Investigation of high flow nasal cannule efficiency with electric impedance tomography based parameters in COVID-19 adults patients: a retrospective study.

Background/Aim: This study aimed to investigate the effects of oxygen therapy using a high flow nasal cannula (HFNC) on patients diagnosed with COVID-19 Acute Respiratory Distress Syndrome (C-ARDS) by utilizing electrical impedance tomography (EIT)-based parameters. Materials and Methods: Oxygen therapy was administered to the patients at two different flow rates and two different positions: T0-baseline measurements were taken in the supine position before any therapy was initiated. T1-HFNC was administered in the supine position with a flow rate of 30 L/min. T2-HFNC was administered in the supine position with a flow rate of 50 L/min. T3-HFNC was administered in the prone position with a flow rate of 30 L/min. T4-HFNC was administered in the prone position with a flow rate of 50 L/min. EIT-based parameters (global inhomogeneity index (GI index), center of ventilation (CoV), regional ventilation delay index (RVD index), region of interest ratio (ROI ratio)), as well as respiratory and hemodynamic parameters of the patients, were recorded from the database. Results: A total of twenty patients were included in this retrospective observational study. The mean age of the included patients was 64.3 ± 10.6 years. Statistically significant differences were observed in the measurements of GI index, CoV, RVD index, ROI ratio, PaO2/FiO2 ratio, respiratory rate, and mean arterial pressure parameters across different time intervals (p < 0.005). Pairwise comparisons of EIT parameters and measurements of respiratory and hemodynamic parameters at five different time points revealed statistically significant differences. For the GI index, significant differences were observed between the mean measurements taken at T0-T1, T0-T2, T0-T3, T0-T4, T1-T3, T1-T4, T2-T3, T2-T4, and T3-T4 time intervals (p < 0.05). Regarding CoV, significant differences were found between the mean measurements taken at T0-T3, T1-T3, T2-T3, and T3-T4 time intervals (p < 0.05). Additionally, for the ROI ratio, significant differences were observed between the measurement averages taken at each time interval (p < 0.05). Conclusion: Our findings suggest that prone positioning during the management of C-ARDS patients leads to improved lung homogeneity, as indicated by EIT parameters. However, further research is required to enhance the visualization of ventilation using EIT.

Multielectrode Contact Measurement Can Improve Long-Term Outcome of Pulmonary Vein Isolation Using Circular Single-Pulse Electroporation Ablation.

BACKGROUND: Irreversible electroporation (IRE) ablation is generally performed with multielectrode catheters. Electrode-tissue contact is an important predictor for the success of pulmonary vein (PV) isolation; however, contact force is difficult to measure with multielectrode ablation catheters. In a preclinical study, we assessed the feasibility of a multielectrode impedance system (MEIS) as a predictor of long-term success of PV isolation. In addition, we present the first-in-human clinical experience with MEIS. METHODS: In 10 pigs, one PV was ablated based on impedance (MEIS group), and the other PV was solely based on local electrogram information (EP group). IRE ablations were performed at 200 J. After 3 months, recurrence of conduction was assessed. Subsequently, in 30 patients undergoing PV isolation with IRE, MEIS was evaluated and MEIS contact values were compared to local electrograms. RESULTS: In the porcine study, 43 IRE applications were delivered in 19 PVs. Acutely, no reconnections were observed in either group. After 3 months, 0 versus 3 (P=0.21) PVs showed conduction recurrence in the MEIS and EP groups, respectively. Results from the clinical study showed a significant linear relation was found between mean MEIS value and bipolar dV/dt (r2=0.49, P<0.001), with a slope of 20.6 mV/s per Ohm. CONCLUSIONS: Data from the animal study suggest that MEIS values predict effective IRE applications. For the long-term success of electrical PV isolation with circular IRE applications, no significant difference in efficacy was found between ablation based on the measurement of electrode interface impedance and ablation using the classical EP approach for determining electrode-tissue contact. Experiences of the first clinical use of MEIS were promising and serve as an important basis for future research.

Comparação entre métodos de análise da composição corporal: síndrome de Down x desenvolvimento típico / Comparison of methods of body composition: Down syndrome x typical developmental

Este estudo buscou comparar as médias do percentual de gordura (%G) e do índice de massa corporal (IMC) entre três métodos distintos de análise da composição corporal em adolescentes com desenvolvimento típico (GC) e com síndrome de Down (GSD). Para tal, contou-se com uma amostra de 60 adolescentes (30 GSD e 30 GC), de ambos os sexos, com idades entre 11 e 14 anos. Na avaliação e comparação do %G utilizou-se as bioimpedâncias elétricas de modelo tetrapolar, de membros superiores (OMRON®) e de membros inferiores (TANITA®) e, para o IMC a bioimpedância tetrapolar, a TANITA® e fórmula antropométrica. Os resultados demonstraram diferenças entre os métodos utilizados, tanto para a percentagem de gordura (GC: x2= 28,78, p=0,000; GSD: x2= 10,85, p=0,004) como para o cálculo do IMC (GC: x2= 7,65, p = 0,22; GSD: x2= 6,655, p=0,036), sendo superior no GSD. Portanto, conclui-se que, a bioimpedância tetrapolar continua sendo o melhor método para mensuração da percentagem de gordura e do IMC havendo diferenciação nos dados apresentados por outros modelos de aferição.

This study sought to compare the means of the fat percentage (BF%) and body mass index (BMI) between three different methods of body composition in teenager with typical developmental (GC) and Down syndrome (GSD). To this end, counted on the sample of 60 teenager (30 GSD and 30 GC), of both sexes, aged between 11 and 14 years. The assessment and comparison of BF% was used electric bioimpedance of quadrupole model, the upper limbs (OMRON®) and lower limbs (TANITA®) and for BMI, the electric bioimpedance of quadrupole model, the TANITA® and anthropometric formula. The results showed difference between the methods used, both the percentage of fat (BF: x2 = 28.78, p = 0.000; GSD: x2 = 10.85, p = 0.004) and for the calculation of BMI (GC: x2 = 7.65, p = 0.22; GSD: x2 = 6.655, p = 0.036), higher than the GSD. Therefore, it is concluded that the tetrapolar bioimpedance remains the best method to measure body fat percentage and BMI there differentiation in the data presented by other measurement models