This extended paper presents the development and implementation at a prototype level of a wireless, low-cost system for the measurement of the electrical bioimpedance of the chest with two channels using the AD5933 in a bipolar electrode configuration to measure impedance pneumography. The measurement device works for impedance measurements ranging from 1 Ω to 1800 Ω. Fifteen volunteers were measured with the prototype. We found that the left hemithorax has higher impedance compared to the right hemithorax, and the acquired signal presents the phases of the respiratory cycle with variations between 1 Ω, in normal breathing, to 6 Ω in maximum inhalation events. The system can measure the respiratory cycle variations simultaneously in both hemithorax with a mean error of −0.18 ± 1.42 BPM (breaths per minute) in the right hemithorax and −0.52 ± 1.31 BPM for the left hemithorax, constituting a useful device for the breathing rate calculation and possible screening applications.

The impairment of insulin signaling on diabetes mellitus has been related to cardiovascular dysfunction, heart failure and sudden death. In human endothelium, cationic amino acid transporter 1 (hCAT-1) is related to the synthesis of nitric oxide (NO). Insulin has a vascular effect in endothelial cells through a signaling pathway that involved increases of hCAT-1 expression and L-arginine transport. This mechanism is disrupted in diabetes, a phenomenon potentiated by excessive accumulation of reactive oxygen species (ROS), which contributes to lower availability of NO and endothelial dysfunction. On the other hand, the electrical remodeling in cardiomyocytes is considered a key factor in heart failure progression associated to diabetes mellitus, generating a challenge to understand the specific role of insulin and the pathways involved in cardiac function. Studies on isolated mammalian cardiomyocytes have shown a prolongated action potential in ventricular repolarization phase that produces a long QT interval. The long QT generated is well explained by attenuation in the repolarizing potassium currents in cardiac ventricles. The impaired insulin signaling causes specific changes in these currents, such a decrease amplitude of the transient outward K+ (Ito) and the ultra-rapid delayed rectifier (IKur) currents where, together, a reduction of mRNA and protein expression levels of α-subunits (Ito, fast; Kv 4.2 and IKs; Kv 1.5) or β-subunits (KChIP2 and MiRP) of K+ channels involved in these currents in a MAPK mediated pathway process have been described. These results support the hypothesis that the lack of insulin signaling can produce an abnormal repolarization in cardiomyocytes. Furthermore, the arrhythmogenic potential due to reduced Ito current can contribute to an increase in the incidence of sudden death in heart failure. This review aims to show, based on pathophysiological models, the regulatory function that would have insulin in vascular system and in cardiac electrophysiology.

Background: A lung rest strategy is recommended during extracorporeal membrane oxygenation in severe acute respiratory distress syndrome (ARDS). However, spontaneous breathing modes are frequently used in this context. The impact of this approach may depend on the intensity of breathing efforts. The authors aimed to determine whether a low spontaneous breathing effort strategy increases lung injury, compared to a controlled near-apneic ventilation, in a porcine severe ARDS model assisted by extracorporeal membrane oxygenation. Methods: Twelve female pigs were subjected to lung injury by repeated lavages, followed by 2-h injurious ventilation. Thereafter, animals were connected to venovenous extracorporeal membrane oxygenation and during the first 3 h, ventilated with near-apneic ventilation (positive end-expiratory pressure, 10 cm H₂O; driving pressure, 10 cm H₂O; respiratory rate, 5/min). Then, animals were allocated into (1) near-apneic ventilation, which continued with the previous ventilatory settings; and (2) spontaneous breathing: neuromuscular blockers were stopped, sweep gas flow was decreased until regaining spontaneous efforts, and ventilation was switched to pressure support mode (pressure support, 10 cm H₂O; positive end-expiratory pressure, 10 cm H₂O). In both groups, sweep gas flow was adjusted to keep Paco ₂ between 30 and 50 mmHg. Respiratory and hemodynamic as well as electric impedance tomography data were collected. After 24 h, animals were euthanized and lungs extracted for histologic tissue analysis. Results: Compared to near-apneic group, the spontaneous breathing group exhibited a higher respiratory rate (52 ± 17 vs. 5 ± 0 breaths/min; mean difference, 47; 95% CI, 34 to 59; P < 0.001), but similar tidal volume (2.3 ± 0.8 vs. 2.8 ± 0.4 ml/kg; mean difference, 0.6; 95% CI, –0.4 to 1.4; P = 0.983). Extracorporeal membrane oxygenation settings and gas exchange were similar between groups. Dorsal ventilation was higher in the spontaneous breathing group. No differences were observed regarding histologic lung injury. Conclusions: In an animal model of severe ARDS supported with extracorporeal membrane oxygenation, spontaneous breathing characterized by low-intensity efforts, high respiratory rates, and very low tidal volumes did not result in increased lung injury compared to controlled near-apneic ventilation. Editor’s Perspective: What We Already Know about This Topic: What This Article Tells Us That Is New:

The spontaneous breathing trial (SBT) assesses the risk of weaning failure by evaluating some physiological responses to the massive venous return increase imposed by discontinuing positive pressure ventilation. This trial can be very demanding for some critically ill patients, inducing excessive physical and cardiovascular stress, including muscle fatigue, heart ischemia and eventually cardiac dysfunction. Extubation failure with emergency reintubation is a serious adverse consequence of a failed weaning process. Some data suggest that as many as 50% of patients that fail weaning do so because of cardiac dysfunction. Unfortunately, monitoring cardiovascular function at the time of the SBT is complex. The aim of our study was to explore if central venous pressure (CVP) changes were related to weaning failure after starting an SBT. We hypothesized that an early rise on CVP could signal a cardiac failure when handling a massive increase on venous return following a discontinuation of positive pressure ventilation. This CVP rise could identify a subset of patients at high risk for extubation failure. Two-hundred and four mechanically ventilated patients in whom an SBT was decided were subjected to a monitoring protocol that included blinded assessment of CVP at baseline, and at 2 minutes after starting the trial (CVP-test). Weaning failure was defined as reintubation within 48-hours following extubation. Comparisons between two parametric or non-parametric variables were performed with student T test or Mann Whitney U test, respectively. A logistic multivariate regression was performed to determine the predictive value on extubation failure of usual clinical variables and CVP at 2-min after starting the SBT. One-hundred and sixty-five patients were extubated after the SBT, 11 of whom were reintubated within 48h. Absolute CVP values at 2-minutes, and the change from baseline (dCVP) were significantly higher in patients with extubation failure as compared to those successfully weaned. dCVP was an early predictor for reintubation (OR: 1.70 [1.31,2.19], p<0.001). An early rise in CVP after starting an SBT was associated with an increased risk of extubation failure. This might represent a warning signal not captured by usual SBT monitoring and could have relevant clinical implications.

Dorsal regions are more recruitable than ventral, decreasing their dynamic strain with PEEP, but relative PEEP effects vary across ARDS phenotypes with different global recruitability. The higher the global recruitability, the higher the effect on the dorsal part. This was demonstrated across two acute lung injury (ALI) animal models and two patient cohorts, mixed ARDS, and COVID-19 ARDS. PEEP can paradoxically increase dynamic dorsal strain despite recruitability if ventral overdistention occurs. EIT can detect this.

Objectives: The coronavirus disease 2019 pandemic led to various intensities of lockdowns, affecting lifestyles globally. This study investigates the impact of partial lockdown versus total lockdown on adult physical activity (PA) and sedentary behavior.Methods: A cross-sectional online survey was conducted from April 2020 to October 2020, with 493 participants included in the analysis.Results: The analysis revealed no significant differences in total PA or total sitting time between partial lockdown and total lockdown scenarios. However, moderate physical activity (MPA) significantly decreased during total lockdowns, with more pronounced reductions among females than males. Notably, a positive correlation was found between household area and MPA, suggesting that larger living spaces may encourage more PA. A negative correlation was observed between sitting time and MPA during both types of lockdown.Conclusions: Total lockdown conditions were associated with a significant decrease in MPA, highlighting sex disparities in PA responses. Living space size emerged as a crucial factor in maintaining PA levels during restricted conditions. This study emphasizes the need to consider environmental and demographic factors in public health strategies during prolonged periods of restricted movement.