Respiratory system compliance at the same PEEP level is similar in COVID and non-COVID ARDS

Background The comparison of respiratory system compliance (Crs) between COVID and non-COVID ARDS patients has been the object of debate, but few studies have evaluated it when considering applied positive end expiratory pressure (PEEP), which is one of the known determinants of Crs itself. The aim of this study was to compare Crs taking into account the applied PEEP. Methods Two cohorts of patients were created: those with COVID-ARDS and those with non-COVID ARDS. In the whole sample the association between Crs and type of ARDS at different PEEP levels was adjusted for anthropometric and clinical variables. As secondary analyses, patients were matched for predicted functional residual capacity and the same association was assessed. Moreover, the association between Crs and type of ARDS was reassessed at predefined PEEP level of 0, 5, 10, and 15 cmH2O with a propensity score-weighted linear model. Results 367 patients were included in the study, 276 patients with COVID-ARDS and 91 with non-COVID ARDS. The association between Crs and type of ARDS was not significant in both the complete cohorts (p = 0.17) and in the matched cohorts (p = 0.92). This was true also for the propensity score weighted association at PEEP 5, 10 and 15 cmH2O, while it was statistically significant at PEEP 0 (with a median difference of 3 ml/cmH2O, which in our opinion is not clinically significant). Conclusions The compliance of the respiratory system is similar between COVID ARDS and non-COVID ARDS when calculated at the same PEEP level and while taking into account patients’ anthropometric characteristics.

Exceptional lithium diffusion through porous aromatic framework (PAF) interlayers delivers high capacity and long-life lithium–sulfur batteries

Sulfonated porous aromatic frameworks (SPAFs) accelerate Li-ion diffusion while retarding the polysulfide shuttle effect in Li–S batteries. This leads to high residual capacity above 1000 mA h g−1 and coulombic efficiency (>99.5%) after 500 cycles.

APPLICATION OF AERIAL PHOTOGRAPHY RESULTS, OBTAINED USING UAV DATA TO ESTIMATE THE RESIDUAL CAPACITY OF THE LANDFILL. PRACTICE OF THE REPUBLIC OF TATARSTAN

Assessment of the current residual capacity is a fundamentally important task, the solution of which is demonstrated on a landfill located in the Republic of Tatarstan. To solve the task, the modern methods of high-precision three-dimensional reconstruction were used based on the survey from an unmanned aircraft DJI Phantom 4, equipped with a global satellite navigation system (GNSS) receiver. As a result of combining the project data and data from field surveys into one coordinate system and elevations and reconstruction of designed underground and ground parts of landfill calculation, the difference of models and the residual capacity of the landfill becomes possible. Based on the materials considered as of July 2020, the residual capacity of the studied landfill is 41.2 % of the project capacity, which allows us to continue to operate this landfill. The proposed approach allows for rapid and high-quality active monitoring of the engineered facility. Photogrammetric processing of the results of low-altitude aerial photography makes it possible to obtain objective data on the current actual state of the landfills, to carry out competent and valid management of the landfill functioning. Significant, this will extend the landfill's lifetime, minimize the adverse effects on the environment and predict the yield to the project capacity much more accurately.

Comparison of cover meter and ground penetrating radar performance in structural health assessment: case studies

An essential step in the condition assessment of reinforced concrete structures and evaluation of the residual capacity is the determination of the arrangement and quantity of reinforcement as well as the geometry of the structural elements. The objective of this paper is to present the fundamentals in the application of two non-destructive methods, cover meter and ground penetrating radar, in the determination of the above structural features. A comparison of the two methods is presented and their capabilities, advantages and disadvantages are shown through nine case studies.

Allocation Control of Multi-functional Grid Connected Inverter and the Power Quality between of Grid Connected Microgrid Based on PSCAD Simulation Platform

On the one hand, the application of microgrid can effectively cut down the effect of distributed generation on distribution network, on the other hand, it helps to improve the power quality of distribution network. However, for the distribution network, a single multi-functional inverter has limited effect on the improvement of its power quality. Therefore, the allocation control of power quality by decentralized multi-functional inverters can further improve the utilization of inverters. This paper proposes to calculate the output current of multiple multi-functional inverters according to the harmonic and reactive current of the parallel node and the residual capacity of the multi-functional inverter. The simulation results show that the allocation control strategy proposed in this paper can effectively control the compensation capacity of the multi-functional inverter, so as to control the harmonic at the grid connection in place.

A new anesthesia protocol enabling longitudinal lung function measurements in neonatal rabbits by micro-CT

Micro-CT imaging is an emerging technology with many applications in small animals, e.g. the study of pulmonary diseases, although clear guidelines and critical mass of evidence are still missing in the preclinical literature. The neonatal rabbit is a valuable model for studying pulmonary development. However, the longitudinal monitoring of lung function by micro-CT can be challenging. Distinctive datasets corresponding to the end-inspiration and end-expiration phases need to be generated and analyzed to derive lung functional parameters. The quality of CT scans and the reliability of parameters obtained remains highly dependent on the anesthesia protocol used. Three different anesthetic protocols were tested. The combination of dexmedetomidine 0.25 mg/kg injected intraperitoneally followed by 1% isoflurane was found to facilitate CT imaging at 4 and 11 days after birth. Contrarily, isoflurane and ketamine plus xylazine were found unsuitable, and thus not investigated further. Total lung volumes significantly increased at day 11 compared to baseline in both respiratory phases, while lung tissue remained constant. As expected, functional residual capacity, air/tissue ratio and minute ventilation were significantly increased at day 11 in each animal. Those parameters were correlated with inspiratory capacity, compliance, elastance and resistance of both respiratory system and tissue component, as measured by flexiVent. Lung development was also evaluated by histomorphometric analyses. In conclusion, we have identified a safe and suitable anesthesia protocol for micro-CT imaging in neonatal rabbits. Moreover, the possibility to longitudinally measure lung function in the same subject dramatically reduced the intra-experimental variability.

The role of diaphragmatic ultrasound as a predictor of successful extubation from mechanical ventilation in respiratory intensive care unit

Background The diaphragm muscle whose dysfunction may be very common in patients undergoing mechanical ventilation (Ferrari G, De Filippi G, Elia F, Panero F, Volpicelli G, Aprà F. Crit Ultrasound J 6:8, 2014). Aim: To evaluate real-time ultrasound in the evaluation of diaphragmatic thickening, thickening fraction, and/or excursion to predict extubation outcomes. We aimed to compare these parameters with other traditional weaning measures is a fundamental. Results Out of 80 included patients, 20 (25%) have failed extubation. Diaphragmatic thickening (DT), thickening fraction (DTF), and/or excursion (DE) were significantly higher in the successful group compared to those who failed extubation (p < 0.05). Cutoff values of diaphragmatic measures associated with successful extubation (during tidal breathing) were ≥ 17 mm for DE; ≥ 2.1 cm for DT inspiration; ≥ 15.5 mm for DT expiration, functional residual capacity (FRC); and ≥ 32.82% for DTF %, giving 68%, 95%, 62%, and 90% sensitivity, respectively, and 65%, 100%, 100%, and 75% specificity, respectively. Cutoff values of diaphragmatic parameters associated with successful extubation (during deep breathing) were > 28.5 mm DT Insp, total lung capacity (TLC); >22.5mm DT Exp (RV); >37 DTF %; and > 31 mm DE, giving 100%, 73%, 97%, and 75% sensitivity and 65%, 75%, 100%, and 55% specificity, respectively. Rapid shallow breathing index (RSBI) had 47% sensitivity but 90% specificity. Conclusion Ultrasound evaluation of diaphragmatic parameters could be a good predictor of weaning in patients who passed the T-tube.

Effect of Mechanical Ventilation During Cardiopulmonary Bypass On End-Expiratory Lung Volume in The Perioperative Period of Cardiac Surgery

Background Many studies explored the impact of ventilation during cardiopulmonary bypass period. However, its effect on Functional residual capacity or End Expiratory Lung Volume (EELV) has not been specifically studied. Our objective was to compare the effect of two ventilation strategies during cardiopulmonary bypass (CPB) on EELV. Methods observational monocenter study in a tertiary teaching hospital. Adult patients undergoing on-pump cardiac surgery by sternotomy were included and ventilated on the GE Carescape R860® ventilator. Maintenance of ventilation during CPB was left to the discretion of the medical team, with division between "ventilated" and "non-ventilated" groups afterwards. Iterative per and postoperative measurements of EELV were carried out by nitrogen washin-washout technique. Results 40 patients were included, 20 in each group. EELV was not significantly different between the ventilated versus non-ventilated groups at the end of surgery (1796±586ml vs. 1844±524ml; p=1). No significant difference between the two groups was observed on oxygenation, duration of mechanical ventilation, need postoperative respiratory support, occurrence of pneumopathy and radiographic atelectasis. Conclusion Maintaining mechanical ventilation during CPB does not seem to allow a better preservation of EELV in our population.