Virtual reality-based early neurocognitive stimulation in critically ill patients: A pilot randomized clinical trial

This study focuses on the application of a non-immersive virtual reality (VR)-based neurocognitive intervention in critically ill patients. Our aim was to assess the feasibility of direct outcome measures to detect the impact of this digital therapy on patients’ cognitive and emotional outcomes. Seventy-two mechanically ventilated adult patients were randomly assigned to the “treatment as usual” (TAU, n = 38) or the “early neurocognitive stimulation” (ENRIC, n = 34) groups. All patients received standard intensive care unit (ICU) care. Patients in the ENRIC group also received adjuvant neurocognitive stimulation during the ICU stay. Outcome measures were a full neuropsychological battery and two mental health questionnaires. A total of 42 patients (21 ENRIC) completed assessment one month after ICU discharge, and 24 (10 ENRIC) one year later. At onemonth follow-up, ENRIC patients had better working memory scores (p = 0.009, d = 0.363) and showed up to 50% less non-specific anxiety (11.8% vs. 21.1%) and depression (5.9% vs. 10.5%) than TAU patients. A general linear model of repeated measures reported a main effect of group, but not of time or group–time interaction, on working memory, with ENRIC patients outperforming TAU patients (p = 0.008, ¿p2 = 0.282). Our results suggest that non-immersive VR-based neurocognitive stimulation may help improve short-term working memory outcomes in survivors of critical illness. Moreover, this advantage could be maintained in the long term. An efficacy trial in a larger sample of participants is feasible and must be conducted. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

La capacidad del barorreflejo como índice de identificación de los pacientes de UCI preparados para el destete

Actualmente, la Prueba de Respiración Espontánea (SBT), indica si un paciente está listo para el destete de la ventilación mecánica. Sin embargo, en torno al 20% de los pacientes “preparados” para ser desintubados, realmente no lo estaban. En este trabajo, se ha estudiado la Capacidad del Barorreflejo durante la hora anterior a la SBT, y se ha visto que existen diferencias significativas entre los pacientes listos para el destete y los que realmente no lo estaban, sugiriendo que la predicción del éxito del destete puede ser mejorada con este nuevo índice

Exact evaluation of a class of nonstationary approximating subdivision algorithms and related applications

For a class of nonstationary approximating subdivision schemes generalizing the cubic B-spline scheme, we derive closed-form expressions to describe the evolution of each initial control vertex during the whole subdivision process, and we find explicit formulas for exact evaluation of the limit curve and its first derivative at any dyadic-rational parameter value. These results provide, for the first time in the subdivision literature, an exact evaluation of limits obtained by nonstationary approximating subdivision algorithms. As will be shown at the end of this paper, the achievement of closed-form expressions for the limit stencils of a nonstationary approximating scheme has immediate benefits in the context of geometric modelling. Moreover, it marks a first step forward towards the development of further new theoretical results aimed at extending the use of nonstationary subdivision algorithms to new fields of application

Inspiratory muscle activation increases with COPD severity as confirmed by non-invasive mechanomyographic analysis

There is a lack of instruments for assessing respiratory muscle activation during the breathing cycle in clinical conditions. The aim of the present study was to evaluate the usefulness of the respiratory muscle mechanomyogram (MMG) for non-invasively assessing the mechanical activation of the inspiratory muscles of the lower chest wall in both patients with chronic obstructive pulmonary disease (COPD) and healthy subjects, and to investigate the relationship between inspiratory muscle activation and pulmonary function parameters. Both inspiratory mouth pressure and respiratory muscle MMG were simultaneously recorded under two different respiratory conditions, quiet breathing and incremental ventilatory effort, in 13 COPD patients and 7 healthy subjects. The mechanical activation of the inspiratory muscles was characterised by the non-linear multistate Lempel-Ziv index (MLZ) calculated over the inspiratory time of the MMG signal. Subsequently, the efficiency of the inspiratory muscle mechanical activation was expressed as the ratio between the peak inspiratory mouth pressure to the amplitude of the mechanical activation. This activation estimated using the MLZ index correlated strongly with peak inspiratory mouth pressure throughout the respiratory protocol in both COPD patients (r = 0.80, p<0.001) and healthy (r = 0.82, p<0.001). Moreover, the greater the COPD severity in patients, the greater the level of muscle activation (r = -0.68, p = 0.001, between muscle activation at incremental ventilator effort and FEV1). Furthermore, the efficiency of the mechanical activation of inspiratory muscle was lower in COPD patients than healthy subjects (7.61±2.06 vs 20.42±10.81, respectively, p = 0.0002), and decreased with increasing COPD severity (r = 0.78, p<0.001, between efficiency of the mechanical activation at incremental ventilatory effort and FEV1). These results suggest that the respiratory muscle mechanomyogram is a good reflection of inspiratory effort and can be used to estimate the efficiency of the mechanical activation of the inspiratory muscles. Both, inspiratory muscle activation and inspiratory muscle mechanical activation efficiency are strongly correlated with the pulmonary function. Therefore, the use of the respiratory muscle mechanomyogram can improve the assessment of inspiratory muscle activation in clinical conditions, contributing to a better understanding of breathing in COPD patients.This work was supported in part by the Secretariat of Universities and Research of the Ministry of Economy and Knowledge of the Generalitat de Catalunya (consolidated research groups GRC 2014 SGR 1569 and 424, and CERCA Programme), the Plan Nacional (SAF2014-54371), and by the Ministry of Economy and Competitiveness of the Spanish Government and the European Regional Development Fund, DPI2015-68820-R (MINECO/FEDER)