determine the prevalence of ventilator-associated events (VAE). To analyze the patients profile, morbidity and mortality compared to patients who did not develope VAE. The preventability of VAE will be assessed by comparing the percentage of adherence to the bundle of preventive measures among patients who developed and did not develope VAE.
Effect of Mechanical Ventilation on Plasma Concentration Level of R-spondin Proteins
Acute Lung InjuryAs novel agonists of Wnt/β-catenin signaling pathway, R-spondin proteins constitute a class of ligands, including R-spondin 1/2/3/4, functioning through their receptors leucine-rich repeat-containing G-protein coupled receptor (LGR)4/5/6 to enhance Wnt/β-catenin activity. Since Wnt signaling plays pivotal roles in the regulation of many life processes involved in embryogenesis and adulthood, R-spondin proteins also take part in cell proliferation, differentiation and morphogenesis.For example, in the formation of respiratory system,R-spondin 2 is required for normal laryngeal-tracheal and lung morphogenesis,and the lack of R-spondin 1 expression results in the absence of duct side-branching development and subsequent alveolar formation. In addition, R-spondins show protective effect in tissue injury and diseases. R-spondin 1 and R-spondin 3 have been reported to prevent chemotherapy- or radiotherapy-induced mucous membrane lesion. R-spondin 1 attenuates oral mucositis contributed by radiotherapy in mouse models and R-spondin 3 potentiates intestinal regeneration elicited via gastrointestinal toxic effect of chemoradiotherapy treatment. However, whether R-spondin proteins exert salient influence on acute lung injury especially induced by mechanical ventilation is deficient. Therefore, this study aims to ascertain the implication of R-spondin proteins in the pathology of mechanical ventilation induced lung injury through detecting human plasma concentration change of R-spondin 1/2/3/4 after mechanical ventilation and interference effects in mouse model, which is helpful for prevention and treatment of ventilation induced lung injury.
68Ga-NOTA-PRGD2 PET/CT in Patients With Lung Injury and Pulmonary Fibrosis
Pulmonary FibrosisUnspecifiedThis is an open-label positron emission tomography/computed tomography (PET/CT) study to investigate the diagnostic performance and evaluation efficacy of 68Ga-NOTA-PRGD2 in lung injury (LI) and pulmonary fibrosis (PF) patients. A single dose of nearly 111 MBq 68Ga-NOTA-PRGD2 (≤ 40 µg NOTA-PRGD2) will be intravenously injected into patients with LI/PF. Visual and semiquantitative method will be used to assess the PET/CT images.