Extracorporeal carbon dioxide removal (ECCO2R) is an emerging technique designed to reduce carbon dioxide (CO2) levels in venous blood while enabling lung-protective ventilation or alleviating the work of breathing. Unlike high-flow extracorporeal membrane oxygenation (ECMO), ECCO2R operates at lower blood flows (0.4–1.5 L/min), making it less invasive, with smaller cannulas and simpler devices. Despite encouraging results in controlling respiratory acidosis, its broader adoption is hindered by complications, including haemolysis, thrombosis, and bleeding. Technological advances, including enhanced membrane design, gas exchange efficiency, and anti-coagulation strategies, are essential to improving safety and efficacy. Innovations such as wearable prototypes that adapt CO2 removal to patient activity and catheter-based systems for lower blood flow are expanding the potential applications of ECCO2R, including as a bridge to lung transplantation and in outpatient settings. Promising experimental approaches include respiratory dialysis, carbonic anhydrase-coated membranes, and electrodialysis to maximise CO2 removal. Further research is needed to optimise device performance, develop cost-effective systems, and establish standardised protocols for safe clinical implementation. As the technology matures, integration with artificial intelligence (AI) and machine learning may personalise therapy, improving outcomes. Ongoing clinical trials will be pivotal in addressing these challenges, ultimately enhancing the role of ECCO2R in critical care and its accessibility across healthcare settings.

The research and development of innovative insulation systems for High Voltage Rotating Machines demand a deeper understanding and characterization of the failure mechanisms involved in the new technology. When only the electrical stress is considered, the literature describes that the breakdown of the insulation is determined by the electrical tree propagation through the material. Hence, it is important to have techniques to characterize the path of electrical tree through insulation after its rupture. Albeit some disruptive technologies are being proposed, most of the insulation still consists of mica, a carrier material, and a binder resin. Such insulation is considerably rigid, making difficult to separate one layer from the other and to follow the damage path left by the breakdown once the mica layers are broken during this process. This work describes an alternative method to characterize this electrical failure path, which consists of submitting the sample to a calcination process at high temperature before peeling it. The calcination process extracts all organic materials from insulation. In this condition, it is much easier to peel the insulation layer by layer and the carbonization path produced by electrical discharge can be clearly observed and characterized. This work illustrates this proposed technique by analyzing samples extracted from stator bars previously submitted to voltage endurance test up to electrical failure.

Background and objective With the increasing incidence of cancer and the rise in the survival rates of cancer patients, more and more oncological candidates are being considered for admission to intensive care units (ICU). Several studies have demonstrated no difference in the outcomes of cancer patients compared to non-cancer patients. Our study aimed to describe and analyze the outcomes related to cancer patients in a polyvalent ICU. Methods We conducted a retrospective study of consecutive oncological patients admitted to a polyvalent ICU (2013-2017). Cox model and receiver operating characteristic (ROC) curve analysis were performed to analyze the results. Results A total of 236 patients were included in the study; the mean age of the patients was 53.5 ± 15.3 years, and 65% of them were male. The main cancer types were those related to the central nervous system (CNS; 31%), as well as gastrointestinal (18%), genitourinary (17%), and hematological (15%). Curative/diagnostic surgeries (49%) and sepsis/septic shock (17%) were the main reasons for admission. The Acute Physiology and Chronic Health Evaluation II (APACHE II) and Simplified Acute Physiology Score II (SAPS II) scores in hematological patients vs. solid tumors were as follows: 30 vs. 20 and 63 vs. 38, respectively (p<0.005). Vasopressors, invasive mechanical ventilation (IMV), and renal replacement therapy (RRT) were used more widely in hematological patients compared to solid-tumor patients. Length of stay was longer in hematological patients vs. solid-tumor patients (12.8 vs. 7 days, p=0.002). The median overall survival in hematological patients was one month and that in solid-tumor patients was 5.8 months (p<0.005). The survival rate at six months was better than described in the existing literature (48 vs. 32.4%). Conclusion Both SAPS II and APACHE II scores were reasonably accurate in predicting mortality, demonstrating their value in cancer patients.

Extracorporeal life support (ECLS) for severe respiratory failure has seen an exponential growth in recent years. Extracorporeal membrane oxygenation (ECMO) and extracorporeal CO2 removal (ECCO2R) represent two modalities that can provide full or partial support of the native lung function, when mechanical ventilation is either unable to achieve sufficient gas exchange to meet metabolic demands, or when its intensity is considered injurious. While the use of ECMO has defined indications in clinical practice, ECCO2R remains a promising technique, whose safety and efficacy are still being investigated. Understanding the physiological principles of gas exchange during respiratory ECLS and the interactions with native gas exchange and haemodynamics are essential for the safe applications of these techniques in clinical practice. In this review, we will present the physiological basis of gas exchange in ECMO and ECCO2R, and the implications of their interaction with native lung function. We will also discuss the rationale for their use in clinical practice, their current advances, and future directions.

Abstract Background Care for the critically ill patient with Cardiovascular Disease (CVD) requires a unique management approach, as the theoretical critical threshold for decompensation is lower and inherent adaptive mechanisms may be compromised. We aimed to characterize the prognostic impact of CVD in patients admitted to an Intensive Care Unit (ICU). Methods We performed a cohort study of consecutive patients admitted to an ICU from January to December 2019. Patients were stratified as follows: (1) established CVD – presence of either atrial fibrillation, heart failure, coronary artery disease and/or peripheral artery disease; (2) at higher risk of CVD – known arterial hypertension, dyslipidemia, diabetes mellitus and/or current smoking, in the absence of established CVD; and (3) at lower risk of CVD – i.e. none of the above. The co-primary endpoints were all-cause death in ICU and death during index hospitalization. Results During 2019, there were 334 admissions in ICU, comprising a total of 296 patients (mean age 67±15 years, 58.1% male). Overall, 69 (23.3%) and 108 (36.5%) died in ICU and during index hospitalization, respectively. Compared to patients at lower risk of CVD, those at higher CVD risk or with established CVD had markers of more severe disease, as noted by higher risk scores (e.g., SAPS-II 35.0±20.0 vs. 43.5±22.3 vs. 52.6±20.0; p<0.001), higher rates of mechanical ventilation (41.5 vs. 57.3 vs. 63.9%; p=0.020), shock during ICU stay (34.0 vs. 52.7 vs. 66.9%; p<0.001) and acute kidney injury (26.4 vs. 35.5 vs. 57.9%; p<0.001), respectively, as well as higher death rates in ICU (5.7 vs. 21.8 vs. 31.6%; p=0.001) and index hospitalization (9.4 vs. 37.3 vs. 46.6%; p<0.001). In multivariate analysis, adjusted for age and cause of admission, established CVD independently predicted the risk of all-cause death in ICU (HR: 2.084; 95% CI: 1.136–3.823; p=0.018) and during index hospitalization (HR 1.712; CI: 1.009–2.889; p=0.046). The analysis for the group of patients at higher risk of CVD yielded similar results to the abovementioned. Conclusion Roughly 4 in every 5 patients admitted in ICU were at risk of or had established CVD. The presence of either of the above independently predicted a two- to three-fold higher risk of death during hospitalization. Our findings emphasize the considerable burden of CVD in ICU and underscore the importance of comprehensive management of the complex critically ill patient. Funding Acknowledgement Type of funding sources: None.

Abstract Background Severity of disease scoring systems, namely the Simplified Acute Physiology Score (SAPS) and Acute Physiology and Chronic Health Evaluation (APACHE), are widely used to predict mortality in Intensive Care Units (ICU). Yet, neither score includes chronic HF in their model. We aimed to evaluate whether these scores perform well in risk prediction of death of patients previously diagnosed with heart failure (HF). Methodology This is a single-center retrospective cohort of patients admitted to an ICU in 2019. Those whose admission lasted <24 hours were excluded from analysis. The SAPS II and APACHE II scores were calculated using data from the first 24 hours of ICU admission, imputing the worst variable obtained within this timeframe. HF was defined according to the ESC recommendations. In order to assess the performance of the scores, Receiver Operating Characteristic (ROC) Curves were used to predict the risk of death in ICU in HF compared to the non-HF population. Results A total of 267 patients were hospitalized in ICU for a period over 24 hours in 2019 (mean age 67±16 years; 58.8% males; 21.7% with chronic HF; 33.7% admitted for sepsis). Compared to patients without HF, those with chronic HF were older (74±13 vs. 65±16 years; p<0.001) and had higher risk scores (mean SAPS II: 43.2±21.7 vs. 56.5±20.7; p<0.001; mean APACHE II: 19.8±10.0 vs. 25.1±10.0; p<0.001). Moreover, these patients were at higher risk of meaningful events during hospitalization (e.g. acute kidney injury: 38.0 vs. 66.1%; p<0.001; shock at any time: 52.4 vs. 67.8%; p=0.036). Furthermore, patients with HF had a trend towards higher mortality rates in ICU (17.3 vs. 28.8%; p=0.051) and a significantly higher death in overall hospitalization (30.8 vs. 45.8%; p=0.032). ROC curves performed well in predicting the risk of ICU death regardless of HF (SAPS II – AUC 0.78 vs. 0.81; p=0.36; APACHE II – AUC 0.75 vs. 0.78; p=0.37). Conclusion Approximately 1 in every 4 patients admitted to the ICU had chronic HF. Traditional risk scoring systems (SAPS II and APACHE II) performed well regardless of HF. While these results are reassuring as far as risk stratification accuracy is concerned, HF patients remained at a higher risk for worse outcomes. Therefore, prognostic tools with a therapeutic clinical applicability are urgently needed to improve the outcome of this population. Funding Acknowledgement Type of funding sources: None.

O Grupo de Coordenação Local – Programa de Prevenção e Controlo de Infeções e de Resistência aos Antimicrobianos (GCL-PPCIRA) do Hospital CUF Infante Santo foi criado em novembro de 2019 e tem por missão implementar uma abordagem estruturada multidisciplinar e multiprofissional de prevenção e controlo de infeção associada a cuidados de saúde, nomeadamente da infeção adquirida durante o internamento hospitalar, e de utilização criteriosa de antimicrobianos, promovendo a sua eficácia clínica e limitando a sua toxicidade e a emergência de resistências microbianas. E o primeiro grande teste da comissão recém-formada foi enfrentar uma pandemia global COVID-19 causado pelo vírus SARS-CoV-2 com início em Wuhan, na China em dezembro de 2019.

João Tavares Rita Ivo Filipe Gonzalez Tomás Lamas João João Mendes 1Internal Medicine Department, Hospital da Luz, Lisbon, Portugal; 2Internal Medicine Department, Hospital Egas Moniz, Lisbon, Portugal; 3Intensive Care Unit, Hospital Garcia de Orta, Almada, Portugal; 4Intensive Care Unit, Hospital CUF Infante Santo, Lisbon, Portugal Abstract: Ultrasound technology is an essential tool in the management of critically ill patients. Point-of-care ultrasonography (POCUS) enables data collection from different anatomic areas to achieve the most probable diagnosis and administer the right therapy at the right time. Despite the increasing utilization of POCUS, there is still a lack of standards to establish how to use different bedside ultrasound protocols, and it is imperative to develop a unifying protocol. Thus, the aim of this paper is to establish a new systematized approach that can be adopted by all physicians to implement POCUS for critically ill patient management. To achieve this, we propose a new systematized approach—Global Ultrasound Check for the Critically Ill (GUCCI)—that integrates multiple protocols. This protocol is organized based on three syndromes (acute respiratory failure, shock, and cardiac arrest) and includes ultrasound-guided procedures.

Ultrasound technology is an essential tool in the management of critically ill patients. Point-of-care ultrasonography (POCUS) enables data collection from different anatomic areas to achieve the most probable diagnosis and administer the right therapy at the right time. Despite the increasing utilization of POCUS, there is still a lack of standards to establish how to use different bedside ultrasound protocols, and it is imperative to develop a unifying protocol. Thus, the aim of this paper is to establish a new systematized approach that can be adopted by all physicians to implement POCUS for critically ill patient management. To achieve this, we propose a new systematized approach-Global Ultrasound Check for the Critically Ill (GUCCI)-that integrates multiple protocols. This protocol is organized based on three syndromes (acute respiratory failure, shock, and cardiac arrest) and includes ultrasound-guided procedures.

Rationale: When and whether nutritional requirements can be attained by parenteral nutrition (PN) in the acute care setting is still a question for debate. Many clinical variables may determine either under- or overfeeding. Guidelines for evidence-based nutritional care in the ICU are still under construction.

The ability of IEEE 1310-2012 test method to simulate the possible insulation aging mechanisms of a generator working under repetitive start-stops was studied. Real stator bars, previously aged under service by about 10,000 start-stops were characterized in the laboratory and then submitted to a limited number of thermal cycles according to IEEE 1310-2012 for comparison. The results suggest that a small number of lab thermal cycles is sufficient to create defects that did not exist in the bars aged solely under operation conditions. It is also found that the lab cycles tend to propagate the very few existing defects towards areas where such features were not present in the original condition, such as the inner portion of the stator core. Therefore, depending on how exactly the test results generated by IEEE 1310-2012 are interpreted, there is a risk that the final assessment of any set of tested bars/coils is partially influenced by such test artifacts.

After showing in a previous work that PD measurements suffer from poor repeatability and reproducibility, the present study turns now to a more qualitative approach, investigating if a method of PD fault location along a Roebel bar length can be used to identify insulation critical areas that later on could fail under electrical stress. Typical insulation “damages” have been created on the components in advance by submitting them to both thermal-mechanical and electrical aging tests. Once such preliminary aging was done, the critical areas along the bars length were identified by mapping the PD readings on each component. Afterwards, every bar was subjected to a destructive electrical breakdown test. At last, the breakdown locations were compared with the PD mappings to search for any possible correlation between the two events. Based upon the present results, such correlation does not exist.

In spite of the fact that no evidence exist that PD amplitudes can somehow be used to estimate the expected "life" of generator components such as Roebel stator bars and multi-turn coils, certain portions of industry have assumed that pass-fail criteria based upon absolute PD amplitudes are meaningful enough to be used as pass-fail tests for Roebel bars and Multi-turn coils. In this context the present work evaluated the ability of expert independent laboratories to generate reproducible PD readings when performing PD tests on the very same set of bars.

The evaluation of high-voltage groundwall insulation aged under long-term operating conditions is addressed using three sets of Roebel bars removed from large hydrogenerators after several decades of service. To cover an important cross-section of the possible operating regimes for typical hydros, the units involved in the study were selected to represent (i) the air-cooled Pumped-storage, (ii) the air-cooled base-load and (iii) the water-cooled base-load service regimes. Experimental techniques were used to permit assessment of the insulation condition under visual, electrical and morphological aspects. Contrary to what is usually assumed, the results suggest that the pumped-storage operating regime, with its repeated thermal-mechanical cycles of start-stops may create only minimum aging to the groundwall insulation while, in some particular cases, units operating at relatively low temperatures and under mild base-load conditions, may be found to exhibit a more severe insulation degradation in the long run.

In this work, doped AlGaAs/GaAs parabolic quantum wells (PQW) with different well widths (from 1000Å up to 3000Å) were investigated by means of photoluminescence (PL) measurements. In order to achieve the 2DEG inside the PQW Si delta doping is placed at both side of the well. We have observed that the thickness of this space layer plays a major rule on the characteristics of the 2DEG. It has to be thicker enough to prevent any diffusions of Si to the well and thin enough to allow electrons migration inside the well. From PL measurement, we have observed beside the intra well transitions, indirect transitions involving still trapped electron on the delta doping and holes inside the PQW. For the thinness sample, we have measured a well defined PL peak at low energy side of the GaAs bulk emission. With the increasing of the well thickness this peak intensity decreases and for the thickest sample it almost disappears. Our theoretical calculation indicated that carriers (electron and holes) are more placed at the center of the PQW. In this way, when the well thickness increases the distance between electrons on the delta doping and holes on the well also increases, it decreases the probability of occurrence of these indirect optical transitions.

In this work the electronic structure of undoped AlGaAs/GaAs wide parabolic quantum wells (PQWs) with different well widths (1000 Å and 3000 Å) were investigated by means of photoluminescence (PL) measurements. Due to the particular potential shape, the sample structure confines photocreated carriers with almost three-dimensional characteristics. Our data show that depending on the well width thickness it is possible to observe very narrow structures in the PL spectra, which were ascribed to emissions associated to the recombination of confined 1s-excitons of the parabolic potential wells. From our measurements, the exciton binding energies (of a few meV) were estimated. Besides the exciton emission, we have also observed PL emissions associated to electrons in the excited subbands of the PQWs.

In this work, we present a detailed study on the optical properties of two GaAs/Al0.35Ga0.65As coupled double quantum wells (CDQWs) with inter-well barriers of different thicknesses, by using photoluminescence (PL) spectroscopy. The two CDQWs were grown in a single sample, assuring very similar experimental conditions for measurements of both. The PL spectrum of each CDQW exhibits two recombination channels which can be accurately identified as the excitonic e1-hh1 transitions originated from CDQWs of different effective dimensions. The PL spectra characteristics and the behavior of the emissions as a function of temperature and excitation power are interpreted in the scenario of the bimodal interface roughness model, taking into account the exciton migration between the two regions considered in this model and the difference in the potential fluctuation levels between those two regions. The details of the PL spectra behavior as a function of excitation power are explained in terms of the competition between the band gap renormalization (BGR) and the potential fluctuation effects. The results obtained for the two CDQWs, which have different degrees of potential fluctuation, are also compared and discussed.

We have studied the quantum Hall effect in Al x Ga 1-x As -double well structure with vanishing g-factor. We determined the density-magnetic field ns - B diagrams for the longitudinal resistance Rxx. In spite of the fact that the ns - B diagram for conventional GaAs double wells shows a striking similarity with the theory, we observed the strong difference between these diagrams for double wells with vanishing g-factor. We argue that the electron-electron interaction is responsible for unusual behavior of the Landau levels in such a system.

The nonlinear regime of low-temperature magnetoresistance of double quantum wells in the region of magnetic fields below 1 T is studied both experimentally and theoretically. The observed inversion of the magnetointersubband oscillation peaks with increasing electric current and splitting of these peaks are described by the theory based on the kinetic equation for the isotropic nonequilibrium part of electron distribution function. The inelastic-scattering time of electrons is determined from the current dependence of the inversion field.