Search Results (3,193)

The ventilation system of a mine determines the comfort and safety of the underground working environment. Although many studies have been devoted to reducing the impact of underground heat damage, there are still few comprehensive studies or optimizations aimed at simultaneously considering heat damage prevention and control, exhaust of mechanical equipment, and methane leakage. To address this knowledge gap, a mine ventilation model was built and validated to analyze the impact of different numbers of top fans on the distribution characteristics of temperature and gas mass fraction. Subsequently, the impact of different blowing duct inlet temperatures and velocities on the capacity to cool and dilute hazardous gases was investigated. Finally, a comprehensive coefficient that removes the effect of dimension was proposed for evaluating the cooling and dilution performance of different top fan cases. The results show that a top fan is the most advantageous for cooling the mine, but has a poor ability to dilute hazardous gases. Three top fans have the best performance for diluting hazardous gases, which leads to some degree of heat diffusion, but obtains the maximum total comprehensive coefficient of 0.71246. Full article

Background/Objectives: Ventilator-free days (VFDs) are a useful composite measure to assess both survival and duration of mechanical ventilation in critically ill patients. This study aimed to determine the factors associated with (VFDs) in neonates with persistent pulmonary hypertension of the newborn (PPHN) and to compare VFDs according to the etiology and severity of PPHN. Methods: We conducted a retrospective cohort study of neonates diagnosed with PPHN between 2013 and 2023. VFDs were defined as days alive and free of mechanical ventilation within the first 28 days. Severe-to-critical PPHN group was defined as an oxygenation index (OI) > 25. Results: Among 175 neonates, the median (interquartile range [IQR]) VFDs were 20 (9–23) days. The factors independently associated with fewer VFDs included maximum OI > 40 (adjusted hazard ratio [aHR] 3.5, 95% confidence interval [CI]: 2.49–4.9), receiving more than two inotropic drugs (aHR 2.27, 95% CI: 1.49–3.45), acute kidney injury (AKI) (aHR 1.54, 95% CI: 1.1–2.17), and ventilator-associated pneumonia (VAP) (aHR 3.42, 95% CI: 1.8–6.48). The median (IQR) number of VFDs in neonates with PPHN secondary to respiratory distress syndrome (RDS), pneumonia/sepsis, meconium aspiration syndrome, and transient tachypnea of the newborn were 16 (0–22), 17 (7–21), 22 (11–24), and 22 (15–24) d, respectively (p = 0.023). Neonates in the severe-to-critical group had markedly fewer VFDs than those in the mild-to-moderate group (8.5 vs. 22 d, p < 0.001). Conclusions: Infants with PPHN from RDS had the fewest VFDs. A maximum OI > 40, use of multiple inotropic agents, AKI, and VAP were associated with a low number of VFDs. Given the retrospective, single-center design, these findings are associative and hypothesis-generating, requiring prospective multi-center validation. Nonetheless, VFDs remain a comprehensive measure of both mortality and respiratory morbidity in this population. Full article

Background/Objectives: Home mechanical ventilation (HMV) has become an essential component of long-term respiratory support for patients with chronic respiratory failure. Despite the growing number of publications, the characteristics and citation patterns of the most influential studies have not been systematically evaluated. This study aimed to analyze the 50 most-cited publications on home mechanical ventilation indexed in the Web of Science Core Collection and explore citation patterns and potential associations with citation impact. Methods: This study was designed as a descriptive citation-based bibliometric analysis. A bibliometric analysis was performed using the Web of Science Core Collection. Publications related to home mechanical ventilation were ranked by total citation count, and the 50 most-cited articles were included. Extracted variables included publication year, total citations, citations per year, journal quartile, impact factor, index status, article type, topic category, geographic origin, and ventilation population category. Descriptive statistics were calculated. Group comparisons were performed using the Kruskal–Wallis and Mann–Whitney U tests, and correlations were evaluated with Spearman’s analysis. Funding status was summarized descriptively because funding was reported in only 8 studies. Results: The median total citation count was 15.5 (range: 1–118), and the median citations per year was 0.89 (range: 0.02–9.83). Most articles were published in Q1 journals and indexed in SCI-Expanded. Exploratory associations were observed between citation metrics and journal quartile/index status (p < 0.05). Articles published between 2005 and 2009 had the highest total citations, whereas those published after 2020 showed the highest citations per year. No association was observed with geographic origin. Conclusions: Distinct exploratory citation patterns were observed according to publication period, journal quartile, and index status. Bibliometric evaluation may help characterize the academic development and visibility of home mechanical ventilation research, but these findings should not be interpreted as confirmatory determinants of citation impact. Full article

Acute hypoxemic respiratory failure (AHRF) represents one of the most common and clinically challenging indications for invasive mechanical ventilation in the intensive care unit, characterized by profound etiological heterogeneity that demands accurate diagnosis to guide treatment. While clinical history, physical examination, and laboratory data remain essential, they are often insufficient to reliably discriminate among conditions such as acute respiratory distress syndrome (ARDS), cardiogenic pulmonary edema, and pneumonia—particularly in mechanically ventilated patients. Lung imaging has therefore emerged as an indispensable complement to clinical assessment. In this narrative review, we systematically describe the physical principles, clinical applications, and limitations of the imaging modalities currently available in critical care: chest X-ray (CXR), computed tomography (CT), lung ultrasound (LUS), electrical impedance tomography (EIT), and positron emission tomography (PET). CXR remains the most widely used bedside tool but is constrained by low sensitivity and significant interobserver variability. CT is the gold standard for morphological and quantitative lung phenotyping, enabling the assessment of recruitability, baby lung characterization, and the identification of complications, but requires patient transport and exposes patients to ionizing radiation. LUS offers real-time, bedside evaluation of aeration with high diagnostic accuracy for pneumothorax and pleural effusion, and is increasingly integrated into revised ARDS diagnostic criteria. EIT enables continuous, radiation-free monitoring of regional ventilation distribution and positive end-expiratory pressure (PEEP)-guided titration directly at the bedside. While PET provides unparalleled quantification of regional inflammation and ventilation-perfusion mismatch, it currently remains a purely investigative research tool. Finally, we discuss emerging technological and AI-driven advances—including dual-energy CT, next-generation EIT, and deep learning algorithms—that are poised to transform lung imaging from a passive diagnostic tool into an active, personalized guide to respiratory management. Full article

Background/Objectives: Weaning failure from mechanical ventilation affects 10–20% of critically ill patients. Cardiovascular dysfunction—particularly diastolic dysfunction with elevated left atrial pressure (LAP)—underlies up to 50–60% of failed spontaneous breathing trials (SBTs) and frequently remains undetected without targeted echocardiographic assessment. This narrative review synthesises current evidence on the echocardiographic evaluation of weaning failure, with emphasis on LAP estimation, right ventricular (RV) dysfunction, and the integration of lung and diaphragm ultrasound. Methods: A structured literature search of PubMed/MEDLINE and EMBASE was performed for publications from January 2000 to April 2026, supplemented by hand-searching of reference lists and current society guidelines. This article is reported as a narrative review; no formal systematic review protocol was registered. A qualitative synthesis emphasising pathophysiological mechanisms, echocardiographic phenotypes, and clinical applicability was performed. Results: Positive pressure ventilation with PEEP provides active LV afterload reduction; extubation abruptly removes this unloading and may precipitate acute filling pressure elevation in vulnerable patients. Multiparametric echocardiographic LAP assessment—integrating the E/e’ ratio, deceleration time, and pulmonary vein flow—supports pre-extubation risk stratification. The dynamic PEEP reduction test, although not yet standardised or multicentre-validated, may identify patients with load-dependent cardiac decompensation before extubation. RV dysfunction is present in 20–50% of ventilated patients and worsens weaning outcomes through ventricular interdependence. Complementary lung ultrasound B-line quantification and diaphragm thickening fraction assessment together support a phenotype-specific diagnostic approach. Conclusions: A structured multimodal ultrasound framework integrating echocardiography, lung ultrasound, and diaphragm ultrasound may support identification and targeted treatment of the dominant mechanism of weaning failure before extubation. Prospective multicentre validation of the integrated protocol as a whole remains a priority research need. Full article

This study aimed to identify the distinct intrinsic response potential of γδ T cells from COVID-19 patients with different illness severities, to better understand the implication of these cells in COVID-19 disease. Forty-four COVID patients were enrolled at hospitalization and classified as: moderate without oxygen support (MWO₂; N = 15), moderate with oxygen support (MO₂; N = 15), or severe disease requiring mechanical ventilation (SD; N = 14). γδ T cells were characterized ex vivo, isolated from peripheral blood cells, stimulated in vitro with OKT3 and K562 cells, and evaluated for functional markers by flow cytometry. Ex vivo analysis identified 16.21% of total γδ T cells as Vδ1⁻Vδ2⁻. SD patients presented a lower frequency of TRAIL⁺ and of IL-17-producing Vδ2 cells, as well as lower value of fluorescence intensity values for TNF-α in Vδ2 cells, than MWO₂ patients (p < 0.05). In addition, paired analyses showed a lower frequency of IL-17-producing than CD161⁺ Vδ2 cells in SD patients (p < 0.05). These observations suggest a more restricted response potential of the Vδ2 subset in severe disease, show the impact of general immune dysregulation on these cells, or even suggest some role for IL-17-producing Vδ2 cells in preventing critical symptoms. Full article

Methamphetamine (METH)-induced cardiomyocyte injury is the leading cause of mortality beyond acute intoxication. METH abuse often occurs in crowded, poorly ventilated environments, and even moderately high ambient temperatures exacerbate METH-related cardiovascular emergencies. However, the underlying mechanisms by which environmental factors drive the progression of cardiac diseases remain poorly understood. This study modeled the real-world scenario in vivo by exposing mice to METH under normothermic condition (NC, 22 °C) or subthreshold thermal stress (STS, 28 °C, a mild thermal challenge for mice) conditions, and in vitro by using H9c2 cardiomyocytes exposed to METH at 37 °C or 39 °C. STS significantly potentiated METH-induced cardiac dysfunction, mitochondrial ultrastructural damage, and oxidative stress (p < 0.05). Mechanistically, the co-exposure impaired mitochondrial respiratory chain complex I and led to excessive mitochondrial ROS (mtROS) production, activating the pro-apoptotic protein BAX, causing mitochondrial outer membrane (MOM) permeabilization and the cytosolic release of mitochondrial DNA (mtDNA). Cytosolic mtDNA-mediated NLRP3 inflammasome activation subsequently executed cardiomyocyte pyroptosis via caspase-1/Gasdermin D (p < 0.05). Crucially, the mitochondria-targeted antioxidant mitoquinone (MitoQ) substantially attenuated the aggravated cardiotoxicity by scavenging the initial mtROS (p < 0.05), thereby preventing the activation of the downstream BAX/mtDNA/NLRP3 axis. These findings provide evidence for a defined signaling basis for this drug-environment interaction and highlight mitochondrial redox modulation as a potential therapeutic strategy for psychostimulant-associated cardiovascular injury. Full article

Objectives: This systematic review and meta-analysis aimed to evaluate the efficacy and safety of phrenic nerve stimulation (PNS) in mechanically ventilated adult patients. Methods: PubMed, Web of Science, Embase, and the Cochrane Library were searched for randomized controlled trials (RCTs) up to 21 February 2026, without language restrictions. Two reviewers independently screened studies, extracted data, and evaluated the risk of bias using the Cochrane RoB 2 tool. The certainty of evidence for each outcome was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. Odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (CIs) were pooled using fixed-effects or random-effects models according to heterogeneity. Results: Five RCTs involving 431 patients were included. PNS was associated with a higher weaning success rate (OR = 2.96, 95% CI: 1.04 to 8.40, p = 0.04), a shorter duration of mechanical ventilation (MD = −2.63, 95% CI: −3.90 to −1.35, p < 0.001), higher maximal inspiratory pressure (MD = 2.95, 95% CI: 1.10 to 4.79, p = 0.002), and higher diaphragm thickening fraction (MD = 15.67, 95% CI: 4.84 to 26.50, p = 0.005). No statistically significant differences were observed in ICU length of stay, rapid shallow breathing index, or tracheostomy rate. Noninvasive stimulation was generally tolerated in the included studies, whereas transvenous stimulation was associated with procedure-related serious adverse events. The certainty of evidence ranged from high to low across outcomes. Conclusions: PNS was associated with improved weaning outcomes and diaphragm function in mechanically ventilated patients. However, the evidence remains limited by the small number of RCTs, clinical heterogeneity, and uncertainty regarding long-term outcomes. Further large-scale, multicenter RCTs with standardized protocols are needed to assess the efficacy and safety of PNS. Full article

Urban green spaces (UGSs) are increasingly recognised as critical infrastructure for mitigating climate extremes and promoting public health; indeed, the microclimatic mechanisms through which vegetation structure translates into measurable improvements in human comfort at the neighbourhood scale are of significant interest, particularly in the context of new urban developments. This study examines the cooling effects of an urban redevelopment project in the Marconi district of Imola, Italy, using ENVI-met (Version 6.0.0, ENVI-met GmbH, Essen, Germany) simulations to compare ex ante (current) and ex post (planned) scenarios under extreme heat conditions. Physiological Equivalent Temperature (PET) was computed at the pedestrian level for both standard adult and elderly models to assess spatial patterns of thermal comfort. The results demonstrate that tree canopies are the primary determinant of local cooling, with newly planted trees reducing PET by up to 3.5 °C at the core of the regenerated block and by 1–2 °C along adjacent pavements, while grass and low vegetation provided negligible mitigation. However, new buildings generated localised warming bands of 0.5–2 °C along façades, revealing a trade-off between densification and outdoor liveability. Elderly populations experienced slightly stronger thermal stress near buildings, highlighting spatial concentrations of vulnerability. These findings reinforce the need to prioritise tree planting and canopy management as core climate adaptation strategies, while simultaneously addressing near-building heat accumulation through integrated design approaches such as façade greening and ventilation preservation. The study demonstrates the value of spatially explicit microclimate simulation for evidence-based urban planning, contributing to the development of sustainable and liveable urban environments. Full article

Background: Extubation failure (EF) is a significant complication, and it is associated with increased mortality, prolonged hospital stays and extended mechanical ventilation (MV). Determining reliable predictors of EF could improve the clinical decision-making and outcomes. Objectives: Determine the outcomes and predictors of EF in a paediatric intensive care unit (PICU) and develop predictive models using machine learning algorithms. Methods: A retrospective cohort study (n = 824) was conducted in two PICUs in participants who underwent planned extubation (January 2018–December 2022). Demographic characteristics, clinical parameters, ventilator setting, laboratory findings and extubation outcomes were collected. Univariate and multivariate analysis were performed to identify significant predictors of EF. Six machine learning algorithms—Logistic Regression (LR), Artificial Neural Network (ANN), Extreme Gradient Boosting (XGBoost), Random Forest (RF), Support Vector Machine (SVM) and Decision Tree (DT)—were developed and validated for prediction of EF. Results: The overall EF rate was 231 (28%). Multivariate analysis identified a mechanical ventilation for a duration of 3 days or more (aOR 4.49, 95% CI 3.24–6.57, p < 0.001), use of neuromuscular blockade (aOR 1.32, 95% CI 1.07–1.63, p = 0.009), and administration of vasopressors (aOR 1.57, 95% CI 1.24–2.01, p < 0.001) as significant independent predictors of EF. The ANN and LR models demonstrated the highest performance with AUCROC of 0.87 ± 0.04 and 0.86 ± 0.02, respectively. Conclusions: Extubation failure was common in our setting (28%) compared to other studies. Days of ventilation, undernutrition, use of neuromuscular blockade, use of vasopressors or inotropes and CNS comorbidity were associated with EF. The main cause of EF was upper airway obstruction. Full article

Background/Objectives: Delirium is a frequent and clinically significant complication in cardiac surgery patients and is associated with prolonged mechanical ventilation, longer Intensive Care Unit (ICU) stay, increased mortality, and long-term cognitive impairment. However, evidence regarding perioperative factors associated with delirium occurrence in cardiac surgery ICU patients remains limited. This study aims to investigate clinical factors associated with postoperative delirium in cardiac surgery patients admitted to the ICU. Methods: A single-center, prospective, observational study was conducted in a 14-bed cardiothoracic ICU in central Italy. Consecutively enrolled adult patients undergoing cardiac surgery were assessed for delirium using the Italian-validated Intensive Care Delirium Screening Checklist (ICDSC) every eight hours for five days. Univariate analysis and multivariate logistic regression were performed to identify factors associated with delirium occurrence. Results: A total of 175 patients were included, and delirium occurred in 44.6%. In the univariate analysis, patients with delirium presented significantly longer mechanical ventilation (10.5 vs. 8.0 h; p = 0.04) and higher APACHE II scores (p = 0.01). In the multivariable analysis, lower Glasgow Coma Scale (GCS) scores were independently associated with delirium occurrence (OR = 0.84; 95% CI: 0.71–0.99; p = 0.04). Urgent admission (OR = 2.02; p = 0.06) and mean arterial pressure (OR = 0.97; p = 0.08) did not reach statistical significance in the multivariable model. Conclusions: Delirium is highly prevalent after cardiac surgery. Lower postoperative GCS scores may represent an early marker of postoperative neurological vulnerability associated with delirium occurrence. Further multicenter studies are warranted to improve delirium risk stratification and clarify the mechanisms underlying postoperative cognitive dysfunction. Full article

Chronic obstructive pulmonary disease remains a leading cause of death worldwide, with emphysema contributing significantly to dyspnea, exercise limitation, and mortality. Bronchoscopic lung volume reduction (BLVR) using endobronchial valves (EBVs) has emerged as a minimally invasive, reversible alternative to lung volume reduction surgery for carefully selected patients with severe emphysema who remain symptomatic despite optimal medical therapy. EBVs are one-way valves placed bronchoscopically to achieve complete lobar occlusion, inducing atelectasis of the most diseased lung segments while allowing better ventilated parenchyma to expand, thereby improving respiratory mechanics and reducing hyperinflation. Landmark randomized controlled trials demonstrated that BLVR using EBVs produces significant improvements in forced expiratory volume in one second (FEV₁), exercise capacity, and quality of life comparable to surgical lung volume reduction but with reduced morbidity and mortality. Critical to treatment success is meticulous patient selection based on emphysema distribution, absence of collateral ventilation, and appropriate physiologic parameters. Pneumothorax represents the most common serious complication, occurring in approximately 26% of patients, though paradoxically, it indicates successful lobar occlusion and predicts favorable long-term outcomes. As the most extensively studied BLVR, endobronchial valve therapy represents a cornerstone intervention for appropriately selected patients with severe emphysema. Full article

Accurate and stable indoor occupancy information is essential for occupant-based intelligent ventilation control. Under a single-camera setting, existing indoor occupancy detection methods commonly suffer from missed detections caused by occlusion and blind zones, false detections caused by people outside the room, and cumulative entry–exit errors that are difficult to correct. These problems lead to false fluctuations in detected occupancy, affect control performance, and may further reduce indoor comfort or cause unnecessary energy use. To address the practical situation in which indoor spaces are commonly equipped with a single security camera, this study proposes an indoor occupancy detection method by fusing field-of-view information and entry–exit events with a single camera. The study covers method development, multi-scenario validation, parameter analysis, and a ventilation control application. The proposed method uses YOLOv8x and DeepSORT as front-end models and performs post-processing on their outputs to extract field-of-view occupancy information, entry–exit events, and blind-zone events. An occupancy confirmation and correction module is then constructed. The blind-zone event mechanism reduces the influence of missed entry–exit events and camera blind zones on occupancy judgment. The correction module integrates frame-by-frame ID counts, historical outputs, and multiple event signals to verify and suppress false occupancy changes caused by false detections, missed detections, and blind zones, thereby producing more stable indoor occupancy results. Experimental results show that the proposed method outperforms the baseline methods based on front-end object detection and tracking in terms of score, RMSE, and F1 score in three typical scenarios: an office, a home, and a classroom. In the office scenario, the proposed method achieved a score of 99.36%, an RMSE of 0.081, and an F1 score of 0.781. The detection stability was also improved in the home and classroom scenarios. In the high-density and strongly occluded classroom scenario, the absolute detection performance of the fusion-based detection method was limited by the front-end models, indicating that the method still has certain applicability boundaries in complex high-density scenes. Parameter sensitivity analysis shows that key parameters, including the entry–exit area depth, confidence threshold, and time threshold, affect the detection results of the fusion-based detection method. Under the test conditions of this study, the method performs well when the entry–exit area depth is approximately 1.5d, the YOLOv8x confidence threshold is 40%, and the time threshold is 5 × FPS. These results can provide a reference for initial parameter setting and on-site calibration in similar scenarios. Using the office scenario as a case study, the method was further applied to occupant-based ventilation control. The average CO₂ concentration during occupied periods under the proposed method was 622.43 ppm, which was closest to the result under ground-truth occupancy control, with a deviation of only 0.9 ppm. This indicates that the method can help improve indoor air quality. Compared with conventional schedule-based control, occupant-based ventilation control driven by the proposed fusion method reduced cumulative fan energy consumption by approximately 65.2%, showing good energy-saving potential at the ventilation-control level. In summary, the proposed method can effectively improve the accuracy and stability of indoor occupancy detection under a single-camera setting and provide more reliable input for occupant-based ventilation control. The framework is modular, and the front-end object detection and tracking models can be replaced according to actual deployment needs. However, the validation in this study is still mainly based on scenarios where existing security cameras can cover the main activity areas and all entry–exit passages. The applicability of the method under more complex camera arrangements, lighting variations, and automatic region configuration requires further investigation. Full article

Endogenous candidiasis remains an underrecognized yet clinically relevant complication in non-neutropenic critically ill patients. This study examines Candida spp. infections in the intensive care unit (ICU) within a patient-safety and risk-management framework, focusing on the identification of patients at highest risk and the development of an early diagnostic and therapeutic strategy. The target population comprises long-stay ICU patients requiring prolonged mechanical ventilation who develop multiple organ dysfunction syndrome (MODS) associated with immunoparalysis, typically reflected by a Sequential Organ Failure Assessment (SOFA) score ≥ 5. In this population, Candida spp. colonization may evolve into multifocal candidiasis and subsequently invasive or disseminated disease. Notably, candidemia often represents a late manifestation and therefore lacks sensitivity as an early diagnostic marker. Drawing on a series of clinical investigations conducted from 1978 to the early 2000s, the authors developed a standardized diagnostic–therapeutic algorithm based on systematic surveillance cultures, identification of multifocal Candida spp. colonization, and early initiation of antifungal therapy. Implementation of this strategy, together with progressive individualization of antifungal treatment, was associated with a marked reduction in attributable mortality related to candidiasis in ICU patients. These findings support the concept of Candida spp. infection as a sentinel indicator of systemic immune dysfunction and physiological fragility in critical illness. Integrating risk-based surveillance with early targeted therapy may substantially improve outcomes and reinforce patient-safety strategies in the ICU. Full article

Background: The timing of tracheostomy in the intensive care unit (ICU) is debated because of its potential effects on comfort, sedation management, and ventilator weaning. Objective: To compare early (≤10 days) versus late (>10 days) tracheostomy with respect to discontinuation of sedation and invasive ventilation. Methods: Single-centre retrospective observational study. We included 52 consecutive ICU patients who underwent tracheostomy (January 2023–June 2025): 16 early and 36 late. Switching to dexmedetomidine was considered discontinuation of hypnotic sedation; transition to home mechanical ventilation (VAM) was considered discontinuation of invasive ventilation. Results: Sedation discontinuation occurred in 15/16 (93.8%) early vs. 35/36 (97.2%) late patients (p = 0.525). Discontinuation of invasive ventilation occurred in 12/16 (75.0%) early vs. 31/36 (86.1%) late patients (p = 0.431). Tracheostomy-to-sedation stop time: median 3 days [IQR 1–10] (overlapping between groups). Tracheostomy-to-ventilation stop time: median 17 days [IQR 10–27] (17 [11–33] early vs. 17 [10–25] late). ICU mortality: 3/16 (18.8%) vs. 6/36 (16.7%) (p = 1.00). Conclusions: In this retrospective cohort, no statistically significant differences emerged between early and late tracheostomy regarding discontinuation of sedation or invasive ventilation. However, given the retrospective design and small sample size, the study may have been underpowered to detect smaller but clinically relevant differences between groups. Prospective studies with larger sample sizes and severity-related variables may clarify any effects of timing. Full article