Mechanical ventilation (MV) is currently widely used in the treatment of respiratory failure and anesthesia surgery, and is a commonly used respiratory support method for critically ill patients; however, improper usage of MV can lead to ventilator-induced lung injury (VILI), which poses a significant threat to patient life. Alveolar epithelial cell (AEC) has the functions of mechanosensation and mechanotransduction. Physiological mechanical stretching is beneficial for maintaining the lineage homeostasis and normal physiological functions of AEC cells, while excessive mechanical stretching can cause damage to AEC cells. Damage to AEC cells is an important aspect in the occurrence and development of VILI. Understanding the effects of mechanical stretching on AEC cells is crucial for developing safe and effective MV strategies, preventing the occurrence of VILI, and improving the clinical prognosis of VILI patients. From the perspective of cell mechanics, this paper aims to briefly elucidate the mechanical properties of AEC cells, mechanosensation and mechanotransduction of mechanical stretching in AEC cells, and the injury and repair of AEC cells under mechanical stretch stimulation, and potential mechanisms with the goal of helping clinical doctors better understand the pathophysiological mechanism of VILI caused by MV, improve their understanding of VILI, provide safer and more effective strategies for the use of clinical MV, and provide theoretical basis for the prevention and treatment of VILI.
Humans ; Mechanotransduction, Cellular ; Ventilator-Induced Lung Injury ; Stress, Mechanical ; Alveolar Epithelial Cells ; Respiration, Artificial/adverse effects* ; Epithelial Cells ; Pulmonary Alveoli/cytology* ; Animals

OBJECTIVE: To analyze the pathogens distribution in patients with ventilator-associated pneumonia (VAP), and their association with anti-β-glucan receptor-1 (Dectin-1)/spleen tyrosine kinase (Syk) signaling pathway, and to provide scientific basis for formulating more effective treatment strategies and preventive measures. METHODS: A prospective study was conducted. 160 patients with VAP admitted to the department of critical care medicine of Xingtai People's Hospital from January 2021 to March 2023 were enrolled. The respiratory secretions of patients were collected for Candida colonization analysis, and then the bacteria in the respiratory secretions were identified by automatic microbial identification instrument. The expression levels of Dectin-1 and Syk in peripheral blood mononuclear cells were detected by fluorescent immunopolymerase chain reaction. Clinical pulmonary infection score (CPIS) was performed based on imaging, clinical and microbiological criteria. The basic data, pathogen distribution, Dectin-1 and Syk expression levels and CPIS score of the two groups were compared. Spearman test was used to analyze the correlation between the expression levels of Dectin-1 and Syk and respiratory Candida colonization and CPIS score. RESULTS: 160 VAP patients, 97 were Candida colonized (colonized group) and 63 were not (non-colonized group). There were significantly differences in gender (males: 57.73% vs. 41.27%, P = 0.042) and age (years: 57.98±12.46 vs. 62.09±10.61, P = 0.029) between the colonized group and the non-colonized group, while there were no significantly differences in the data of duration of mechanical ventilation, underlying diseases and primary diseases. The distribution of pathogenic bacteria showed that the infection rate of Staphylococcus aureus in the colonized group was significantly higher than that in the non-colonized group (24.74% vs. 7.94%, P < 0.05), and there was no significantly difference in the infection rate of other G-positive and G-negative bacteria between the two groups. The CPIS score in the colonized group was significantly higher than that in the non-colonized group (8.73±0.43 vs. 7.31±0.39, P < 0.01), and the expression levels of Dectin-1 and Syk in peripheral blood mononuclear cells were significantly higher than those in the non-colonized group (Dectin-1/U6: 0.86±0.22 vs. 0.47±0.16, Syk/U6: 0.77±0.18 vs. 0.42±0.11, both P < 0.01). The expression levels of Dectin-1 and Syk in peripheral blood mononuclear cells of VAP patients were significantly positively correlated with the colonization of respiratory Candida (r values were 0.754 and 0.631, respectively, both P < 0.05), and were significantly positively correlated with CPIS score (r values were 0.594 and 0.618, respectively, both P < 0.05). CONCLUSION The proportion of Staphylococcus aureus in VAP patients with respiratory Candida colonization is higher, and Dectin-1/Syk signaling pathway is significantly positively correlated with respiratory Candida colonization and CPIS score.
Humans ; Syk Kinase ; Lectins, C-Type/metabolism* ; Signal Transduction ; Pneumonia, Ventilator-Associated/metabolism* ; Prospective Studies ; Male ; Female ; Middle Aged ; Candida ; Aged

Mechanical ventilation is commonly employed for respiratory support in patients with respiratory failure. Despite the optimization of ventilator parameters and treatment methods, mechanical ventilation can still lead to both acute and chronic lung injury in patients with acute respiratory distress syndrome (ARDS) as well as in those without ARDS, a phenomenon referred to as ventilator-induced lung injury (VILI). VILI can be categorized into four types: barotrauma, volumetric injury, atelectasis injury, and biotic injury. Among these, biotic injury, characterized by inflammation, plays a significant role in the pathogenesis of VILI. Numerous studies have investigated the inflammatory mechanisms underlying VILI; however, these mechanisms remain complex and not entirely understood. At present, clinical practice lacks specific prevention and treatment strategies for VILI, aside from the implementation of protective ventilation strategies. Long non-coding RNAs (lncRNA) are a category of non-coding RNA longer than 200 nucleotides. LncRNAs regulate physiological and pathological processes such as cell proliferation, apoptosis, inflammatory response, and immune regulation, this regulation occurs through mechanisms such as modulating gene activity, inhibiting specific states, assisting in transcription initiation, affecting pre-mRNA splicing modifications, influencing translation processes, and expressing biofunctional peptides. They play an important role in the course of multiple diseases. Studies have shown that compared with control animals and cell models, lncRNAs are differentially expressed in VILI animal models and cell stretch models. Experiments have verified that certain lncRNAs play a crucial role in the pathogenesis of VILI by regulating the expression of inflammatory factors, the transformation of macrophage types, neutrophil activation, and cell apoptosis. Given the adverse effects of VILI on mechanical ventilation in critically ill patients, the important role of lncRNAs in biological regulation, and the urgent need to explore more effective strategies for the prevention and treatment of VILI, this paper summarizes the mechanisms through which lncRNA contributes to the VILI process, and discusses its possibility as a diagnostic and therapeutic target of VILI, in order to provide a reference for the clinical treatment of VILI.
RNA, Long Noncoding ; Ventilator-Induced Lung Injury ; Humans ; Respiration, Artificial/adverse effects* ; Animals ; Respiratory Distress Syndrome ; Apoptosis

Since the beginning of the 21st century, the severe respiratory infectious diseases worldwide [such as severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), influenza A H1N1 and novel coronavirus infection have attracted wide attention from all walks of life due to their superior pathogenicity and transmissibility. Aerosols-carrying pathogens are the main transmission route of many severe respiratory infectious diseases, which can lead to severe respiratory failure and even acute respiratory distress syndrome (ARDS) in infected individuals. Mechanical ventilation is the primary treatment for ARDS, and the small tidal volume, appropriate level of positive end-expiratory pressure based lung protective ventilation strategy can effectively reduce the incidence of ventilator-induced lung injury (VILI). However, in the process of clinical treatment, it is sometimes necessary to briefly disconnect the connection between the artificial airway and the ventilator circuit, which will not only cause the residual aerosol in the respiratory system to spill out and pollute the surrounding environment, increase the risk of nosocomial infection including medical staff, but also interfere with the implementation of lung protective ventilation strategy and aggravate ventilator-induced lung injury. In addition, studies have shown that a lot of medical staff have nosocomial infections, especially staff involved in tracheal intubation, extubation and other airway related operations. In addition to enhancing personal protective measures, it is crucial to safeguard healthcare workers from aerosol contamination and minimize associated risks during airway management. At present, there are few researches on the temporary sealing of airway lines and ventilator system, and there is a lack of clear guidance. This review summarizes the research status in related fields to provide a reference for corresponding solutions and programs.
Humans ; Respiratory Distress Syndrome/etiology* ; Respiration, Artificial ; Ventilator-Induced Lung Injury/prevention & control* ; Severe Acute Respiratory Syndrome ; COVID-19 ; Clinical Relevance

With the continuous advancement and innovation in medical equipment technology, the transition between high-flow oxygen therapy, non-invasive ventilation, and invasive ventilation can be easily achieved by adjusting the ventilation mode of ventilators. During the weaning phase for tracheotomized patients, it is necessary to disconnect the ventilator circuit, change the ventilator mode, and gradually extend the weaning time to achieve complete ventilator liberation. During the weaning process, due to patients' excessive dependence on the ventilator, there may be situations where respiratory endpoints and Y-connectors of the ventilator are reconnected for invasive ventilation. However, during the weaning process, the Y-connector and expiratory end connectors are exposed to the air, which cannot ensure the tightness of the ventilator circuit, easily increasing the probability of ventilator circuit contamination and subsequently the risk of ventilator-associated pneumonia (VAP). To overcome these issues, the research team of department of critical care medicine of Zhongda Hospital Southeast University has designed a ventilator circuit interface protective device for weaning and has obtained a National Utility Model Patent of China (ZL 2023 2 1453385.8). The main body of the protective device is a Y-connector plug, consisting of multiple components, including a sealing piece, a protective cover, a sealing plug, an interface 1 (connects with the patient's tracheal tube), an interface 2 (connects with the respiratory branch of the ventilator), and an interface 3 (connects with the expiratory branch of the ventilator), featuring a unique design and easy operation. During the patient's weaning training process, the interface 1 and interface 2 is disconnected from the patient's tracheal tube and respiratory branch, respectively. The interface 1 is plugged with a stopper, and the interface 2 is covered with a protective cover to ensure the tightness of the expiratory branch and Y-connector of the ventilator. During the period when the patient is using the ventilator, the protective cover and plug are removed, and connecting them together ensures the tightness of the device itself, reducing the incidence of VAP caused by ventilator circuit contamination, avoiding nosocomial infections, and shortening the prolonged use of invasive ventilation, increased complication rate, extended hospital stay, and increased medical cost associated with weaning.
Humans ; Ventilator Weaning/methods* ; Equipment Design ; Ventilators, Mechanical ; Respiration, Artificial/instrumentation* ; Pneumonia, Ventilator-Associated/prevention & control*

OBJECTIVE: To investigate the interaction between α-amylase (α-AMS) and inflammatory response in patients with ventilator-associated pneumonia (VAP) and their predictive value for prognosis. METHODS: A prospective cohort study was conducted. Patients with mechanical ventilation who were treated in the intensive care unit (ICU) of the Second Hospital of Hebei Medical University from June 2020 to June 2023 were enrolled, and the patients were divided into VAP group and non-VAP group according to whether VAP occurred. VAP patients were stratified into mild [acute physiology and chronic health evaluation II (APACHE II) < 10 scores], moderate (APACHE II were 10-20 scores), and severe (APACHE II > 20 scores) groups based on the APACHE II. All patients were followed up for 28 days. In addition, healthy subjects who underwent health examination in our hospital at the same time were selected as the healthy control group. Baseline data including gender, age, mechanical ventilation mode, mechanical ventilation time, underlying diseases, drug use, and laboratory test indicators were collected. The serum levels of α-AMS, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), C-reactive protein (CRP) and other inflammatory factors were analyzed and compared. Pearson correlation analysis was performed to analyze the correlation between serum α-AMS and inflammatory factors. Logistic regression was used to analyze the influencing factors of poor prognosis in patients with VAP. The receiver operator characteristic curve (ROC curve) was plotted to evaluate the predictive value of α-AMS on the poor prognosis of patients with VAP. RESULTS: A total of 100 mechanically ventilated patients were enrolled, including 60 cases in the VAP group and 40 cases in the non-VAP group. Among the patients with VAP, there were 24 cases in the mild group, 20 cases in the moderate group, and 16 cases in the severe group. A total of 44 patients survived at 28 days, while 16 died. Additionally, 100 healthy individuals were included as the healthy control group. Serum levels of α-AMS, IL-6, TNF-α and CRP in the VAP group were significantly higher than those in the non-VAP group and the healthy control group, while the levels of α-AMS, IL-6, TNF-α and CRP in the non-VAP group were significantly higher than those in the healthy control group. There were statistically significant differences in serum α-AMS, IL-6, TNF-α, CRP levels and APACHE II scores among VAP patients with different disease severities, and the levels of the above indicators in the severe group were significantly higher than those in the moderate group and mild group, and the levels of the above indicators in the moderate VAP group were significantly higher than those in the mild group. Pearson correlation analysis showed that serum α-AMS was positively correlated with IL-6, TNF-α, CRP, and APACHE II scores (r values were 0.404, 0.392 and 0.493, 0.493, all P < 0.01). Univariate analysis showed that age, mechanical ventilation, diabetes mellitus, ventilation time, ventilation position, prophylactic use of antimicrobial drugs, and serum α-AMS, IL-6, TNF-α, CRP, and APACHE II scores were correlated with the prognosis of VAP patients (all P < 0.05). Multivariate Logistic regression analysis identified age [odds ratio (OR) = 1.340, 95% confidence interval (95%CI) was 1.119-1.605], tracheostomy (OR = 3.050, 95%CI was 1.016-9.157), diabetes mellitus (OR = 1.379, 95%CI was 1.102-1.724), and ventilation time ≥ 7 days (OR = 2.557, 95%CI was 1.163-5.623) and serum α-AMS (OR = 1.428, 95%CI was 1.098-1.856), IL-6 (OR = 1.543, 95%CI was 1.005-2.371), TNF-α (OR = 2.228, 95%CI was 1.107-4.485), CRP (OR = 1.252, 95%CI was 1.131-1.387), APACHE II scores (OR = 1.422, 95%CI was 1.033-1.957) were independent influencing factors for the 28-day prognosis of patients with VAP (all P < 0.05). ROC curve analysis demonstrated that serum α-AMS, IL-6, TNF-α and CRP exhibited significant predictive performance on the prognosis of patients with VAP. The best cut-off value for α-AMS had a sensitivity of 81.3%, specificity of 75.0%, and an area under the ROC curve (AUC) of 0.791, which was significantly higher than those of inflammatory markers IL-6, TNF-α, and CRP (P < 0.05). The combined parameter diagnostic performance was significantly better than those of individual parameters (P < 0.05), with the highest diagnostic performance when combined, corresponding to an AUC of 0.868 (95%CI was 0.798-0.938), sensitivity of 87.5%, and specificity of 79.5%. CONCLUSIONS VAP in mechanically ventilated patients can lead to an increase in the levels of peripheral blood α-AMS and inflammatory factors, and there is an interaction between α-AMS and inflammatory markers in severe VAP patients. These markers are closely related to the severity of the disease and prognosis and have significant implications for predicting patient outcomes.
Humans ; Pneumonia, Ventilator-Associated/diagnosis* ; Prognosis ; Prospective Studies ; Respiration, Artificial ; alpha-Amylases/blood* ; Interleukin-6/blood* ; Male ; Female ; C-Reactive Protein/metabolism* ; APACHE ; Inflammation ; Middle Aged ; Intensive Care Units ; Tumor Necrosis Factor-alpha/blood* ; Aged

OBJECTIVE: To analyze the risk factors for ventilator-associated pneumonia (VAP) and its prognosis in patients with severe craniocerebral injury. METHODS: A prospective observational study was conducted. Patients with severe craniocerebral injury admitted to the Second Affiliated Hospital of Xingtai Medical College from January 2020 to December 2022 were enrolled as the study subjects. Patients were divided into VAP group and non-VAP group based on the occurrence of VAP. VAP patients were further stratified into low-risk group [sequential organ failure assessment (SOFA) score 0-5], moderate-risk group (SOFA score 6-8), and high-risk group (SOFA score ≥ 9). General data, serological indicators [interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and signal transducer and activator of transcription 3 (STAT3)], and 28-day prognosis (with mortality as the endpoint event) were compared. Multivariate Logistic regression was used to identify risk factors for VAP and 28-day mortality. Linear regression was applied to analyze the correlations between risk factors and outcomes. RESULTS: A total of 140 patients with severe craniocerebral injury were enrolled, including 49 in the VAP group and 91 in the non-VAP group. The primary cause of injury was traffic accidents, followed by falls and heavy object impacts. Among VAP patients, 38 survived and 11 died within 28 days; 112 were classified as low-risk, 25 as moderate-risk, and 12 as high-risk. Significant differences were observed in age, body mass index (BMI), smoking history, hypertension, diabetes, hyperlipidemia, length of hospital stay, duration of mechanical ventilation, serum albumin levels, and frequency of sputum suction among different subgroups. Serologically, IL-1β, TNF-α, IL-6, and STAT3 mRNA expression levels in the VAP group were significantly higher than those in the non-VAP group. Deceased VAP patients exhibited higher IL-1β, TNF-α, IL-6, and STAT3 mRNA levels compared to survivors. These biomarkers progressively increased from low-risk to high-risk subgroups. Multivariate Logistic regression identified age [odds ratio (OR) were 0.328 and 0.318], BMI (OR were 0.340 and 0.268), hypertension (OR were 0.275 and 0.245), diabetes (OR were 0.319 and 0.307), hyperlipidemia (OR were 0.228 and 0.235), smoking history (OR were 0.255 and 0.240), length of hospital stay (OR were 0.306 and 0.230), duration of mechanical ventilation (OR were 0.247 and 0.219), frequency of sputum suction (OR were 0.325 and 0.228), IL-1β (OR were 0.231 and 0.259), TNF-α (OR were 0.308 and 0.235), IL-6 (OR were 0.298 and 0.277), and STAT3 (OR were 0.259 and 0.265) as independent risk factors for both VAP occurrence and 28-day mortality (all P < 0.05). Correlation analysis revealed that serum albumin levels were negatively correlated with VAP occurrence and mortality (all P < 0.01), while other factors showed positive correlations (all P < 0.01). CONCLUSIONS Age, BMI, length of hospital stay, duration of mechanical ventilation, frequency of sputum suction, hypertension, diabetes, hyperlipidemia, smoking history, IL-1β, TNF-α, and IL-6/STAT3 signaling pathway activation are significantly associated with VAP development and poor prognosis in patients with severe craniocerebral injury, providing a scientific basis for targeted clinical interventions.
Humans ; Risk Factors ; Pneumonia, Ventilator-Associated ; Prognosis ; Prospective Studies ; Craniocerebral Trauma/complications* ; Interleukin-6/blood* ; Male ; Female ; STAT3 Transcription Factor/blood* ; Interleukin-1beta/blood* ; Tumor Necrosis Factor-alpha/blood* ; Middle Aged ; Adult ; Logistic Models

Children with bronchopulmonary dysplasia (BPD) often exhibit severe respiratory problems and significant pulmonary dysfunction during school age and adulthood. Exercise tests show a decline in cardiopulmonary function and physical performance in children with BPD, who also have a higher incidence of pulmonary hypertension. These children generally perform poorly in terms of intelligence, language, and motor development. As they age, the risk of neurodevelopmental disorders increases, and health-related quality of life is also affected. This article reviews the prognosis of the respiratory system, physical capacity, cardiovascular system, nervous system, and health-related quality of life in children with BPD, aiming to improve the management of these patients and enhance their subsequent quality of life.
Humans ; Bronchopulmonary Dysplasia/complications* ; Prognosis ; Quality of Life ; Child

OBJECTIVES: To study the effects of early respiratory training combined with swallowing function training on physical development and neurodevelopment at a corrected gestational age of 6 months in infants with bronchopulmonary dysplasia (BPD). METHODS: A total of 69 BPD infants who could not be fed completely orally were prospectively selected from the Department of Neonatology of Hunan Children's Hospital between January 2018 and January 2021. Based on a random number table, the infants were divided into a conventional group (35 cases) and a training group (34 cases) (with 8 cases lost to follow-up; the final follow-up included 31 cases in the training group and 30 cases in the conventional group). Both groups received routine clinical treatment and care, while the training group additionally received respiratory and swallowing function training until the infants could independently feed orally. The weight, length, Gesell Developmental Schedule (GDS) results, readmission rate, and multiple readmission rate (two or more admissions) were compared between the two groups at a corrected age of 6 months. RESULTS: At corrected gestational age of 6 months, the training group had higher weight, length, and GDS scores in personal-social, language, gross motor, fine motor, and adaptive development compared to the conventional group (P<0.05). The readmission rate and multiple readmission rate were lower in the training group compared to the conventional group (P<0.05). CONCLUSIONS Early respiratory training combined with swallowing function training for BPD infants in a neonatal intensive care unit setting helps improve physical and neurological development and reduces the readmission rate.
Humans ; Bronchopulmonary Dysplasia/physiopathology* ; Prospective Studies ; Male ; Female ; Infant ; Deglutition/physiology* ; Gestational Age ; Infant, Newborn ; Breathing Exercises ; Child Development

OBJECTIVES: To investigate the role and mechanism of Brahma-related gene 1 (Brg1) in regulating the Wnt/β-catenin signaling pathway in a bronchopulmonary dysplasia (BPD) model. METHODS: Wild-type C57BL/6 and Brg1^f1/f1 mice were randomly divided into four groups: wild-type control, wild-type BPD, Brg1^f1/f1 control, and Brg1^f1/f1 BPD (n=5 each). Immortalized mouse pulmonary alveolar type 2 cells (imPAC2) were cultured, and Brg1 gene was knocked down using lentivirus transfection technology. Cells were divided into three groups: control, empty vector, and Brg1 knockdown. Hematoxylin and eosin staining and immunofluorescence were used to detect pathological changes in mouse lung tissue. Western blot and real-time fluorescent quantitative PCR were used to measure Brg1 protein and mRNA expression levels in mouse lung tissue. Western blot and immunofluorescence were used to detect the expression of homeodomain-containing protein homeobox (HOPX), surfactant protein C (SPC), and Wnt/β-catenin signaling pathway proteins in mouse lung tissue and imPAC2 cells. The CCK8 assay was used to assess the proliferation of imPAC2 cells, and co-immunoprecipitation was performed to verify the interaction between Brg1 and β-catenin proteins in imPAC2 cells. RESULTS: Compared to the Brg1^f1/f1 control group and wild-type BPD group, the Brg1^f1/f1 BPD group showed increased alveolar diameter and SPC protein expression, and decreased relative density of pulmonary vasculature and HOPX protein expression (P<0.05). Compared to the control group, the Brg1 knockdown group showed increased cell proliferation ability, protein expression levels of SPC, Wnt5a and β-catenin, and β-catenin protein fluorescence intensity, along with decreased HOPX protein expression (P<0.05). An interaction between Brg1 and β-catenin proteins was confirmed. CONCLUSIONS The Brg1 gene may promote the proliferation of alveolar type 2 epithelial cells by regulating the Wnt/β-catenin signaling pathway, thus influencing the occurrence and development of BPD.
Animals ; DNA Helicases/genetics* ; Transcription Factors/genetics* ; Wnt Signaling Pathway/physiology* ; Nuclear Proteins/genetics* ; Mice ; Bronchopulmonary Dysplasia/etiology* ; Mice, Inbred C57BL ; beta Catenin/physiology* ; Disease Models, Animal ; Cell Proliferation ; Lung/pathology* ; Male