Mechanical Ventilation Strategies Research Articles

Transpulmonary Pressure-Guided Mechanical Ventilation in Severe Acute Respiratory Distress Syndrome in PICU: Single-Center Retrospective Study in North India, 2018–2021

Objectives: In this study, we have reviewed the association between esophageal pressure-guided positive end-expiratory pressure (PEEP) setting and oxygenation and lung mechanics with a conventional mechanical ventilation (MV) strategy in patient with moderate to severe pediatric acute respiratory distress syndrome (PARDS). Design: Retrospective cohort, 2018–2021. Setting: Tertiary PICU. Patients: Moderate to severe PARDS patients who required MV with PEEP of greater than or equal to 8 cm H2O. Interventions: Esophageal pressure (i.e., transpulmonary pressure [PTP]) guided MV vs. not. Measurements and Main Results: We identified 26 PARDS cases who were divided into those who had been managed with PTP-guided MV (PTP group) and those managed with conventional ventilation strategy (non-PTP). Oxygenation and lung mechanics were compared between groups at baseline (0 hr) and 24, 48, and 72 hours of MV. There were 13 patients in each group in the first 24 hours. At 48 and 72 hours, there were 11 in PTP group and 12 in non-PTP group. On comparing these groups, first, use of PTP monitoring was associated with higher median (interquartile range) mean airway pressure at 24 hours (18 hr [18–20 hr] vs. 15 hr [13–18 hr]; p = 0.01) and 48 hours (19 hr [17–19 hr] vs. 15 hr [13–17 hr]; p = 0.01). Second, use of PTP was associated with higher PEEP at 24, 48, and 72 hours (all p < 0.05). Third, use of PTP was associated with lower Fio 2 and greater Pao 2 to Fio 2 ratio at 72 hours. Last, there were 18 of 26 survivors, and we failed to identify an association between use of PTP monitoring and survival. Conclusions: In this cohort of moderate to severe PARDS cases undergoing MV with PEEP greater than or equal to 8 cm H2O, we have identified some favorable associations of oxygenation status when PTP-guided MV was used vs. not. Larger studies are required.

Mechanical ventilation settings during weaning from venovenous extracorporeal membrane oxygenation

BackgroundThe optimal timing of weaning from venovenous extracorporeal membrane oxygenation (VV ECMO) and its modalities have been rarely studied.MethodsRetrospective, multicenter cohort study over 7 years in two tertiary ICUs, high-volume ECMO centers in France and Italy. Patients with ARDS on ECMO and successfully weaned from VV ECMO were classified based on their mechanical ventilation modality during the sweep gas-off trial (SGOT) with either controlled mechanical ventilation or spontaneous breathing (i.e. pressure support ventilation). The primary endpoint was the time to successful weaning from mechanical ventilation within 90 days post-ECMO weaning.Results292 adult patients with severe ARDS were weaned from controlled ventilation, and 101 were on spontaneous breathing during SGOT. The 90-day probability of successful weaning from mechanical ventilation was not significantly different between the two groups (sHR [95% CI], 1.23 [0.84–1.82]). ECMO-related complications were not statistically different between patients receiving these two mechanical ventilation strategies. After adjusting for covariates, older age, higher pre-ECMO sequential organ failure assessment score, pneumothorax, ventilator-associated pneumonia, and renal replacement therapy, but not mechanical ventilation modalities during SGOT, were independently associated with a lower probability of successful weaning from mechanical ventilation after ECMO weaning.ConclusionsTime to successful weaning from mechanical ventilation within 90 days post-ECMO was not associated with the mechanical ventilation strategy used during SGOT. Further research is needed to assess the optimal ventilation strategy during weaning off VV ECMO and its impact on short- and long-term outcomes.

Mapping a Decade (2014-2024) of Research on Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome: A Visual Analysis with CiteSpace and VOSviewer.

Acute Respiratory Distress Syndrome (ARDS) stands as a primary cause of mortality among critically ill patients. Extracorporeal Membrane Oxygenation (ECMO) is increasingly employed in the rescue therapy of ARDS patients. However, the current status of research in the field of ECMO-assisted ARDS remains unclear. This research aims to categorize and evaluate the literature regarding Extracorporeal Membrane Oxygenation (ECMO) support for Acute Respiratory Distress Syndrome (ARDS), offering a comprehensive analysis of bibliometric properties, research hotspots, and developmental trends within the domain of ECMO-assisted ARDS. A literature search was conducted for ECMO-assisted support for patients with ARDS in the Web of Science Core Collection (WoSCC) database from 2014 to 2024. We employed visualization tools such as CiteSpace and VOSviewer to explore and assess connections among nations, institutions, researchers, and co-cited journals, authors, references, and keywords. This study included 1739 publications. The United States leads in publication volume with Columbia University at the forefront of ECMO research. Intensive Care Medicine has been identified as the most cited journal in this field. Alain Combes from France stands out as a key contributor, particularly in his 2018 publication in the New England Journal of Medicine, which is the most cited work in the discipline. Furthermore, keyword analysis identified three distinct research phases: examining complications associated with ECMO therapy, exploring optimal strategies for mechanical ventilation under ECMO support, and compiling insights into the application of ECMO in treating COVID-19 patients and in the development of predictive models for patient outcomes. Using bibliometric visualization techniques, this study revealed significant progress in the use of ECMO for treating ARDS respiratory support, evaluated the impact of these findings, and outlined potential areas for future studies.

Comparing mechanical ventilation control strategies for indoor air quality: Monitoring and simulation results of a school building in northern Italy

Demand-controlled ventilation systems and carbon dioxide monitoring are critical to ensure indoor air quality (IAQ) comfort conditions. Their importance has become significantly more evident since the COVID-19 pandemic crisis. Control strategies for mechanical ventilation based on CO2 concentration are commonly used, although they are rarely applied in Italian and other Southern European country schools. Moreover, optimised ventilation systems can help maintain indoor air quality while reducing energy consumption for heating (i.e. exploiting heat recovery). The proposed paper aims to compare different remote-control strategies to manage three detached mechanical ventilation units (DMV) installed in a junior-high-school demo building in Torre Pellice (Northwest Italy), monitored with room detail since April 2021. Eight IAQ control logics are analysed considering both in situ tests, handling DMV accordingly to room sensors, and simulation tests using the Energy Management System of EnergyPlus in the neutral season. All different solutions are compared by considering air quality, temperature, and energy need indicators. Additionally, a yearly energy verification via hourly simplified analyses is performed by considering fan consumption and energy conservation. Threshold-based control logics result to be more effective than time-dependent ones, while all cases guarantee very high IAQ levels, although energy savings are limited. The choice of the correct control threshold(s) is site-dependent being influenced by user local habits.

Visualization method of mechanical power exposure intensity and duration in mechanical ventilation patients

To visualize the relationship between different combinations of mechanical power exposure intensity-duration and death risk in mechanical ventilation patients using a visualization method. Critically ill patients receiving mechanical ventilation were selected from the Medical Information Mart for Intensive Care- IV v1.0 (MIMIC- IV v1.0) database. The patients were divided into four subgroups according to oxygenation index (PaO2/FiO2) including > 300 mmHg (1 mmHg ≈ 0.133 kPa) group, 201-300 mmHg group, 101-200 mmHg group and ≤100 mmHg group. The baseline characteristics, ventilator parameters, and prognostic indicators for different patient populations were collected. For each patient, the mechanical power thresholds from low to high (5-30 J/min, increasing at intervals of 1 J/min) were used to evaluate the different exposures of mechanical power (above the set threshold was recorded as one exposure), and the number of events with different exposure intensity-duration combinations was counted based on their corresponding durations. Based on the 28-day survival/non-survival status, the number of exposures for survivors and non-survivors in each exposure intensity-duration combination was calculated, and the survival odds ratio (OR) for different mechanical power exposure intensity-duration combinations was subsequently computed. Two-dimensional tables were generated with mechanical power exposure duration on the x-axis and exposure intensity on the y-axis, and the heatmap and its corresponding equipotential line view were used to visualize the OR value to assess the risk of death. A total of 5 378 patients receiving mechanical ventilation were enrolled in the study, of whom 2 069 patients in the PaO2/FiO2 > 300 mmHg group, 813 patients in the 201-300 mmHg group, 1 493 patients in the 101-200 mmHg group, and 1 003 patients in the ≤100 mmHg group. The severity scores of patients, including sequential organ failure assessment (SOFA) score and simplified acute physiology score II (SAPS II), gradually increased following the decrease in PaO2/FiO2, and the incidence of co-morbidities also gradually increased. In terms of ventilator parameters, mechanical power was increased gradually with decrease in PaO2/FiO2, measuring 10.4 (7.8, 13.9), 11.3 (8.5, 14.7), 13.6 (10.0, 18.2), and 16.7 (12.5, 22.0) J/min (P < 0.01). In terms of prognosis, 28-day mortality of patients was gradually increased with decrease in PaO2/FiO2 [29.1% (601/2 069), 26.9% (219/813), 28.1% (420/1 493), and 33.3% (334/1 003), respectively, P < 0.05]. In the heatmap, it could be observed that the 28-day death risk of mechanical ventilation patients was gradually increased with increase in mechanical power exposure intensity and long duration, showing two distinct areas: a region near the bottom left corner (representing low mechanical power exposure intensity and short duration) was blue, indicating a greater chance of survival. In contrast, another region near the top right corner (representing high mechanical power exposure intensity and long duration) was red, indicating a higher risk of death. According to the fitted lines of death risk, for the same risk of death, a shorter mechanical power exposure duration was required for higher exposure intensity, while lower mechanical power exposure intensity required a longer exposure duration. The above trend of change was similarly reflected in the overall population and different oxygenation populations. Cumulative mechanical power exposure to higher intensity and/or longer duration is associated with worse outcomes in mechanical ventilation patients. Considering both the mechanical power exposure intensity and duration may help to evaluate the effectiveness of lung protection in mechanical ventilation patients and guide adjustments in mechanical ventilation strategy to reduce the risk of ventilator-induced lung injury.

Diaphragmatic Herniation with Pneumothorax Due to Barotrauma – Lessons to Learn: A Case Report

Diaphragmatic hernia is usually congenital or follows thoracoabdominal injury. Diaphragmatic hernia combined with pneumothorax is a rare combination in the clinical setting, where pneumothorax is usually secondary to hollow viscera perforation in the long-term complications of diaphragmatic herniation or rupture of ectopic endometrium over the diaphragm during menstruation. Unlike the aforementioned conditions, we describe a 67-year-old man with chronic diaphragmatic hernia who suffered from pneumothorax and pneumoperitoneum secondary to pulmonary bulla by barotrauma during mechanical ventilation. Computed tomography showed scattered free gas in the thoracic and abdominal cavities, while there was no tenderness and rebound tenderness. The patient was managed conservatively with low PEEP and a lung-protective mechanical ventilation strategy. Finally, the oxygenation index gradually rose from 58 to 107. Unfortunately, in light of the patient’s poor clinical status and significant comorbidities, the patient passed away peacefully 3 weeks after hospital admission. Diaphragmatic hernia combined with pneumothorax should be differentiated from tension pneumothorax. Whether to intubate chest drainage depends on the cause of pneumothorax and pneumoperitoneum, as well as the risks and benefits of chest drainage. Additionally, mechanical ventilation should be applied cautiously, and respiratory parameters should be adjusted reasonably in patients at high risk of pneumothorax.

Inhibition of aquaporin-9 ameliorates severe acute pancreatitis and associated lung injury by NLRP3 and Nrf2/HO-1 pathways

Inflammation, apoptosis and oxidative stress play crucial roles in the deterioration of severe acute pancreatitis-associated acute respiratory distress syndrome (SAP-ARDS). Unfortunately, despite a high mortality rate of 45 %[1], there are limited treatment options available for ARDS outside of last resort options such as mechanical ventilation and extracorporeal support strategies[2]. This study investigated the potential therapeutic role and mechanisms of AQP9 inhibitor RG100204 in two animal models of severe acute pancreatitis, inducing acute respiratory distress syndrome: 1) a sodium-taurocholate induced rat model, and 2) and Cerulein and lipopolysaccharide induced mouse model. RG100204 treatment led to a profound reduction in inflammatory cytokine expression in pancreatic, and lung tissue, in both models. In addition, infiltration of CD68 + and CD11b + cells into these tissues were reduced in RG100204 treated SAP animals, and edema and SAP associated tissue damage were improved. Moreover, we demonstrate that RG100204 reduced apoptosis in the lungs of rat SAP animals, and reduces NF-κB signaling, NLRP3, expression, while profoundly increasing the Nrf2-dependent anti oxidative stress response. We conclude that AQP9 inhibition is a promising strategy for the treatment of pancreatitis and its systemic complications, such as ARDS.

Analysis of compliance with lung protective mechanical ventilation strategy in patients with acute respiratory distress syndrome

Objective: To assess the compliance with a lung protective ventilation strategy and to evaluate the relationship with prognosis in patients with acute respiratory distress syndrome (ARDS). Methods: In the prospective multicenter cohort study (CHARDS), patients with ARDS undergoing invasive mechanical ventilation were enrolled to collect essential information, mechanical ventilation data, and prognostic data. Compliance was operationally defined as tidal volume ≤7 ml/kg predicted body weight (PBW) or plateau pressure ≤30 cmH2O or driving pressure≤15 cmH2O. Tidal volume data collected 7 days prior to ventilation after ARDS diagnosis were categorized into four groups: standard group (Group A, 100% compliance), non-standard group (Group B, 50%-99% compliance, Group C,1%-49% compliance,and Group D,totally non-compliant). Plateau pressure and drive pressure measurements were recorded on the first day. Stepwise regression, specifically Logistics regression, was used to identify the factors influencing ICU survival. Results: A total of 449 ARDS patients with invasive mechanical ventilation were included; the proportion of mild, moderate, and severe patients was 71 (15.8%), 198 (44.1%) and 180 (40.1%), respectively. During the first 7 days, a total of 2880 tidal volume measurements were recorded with an average tidal volume of (6.89±1.93) ml/kg PBW. Of these measurements, 53.2% were found to be≤7 ml/kg PBW. The rates of compliance with lung protective mechanical ventilation were 29.8% (134/449), 24.5% (110/449), 23.6% (106/449), and 22% (99/449) in groups A, B, C, and D, respectively. In the standard group, the tidal volume for mild ARDS patients was 18.3%(13/71), while it was 81.7%(58/71)in the non-standard group. Similarly, in patients with moderate ARDS, the tidal volume was 25.8% (51/198) in the standard group, while it was 74.2% (147/198) in the non-standard group. Finally, in patients with severe ARDS, the tidal volume was 38.9% (70/180) in the standard group, while it was 61.1% (110/180) in the non-standard group. Notably, the compliance rate was higher in patients with moderate and severe ARDS in group A compared to patients with mild and moderate ARDS (18.3% vs. 25.8% vs. 38.9%, χ2=13.124, P=0.001). Plateau pressure was recorded in 221 patients, 95.9% (212/221) patients with plateau pressure≤30 cmH2O, and driving pressure was recorded in 207 patients, 77.8% (161/207) patients with a driving pressure ≤15 cmH2O.During the first 7 days, the mortality rate in the intensive care unit (ICU) was lower in the tidal volume standard group compared to the non-standard group (34.6% vs. 51.3%, χ2=10.464, P=0.001). In addition, the in-hospital mortality rate was lower in the standard group compared to the non-standard group (39.8% vs. 57%, χ2=11.016, P=0.001).The results of the subgroup analysis showed that the mortality rates of moderate and severe ARDS patients in the standard group were significantly lower than those in the non-standard group, both in the ICU and in the hospital (all P<0.05). However, there was no statistically significant difference in mortality among mild ARDS patients (all P>0.05). Conclusions: There was high compliance with recommended lung protective mechanical ventilation strategies in ARDS patients, with slightly lower compliance in patients with mild ARDS, and high compliance rates for plateau and drive pressures. The tidal volume full compliance group had a lower mortality than the non-compliance group, and showed a similar trend in the moderate-to-severe ARDS subgroup, but there was no significant correlation between compliance and prognosis in patients with mild ARDS subgroup.

Personalized mechanical ventilation guided by ultrasound in patients with acute respiratory distress syndrome (PEGASUS): study protocol for an international randomized clinical trial

BackgroundAcute respiratory distress syndrome (ARDS) is a frequent cause of hypoxemic respiratory failure with a mortality rate of approximately 30%. Identifying ARDS subphenotypes based on “focal” or “non-focal” lung morphology has the potential to better target mechanical ventilation strategies of individual patients. However, classifying morphology through chest radiography or computed tomography is either inaccurate or impractical. Lung ultrasound (LUS) is a non-invasive bedside tool that can accurately distinguish “focal” from “non-focal” lung morphology. We hypothesize that LUS-guided personalized mechanical ventilation in ARDS patients leads to a reduction in 90-day mortality compared to conventional mechanical ventilation.MethodsThe Personalized Mechanical Ventilation Guided by UltraSound in Patients with Acute Respiratory Distress Syndrome (PEGASUS) study is an investigator-initiated, international, randomized clinical trial (RCT) that plans to enroll 538 invasively ventilated adult intensive care unit (ICU) patients with moderate to severe ARDS. Eligible patients will receive a LUS exam to classify lung morphology as “focal” or “non-focal”. Thereafter, patients will be randomized within 12 h after ARDS diagnosis to receive standard care or personalized ventilation where the ventilation strategy is adjusted to the morphology subphenotype, i.e., higher positive end-expiratory pressure (PEEP) and recruitment maneuvers for “non-focal” ARDS and lower PEEP and prone positioning for “focal” ARDS. The primary endpoint is all-cause mortality at day 90. Secondary outcomes are mortality at day 28, ventilator-free days at day 28, ICU length of stay, ICU mortality, hospital length of stay, hospital mortality, and number of complications (ventilator-associated pneumonia, pneumothorax, and need for rescue therapy). After a pilot phase of 80 patients, the correct interpretation of LUS images and correct application of the intervention within the safe limits of mechanical ventilation will be evaluated.DiscussionPEGASUS is the first RCT that compares LUS-guided personalized mechanical ventilation with conventional ventilation in invasively ventilated patients with moderate and severe ARDS. If this study demonstrates that personalized ventilation guided by LUS can improve the outcomes of ARDS patients, it has the potential to shift the existing one-size-fits-all ventilation strategy towards a more individualized approach.Trial registrationThe PEGASUS trial was registered before the inclusion of the first patient, https://clinicaltrials.gov/ (ID: NCT05492344).

Designing a Bayesian adaptive clinical trial to evaluate novel mechanical ventilation strategies in acute respiratory failure using integrated nested Laplace approximations

BackgroundAdaptive trials usually require simulations to determine values for design parameters, demonstrate error rates, and establish the sample size. We designed a Bayesian adaptive trial comparing ventilation strategies for patients with acute hypoxemic respiratory failure using simulations. The complexity of the analysis would usually require computationally expensive Markov Chain Monte Carlo methods but this barrier to simulation was overcome using the Integrated Nested Laplace Approximations (INLA) algorithm to provide fast, approximate Bayesian inference. MethodsWe simulated two-arm Bayesian adaptive trials with equal randomization that stratified participants into two disease severity states. The analysis used a proportional odds model, fit using INLA. Trials were stopped based on pre-specified posterior probability thresholds for superiority or futility, separately for each state. We calculated the type I error and power across 64 scenarios that varied the probability thresholds and the initial minimum sample size before commencing adaptive analyses. Two designs that maintained a type I error below 5%, a power above 80%, and a feasible mean sample size were evaluated further to determine the optimal design. ResultsPower generally increased as the initial sample size and the futility threshold increased. The chosen design had an initial recruitment of 500 and a superiority threshold of 0.9925, and futility threshold of 0.95. It maintained high power and was likely to reach a conclusion before exceeding a feasible sample size. ConclusionsWe designed a Bayesian adaptive trial to evaluate novel strategies for ventilation using the INLA algorithm to efficiently evaluate a wide range of designs through simulation.

Experimental study of ambient temperature and humidity distribution in large multi-span greenhouse based on different crop heights and ventilation conditions

Analyzing the distribution of temperature and humidity within a greenhouse is essential for optimizing ventilation strategies and improving crop quality and yield. The temperature and humidity distribution of eight-span greenhouse under natural ventilation and mechanical ventilation is studied experimentally. The influence of different crop height on temperature and humidity distribution in greenhouse and the influence of different mechanical ventilation strategies on temperature regulation were discussed. The results showed that the temperature difference between inside and outside the greenhouse decreased with the increase of crop height. Under natural ventilation conditions, the soil surface temperature is the highest, and the temperature at 0.5 m above the surface is the lowest, with the maximum temperature difference of 0.9 ℃. The temperature in the greenhouse was higher in the west and lower in the east, and the temperature difference decreased with the increase of crop height. In the east–west direction, the maximum temperature difference between tall crops, short crops and non-planted crops was 0.7 ℃, 0.9 ℃ and 1.0 ℃, respectively. High crops increase the relative humidity in the greenhouse and increase the uneven distribution of relative humidity. When growing tall crops, the difference between indoor and outdoor relative humidity is only 2.3 %. When the external shade and fan are turned on at the same time, the cooling effect is the best, the energy consumption is lower, and the temperature distribution is the most uniform. The results provide a valuable reference for optimizing greenhouse structure, formulating ventilation strategy and reducing agricultural energy consumption.

Severe Community-Acquired Pneumonia: Noninvasive Mechanical Ventilation, Intubation, and HFNT.

Severe acute respiratory failure (ARF) is a major issue in patients with severe community-acquired pneumonia (CAP). Standard oxygen therapy is the first-line therapy for ARF in the less severe cases. However, respiratory supports may be delivered in more severe clinical condition. In cases with life-threatening ARF, invasive mechanical ventilation (IMV) will be required. Noninvasive strategies such as high-flow nasal therapy (HFNT) or noninvasive ventilation (NIV) by either face mask or helmet might cover the gap between standard oxygen and IMV. The objective of all the supporting measures for ARF is to gain time for the antimicrobial treatment to cure the pneumonia. There is uncertainty regarding which patients with severe CAP are most likely to benefit from each noninvasive support strategy. HFNT may be the first-line approach in the majority of patients. While NIV may be relatively contraindicated in patients with excessive secretions, facial hair/structure resulting in air leaks or poor compliance, NIV may be preferable in those with increased work of breathing, respiratory muscle fatigue, and congestive heart failure, in which the positive pressure of NIV may positively impact hemodynamics. A trial of NIV might be considered for select patients with hypoxemic ARF if there are no contraindications, with close monitoring by an experienced clinical team who can intubate patients promptly if they deteriorate. In such cases, individual clinician judgement is key to choose NIV, interface, and settings. Due to the paucity of studies addressing IMV in this population, the protective mechanical ventilation strategies recommended by guidelines for acute respiratory distress syndrome can be reasonably applied in patients with severe CAP.

Progress in the relationship between mechanical ventilation parameters and ventilator-related complications during perioperative anesthesia.

Mechanical ventilation, as an important respiratory support, plays an important role in general anesthesia and it is the cornerstone of intraoperative management of surgical patients. Different from spontaneous respiration, intraoperative mechanical ventilation can lead to postoperative lung injury, and its impact on surgical mortality cannot be ignored. Postoperative lung injury increases hospital stay and is related to preoperative conditions, anesthesia time, and intraoperative ventilation settings. Through reading literature and research reports, the relationship between perioperative input parameters and output parameters related to mechanical ventilation and ventilator-related complications was reviewed, providing reference for the subsequent setting of input parameters of mechanical ventilation and new ventilation strategies. The parameters of inspiratory pressure rise time and inspiratory time can change the gas distribution, gas flow rate and airway pressure into the lungs, but there are few clinical studies on them. It can be used as a prospective intervention to study the effect of specific protective ventilation strategies on pulmonary complications after perioperative anesthesia. There are many factors affecting lung function after perioperative mechanical ventilation. Due to the difference of human body, the ventilation parameters suitable for each patient are different, and the deviation of each ventilation parameter can lead to postoperative pulmonary complications. Inspiratory pressure rise time and inspiratory time will be used as the new ventilation strategy.

Incidence of circular refurbishment measures on indoor air quality and comfort conditions in two real buildings: Experimental and numerical analysis

The application of Circular Economy to construction sector is a key to attain carbon neutrality, since it is responsible of 40 % of natural resource consumption. In this frame the importance of an efficient building refurbishment process throughout recycled material and renewable energy is fundamental. From an overview about building refurbishment emerges the need to investigate aspects related to Indoor Environmental Quality and the comparison between in-field measurements with output of dynamic simulation models. The present study aims to fill these two gaps by means an energy renovation of two real buildings in Greece. The work develops within the European project “Drive 0″, born to promote deep environmentally friendly retrofitting by means of circular renovation concepts. The methodological approach involves on-site monitoring of a series of parameters describing the energy, microclimate environmental and air quality, before and after the energy requalification. In addition, a numerical model developed in Building Energy Simulation program is calibrated and a Computational Fluid Dynamics is developed. From the in-field measurements emerges that, on one hand, the refurbishment of heating system shows a great improvement of indoor thermal conditions, with Total Volatile Organic Compounds concentration that sometimes exceed 3.0 mg/m3; on the other hand an integrated thermal insulation reduces infiltrations and changes the envelope behaviour, with a global energy saving of 30 % during winter and autumn periods.Another result of the study shows that a numerical model developed in Building Energy Simulation program and calibrated on energy consumption can greatly fit the local thermal comfort distribution of the occupant zone and predict the indoor air quality, if it outputs are used as input data in a Computational Fluid Dynamics study. These results can be beneficial to decision makers and designers for evaluating emitters positioning, opening design and mechanical ventilation strategies, aimed at reducing energy costs.

Tiny Guides, Big Impact: Focus on the Opportunities and Challenges of miR-Based Treatments for ARDS.

Acute Respiratory Distress Syndrome (ARDS) is characterized by lung inflammation and increased membrane permeability, which represents the leading cause of mortality in ICUs. Mechanical ventilation strategies are at the forefront of supportive approaches for ARDS. Recently, an increasing understanding of RNA biology, function, and regulation, as well as the success of RNA vaccines, has spurred enthusiasm for the emergence of novel RNA-based therapeutics. The most common types of RNA seen in development are silencing (si)RNAs, antisense oligonucleotide therapy (ASO), and messenger (m)RNAs that collectively account for 80% of the RNA therapeutics pipeline. These three RNA platforms are the most mature, with approved products and demonstrated commercial success. Most recently, miRNAs have emerged as pivotal regulators of gene expression. Their dysregulation in various clinical conditions offers insights into ARDS pathogenesis and offers the innovative possibility of using microRNAs as targeted therapy. This review synthesizes the current state of the literature to contextualize the therapeutic potential of miRNA modulation. It considers the potential for miR-based therapeutics as a nuanced approach that incorporates the complexity of ARDS pathophysiology and the multifaceted nature of miRNA interactions.

A Taxonomy for Noninvasive Modes Provided by Portable Ventilators.

The purpose of this article is to identify (by brand name) and then classify the modes available on contemporary portable ventilators used for noninvasive ventilation in the United States. We propose a formal taxonomy that identifies the modes by their control variable, breath sequence, and targeting scheme, therefore describing what the mode does. Use of this taxonomy should be helpful in finding modes with comparable functionality that cater to the specific goal of mechanical ventilation and effective ventilatory strategies for each disease state.

Modern mechanical ventilation strategies for the acute care surgeon: What you need to know.

Acute respiratory failure (ARF) is associated with significant morbidity and mortality in trauma and emergency surgery patients. Pulmonary complications following surgery among the most frequent and costly postoperative events. ARF support with mechanical ventilation is life-saving but may lead to ventilator-induced lung injury (VILI), worsening secondary injury. Decades of randomized clinical trials have demonstrated that evidence-based ventilator management can improve outcomes, but one-size-fits-all mechanical ventilation protocols fail to achieve true individualized, personalized care for ARF. This review presents the current evidence for mechanical ventilation support strategies for ARF including lung protective ventilation, judicious target setting, conservative fluid management appropriate light sedation, strategies to prevent ventilator-associated pneumonia and early attempts at ventilator weaning and extubation to be deployed to optimized patient outcomes. Specific mechanical ventilation strategies for patients with traumatic brain injury, obesity and acute respiratory distress syndrome will also be reviewed.

Adjustments of Ventilator Parameters during Operating Room-to-ICU Transition and 28-Day Mortality.

Rationale: Lung-protective mechanical ventilation strategies have been proven beneficial in the operating room (OR) and the ICU. However, differential practices in ventilator management persist, often resulting in adjustments of ventilator parameters when transitioning patients from the OR to the ICU. Objectives: To characterize patterns of ventilator adjustments during the transition of mechanically ventilated surgical patients from the OR to the ICU and assess their impact on 28-day mortality. Methods: Hospital registry study including patients undergoing general anesthesia with continued, controlled mechanical ventilation in the ICU between 2008 and 2022. Ventilator parameters were assessed 1 hour before and 6 hours after the transition. Measurements and Main Results: Of 2,103 patients, 212 (10.1%) died within 28 days. Upon OR-to-ICU transition, VT and driving pressure decreased (-1.1 ml/kg predicted body weight [IQR, -2.0 to -0.2]; P < 0.001; and -4.3 cm H2O [-8.2 to -1.2]; P < 0.001). Concomitantly, respiratory rates increased (+5.0 breaths/min [2.0 to 7.5]; P < 0.001), resulting overall in slightly higher mechanical power (MP) in the ICU (+0.7 J/min [-1.9 to 3.0]; P < 0.001). In adjusted analysis, increases in MP were associated with a higher 28-day mortality rate (adjusted odds ratio, 1.10; 95% confidence interval, 1.06-1.14; P < 0.001; adjusted risk difference, 0.7%; 95% confidence interval, 0.4-1.0, both per 1 J/min). Conclusion: During transition of mechanically ventilated patients from the OR to the ICU, ventilator adjustments resulting in higher MP were associated with a greater risk of 28-day mortality.

Management of severe acute pulmonary oedema, from expert guidelines to bedside strategies: multidisciplinary survey involving 1048 physicians

Abstract Introduction Current recommendations regarding the management of severe acute pulmonary oedema (APE) have low levels of recommendation and/or evidence (LOR/E) that may lead to high heterogeneity in clinical practice 1–3. We hypothesized that practice may diverge from guidelines and differ according to medical specialty and level of expertise. The objective of this survey was to evaluate the clinical management of 4 phenotypes of APE by physicians of 3 specialties and their divergence from guidelines. Methods Four vignettes were designed by a scientific committee representing the French scientific societies of cardiology, emergency medicine, and intensive care (Table 1). In addition, 20 experts in the field of APE care were enrolled. Target participants and designated experts were French physicians of the 3 specialties. From 06/2022 to 09/2022, the vignettes were submitted to the physicians and experts using an open online survey. Results Among the 1048 respondents, 781 completed the 4 cases whereas all 20 experts completed the whole survey (Table 1). Accordance with international guidelines was heterogenous (Table 2). Compliance with SpO2&amp;lt;90% threshold for O2 administration (LOE/R: I-C 1): 22% of physicians and 53% of experts were in accordance with the guidelines. Initiation of non-invasive ventilation (NIV) for respiratory distress (LOE/R: IIa-B 1): concordance was 54% and 93%, respectively. Intubation for progressive respiratory failure despite O2 or NIV (LOE/R: I-C 1): in case of pre-hospital NSTEMI worsening despite NIV and medications, compliance was 55% among physicians and 85% among experts. In case of STEMI with worsening respiratory failure, compliance was respectively 44% and 70%. Intravenous (iv) loop diuretics indications and choice of a loop diuretic (LOE/R: I-C 1): 91% of physicians and 95% of experts were in accordance. For the systolic blood pressure&amp;gt;110 mmHg threshold for iv vasodilators (LOE/R: IIb-C 1) and iv nitrates during NSTEMI with signs of APE (LOE/R: I-C 2): concordance was respectively 8% and 96% among physicians, 32% and 100% among experts. For reperfusion strategies, 20% of physicians and experts acted according to the guidelines. For early PCI within 24h of NSTEMI (LOE/R: I-A 2) and immediate strategy (&amp;lt; 2 hours) for very high-risk NSTEMI (LOE/R: I-C 2): concordance was respectively 62% and 12% among physicians, 80% and 10% among experts. Except for indications of mechanical ventilation and NSTEMI early invasive strategy, results were homogenous among medical specialties (Table 2). Conclusion Our data show that therapeutic strategies regarding classical clinical cases of severe APE often diverge from guidelines with expected differences between specialties. The low level of evidence fuelling the Guidelines may explain these heterogeneities 4. There is a need for more clinical investigation to fill the current gap in evidence and strengthen future guidelines that may reduce heterogeneity in care.Table 1Table 2

Impact on cerebral hemodynamics of the use of volume guarantee combined with high frequency oscillatory ventilation in a neonatal animal respiratory distress model.

No differences were observed at cerebral hemodynamic between respiratory assistance in HFOV with and without VG, being the latter ventilatory strategy equally safe. • Preterm have a situation of fragility of cerebral perfusion wich means that any mechanical ventilation strategy can have a significant influence. High-frequency oscillatory ventilation (HFOV) is an alternative to conventional mechanical ventilation (CMV). Recently, the use of volume guarantee (VG) combined with HFOV has been suggested as a safe strategy capable of reducing the damage induced by ventilation in immature lungs. Several studies have compared CMV and HFOV and their effects at hemodynamic level. It is known that the use of high mean airway pressure in HFOV can cause an increase in pulmonary vascular resistance with a decrease in thoracic venous return. • The possible impact of VAFO + VG on cerebral hemodynamics is unknown. Due the lack of studies and the existing controversy, we have carried out this research project in an experimental animal model with the aim of evaluating the cerebral hemodynamic repercussion of the use of VG in HFOV compared to the classic strategy without VG.