BACKGROUND:In this study,we aimed to evaluate the impact of mechanical ventilator(MV)utilizaton during cardiopulmonary resuscitation(CPR)on out-of-hospital cardiac arrest(OHCA)patient clinical outcomes in the emergenc...BACKGROUND:In this study,we aimed to evaluate the impact of mechanical ventilator(MV)utilizaton during cardiopulmonary resuscitation(CPR)on out-of-hospital cardiac arrest(OHCA)patient clinical outcomes in the emergency department.METHODS:This single-centered,retrospective,case-control study analyzed electronic medical records.Patients aged>18 years with non-traumatic OHCA who were treated at an emergency medical center between January 2019 and December 2023 were included.These patients were accessed according to the ventilatory method used:MV ventilation(volume control,tidal volume 6-8 mL/kg,frequency 10 beat per minute,inspiratory time 1 s)and manual resuscitator bag valve(BV)ventilation.The primary outcome was the return of spontaneous circulation(ROSC).After 1:1 propensity score matching,the clinical outcomes were analyzed.RESULTS:A total of 649 patients were enrolled in this study.Before matching,the clinical outcomes and pneumothorax incidence did not differ between the MV and BV groups.After 1:1 matching between the two groups using propensity scores,522 patients(261 MV and 261 BV)were analyzed.Propensity score matching yielded an adequate balance(standardized mean difference<0.10)for all covariates.The estimated odds ratio(OR)for ROSC was 1.23(95%confidence interval[CI]:0.85-1.77;P=0.267),for survival at hospital admission was 1.02(95%CI:0.68-1.53;P=0.918),for survival at hospital discharge was 2.31(95%CI:1.10-5.20;P=0.033),and for good neurologic outcome was 2.56(95%CI:0.84-9.43;P=0.116).CONCLUSION:In patients with OHCA admitted to the emergency department,MV ventilation during CPR showed clinical outcomes similar to those of BV ventilation in most measures.However,survival at hospital discharge was significantly higher in the MV group,suggesting potential benefits of MV use in selected patients.展开更多
Mechanical ventilation is a specialized oxygen therapy and life support technology with significant importance for critically ill patients. In fact, 40%–66% of patients in the intensive care unit(ICU) require mechani...Mechanical ventilation is a specialized oxygen therapy and life support technology with significant importance for critically ill patients. In fact, 40%–66% of patients in the intensive care unit(ICU) require mechanical ventilation.^([1,2]) However, the mechanical ventilation can lead to ventilatorassociated lung injury(VALI),^([3]) ultimately resulting in difficulties in weaning from mechanical ventilation,prolonged hospital stays, and even increased mortality.展开更多
A recent study on the rapid imaging of pulmonary ventilation using hyperpolarized ^(129)Xe MRI has demonstrated the ability to achieve isotropic 3D ventilation imaging with a spatial resolution of 3×3×3mm^(3...A recent study on the rapid imaging of pulmonary ventilation using hyperpolarized ^(129)Xe MRI has demonstrated the ability to achieve isotropic 3D ventilation imaging with a spatial resolution of 3×3×3mm^(3) in humans,within an acquisition time of just 3.5 seconds(https://doi.org/10.1002/mrm.30120).展开更多
With different structural forms of ventilation pipes have various attenuation effects on incident shock waves while meeting ventilation requirements.The attenuation mechanism and the propagation law of shock waves in ...With different structural forms of ventilation pipes have various attenuation effects on incident shock waves while meeting ventilation requirements.The attenuation mechanism and the propagation law of shock waves in ventilation pipes of different structures are investigated by experiments and numerical simulations.Furthermore,for the same structure,the effects of peak pressure and positive pressure time on the attenuation rate are discussed.It is found that the attenuation rate increases with the incident shock wave pressure,and the shock wave attenuation rate tends to reach its limiting value k for the same structure and reasonably short positive pressure time.Under the same conditions,the attenuation rate is calculated using the pressure of the shock wave as follows:diffusion chamber pipe,branch pipe and selfconsumption pipe;the attenuation rate per unit volume is calculated as follows:self-consumption pipe,branch pipe and diffusion chamber pipe.In addition,an easy method is provided to calculate the attenuation rate of the shock wave in single and multi-stage ventilation pipes.Corresponding parameters are provided for various structures,and the margin of error between the formulae and experimental results is within 10%,which is significant for engineering applications.展开更多
Prediction of weaning success from invasive mechanical ventilation remains a challenge in everyday clinical practice.Several prediction scores have been developed to guide success during spontaneous breathing trials t...Prediction of weaning success from invasive mechanical ventilation remains a challenge in everyday clinical practice.Several prediction scores have been developed to guide success during spontaneous breathing trials to help with weaning decisions.These scores aim to provide a structured framework to support clinical judgment.However,their effectiveness varies across patient populations,and their predictive accuracy remains inconsistent.In this review,we aim to identify the strengths and limitations of commonly used clinical prediction tools in assessing readiness for ventilator liberation.While scores such as the Rapid Shallow Breathing Index and the Integrative Weaning Index are widely adopted,their sensitivity and specificity often fall short in complex clinical settings.Factors such as underlying disease pathophysiology,patient characteristics,and clinician subjectivity impact score performance and reliability.Moreover,disparities in validation across diverse populations limit generalizability.With growing interest in artificial intelligence(AI)and machine learning,there is potential for enhanced prediction models that integrate multidimensional data and adapt to individual patient profiles.However,current AI approaches face challenges related to interpretability,bias,and ethical implementation.This paper underscores the need for more robust,individualized,and transparent prediction systems and advocates for careful integration of emerging technologies into clinical workflows to optimize weaning success and patient outcomes.展开更多
During the train meeting events,train equipment compartments are exposed to the worst pressure changes,potentially affecting the ventilation performance of equipment,particularly for electrical facilities equipped wit...During the train meeting events,train equipment compartments are exposed to the worst pressure changes,potentially affecting the ventilation performance of equipment,particularly for electrical facilities equipped with independent air ducts.In this paper,a two-step method is used for numerical computation:(1)obtaining the temporal and spatial transient node data of the flow field sections during the train-passing simulation and(2)using the data as the input data for the equipment compartment simulation.In addition,this paper also compares the difference in equipment ventilation between the single-train and trainpassing scenarios in real vehicle tests.The results indicate that the primary factors influencing ventilation effectiveness are the aerodynamic compression and deceleration of airflow induced by the other train's nose,as well as the instability of the external flow field in the wake of the other train.During train crossing,the air is forced into the air duct,with a maximum ratio of the airflow in-duct to the airflow out-duct reaching 3.2.The average mass flow falls below the rated mass flow for the converter.Compared to the rated air volume of converter,the maximum suppression rates obtained from testing and simulation are-24.5%and-16.8%,respectively.Compared to the single-train operation,the maximum suppression rates obtained from testing and simulation are-15%and-18%,respectively.These findings provide valuable insights into the design and operation of high-speed trains.展开更多
The longitudinal ventilation strategy is commonly used for road tunnels in urban environment in Sweden.This is partly due to how tunnels in urban environment was planned and designed before the EU Directive[1](2004/54...The longitudinal ventilation strategy is commonly used for road tunnels in urban environment in Sweden.This is partly due to how tunnels in urban environment was planned and designed before the EU Directive[1](2004/54/EC)came in place.Even in new tunnels both to practical and economic reasons the use of longitudinal ventilation has been an outspoken demand from the Swedish road authority,SRA.Swedish law[2]requires that a risk analysis is carried out to demonstrate that an acceptable level of risk is achieved in the tunnels with longitudinal ventilation if there is a risk of queues.Otherwise transverse or semi-transverse ventilation strategy shall be used.During recent development,or a late awakening,it is clear that dense populated areas in Sweden will experience queues.This threatens the foundation of the Swedish modern tunnel safety concept which calls for enhancement.This paper presents the risk-reducing effect of three alternative strategies,enhancements package,focusing on evacuation safety for road users.It is a combination of traffic management,fixed firefighting systems,reduced distance between escape routes and regulation of traffic with dangerous goods.In addition,it provides a comprehensive review of safety system details,combined with a longitudinal ventilation concept.展开更多
BACKGROUND Lung ultrasonography is being increasingly used in mechanically ventilated patients to evaluate the lung aeration during incremental positive end expiratory pressure(PEEP)adjustments and to evaluate the wea...BACKGROUND Lung ultrasonography is being increasingly used in mechanically ventilated patients to evaluate the lung aeration during incremental positive end expiratory pressure(PEEP)adjustments and to evaluate the weaning process from mechanical ventilation.The effects of PEEP may vary across different lung pathologies and may not consistently correlate with changes in lung aeration as assessed by lung ultrasound scores(LUSs).AIM To assess the role of lung ultrasonography in evaluating lung aeration during the application of PEEP in mechanically ventilated patients with various lung pathologies.METHODS An observational study was conducted over 18 months in a tertiary care hospital.Patients of both genders,aged between 18-75 years,who had been admitted to the intensive care unit,and required mechanical ventilation,were studied.A standard ventilatory strategy was used and incremental levels of PEEP[5,10,and 15 cm water(H_(2)O)]were applied.Baseline characteristics,including oxygen saturation(SpO2),LUS,mean arterial pressure(MAP),heart rate(HR),and their changes with incremental PEEP levels,were recorded and analyzed.RESULTS In this study,45.9%of patients required a PEEP of 5 cm H_(2)O to achieve the endpoint of lung aeration(LUS of 0).In addition,86.5% and 13.5% of patients reached the endpoint of lung aeration at PEEP levels of 10 and 15 cm H_(2)O,respectively.The proportion of patients with higher lung scores decreased significantly with increasing PEEP levels(P<0.001 for 5 and 10 cm H_(2)O and P=0.032 for 15 cm H_(2)O).SpO2 increased significantly with higher PEEP levels(P<0.001),confirming the effectiveness of PEEP in improving oxygenation.The results also revealed a significant increase in HR and a decrease in MAP following the application of higher PEEP levels.CONCLUSION Increasing PEEP levels in mechanically ventilated patients improves lung aeration,which can be effectively assessed using bedside lung ultrasonography.展开更多
Objective:To explore the role of lung ultrasound combined with multi-organ evaluation in assessing the risk of weaning from mechanical ventilation(MV)in severe patients.Methods:A retrospective analysis was conducted o...Objective:To explore the role of lung ultrasound combined with multi-organ evaluation in assessing the risk of weaning from mechanical ventilation(MV)in severe patients.Methods:A retrospective analysis was conducted on 60 severe patients admitted to the hospital from December 2022 to December 2024,all of whom underwent MV treatment.Based on weaning status,thirty-eight patients were successfully weaned(success group),and 22 patients failed weaning(failure group).All patients underwent lung ultrasound and multi-organ evaluation.The parameter differences between the two groups were compared,risk factors for weaning risk were evaluated,and a receiver operating characteristic curve(ROC)was drawn to assess the predictive value of lung ultrasound combined with multi-organ evaluation for weaning risk.Results:The lung ultrasound score(LUS)of the success group was lower than that of the failure group,the left ventricular ejection fraction(LVEF)was higher than that of the failure group,and the diaphragmatic excursion(DE)and diaphragmatic thickening fraction(DTF)were higher than those of the failure group(P<0.05).Multifactor analysis showed that LUS was a risk factor for weaning risk,while LVEF,DE,and DTF were protective factors(P<0.05).The ROC showed that the area under the curve(AUC)of a single parameter for weaning risk was smaller than that of the combined parameters(P<0.05).Conclusion:Lung ultrasound combined with multi-organ evaluation can predict the weaning risk of severe patients undergoing MV treatment,and the diagnostic efficiency of multiple parameters combined evaluation is higher.展开更多
Indoor air quality(IAQ)is often overlooked,yet a poorly maintained environment can lead to significant health issues and reduced concentration and productivity in work or educational settings.This study presents an in...Indoor air quality(IAQ)is often overlooked,yet a poorly maintained environment can lead to significant health issues and reduced concentration and productivity in work or educational settings.This study presents an innovative control system for mechanical ventilation specifically designed for university classrooms,with the dual goal of enhancing IAQ and increasing energy efficiency.Two classrooms with distinct construction characteristics were analyzed:one with exterior walls and windows,and the other completely underground.For each classroom,a model was developed using DesignBuilder software,which was calibrated with experimental data regarding CO_(2) concentration,temperature,and relative humidity levels.The proposed ventilation system operates based on CO_(2) concentration,relative humidity,and potential for free heating and cooling.In addition,the analysis was conducted for other locations,demonstrating consistent energy savings across different climates and environments,always showing an annual reduction in energy consumption.Results demonstrate that mechanical ventilation,when integrated with heat recovery and free cooling strategies,significantly reduces energy consumption by up to 25%,while also maintaining optimal CO_(2) levels to enhance comfort and air quality.These findings emphasize the essential need for well-designed mechanical ventilation systems to ensure both psychophysical well-being and IAQ in enclosed spaces,particularly in environments intended for extended occupancy,such as classrooms.Furthermore,this approach has broad applicability,as it could be adapted to various building types,thereby contributing to sustainable energy management practices and promoting healthier indoor spaces.This study serves as a model for future designs aiming to balance energy efficiency with indoor air quality,especially relevant in the post-COVID era,where the importance of indoor air quality has become more widely recognized.展开更多
Objective:To investigate the predictive value of diaphragm thickening fraction(DTF)combined with cough peak expiratory flow(CPEF)on the success rate of weaning from mechanical ventilation.Methods:The clinical data of ...Objective:To investigate the predictive value of diaphragm thickening fraction(DTF)combined with cough peak expiratory flow(CPEF)on the success rate of weaning from mechanical ventilation.Methods:The clinical data of patients undergoing invasive mechanical ventilation via oral endotracheal intubation in the ICU of our hospital from January 2022 to December 2023 were studied.All patients underwent a 30-minute spontaneous breathing trial(SBT)using low-level pressure support ventilation(PSV)after meeting the clinical weaning screening criteria.Among them,150 patients who met the clinical weaning criteria were weaned from the ventilator.They were divided into a successful weaning group(n=100)and a failed weaning group(n=50)based on the weaning outcome.Clinical data,including age,gender,APACHE II score,duration of mechanical ventilation,DTF,and CPEF,were collected from 150 patients.The differences in clinical data between the two groups were compared,and the correlation between DTF,CPEF,and the success rate of weaning was analyzed.Results:There were no significant differences between the two groups in gender ratio(χ^(2)=0.884,P=0.347>0.05),age(t=0.350,P=0.727>0.05),and APACHE II score(t=1.295,P=0.197>0.05),but there was a significant difference in the duration of mechanical ventilation(t=3.766,P<0.001).The DTF and CPEF values in the successful weaning group were significantly higher than those in the failed weaning group(P<0.05).ROC curves were drawn to predict the weaning results using DTF,CPEF,and the combination of DTF and CPEF.The results showed that the specificity of the combination of DTF and CPEF was comparable to that of either metric alone,but the sensitivity and AUC were significantly higher than those of either metric alone.Conclusion:The combination of DTF and CPEF can be used as an effective indicator to evaluate the weaning efficacy of mechanically ventilated patients,which has important clinical significance for guiding clinical weaning treatment,improving the success rate of weaning,reducing the incidence of ventilator-associated pneumonia,and shortening the length of hospital stay.展开更多
Objectives:To propose a new idea of“lung ventilation and Qi regulation”for preventing and treating lung cancer,and to summarize the corresponding Tongfei Huajie prescription,as a systematic theoretical and practical...Objectives:To propose a new idea of“lung ventilation and Qi regulation”for preventing and treating lung cancer,and to summarize the corresponding Tongfei Huajie prescription,as a systematic theoretical and practical innovation.Methods:Based on the etiology and pathogenesis of lung cancer,the anatomy,physiology and pathology of the lung,and inspired by the ancient“Tuoyue”(bellows)theory,this study combined the clinical observation of ventilation issues in lung cancer patients.The Tongfei Huajie prescription was formulated following the classic principle of monarch(Jun),minister(Chen),assistant(Zuo),and guide(Shi),and was interpreted with modern pharmacological research.Results:A novel therapeutic concept of“lung ventilation and Qi regulation”was proposed.The corresponding Tongfei Huajie prescription was developed,which has the effects of ventilating the lung,expelling phlegm dampness,tonifying Qi,tonifying the kidney and spleen for lung health,soothing the liver and descending lung Qi,and clearing the heart and moistening the lung.Clinical application has achieved obvious curative effect.Conclusions:This work presents a systematic summary of the innovation in“theory,method,formula and herb”for lung cancer treatment,demonstrating the advantages of Traditional Chinese Medicine in this field.展开更多
Carbon dioxide(CO_(2))is often monitored as a convenient yardstick for indoor air safety,yet its ability to stand in for pathogen-laden aerosols has never been settled.To probe the question,we reproduced an open-plan ...Carbon dioxide(CO_(2))is often monitored as a convenient yardstick for indoor air safety,yet its ability to stand in for pathogen-laden aerosols has never been settled.To probe the question,we reproduced an open-plan office at full scale(7.2m×5.2m×2.8m)and introduced a breathing plume that carried 4% CO_(2),together with a polydisperse aerosol spanning 0.5–10μm(1320 particles s^(−1)).Inlet air was supplied at 0.7,1.4,and 2.1 m s^(−1),and the resulting fields were simulated with a Realisable k–εRANS model coupled to Lagrangian particle tracking.Nine strategically placed probes provided validation;the calibrated solution deviated fromthe experiment by 58 ppm for CO_(2)(8.1%RMSE)and 0.008 m s^(−1)for velocity(15.7%RMSE).Despite this agreement,gas and particles behaved in sharply different ways.Room-averaged CO_(2)varied by<15%,whereas the aerosol mass rose to almost three-fold the background within slowmoving corner vortices.Sub-micron particles stayed aloft along streamlines,while those≥5μmpeeled away and settled on nearby surfaces.The divergence shows that neither the CO_(2)level nor themeanageof air,taken in isolation,delineates all high-exposure zones.We therefore recommend that ventilation design be informed by a composite diagnosis that couples gas data,size-resolved particle measurements,and rapid CFD appraisal.展开更多
The breakage and bending of ducts result in a difficulty to cope with ventilation issues in bidirectional excavation tunnels with a long inclined shaft using a single ventilation method based on ducts.To discuss the h...The breakage and bending of ducts result in a difficulty to cope with ventilation issues in bidirectional excavation tunnels with a long inclined shaft using a single ventilation method based on ducts.To discuss the hybrid ventilation system applied in bidirectional excavation tunnels with a long inclined shaft,this study has established a full-scale computational fluid dynamics model based on field tests,the Poly-Hexcore method,and the sliding mesh technique.The distribution of wind speed,temperature field,and CO in the tunnel are taken as indices to compare the ventilation efficiency of three ventilation systems(duct,duct-ventilation shaft,duct–ventilated shaft-axial fan).The results show that the hybrid ventilation scheme based on duct-ventilation shaft–axial fan performs the best among the three ventilation systems.Compared to the duct,the wind speed and cooling rate in the tunnel are enhanced by 7.5%–30.6%and 14.1%–17.7%,respectively,for the duct-vent shaft-axial fan condition,and the volume fractions of CO are reduced by 26.9%–73.9%.This contributes to the effective design of combined ventilation for bidirectional excavation tunnels with an inclined shaft,ultimately improving the air quality within the tunnel.展开更多
In order to study the problems of unreasonable airflow distribution and serious dust pollution in a heading surface,an experimental platform for forced ventilation and dust removal was built based on the similar princ...In order to study the problems of unreasonable airflow distribution and serious dust pollution in a heading surface,an experimental platform for forced ventilation and dust removal was built based on the similar principles.Through the similar experiment and numerical simulation,the distribution of airflow field in the roadway and the spatial and temporal evolution of dust pollution under the conditions of forced ventilation were determined.The airflow field in the roadway can be divided into three zones:jet zone,vortex zone and reflux zone.The dust concentration gradually decreases from the head to the rear of the roadway.Under the forced ventilation conditions,there is a unilateral accumulation of dust,with higher dust concentrations away from the ducts.The position of the equipment has an interception effect on the dust.The maximum error between the test value and the simulation result is 12.9%,which verifies the accuracy of the experimental results.The research results can provide theoretical guidance for the application of dust removal technology in coal mine.展开更多
Driving pressure(ΔP)is a core therapeutic component of mechanical ventilation(MV).Varying levels ofΔP have been employed during MV depending on the type of underlying pathology and severity of injury.However,ΔP lev...Driving pressure(ΔP)is a core therapeutic component of mechanical ventilation(MV).Varying levels ofΔP have been employed during MV depending on the type of underlying pathology and severity of injury.However,ΔP levels have also been shown to closely impact hard endpoints such as mortality.Considering this,conducting an in-depth review ofΔP as a unique,outcome-impacting therapeutic modality is extremely important.There is a need to understand the subtleties involved in making sureΔP levels are optimized to enhance outcomes and minimize harm.We performed this narrative review to further explore the various uses ofΔP,the different parameters that can affect its use,and how outcomes vary in different patient populations at different pressure levels.To better utilizeΔP in MV-requiring patients,additional large-scale clinical studies are needed.展开更多
BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease(AECOPD)is often combined with respiratory failure,which increases the patient's morbidity and mortality.Diaphragm ultrasound(DUS)has developed...BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease(AECOPD)is often combined with respiratory failure,which increases the patient's morbidity and mortality.Diaphragm ultrasound(DUS)has developed rapidly in the field of critical care in recent years.Studies with DUS monitoring diaphragm-related rapid shallow breathing index have demonstrated important results in guiding intensive care unit patients out of the ventilator.Early prediction of the indications for withdrawal of non-invasive ventilator and early evaluation of patients to avoid or reduce disease progression are very important.AIM To explore the predictive value of DUS indexes for non-invasive ventilation outcome in patients with AECOPD.METHODS Ninety-four patients with AECOPD who received mechanical ventilation in our hospital from January 2022 to December 2023 were retrospectively analyzed,and they were divided into a successful ventilation group(68 cases)and a failed ventilation group(26 cases)according to the outcome of ventilation.The clinical data of patients with successful and failed noninvasive ventilation were compared,and the independent predictors of noninvasive ventilation outcomes in AECOPD patients were identified by multivariate logistic regression analysis.RESULTS There were no significant differences in gender,age,body mass index,complications,systolic pressure,heart rate,mean arterial pressure,respiratory rate,oxygen saturation,partial pressure of oxygen,oxygenation index,or time of inspiration between patients with successful and failed mechanical ventilation(P>0.05).The patients with successful noninvasive ventilation had shorter hospital stays and lower partial pressure of carbon dioxide(PaCO_(2))than those with failed treatment,while potential of hydrogen(pH),diaphragm thickening fraction(DTF),diaphragm activity,and diaphragm movement time were significantly higher than those with failed treatment(P<0.05).pH[odds ratio(OR)=0.005,P<0.05],PaCO_(2)(OR=0.430,P<0.05),and DTF(OR=0.570,P<0.05)were identified to be independent factors influencing the outcome of mechanical ventilation in AECOPD patients.CONCLUSION The DUS index DTF can better predict the outcome of non-invasive ventilation in AECOPD patients.展开更多
BACKGROUND Laparoscopic-assisted radical gastrectomy(LARG)is the standard treatment for early-stage gastric carcinoma(GC).However,the negative impact of this proce-dure on respiratory function requires the optimized i...BACKGROUND Laparoscopic-assisted radical gastrectomy(LARG)is the standard treatment for early-stage gastric carcinoma(GC).However,the negative impact of this proce-dure on respiratory function requires the optimized intraoperative management of patients in terms of ventilation.AIM To investigate the influence of pressure-controlled ventilation volume-guaranteed(PCV-VG)and volume-controlled ventilation(VCV)on blood gas analysis and pulmonary ventilation in patients undergoing LARG for GC based on the lung ultrasound score(LUS).METHODS The study included 103 patients with GC undergoing LARG from May 2020 to May 2023,with 52 cases undergoing PCV-VG(research group)and 51 cases undergoing VCV(control group).LUS were recorded at the time of entering the operating room(T0),20 minutes after anesthesia with endotracheal intubation(T1),30 minutes after artificial pneumoperitoneum(PP)establishment(T2),and 15 minutes after endotracheal tube removal(T5).For blood gas analysis,arterial partial pressure of oxygen(PaO_(2))and partial pressure of carbon dioxide(PaCO_(2))were observed.Peak airway pressure(P_(peak)),plateau pressure(Pplat),mean airway pressure(P_(mean)),and dynamic pulmonary compliance(C_(dyn))were recorded at T1 and T2,1 hour after PP establishment(T3),and at the end of the operation(T4).Postoperative pulmonary complications(PPCs)were recorded.Pre-and postoperative serum interleukin(IL)-1β,IL-6,and tumor necrosis factor-α(TNF-α)were measured by enzyme-linked immunosorbent assay.RESULTS Compared with those at T0,the whole,anterior,lateral,posterior,upper,lower,left,and right lung LUS of the research group were significantly reduced at T1,T2,and T5;in the control group,the LUS of the whole and partial lung regions(posterior,lower,and right lung)decreased significantly at T2,while at T5,the LUS of the whole and some regions(lateral,lower,and left lung)increased significantly.In comparison with the control group,the whole and regional LUS of the research group were reduced at T1,T2,and T5,with an increase in PaO_(2),decrease in PaCO_(2),reduction in P_(peak) at T1 to T4,increase in P_(mean) and C_(dyn),and decrease in Pplat at T4,all significant.The research group showed a significantly lower incidence of PPCs than the control group within 3 days postoperatively.Postoperative IL-1β,IL-6,and TNF-αsignificantly increased in both groups,with even higher levels in the control group.CONCLUSION LUS can indicate intraoperative non-uniformity and postural changes in pulmonary ventilation under PCV-VG and VCV.Under the lung protective ventilation strategy,the PCV-VG mode more significantly improved intraop-erative lung ventilation in patients undergoing LARG for GC and reduced lung injury-related cytokine production,thereby alleviating lung injury.展开更多
BACKGROUND Dexmedetomidine and propofol are two sedatives used for long-term sedation.It remains unclear whether dexmedetomidine provides superior cerebral protection for patients undergoing long-term mechanical venti...BACKGROUND Dexmedetomidine and propofol are two sedatives used for long-term sedation.It remains unclear whether dexmedetomidine provides superior cerebral protection for patients undergoing long-term mechanical ventilation.AIM To compare the neuroprotective effects of dexmedetomidine and propofol for sedation during prolonged mechanical ventilation in patients without brain injury.METHODS Patients who underwent mechanical ventilation for>72 h were randomly assigned to receive sedation with dexmedetomidine or propofol.The Richmond Agitation and Sedation Scale(RASS)was used to evaluate sedation effects,with a target range of-3 to 0.The primary outcomes were serum levels of S100-βand neuron-specific enolase(NSE)every 24 h.The secondary outcomes were remifentanil dosage,the proportion of patients requiring rescue sedation,and the time and frequency of RASS scores within the target range.RESULTS A total of 52 and 63 patients were allocated to the dexmedetomidine group and propofol group,respectively.Baseline data were comparable between groups.No significant differences were identified between groups within the median duration of study drug infusion[52.0(IQR:36.0-73.5)h vs 53.0(IQR:37.0-72.0)h,P=0.958],the median dose of remifentanil[4.5(IQR:4.0-5.0)μg/kg/h vs 4.6(IQR:4.0-5.0)μg/kg/h,P=0.395],the median percentage of time in the target RASS range without rescue sedation[85.6%(IQR:65.8%-96.6%)vs 86.7%(IQR:72.3%-95.3),P=0.592],and the median frequency within the target RASS range without rescue sedation[72.2%(60.8%-91.7%)vs 73.3%(60.0%-100.0%),P=0.880].The proportion of patients in the dexmedetomidine group who required rescue sedation was higher than in the propofol group with statistical significance(69.2%vs 50.8%,P=0.045).Serum S100-βand NSE levels in the propofol group were higher than in the dexmedetomidine group with statistical significance during the first six and five days of mechanical ventilation,respectively(all P<0.05).CONCLUSION Dexmedetomidine demonstrated stronger protective effects on the brain compared to propofol for long-term mechanical ventilation in patients without brain injury.展开更多
BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease(AECOPD)is a serious complication of chronic obstructive pulmonary disease,often characterized by increased morbidity and mortality.In traditional ...BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease(AECOPD)is a serious complication of chronic obstructive pulmonary disease,often characterized by increased morbidity and mortality.In traditional Chinese medicine,AECOPD is linked to phlegm-heat and blood-stasis,presenting symptoms like thick sputum,fever,and chest pain.It has been shown that acetylcysteine inhalation in conjunction with conventional therapy significantly reduced inflammatory markers and improved lung function parameters in patients with AECOPD,suggesting that acetylcysteine may be an important adjunctive therapy for patients with phlegm-heat-blood stasis type AECOPD.AIM To investigate the effect of acetylcysteine on microinflammation and lung ventilation in patients with phlegm-heat and blood-stasis-type AECOPD.METHODS One hundred patients with phlegm-heat and blood-stasis-type AECOPD were randomly assigned to two groups.The treatment group received acetylcysteine inhalation(10%solution,5 mL,twice daily)along with conventional therapy,whereas the control group received only conventional therapy.The treatment duration was 14 d.Inflammatory markers(C-reactive protein,interleukin-6,and tumor necrosis factor-alpha)in the serum and sputum as well as lung function parameters(forced expiratory volume in one second,forced vital capacity,and peak expiratory flow)were assessed pre-and post-treatment.Acetylcysteine inhalation led to significant reductions in inflammatory markers and improvements in lung function parameters compared to those in the control group(P<0.05).This suggests that acetylcysteine could serve as an effective adjunct therapy for patients with phlegm-heat and blood-stasis-type AECOPD.RESULTS Acetylcysteine inhalation significantly reduced inflammatory markers in the serum and sputum and improved lung ventilation function parameters in patients with phlegm-heat and blood-stasis type AECOPD compared with the control group.These differences were statistically significant(P<0.05).The study concluded that acetylcysteine inhalation had a positive effect on microinflammation and lung ventilation function in patients with this type of AECOPD,suggesting its potential as an adjuvant therapy for such cases.CONCLUSION Acetylcysteine inhalation demonstrated significant improvements in reducing inflammatory markers in the serum and sputum,as well as enhancing lung ventilation function parameters in patients with phlegm-heat and bloodstasis type AECOPD.These findings suggest that acetylcysteine could serve as a valuable adjuvant therapy for individuals with this specific type of AECOPD,offering benefits for managing microinflammation and optimizing lung function.展开更多
文摘BACKGROUND:In this study,we aimed to evaluate the impact of mechanical ventilator(MV)utilizaton during cardiopulmonary resuscitation(CPR)on out-of-hospital cardiac arrest(OHCA)patient clinical outcomes in the emergency department.METHODS:This single-centered,retrospective,case-control study analyzed electronic medical records.Patients aged>18 years with non-traumatic OHCA who were treated at an emergency medical center between January 2019 and December 2023 were included.These patients were accessed according to the ventilatory method used:MV ventilation(volume control,tidal volume 6-8 mL/kg,frequency 10 beat per minute,inspiratory time 1 s)and manual resuscitator bag valve(BV)ventilation.The primary outcome was the return of spontaneous circulation(ROSC).After 1:1 propensity score matching,the clinical outcomes were analyzed.RESULTS:A total of 649 patients were enrolled in this study.Before matching,the clinical outcomes and pneumothorax incidence did not differ between the MV and BV groups.After 1:1 matching between the two groups using propensity scores,522 patients(261 MV and 261 BV)were analyzed.Propensity score matching yielded an adequate balance(standardized mean difference<0.10)for all covariates.The estimated odds ratio(OR)for ROSC was 1.23(95%confidence interval[CI]:0.85-1.77;P=0.267),for survival at hospital admission was 1.02(95%CI:0.68-1.53;P=0.918),for survival at hospital discharge was 2.31(95%CI:1.10-5.20;P=0.033),and for good neurologic outcome was 2.56(95%CI:0.84-9.43;P=0.116).CONCLUSION:In patients with OHCA admitted to the emergency department,MV ventilation during CPR showed clinical outcomes similar to those of BV ventilation in most measures.However,survival at hospital discharge was significantly higher in the MV group,suggesting potential benefits of MV use in selected patients.
文摘Mechanical ventilation is a specialized oxygen therapy and life support technology with significant importance for critically ill patients. In fact, 40%–66% of patients in the intensive care unit(ICU) require mechanical ventilation.^([1,2]) However, the mechanical ventilation can lead to ventilatorassociated lung injury(VALI),^([3]) ultimately resulting in difficulties in weaning from mechanical ventilation,prolonged hospital stays, and even increased mortality.
基金supported by the National Natural Science Foundation of China(81930049 and 82171926).
文摘A recent study on the rapid imaging of pulmonary ventilation using hyperpolarized ^(129)Xe MRI has demonstrated the ability to achieve isotropic 3D ventilation imaging with a spatial resolution of 3×3×3mm^(3) in humans,within an acquisition time of just 3.5 seconds(https://doi.org/10.1002/mrm.30120).
文摘With different structural forms of ventilation pipes have various attenuation effects on incident shock waves while meeting ventilation requirements.The attenuation mechanism and the propagation law of shock waves in ventilation pipes of different structures are investigated by experiments and numerical simulations.Furthermore,for the same structure,the effects of peak pressure and positive pressure time on the attenuation rate are discussed.It is found that the attenuation rate increases with the incident shock wave pressure,and the shock wave attenuation rate tends to reach its limiting value k for the same structure and reasonably short positive pressure time.Under the same conditions,the attenuation rate is calculated using the pressure of the shock wave as follows:diffusion chamber pipe,branch pipe and selfconsumption pipe;the attenuation rate per unit volume is calculated as follows:self-consumption pipe,branch pipe and diffusion chamber pipe.In addition,an easy method is provided to calculate the attenuation rate of the shock wave in single and multi-stage ventilation pipes.Corresponding parameters are provided for various structures,and the margin of error between the formulae and experimental results is within 10%,which is significant for engineering applications.
文摘Prediction of weaning success from invasive mechanical ventilation remains a challenge in everyday clinical practice.Several prediction scores have been developed to guide success during spontaneous breathing trials to help with weaning decisions.These scores aim to provide a structured framework to support clinical judgment.However,their effectiveness varies across patient populations,and their predictive accuracy remains inconsistent.In this review,we aim to identify the strengths and limitations of commonly used clinical prediction tools in assessing readiness for ventilator liberation.While scores such as the Rapid Shallow Breathing Index and the Integrative Weaning Index are widely adopted,their sensitivity and specificity often fall short in complex clinical settings.Factors such as underlying disease pathophysiology,patient characteristics,and clinician subjectivity impact score performance and reliability.Moreover,disparities in validation across diverse populations limit generalizability.With growing interest in artificial intelligence(AI)and machine learning,there is potential for enhanced prediction models that integrate multidimensional data and adapt to individual patient profiles.However,current AI approaches face challenges related to interpretability,bias,and ethical implementation.This paper underscores the need for more robust,individualized,and transparent prediction systems and advocates for careful integration of emerging technologies into clinical workflows to optimize weaning success and patient outcomes.
基金support by Technology R&D Program of China State Railway Group Co.,Ltd(Grant number N2022J013)the Hunan Provincial Innovation Foundation for Postgraduate(Grant number CX20220279)+1 种基金the Fundamental Research Funds for the Central Universities of Central South University(Grant number 2022ZZTS0193)China Scholarship Council(202106370112)。
文摘During the train meeting events,train equipment compartments are exposed to the worst pressure changes,potentially affecting the ventilation performance of equipment,particularly for electrical facilities equipped with independent air ducts.In this paper,a two-step method is used for numerical computation:(1)obtaining the temporal and spatial transient node data of the flow field sections during the train-passing simulation and(2)using the data as the input data for the equipment compartment simulation.In addition,this paper also compares the difference in equipment ventilation between the single-train and trainpassing scenarios in real vehicle tests.The results indicate that the primary factors influencing ventilation effectiveness are the aerodynamic compression and deceleration of airflow induced by the other train's nose,as well as the instability of the external flow field in the wake of the other train.During train crossing,the air is forced into the air duct,with a maximum ratio of the airflow in-duct to the airflow out-duct reaching 3.2.The average mass flow falls below the rated mass flow for the converter.Compared to the rated air volume of converter,the maximum suppression rates obtained from testing and simulation are-24.5%and-16.8%,respectively.Compared to the single-train operation,the maximum suppression rates obtained from testing and simulation are-15%and-18%,respectively.These findings provide valuable insights into the design and operation of high-speed trains.
文摘The longitudinal ventilation strategy is commonly used for road tunnels in urban environment in Sweden.This is partly due to how tunnels in urban environment was planned and designed before the EU Directive[1](2004/54/EC)came in place.Even in new tunnels both to practical and economic reasons the use of longitudinal ventilation has been an outspoken demand from the Swedish road authority,SRA.Swedish law[2]requires that a risk analysis is carried out to demonstrate that an acceptable level of risk is achieved in the tunnels with longitudinal ventilation if there is a risk of queues.Otherwise transverse or semi-transverse ventilation strategy shall be used.During recent development,or a late awakening,it is clear that dense populated areas in Sweden will experience queues.This threatens the foundation of the Swedish modern tunnel safety concept which calls for enhancement.This paper presents the risk-reducing effect of three alternative strategies,enhancements package,focusing on evacuation safety for road users.It is a combination of traffic management,fixed firefighting systems,reduced distance between escape routes and regulation of traffic with dangerous goods.In addition,it provides a comprehensive review of safety system details,combined with a longitudinal ventilation concept.
文摘BACKGROUND Lung ultrasonography is being increasingly used in mechanically ventilated patients to evaluate the lung aeration during incremental positive end expiratory pressure(PEEP)adjustments and to evaluate the weaning process from mechanical ventilation.The effects of PEEP may vary across different lung pathologies and may not consistently correlate with changes in lung aeration as assessed by lung ultrasound scores(LUSs).AIM To assess the role of lung ultrasonography in evaluating lung aeration during the application of PEEP in mechanically ventilated patients with various lung pathologies.METHODS An observational study was conducted over 18 months in a tertiary care hospital.Patients of both genders,aged between 18-75 years,who had been admitted to the intensive care unit,and required mechanical ventilation,were studied.A standard ventilatory strategy was used and incremental levels of PEEP[5,10,and 15 cm water(H_(2)O)]were applied.Baseline characteristics,including oxygen saturation(SpO2),LUS,mean arterial pressure(MAP),heart rate(HR),and their changes with incremental PEEP levels,were recorded and analyzed.RESULTS In this study,45.9%of patients required a PEEP of 5 cm H_(2)O to achieve the endpoint of lung aeration(LUS of 0).In addition,86.5% and 13.5% of patients reached the endpoint of lung aeration at PEEP levels of 10 and 15 cm H_(2)O,respectively.The proportion of patients with higher lung scores decreased significantly with increasing PEEP levels(P<0.001 for 5 and 10 cm H_(2)O and P=0.032 for 15 cm H_(2)O).SpO2 increased significantly with higher PEEP levels(P<0.001),confirming the effectiveness of PEEP in improving oxygenation.The results also revealed a significant increase in HR and a decrease in MAP following the application of higher PEEP levels.CONCLUSION Increasing PEEP levels in mechanically ventilated patients improves lung aeration,which can be effectively assessed using bedside lung ultrasonography.
基金Sichuan Provincial Medical Scientific Research Project(Project No.:s19085)。
文摘Objective:To explore the role of lung ultrasound combined with multi-organ evaluation in assessing the risk of weaning from mechanical ventilation(MV)in severe patients.Methods:A retrospective analysis was conducted on 60 severe patients admitted to the hospital from December 2022 to December 2024,all of whom underwent MV treatment.Based on weaning status,thirty-eight patients were successfully weaned(success group),and 22 patients failed weaning(failure group).All patients underwent lung ultrasound and multi-organ evaluation.The parameter differences between the two groups were compared,risk factors for weaning risk were evaluated,and a receiver operating characteristic curve(ROC)was drawn to assess the predictive value of lung ultrasound combined with multi-organ evaluation for weaning risk.Results:The lung ultrasound score(LUS)of the success group was lower than that of the failure group,the left ventricular ejection fraction(LVEF)was higher than that of the failure group,and the diaphragmatic excursion(DE)and diaphragmatic thickening fraction(DTF)were higher than those of the failure group(P<0.05).Multifactor analysis showed that LUS was a risk factor for weaning risk,while LVEF,DE,and DTF were protective factors(P<0.05).The ROC showed that the area under the curve(AUC)of a single parameter for weaning risk was smaller than that of the combined parameters(P<0.05).Conclusion:Lung ultrasound combined with multi-organ evaluation can predict the weaning risk of severe patients undergoing MV treatment,and the diagnostic efficiency of multiple parameters combined evaluation is higher.
基金Funding Statement:This research was conducted as part of the Tech4You Project“Technologies for climate change adaptation and quality of life improvement”,n.ECS0000009,CUP H23C22000370006,Italian PNRR,Mission 4,Component 2,Investment 1.5 funded by the European Union-NextGenerationEU.
文摘Indoor air quality(IAQ)is often overlooked,yet a poorly maintained environment can lead to significant health issues and reduced concentration and productivity in work or educational settings.This study presents an innovative control system for mechanical ventilation specifically designed for university classrooms,with the dual goal of enhancing IAQ and increasing energy efficiency.Two classrooms with distinct construction characteristics were analyzed:one with exterior walls and windows,and the other completely underground.For each classroom,a model was developed using DesignBuilder software,which was calibrated with experimental data regarding CO_(2) concentration,temperature,and relative humidity levels.The proposed ventilation system operates based on CO_(2) concentration,relative humidity,and potential for free heating and cooling.In addition,the analysis was conducted for other locations,demonstrating consistent energy savings across different climates and environments,always showing an annual reduction in energy consumption.Results demonstrate that mechanical ventilation,when integrated with heat recovery and free cooling strategies,significantly reduces energy consumption by up to 25%,while also maintaining optimal CO_(2) levels to enhance comfort and air quality.These findings emphasize the essential need for well-designed mechanical ventilation systems to ensure both psychophysical well-being and IAQ in enclosed spaces,particularly in environments intended for extended occupancy,such as classrooms.Furthermore,this approach has broad applicability,as it could be adapted to various building types,thereby contributing to sustainable energy management practices and promoting healthier indoor spaces.This study serves as a model for future designs aiming to balance energy efficiency with indoor air quality,especially relevant in the post-COVID era,where the importance of indoor air quality has become more widely recognized.
文摘Objective:To investigate the predictive value of diaphragm thickening fraction(DTF)combined with cough peak expiratory flow(CPEF)on the success rate of weaning from mechanical ventilation.Methods:The clinical data of patients undergoing invasive mechanical ventilation via oral endotracheal intubation in the ICU of our hospital from January 2022 to December 2023 were studied.All patients underwent a 30-minute spontaneous breathing trial(SBT)using low-level pressure support ventilation(PSV)after meeting the clinical weaning screening criteria.Among them,150 patients who met the clinical weaning criteria were weaned from the ventilator.They were divided into a successful weaning group(n=100)and a failed weaning group(n=50)based on the weaning outcome.Clinical data,including age,gender,APACHE II score,duration of mechanical ventilation,DTF,and CPEF,were collected from 150 patients.The differences in clinical data between the two groups were compared,and the correlation between DTF,CPEF,and the success rate of weaning was analyzed.Results:There were no significant differences between the two groups in gender ratio(χ^(2)=0.884,P=0.347>0.05),age(t=0.350,P=0.727>0.05),and APACHE II score(t=1.295,P=0.197>0.05),but there was a significant difference in the duration of mechanical ventilation(t=3.766,P<0.001).The DTF and CPEF values in the successful weaning group were significantly higher than those in the failed weaning group(P<0.05).ROC curves were drawn to predict the weaning results using DTF,CPEF,and the combination of DTF and CPEF.The results showed that the specificity of the combination of DTF and CPEF was comparable to that of either metric alone,but the sensitivity and AUC were significantly higher than those of either metric alone.Conclusion:The combination of DTF and CPEF can be used as an effective indicator to evaluate the weaning efficacy of mechanically ventilated patients,which has important clinical significance for guiding clinical weaning treatment,improving the success rate of weaning,reducing the incidence of ventilator-associated pneumonia,and shortening the length of hospital stay.
基金supported by the Project of LI Ruiyu National Famous Traditional Chinese Medicine Expert Inheritance Studio(No.[2022]4 issued by the National Administration of Traditional Chinese Medicine and No.[2024]3 issued by Hebei Administration of Traditional Chinese Medicine)the Seventh Batch of National Academic Experience Inheritance Project for Senior Traditional Chinese Medicine Experts(No.[2022]76 issued by the National Administration of Traditional Chinese Medicinethe Scientific Research Project of Hebei Administration of Traditional Chinese Medicine(No.2025593).
文摘Objectives:To propose a new idea of“lung ventilation and Qi regulation”for preventing and treating lung cancer,and to summarize the corresponding Tongfei Huajie prescription,as a systematic theoretical and practical innovation.Methods:Based on the etiology and pathogenesis of lung cancer,the anatomy,physiology and pathology of the lung,and inspired by the ancient“Tuoyue”(bellows)theory,this study combined the clinical observation of ventilation issues in lung cancer patients.The Tongfei Huajie prescription was formulated following the classic principle of monarch(Jun),minister(Chen),assistant(Zuo),and guide(Shi),and was interpreted with modern pharmacological research.Results:A novel therapeutic concept of“lung ventilation and Qi regulation”was proposed.The corresponding Tongfei Huajie prescription was developed,which has the effects of ventilating the lung,expelling phlegm dampness,tonifying Qi,tonifying the kidney and spleen for lung health,soothing the liver and descending lung Qi,and clearing the heart and moistening the lung.Clinical application has achieved obvious curative effect.Conclusions:This work presents a systematic summary of the innovation in“theory,method,formula and herb”for lung cancer treatment,demonstrating the advantages of Traditional Chinese Medicine in this field.
文摘Carbon dioxide(CO_(2))is often monitored as a convenient yardstick for indoor air safety,yet its ability to stand in for pathogen-laden aerosols has never been settled.To probe the question,we reproduced an open-plan office at full scale(7.2m×5.2m×2.8m)and introduced a breathing plume that carried 4% CO_(2),together with a polydisperse aerosol spanning 0.5–10μm(1320 particles s^(−1)).Inlet air was supplied at 0.7,1.4,and 2.1 m s^(−1),and the resulting fields were simulated with a Realisable k–εRANS model coupled to Lagrangian particle tracking.Nine strategically placed probes provided validation;the calibrated solution deviated fromthe experiment by 58 ppm for CO_(2)(8.1%RMSE)and 0.008 m s^(−1)for velocity(15.7%RMSE).Despite this agreement,gas and particles behaved in sharply different ways.Room-averaged CO_(2)varied by<15%,whereas the aerosol mass rose to almost three-fold the background within slowmoving corner vortices.Sub-micron particles stayed aloft along streamlines,while those≥5μmpeeled away and settled on nearby surfaces.The divergence shows that neither the CO_(2)level nor themeanageof air,taken in isolation,delineates all high-exposure zones.We therefore recommend that ventilation design be informed by a composite diagnosis that couples gas data,size-resolved particle measurements,and rapid CFD appraisal.
基金Project(N2022G031)supported by the Science and Technology Research and Development Program Project of China RailwayProjects(2022-Key-23,2021-Special-01A)supported by the Science and Technology Research and Development Program Project of China Railway Group LimitedProject(52308419)supported by the National Natural Science Foundation of China。
文摘The breakage and bending of ducts result in a difficulty to cope with ventilation issues in bidirectional excavation tunnels with a long inclined shaft using a single ventilation method based on ducts.To discuss the hybrid ventilation system applied in bidirectional excavation tunnels with a long inclined shaft,this study has established a full-scale computational fluid dynamics model based on field tests,the Poly-Hexcore method,and the sliding mesh technique.The distribution of wind speed,temperature field,and CO in the tunnel are taken as indices to compare the ventilation efficiency of three ventilation systems(duct,duct-ventilation shaft,duct–ventilated shaft-axial fan).The results show that the hybrid ventilation scheme based on duct-ventilation shaft–axial fan performs the best among the three ventilation systems.Compared to the duct,the wind speed and cooling rate in the tunnel are enhanced by 7.5%–30.6%and 14.1%–17.7%,respectively,for the duct-vent shaft-axial fan condition,and the volume fractions of CO are reduced by 26.9%–73.9%.This contributes to the effective design of combined ventilation for bidirectional excavation tunnels with an inclined shaft,ultimately improving the air quality within the tunnel.
基金National Key R&D Program of China(2022YFC2503200,2022YFC2503201)National Natural Science Foundation of China(52074012,52204191)+5 种基金Anhui Provincial Natural Science Foundation(2308085J19)University Distinguished Youth Foundation of Anhui Province(2022AH020057)Anhui Province University Discipline(Major)Top Talent Academic Support Project(gxbjZD2022017)Funding for academic research activities of reserve candidates for academic and technological leaders in Anhui Province(2022H301)Independent Research fund of Key Laboratory of Industrial Dust Prevention and Control&Occupational Health and Safety,Ministry of Education(Anhui University of Science and Technology)(EK20211004)Graduate Innovation Fund of Anhui University of Science and Technology(2023CX1003).
文摘In order to study the problems of unreasonable airflow distribution and serious dust pollution in a heading surface,an experimental platform for forced ventilation and dust removal was built based on the similar principles.Through the similar experiment and numerical simulation,the distribution of airflow field in the roadway and the spatial and temporal evolution of dust pollution under the conditions of forced ventilation were determined.The airflow field in the roadway can be divided into three zones:jet zone,vortex zone and reflux zone.The dust concentration gradually decreases from the head to the rear of the roadway.Under the forced ventilation conditions,there is a unilateral accumulation of dust,with higher dust concentrations away from the ducts.The position of the equipment has an interception effect on the dust.The maximum error between the test value and the simulation result is 12.9%,which verifies the accuracy of the experimental results.The research results can provide theoretical guidance for the application of dust removal technology in coal mine.
文摘Driving pressure(ΔP)is a core therapeutic component of mechanical ventilation(MV).Varying levels ofΔP have been employed during MV depending on the type of underlying pathology and severity of injury.However,ΔP levels have also been shown to closely impact hard endpoints such as mortality.Considering this,conducting an in-depth review ofΔP as a unique,outcome-impacting therapeutic modality is extremely important.There is a need to understand the subtleties involved in making sureΔP levels are optimized to enhance outcomes and minimize harm.We performed this narrative review to further explore the various uses ofΔP,the different parameters that can affect its use,and how outcomes vary in different patient populations at different pressure levels.To better utilizeΔP in MV-requiring patients,additional large-scale clinical studies are needed.
文摘BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease(AECOPD)is often combined with respiratory failure,which increases the patient's morbidity and mortality.Diaphragm ultrasound(DUS)has developed rapidly in the field of critical care in recent years.Studies with DUS monitoring diaphragm-related rapid shallow breathing index have demonstrated important results in guiding intensive care unit patients out of the ventilator.Early prediction of the indications for withdrawal of non-invasive ventilator and early evaluation of patients to avoid or reduce disease progression are very important.AIM To explore the predictive value of DUS indexes for non-invasive ventilation outcome in patients with AECOPD.METHODS Ninety-four patients with AECOPD who received mechanical ventilation in our hospital from January 2022 to December 2023 were retrospectively analyzed,and they were divided into a successful ventilation group(68 cases)and a failed ventilation group(26 cases)according to the outcome of ventilation.The clinical data of patients with successful and failed noninvasive ventilation were compared,and the independent predictors of noninvasive ventilation outcomes in AECOPD patients were identified by multivariate logistic regression analysis.RESULTS There were no significant differences in gender,age,body mass index,complications,systolic pressure,heart rate,mean arterial pressure,respiratory rate,oxygen saturation,partial pressure of oxygen,oxygenation index,or time of inspiration between patients with successful and failed mechanical ventilation(P>0.05).The patients with successful noninvasive ventilation had shorter hospital stays and lower partial pressure of carbon dioxide(PaCO_(2))than those with failed treatment,while potential of hydrogen(pH),diaphragm thickening fraction(DTF),diaphragm activity,and diaphragm movement time were significantly higher than those with failed treatment(P<0.05).pH[odds ratio(OR)=0.005,P<0.05],PaCO_(2)(OR=0.430,P<0.05),and DTF(OR=0.570,P<0.05)were identified to be independent factors influencing the outcome of mechanical ventilation in AECOPD patients.CONCLUSION The DUS index DTF can better predict the outcome of non-invasive ventilation in AECOPD patients.
文摘BACKGROUND Laparoscopic-assisted radical gastrectomy(LARG)is the standard treatment for early-stage gastric carcinoma(GC).However,the negative impact of this proce-dure on respiratory function requires the optimized intraoperative management of patients in terms of ventilation.AIM To investigate the influence of pressure-controlled ventilation volume-guaranteed(PCV-VG)and volume-controlled ventilation(VCV)on blood gas analysis and pulmonary ventilation in patients undergoing LARG for GC based on the lung ultrasound score(LUS).METHODS The study included 103 patients with GC undergoing LARG from May 2020 to May 2023,with 52 cases undergoing PCV-VG(research group)and 51 cases undergoing VCV(control group).LUS were recorded at the time of entering the operating room(T0),20 minutes after anesthesia with endotracheal intubation(T1),30 minutes after artificial pneumoperitoneum(PP)establishment(T2),and 15 minutes after endotracheal tube removal(T5).For blood gas analysis,arterial partial pressure of oxygen(PaO_(2))and partial pressure of carbon dioxide(PaCO_(2))were observed.Peak airway pressure(P_(peak)),plateau pressure(Pplat),mean airway pressure(P_(mean)),and dynamic pulmonary compliance(C_(dyn))were recorded at T1 and T2,1 hour after PP establishment(T3),and at the end of the operation(T4).Postoperative pulmonary complications(PPCs)were recorded.Pre-and postoperative serum interleukin(IL)-1β,IL-6,and tumor necrosis factor-α(TNF-α)were measured by enzyme-linked immunosorbent assay.RESULTS Compared with those at T0,the whole,anterior,lateral,posterior,upper,lower,left,and right lung LUS of the research group were significantly reduced at T1,T2,and T5;in the control group,the LUS of the whole and partial lung regions(posterior,lower,and right lung)decreased significantly at T2,while at T5,the LUS of the whole and some regions(lateral,lower,and left lung)increased significantly.In comparison with the control group,the whole and regional LUS of the research group were reduced at T1,T2,and T5,with an increase in PaO_(2),decrease in PaCO_(2),reduction in P_(peak) at T1 to T4,increase in P_(mean) and C_(dyn),and decrease in Pplat at T4,all significant.The research group showed a significantly lower incidence of PPCs than the control group within 3 days postoperatively.Postoperative IL-1β,IL-6,and TNF-αsignificantly increased in both groups,with even higher levels in the control group.CONCLUSION LUS can indicate intraoperative non-uniformity and postural changes in pulmonary ventilation under PCV-VG and VCV.Under the lung protective ventilation strategy,the PCV-VG mode more significantly improved intraop-erative lung ventilation in patients undergoing LARG for GC and reduced lung injury-related cytokine production,thereby alleviating lung injury.
文摘BACKGROUND Dexmedetomidine and propofol are two sedatives used for long-term sedation.It remains unclear whether dexmedetomidine provides superior cerebral protection for patients undergoing long-term mechanical ventilation.AIM To compare the neuroprotective effects of dexmedetomidine and propofol for sedation during prolonged mechanical ventilation in patients without brain injury.METHODS Patients who underwent mechanical ventilation for>72 h were randomly assigned to receive sedation with dexmedetomidine or propofol.The Richmond Agitation and Sedation Scale(RASS)was used to evaluate sedation effects,with a target range of-3 to 0.The primary outcomes were serum levels of S100-βand neuron-specific enolase(NSE)every 24 h.The secondary outcomes were remifentanil dosage,the proportion of patients requiring rescue sedation,and the time and frequency of RASS scores within the target range.RESULTS A total of 52 and 63 patients were allocated to the dexmedetomidine group and propofol group,respectively.Baseline data were comparable between groups.No significant differences were identified between groups within the median duration of study drug infusion[52.0(IQR:36.0-73.5)h vs 53.0(IQR:37.0-72.0)h,P=0.958],the median dose of remifentanil[4.5(IQR:4.0-5.0)μg/kg/h vs 4.6(IQR:4.0-5.0)μg/kg/h,P=0.395],the median percentage of time in the target RASS range without rescue sedation[85.6%(IQR:65.8%-96.6%)vs 86.7%(IQR:72.3%-95.3),P=0.592],and the median frequency within the target RASS range without rescue sedation[72.2%(60.8%-91.7%)vs 73.3%(60.0%-100.0%),P=0.880].The proportion of patients in the dexmedetomidine group who required rescue sedation was higher than in the propofol group with statistical significance(69.2%vs 50.8%,P=0.045).Serum S100-βand NSE levels in the propofol group were higher than in the dexmedetomidine group with statistical significance during the first six and five days of mechanical ventilation,respectively(all P<0.05).CONCLUSION Dexmedetomidine demonstrated stronger protective effects on the brain compared to propofol for long-term mechanical ventilation in patients without brain injury.
文摘BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease(AECOPD)is a serious complication of chronic obstructive pulmonary disease,often characterized by increased morbidity and mortality.In traditional Chinese medicine,AECOPD is linked to phlegm-heat and blood-stasis,presenting symptoms like thick sputum,fever,and chest pain.It has been shown that acetylcysteine inhalation in conjunction with conventional therapy significantly reduced inflammatory markers and improved lung function parameters in patients with AECOPD,suggesting that acetylcysteine may be an important adjunctive therapy for patients with phlegm-heat-blood stasis type AECOPD.AIM To investigate the effect of acetylcysteine on microinflammation and lung ventilation in patients with phlegm-heat and blood-stasis-type AECOPD.METHODS One hundred patients with phlegm-heat and blood-stasis-type AECOPD were randomly assigned to two groups.The treatment group received acetylcysteine inhalation(10%solution,5 mL,twice daily)along with conventional therapy,whereas the control group received only conventional therapy.The treatment duration was 14 d.Inflammatory markers(C-reactive protein,interleukin-6,and tumor necrosis factor-alpha)in the serum and sputum as well as lung function parameters(forced expiratory volume in one second,forced vital capacity,and peak expiratory flow)were assessed pre-and post-treatment.Acetylcysteine inhalation led to significant reductions in inflammatory markers and improvements in lung function parameters compared to those in the control group(P<0.05).This suggests that acetylcysteine could serve as an effective adjunct therapy for patients with phlegm-heat and blood-stasis-type AECOPD.RESULTS Acetylcysteine inhalation significantly reduced inflammatory markers in the serum and sputum and improved lung ventilation function parameters in patients with phlegm-heat and blood-stasis type AECOPD compared with the control group.These differences were statistically significant(P<0.05).The study concluded that acetylcysteine inhalation had a positive effect on microinflammation and lung ventilation function in patients with this type of AECOPD,suggesting its potential as an adjuvant therapy for such cases.CONCLUSION Acetylcysteine inhalation demonstrated significant improvements in reducing inflammatory markers in the serum and sputum,as well as enhancing lung ventilation function parameters in patients with phlegm-heat and bloodstasis type AECOPD.These findings suggest that acetylcysteine could serve as a valuable adjuvant therapy for individuals with this specific type of AECOPD,offering benefits for managing microinflammation and optimizing lung function.
