Effects Of Ventilation Research Articles

Efficacy of A Ventilation Care Bundle to Prevent Ventilator-Associated Pneumonia: A Literature Review

Ventilator-associated pneumonia (VAP) is a kind of pneumonia that arises within 48–72 hours or later after the insertion of a breathing tube into the windpipe. The fundamental idea of preventing ventilator-associated pneumonia is to minimize the length of time a patient is on mechanical ventilation and to extubate them as early as possible. Adhering to the bundle of care can influence the risk of VAP. Researchers conducted several studies between 2020 and 2023 to assess the effectiveness of a ventilation care bundle in preventing ventilator-associated pneumonia. Each study varied in terms of the specific version of the care bundle used, compliance rates, sample size, and duration of the research. The conclusion drawn on the effectiveness in question may be impacted by these disparities. Proper execution of an effective ventilator care package can decrease the occurrence of ventilator-associated pneumonia in patients who are critically ill. Employing a variety of tactics backed by long-term teaching initiatives is crucial to ensure adherence to the care bundle.

The Age of Older Patients Requiring Prolonged Mechanical Ventilation Is Not the Sole Determinant of Their Long-Term Survival.

Background and Objectives: There are few data on the effects of prolonged mechanical ventilation on elderly patients. Our objective is to investigate the effects of prolonged mechanical ventilation on older patients' successful weaning and long-term survival. Methods: We examined how aging affected the course and results of elderly patients on prolonged mechanical ventilation by contrasting five age groups. Age, sex, cause of acute respiratory failure, comorbidities, discharge status, weaning status, and long-term survival outcomes were among the information we gathered. Results: Patients on prolonged mechanical ventilation who had undergone tracheostomy and had been successfully weaned had a greater one-year survival rate. The 1-year survival rate was poorer for older patients with four or more comorbidities. Regarding the 5-year survival rate, the risk of death was 45% lower in the successfully weaned patients than in the unsuccessfully weaned patients. The risk of death was 46% lower in patients undergoing tracheostomy than in those not undergoing tracheostomy. Older prolonged mechanical ventilation (PMV) patients with four or more comorbidities had an increased risk of death. Conclusions: When it comes to elderly patients on prolonged mechanical ventilation, there are other factors in addition to age that influence long-term survival. Long-term survival is likewise linked to successful weaning and undergoing tracheostomy.

Evaluation of Health and Safety Status of Public and Private Building Construction Projects in Pokhara

Health and safety (H&S) in the construction industry encompasses a set of principles, regulations, practices, and measures designed to safeguard the well-being and safety of construction teams within construction environments. Developing countries like Nepal lag in establishing and implementing robust H&S regulations, impacting overall project performance. This research assesses the H&S status in public and private building construction projects within Pokhara Valley, Nepal. One private and one public project were selected for the investigation. After conducting a thorough literature review and consulting key informants, a structured five-point Likert scale questionnaire was developed for efficient data collection. Findings revealed that H&S aspects in privately and publicly owned building construction projects. Privately owned projects underscored effective ventilation, hard hats, and daily safety briefings are significant factors. Slip, trip, and fall incidents are major accident causes, highlighting the importance of proper lighting. Public projects emphasized ventilation, hard hats, and safety rules, with toolbox talks and qualified team members deemed critical. Slip, trip, and fall incidents remained the primary accidents, and safety signs played a pivotal role. These findings offer essential guidance for policymakers and construction managers to enhance H&S practices in diverse construction environments.

Effect of Combining Non-Invasive Ventilation with Vitamin D on Acute Exacerbation of Chronic Obstructive Pulmonary Disease

This study aims to explore the effect of noninvasive ventilation combined with vitamin D in acute exacerbation of chronic obstructive pulmonary disease. Ninety-eight patients admitted to Mengcheng County NO.1 People’s Hospital were included. The control group received comprehensive treatment, including bronchodilators, glucocorticoids, antibiotics, and expectorants, correction of water and electrolyte imbalance, and nutritional support. Based on the control group, patients in the treatment group received non-invasive ventilation combined with vitamin D. After therapy, the treatment group showed a higher total effective rate compared to the control group. The treatment group exhibited a more pronounced decrease in the partial pressure of carbon dioxide and an increase in the partial pressure of oxygen in arterial blood and arterial oxygen saturation compared with the control group. The levels of forced vital capacity and forced expiratory volume in the first second were higher in the treatment group. Moreover, interleukin-6, C-reactive protein, and procalcitonin levels were lower, while CD3+, CD4+, CD8+, and CD4+/CD8+ levels were higher; quality-of-life scores were lower. Combining non-invasive ventilation with vitamin D can improve blood gas indexes, promote lung function, reduce inflammatory response, and promote immune function in patients with acute exacerbation of chronic obstructive pulmonary disease.

Indoor thermal nonuniformity of atrium-centered public building: Monitoring and diagnosis for energy saving

Heating ventilation and air conditioning system accounts for over one third of building energy usage, especially for public buildings due to large indoor heat source and high ventilation and thermal comfort requirement compared to residential buildings. Natural ventilation shows high application potentials in public buildings because of its high-efficient ventilation effect and energy saving potential for indoor heat dissipation. In this paper, the building design is conducted for a science museum and library with atrium-centered natural ventilation consideration. The floor layout, building orientation and internal structure are optimized to make full use of natural ventilation for space cooling under local climatic conditions. A natural ventilation model is established through building field tests to evaluate the air flow and thermal environment under indoor and outdoor pressure differences. The preliminary results show that Building A's courtyard exhibited overheating issues, likely attributed to outdoor solar radiation, whereas Building B's courtyard experienced localized cooling, possibly due to indoor air conditioning system controls. Addressing these concerns necessitates modifications in courtyard design and structure. Moreover, both courtyards displayed vertical temperature gradients, emphasizing the need for effective management of outdoor heat influx and enhancements in indoor ventilation and shading strategies. To mitigate these issues, the study proposed three distinct roof design models and more refined indoor air conditioning system control strategies. The optimization of architectural design can achieve a maximum energy-saving rate of 46.54 %. Furthermore, aligning functional zones with thermal comfort areas was recommended to enhance overall building thermal comfort. The findings and proposed solutions from this study are anticipated to contribute to the enhancement of thermal comfort, energy efficiency, and vertical temperature distribution in large public buildings, catering to user requirements while reducing energy consumption. This research holds significant implications for advancing sustainability and environmental preservation in the realm of architecture.

Computational Fluid Dynamics-Based Calculation of Aerosol Transport in a Classroom with Window Ventilation, Mechanical Ventilation and Mobile Air Purifier

During the SARS-CoV-2 pandemic, the air quality and infection risk in classrooms were the focus of many investigations. Despite general recommendations for sufficient ventilation, quantitative analyses were often lacking due to the large number of combinations of boundary conditions. Hence, in this paper, we describe a computational fluid dynamics model that predicts the time-resolved airflow for a typical 45 min classroom scenario. We model 28 students and a teacher, each emitting CO2 and an individual aerosol. We investigated 13 ventilation setups with window or mechanical ventilation and different positions and operating conditions of an additional air purifier. The ventilation performance is assessed by evaluating the ventilation effectiveness, aerosol removal effectiveness, local air exchange efficiency and overall inhaled aerosol mass of the occupants, which is a measure of the infection risk. If the window is opened according to the “20-5-20” recommendation, the incoming airflow reduces both the CO2 and aerosol concentration whilst decreasing the thermal comfort at low ambient temperatures. An active air purifier enhances aerosol removal, but, depending on the position, the local air exchange efficiency and individual aerosol inhalation vary. If mechanical ventilation with 700 m3/h is utilised, the CO2 concentration is kept below 1250 ppm while also effectively removing aerosol from the classroom.

Experimental comparison on the smoke movement in horizontal and downhill tunnel fires under subcritical ventilation

In longitudinally ventilated tunnel fires, subcritical ventilation is widely used in the early stage of accidents to maintain smoke stratification. Due to the stack effect, the smoke movement in inclined tunnels is different from that in horizontal tunnels. In this study, a series of brine-water experiments are carried out to compare the characteristics of buoyant contaminants flow in horizontal and downhill tunnels under subcritical ventilation, which has not been experimentally investigated. The results suggest that subcritical ventilation is an effective longitudinal ventilation strategy in the early stage of horizontal tunnel fires, as it can retain the smoke stratification and an acceptable back-layering flow. Moreover, the critical ventilation condition can be resumed after the ventilation pressure increases to the critical value. However, if subcritical ventilation is first adopted in downhill tunnel fires, no stable back-layering flow will be observed, the buoyant contaminants consistently flow out from the higher exit, ultimately leading to the establishment of a “stack-dominated flow regime”. Under this circumstance, even if the ventilation pressure increases to the critical value or slightly higher, the buoyant contaminants upstream of the source still cannot be pushed back. Moreover, the reduced gravity of the smoke in the tunnel increases as the ventilation pressure rises. Therefore, subcritical ventilation is not suitable for downhill tunnel fires. The study is helpful for understanding the smoke movement in horizontal and inclined tunnel fires under subcritical ventilation.

Effects of operating room ventilation on particle exposure and removal during general endotracheal anesthesia

The operating room (OR) ventilation system is a primary method for reducing particle exposure in the OR. However, most ventilation studies in operating rooms were conducted using computational fluid dynamics (CFD) models, which may not be able to predict the complexity of real operating conditions. In this study, we recruited 40 patients undergoing general endotracheal anesthesia in a total of 13 operating rooms. We tested the effectiveness of OR ventilation on mitigating patient and nebulizer-generated particles during the preoxygenation, induction, and intubation phases of care. Sampling locations were selected close to the patient's face (reference), physician's head area, and medical assistant's standing location. A total of six sampling sessions characterizing patient and healthcare worker activities were included. We observed a significantly higher number of particles during endotracheal intubation compared to preoxygenation with deep breathing and coughing, suggesting potential disruptive effect of surgical activities (i.e., intubation) on airflow, which affected particle concentration. Particle decay rates measured at all three locations (reference 50 ± 20 h-1; physician 46 ± 22 h-1; medical assistant 33 ± 21 h-1) were considerably higher than the regulated operating room air exchange rate of 20 h-1, indicating highly effective overall ventilation function. Nevertheless, healthcare workers should still be cautious about particle exposure risks in operations that generate large number of particles. Results from this study reflect the effectiveness of OR ventilation on particle mitigation in real-world scenario and may facilitate the validation of future CFD studies as well as the establishment of effective OR regulation guidelines to protect healthcare workers from particle exposures.

Willingness to pay for well-being housing attributes driven by design layout: Evidence from Hong Kong

Housing design layout plays a crucial role in occupant well-being, yet existing research has not clearly understood occupants’ preferences for different housing design layout attributes. This study aims to elucidate preferences by measuring demand-side willingness to pay (WTP) for housing attributes related to well-being and influenced by design layout. We first simulate the metrics of five housing attributes under different layouts, i.e., spatial daylight autonomy (sDA), spatial glare autonomy (sGA), natural ventilation effectiveness (NVE), predicted mean vote (PMV), and energy use intensity (EUI). Then, WTP for these attributes is disentangled from housing prices using the hedonic model. The findings demonstrate that a 1 % increase in sDA, sGA, and NVE corresponds to respective increases of 1.342 %, 0.694 %, and 2.842 % in housing prices, showing that residents value greatly the presence of natural ventilation and well-lit spaces with appropriate daylight. However, no significant correlations are found for PMV and EUI, suggesting a lack of a general preference towards thermal comfort or energy consumption in the Hong Kong context. This study contributes to a deeper knowledge of key well-being attributes in housing design as well as practical insights to create housing environments that prioritise occupant well-being and enhance market value. Future research should consider expanding to diverse housing markets, incorporating more well-being attributes, and examining the temporal variations of WTP.

The effects of mechanical ventilation on heart rate variability and complexity in mice

In a variety of diseases, altered respiratory modulation is often an early sign of autonomic dysfunction. Therefore, understanding and evaluating the effects of artificial ventilation on the autonomic nervous system is vital. The effects of artificial ventilation on autonomic balance have been assessed by heart rate variability using frequency domain and non-linear analysis including fractal complexity and entropy analysis in anesthetized mice. BALB/c mice (n=48) were divided into two groups: Spontaneous breathing and artificial ventilation. The electrocardiograms were recorded. Four different analyses were used: i. frequency domain analysis, ii. Poincaré plots, iii. DFA and iv. Entropy analysis. An unpaired t-test was used for statistical analysis. In a ventilated group, VLF and LF parameters were not changed, whereas the HF parameter was decreased compared to spontaneous breathing mice. DFAα1 was significantly increased due to artificial ventilation but DFAα2 was unchanged. SD2/SD1 ratio was increased, however, SD1 and SD2 were not significantly affected. Also, ApEn and SampEn remained unchanged. HF parameter, DFAα1, and SD2/SD1 were affected by artificial ventilation. Decreased HF and increased DFAα1, further support the notion that HRV is dominated by respiratory sinus arrhythmia at high frequencies, this may be due to decreased vagal tone caused by artificial ventilation.

Air flow prediction and evaluation of ventilation effectiveness with different zonal configurations

This paper proposes a numerical method for the study of ventilation efficiency in buildings. The developed model is validated with the experimental results of Nielsen [5] who tested the isothermal flow in a scaled model of a ventilated room. A zonal method is used to predict airflow patterns in the same ventilated room. The different equations governing the flow in the room were coded in Matlab for different operating conditions, different zonal configurations of the room and different number of cells (control volumes). The efficiency of the ventilation was determined by calculating the number of air changes per hour (ACH) for each cell. The present results show the importance of the inlet air flow rate, the space resolution and the jet inlet dimensions on the determination of air quality.

Natural Ventilation for Cooling Energy Saving: Typical Case of Public Building Design Optimization in Guangzhou, China

Heating ventilation and air conditioning systems account for over one-third of building energy usage, especially for public buildings, due to large indoor heat sources and high ventilation and thermal comfort requirements compared to residential buildings. Natural ventilation shows high application potential in public buildings because of its highly efficient ventilation effect and energy-saving potential for indoor heat dissipation. In this paper, a building design is proposed for a science museum with atrium-centered natural ventilation consideration. The floor layout, building orientation, and internal structure are optimized to make full use of natural ventilation for space cooling under local climatic conditions. The natural ventilation model is established through computational fluid dynamics (CFD) for airflow evaluation under indoor and outdoor pressure differences. The preliminary results show that such an atrium-centered architectural design could facilitate an average air exchange rate over 2 h−1 via the natural ventilation effect. Moreover, indoor thermal environment simulation results indicate that the exhaust air temperature can be about 5 °C higher than the indoor air mean temperature during the daytime, resulting in about 41.2% air conditioning energy saving ratio due to the free cooling effect of natural ventilation. This work can provide guidance and references for natural ventilation optimization design in public buildings.

The Effect of Lower Tidal Volume Ventilation Facilitated by Extracorporeal Carbon Dioxide Removal Compared With Conventional Lung Protective Ventilation on Cardiac Function.

Lower tidal volume ventilation (targeting 3 mL/kg predicted body weight, PBW) facilitated by extracorporeal carbon dioxide removal (ECCO2R) has been investigated as a potential therapy for acute hypoxemic respiratory failure (AHRF) in the pRotective vEntilation with veno-venouS lung assisT in respiratory failure (REST) trial. We investigated the effect of this strategy on cardiac function, and in particular the right ventricle. Substudy of the REST trial. Nine U.K. ICUs. Patients with AHRF (Pao2/Fio2 < 150 mm Hg [20 kPa]). Transthoracic echocardiography and N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurements were collected at baseline and postrandomization in patients randomized to ECCO2R or usual care. The primary outcome measures were a difference in tricuspid annular plane systolic excursion (TAPSE) on postrandomization echocardiogram and difference in NT-proBNP postrandomization. There were 21 patients included in the echocardiography cohort (ECCO2R, n = 13; usual care, n = 8). Patient characteristics were similar in both groups at baseline. Median (interquartile range) tidal volumes were lower in the ECCO2R group compared with the usual care group postrandomization; 3.6 (3.1-4.2) mL/kg PBW versus 5.2 (4.9-5.7) mL/kg PBW, respectively (p = 0.01). There was no difference in the primary outcome measure of mean (sd) TAPSE in the ECCO2R and usual care groups postrandomization; 21.3 (5.4) mm versus 20.1 (3.2) mm, respectively (p = 0.60). There were 75 patients included in the NT-proBNP cohort (ECCO2R, n = 36; usual care, n = 39). Patient characteristics were similar in both groups at baseline. Median (interquartile range [IQR]) tidal volumes were lower in the ECCO2R group than the usual care group postrandomization; 3.8 (3.3-4.2) mL/kg PBW versus 6.7 (5.8-8.1) mL/kg PBW, respectively (p < 0.0001). There was no difference in median (IQR) NT-proBNP postrandomization; 1121 (241-5370) pg/mL versus 1393 (723-4332) pg/mL in the ECCO2R and usual care groups, respectively (p = 0.30). In patients with AHRF, a reduction in tidal volume facilitated by ECCO2R, did not modify cardiac function.

Environmental data monitoring and infection risks in UK care-homes in the context of COVID-19

The COVID-19 pandemic drew attention to the critical role of building ventilation as a measure for controlling infection transmission. With the substantial number of COVID-19 outbreaks in care homes worldwide, the effectiveness of ventilation is an important consideration for infection control and wider exposure to indoor air pollutants. In this study, we used IoT-based sensors in two residential care homes to evaluate ventilation in various areas, including bedrooms, corridors, and communal spaces. Our monitoring focused on carbon dioxide (CO2) levels as a proxy for ventilation, as well as temperature and humidity, during the spring of 2022. We also developed a ventilation model using the software CONTAM and coupled it with an infection risk model to assess airborne transmission risks under different weather and occupancy conditions. Our results suggest that ventilation is generally adequate based on UK COVID-19 guidelines at the time, with CO2 below 800 ppm for the majority of the time, and opening windows in communal spaces in elderly care environments can help preserve indoor ventilation during periods of high occupancy. However, modelling data suggests that low CO2 values may be indicative of low occupancy in many spaces and therefore ventilation rates may not be sufficient to mitigate infection transmission. Encouraging positive ventilation behaviours in staff and residents, potentially supported by visible CO2 monitors, and taking additional precautions such as using air cleaners, enabling additional window openings or staff wearing masks during outbreaks and periods of high disease prevalence is likely to be beneficial for resident and staff health.

The effect of cave ventilation on carbon and oxygen isotopic fractionation between calcite and drip water

Rapid CO2 degassing and calcite precipitation driven by cave ventilation influence the speleothem δ18O and δ13C. However, the drivers of cave ventilation are not completely understood due to the lack of monitoring of multiple environmental factors. Furthermore, the understanding of isotope fractionation caused by the dissolution of speleothem in undersaturated drip water is limited during the cave air stagnation. In this study, we displayed four years of cave microenvironment monitoring in Shawan Cave, Southwestern China, and analyzed the δ13CDIC and δ18O of drip water, and calcite precipitation δ18O and δ13C. The results show that the ventilation process is attributed to buoyancy airflow between external atmosphere, fissure air, and cave air. This causes that the higher (lower) cave air pCO2 in the summer (winter) is associated with upward airflow mode (downward airflow mode). Furthermore, cave ventilation could control the isotopic fractionation. Specifically, when cave air pCO2 is lower, the carbon isotopic disequilibrium between calcite and dissolved inorganic carbon (DIC) is controlled by the degassing of CO2 associated with calcite precipitation. The disequilibrium fractionation in carbon isotopes is less pronounced at slower drip-rate sites. The oxygen isotope fractionation between calcite and the drip water is found to be close to equilibrium. However, the high cave air pCO2 (exceeding 10,000 ppm) may result in drip water undersaturation to drive the dissolution of speleothem calcite. The δ18O values of drip water are pulled away from their original values to disequilibrate to the calcite because the exchange time of oxygen in the dissolved carbonates with the oxygen in the water is sufficiently long. Hence, the dissolution of speleothems may be a new mechanism to explain the oxygen isotopic disequilibrium between the calcite and drip water during the cave air stagnation. The carbon isotope fractionation between calcite and drip water is close to equilibrium.

Smoke exhaust characteristics under stack effect of natural ventilation by shaft in high-altitude tunnel

The number of high-altitude tunnels is increasing year by year and natural ventilation of shafts is widely used as a critical component of the ventilation system. For the design of ventilation systems, it is particularly crucial to consider the smoke exhaust performance of shafts in low-pressure environment. Therefore, this study simulates tunnel fires with natural ventilation by shaft in high-altitude areas, aiming to analyze the impact of atmospheric pressure on smoke exhaust performance and smoke exhaust capacity by natural ventilated shafts at 50 to 100 kPa atmospheric pressure. It appears from the results that the increasing of ambient pressure can enhance the ability of air entrainment and natural smoke exhaust, and thus plug-holing is more likely. In which condition, fresh air can be expelled straight from the shaft, reducing smoke exhaust efficiency. As ambient pressure increases, the critical shaft height for plug-holing decreases. By analyzing the smoke exhausting process by shaft and smoke flow, smoke exhaust capacity can be evaluated by obtaining the mass flow rate of exhausted smoke and fresh air from the shaft under various atmospheric pressures and fire source power and. It could be said that increasing ambient pressure and shaft height can improve the smoke expulsion performance before plug-holing. However, once plug-holing happens, the increase of shaft height can no longer expel more smoke but much more air is exhausted by shaft. It is hoped that this work will serve as a guideline for ventilation systems design in high-altitude tunnels.

Design of the external forced air cooling control strategy for the bulb tubular turbine generator based on multi-objective optimization

The compact internal structure of the bulb tubular turbine generator (BTTG) leads to poor ventilation and heat dissipation capability (VHDC). It will result in high-temperature faults and lead to losses for the hydro-power station, if the staff at the hydropower station fail to promptly regulate the external forced air cooling for effective heat dissipation. Thus, a specific and effective ventilation control strategy (VCS) is of utmost importance for the operation of the BTTG. In this study, the finite element method (FEM) was employed to solve the magnetic-flow-thermal coupled field of a 24-MW BTTG. The distribution characteristics of electromagnetic losses and their impact on the temperature field were revealed. Experimental validation was conducted to verify the effectiveness of the numerical results. The response surface methodology (RSM) was employed to design an experimental plan by building upon this foundation. Integrated with a multiobjective genetic algorithm (MOGA), an optimal relationship between ambient temperature, fan flow rate, and heating components’ temperature was established. This relationship serves as the optimized ventilation control strategy for the BTTG. This research provides a theoretical framework for the formulation of operational guidelines to ensure the safe operation of generators.

Effects of high frequency non-invasive ventilation in premature newborn infants: systematic review protocol

Introduction: Premature birth is a condition, which can be induced by several factors. High Frequency non-invasive ventilation is a promising new mode of non-invasive ventilation that aims to offer adequate ventilation and oxygenation, but much has yet been discussed about its effectiveness and safety. Objective: To evaluate the effectiveness and safety of high frequency non-invasive ventilation in premature infants. Methods: To this end, we will carry out a systematic review. The study protocol was recorded on the Prosperous Platform. We will include premature newborns who used high-frequency non-invasive ventilation requiring ventilation as an initial support, after extubation or as a rescue mode (after failure of initial non-invasive therapy). The searches will be carried out in the databases: Medical Literature Analysis and Retrieval System Online (Medline) via Pubmed, Excerpta Medica dataBASE (Embase) via Elsevier, Cochrane Central Register of Controlled Trials (CENTRAL) via Cochrane Library, Latin American and Caribbean Literature in Health Sciences (LILACS) via the Virtual Health Library Portal and Physiotherapy Evidence Database We will evaluate the methodological rigor of the included studies and the certainty of the evidence of the main outcomes of the systematic review using Cochrane's Risk of Bias 2.0 tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, respectively. The selection of studies, data extraction, evaluation of the bias of the included studies and evaluation of the certainty of the evidence will be carried out by two independent researchers. Expected Results: The results of this review are expected to present a critical and up-to-date summary of the topic and facilitate safer decision-making by physiotherapists regarding the best recommendation for ventilatory support in the NICU, based on the best scientific evidence currently available.

Arctic/North Atlantic atmospheric variability causes Severe PM10 events in South Korea

Severe PM10 (particulate matter with a diameter of <10 μm) events in South Korea are known to be caused by stable atmospheric circulation conditions related to high-pressure anomalies in the upper troposphere. However, research on why these atmospheric circulation patterns occur is unknown. In this study, we propose new large-scale teleconnection pathways that cause severe PM10 events during the midwinter in South Korea. This study investigated instances of extremely high (EH)-PM10 in South Korea during mid-winter and examined the corresponding atmospheric teleconnection patterns to identify the factors contributing to EH-PM10 events. K-means clustering analysis revealed that EH-PM10 instances were associated with two large-scale teleconnection patterns. Cluster 1 exhibited a wave train pattern originating in the North Atlantic that developed from Eurasia to the Korean Peninsula. Cluster 2 was associated with a wave-like teleconnection pattern from the Barents-Kara Sea to the Korean Peninsula. The Rossby waves, triggered by the North Atlantic and the Arctic, propagated and weakened the surface pressure system. This led to a high-pressure anomaly over the Korean Peninsula, reducing atmospheric ventilation and causing a rapid increase in PM10 concentration within a few days. Furthermore, an experiment involving a linear baroclinic model established that atmospheric forcing in upstream regions has the potential to induce large-scale atmospheric teleconnection patterns, resulting in EH-PM10 cases in South Korea. These findings emphasize the ventilation effect and transport of PM10 concentrations modulated by two large-scale teleconnection patterns originating from the Arctic and North Atlantic, leading to EH-PM10 events in South Korea. Understanding this combined phenomenon may assist in the implementation of emission reduction measures based on the results of short-term forecasts of severe PM10 events.

The effect of inverse ratio ventilation on cardiopulmonary function in obese laparoscopic surgery patients: A systematic review and meta-analysis.

This study aimed to evaluate the effect of inverse ratio ventilation (IRV) strategy on cardiopulmonary function in obese patients under general anesthesia. Databases such as China National Knowledge Infrastructure (CNKI), Wangfang, WeiP, Web of Science, the Cochrane Library, and PubMed were systematically searched. All randomized controlled trials' literature on IRV during laparoscopic surgery in obese patients under general anesthesia was collected. After data were extracted and cross-checked, Rev Man 5.3 software was used for meta-analysis. Finally, five randomized controlled clinical trials (RCTs) were included in the meta-analysis, with a total of 312 patients. Compared with the conventional ventilation group, the inspiratory peak pressure was lower at pneumoperitoneum 30 min and pneumoperitoneum 60 min; the PaO2 and oxygenation index were higher at pneumoperitoneum 60 min, and mean airway pressure was higher at pneumoperitoneum 30 min and pneumoperitoneum 60 min; the dynamic lung compliance was superior at pneumoperitoneum 30 min and pneumoperitoneum 60 min. IRV applied to laparoscopic surgery in obese patients under general anesthesia not only reduces peak airway pressure and improves intraoperative oxygenation index and PaO2 but also enhances mean airway pressure and dynamic lung compliance, which has a specific lung protective effect. It can be used as an option for the mechanical ventilation model in obese patients in clinical practice.