NAVA enhances tidal volume and diaphragmatic electro-myographic activity matching: a Range90 analysis of supply and demand

in Journal of Clinical Monitoring and Computing (2012)

Neurally adjusted ventilatory assist (NAVA) is a ventilation assist mode that delivers pressure in proportionality to electrical activity of the diaphragm (Eadi). Compared to pressure support ventilation ... [more ▼]

Neurally adjusted ventilatory assist (NAVA) is a ventilation assist mode that delivers pressure in proportionality to electrical activity of the diaphragm (Eadi). Compared to pressure support ventilation (PS), it improves patient-ventilator synchrony and should allow a better expression of patient's intrinsic respiratory variability. We hypothesize that NAVA provides better matching in ventilator tidal volume (Vt) to patients inspiratory demand. 22 patients with acute respiratory failure, ventilated with PS were included in the study. A comparative study was carried out between PS and NAVA, with NAVA gain ensuring the same peak airway pressure as PS. Robust coefficients of variation (CVR) for Eadi and Vt were compared for each mode. The integral of Eadi (sh{phonetic}Eadi) was used to represent patient's inspiratory demand. To evaluate tidal volume and patient's demand matching, Range90 = 5-95 % range of the Vt/sh{phonetic}Eadi ratio was calculated, to normalize and compare differences in demand within and between patients and modes. In this study, peak Eadi and sh{phonetic}Eadi are correlated with median correlation of coefficients, R > 0.95. Median sh{phonetic}Eadi, Vt, neural inspiratory time (Ti_ <br /> Neural), inspiratory time (Ti) and peak inspiratory pressure (PIP) were similar in PS and NAVA. However, it was found that individual patients have higher or smaller sh{phonetic}Eadi, Vt, Ti_ <br /> Neural, Ti and PIP. CVR analysis showed greater Vt variability for NAVA (p < 0.005). Range90 was lower for NAVA than PS for 21 of 22 patients. NAVA provided better matching of Vt to sh{phonetic}Eadi for 21 of 22 patients, and provided greater variability Vt. These results were achieved regardless of differences in ventilatory demand (Eadi) between patients and modes. © 2012 Springer Science+Business Media New York. [less ▲]

NAVA enhances ventilatory variability and diaphragmaticactivity/tidal volume coupling

in Intensive Care Medicine (2010), 36(2), 326-326

Navicular syndrome - The comparison of MRI and histopathological findings

Poster (2003)

Navigating Polyfunctionality in the Lexicon

Conference (2009, December 10)

La navigation fluviale et l'avenir de la région liègeoise

in Revue Etudes et Expansion, Demain (1982), (293), 9

Nawoord

in Borgers, Gerrit (Ed.) Paul van Ostaijen. Een documentatie (1996)

This is an afterword to a reprint of the main biographical work on Paul van Ostaijen, which was first published in 1971.

Nazinga

Conference given outside the academic context (2008)

NbVO5 Mesoporous Thin Films by Evaporation Induced Micelles Packing: Pore Size Dependence of the Mechanical Stability upon Thermal Treatment and Li Insertion/Extraction

in Chemistry Of Materials (2011), 23(18), 4124-4131

Mesoporous thin films (MTFs) appear as an interesting architecture for positive electrodes in Li-ion energy storage systems because they offer high specific area and interconnected porosity presenting ... [more ▼]

Mesoporous thin films (MTFs) appear as an interesting architecture for positive electrodes in Li-ion energy storage systems because they offer high specific area and interconnected porosity presenting homogeneous pore size and wall thickness. However, it must be ascertained that the mesostructure survives template removal or/and crystallization and is retained on electrochemical cycling. In order to investigate the potentialities and limits of the soft-templating approach in the case of complex transition metal oxide networks, we deliberately selected a "difficult" compound: NbVO5 was chosen because it combines a challenging synthesis with reported severe structural distortions during the first lithium insertion in the bulk material. In this work, NbVO5 MTFs with different pore sizes were synthesized using the evaporation induced micelles packing (EIMP) method. PS-b-PEO diblock copolymers of different molar weights were used as structure directing agent in order to obtain wormlike porous networks with pore size and wall thickness ranging from 15 to 100 nm. Thermal ellipsometry analysis, used to track surfactant removal and crystallization of the layer, reveals that partial crystallization is possible while retaining the mesoporous architecture. Electron tomography complements result from environmental ellipsometric porosimetry, atomic force microscopy, and transmission electron microscopy to provide a comprehensive description of the structure. A multilayer process is also proposed to build crack-free thick mesoporous films. The mechanical stability of MTFs presenting three different pore sizes is tested by inserting Li(+) in amorphous NbVO5 MTFs using cyclic voltammetry. Capacity retention data show that the mechanical stresses associated with Li+ insertion are better accommodated by MTFs compared to nonporous films, and this ability is enhanced as the pore size decreases. [less ▲]

NCA asymmetric synthesis of 6-[18F]fluoro-L-dopa.

in Journal of Labelled Compounds & Radiopharmaceuticals (1991), 30

NCX3 knockout mice exhibit increased hippocampal CA1 and CA2 neuronal damage compared to wild-type mice following global cerebral ischemia

in Experimental Neurology (2008), 210

There is uncertainty as to whether the plasma membrane Na(+)/Ca(2+)exchanger (NCX) has a neuroprotective or neurodamaging role following cerebral ischemia. To address this issue we compared hippocampal ... [more ▼]

There is uncertainty as to whether the plasma membrane Na(+)/Ca(2+)exchanger (NCX) has a neuroprotective or neurodamaging role following cerebral ischemia. To address this issue we compared hippocampal neuronal injury in NCX3 knockout mice (Ncx3(-/-)) and wild-type mice (Ncx3(+/+)) following global cerebral ischemia. Using a bilateral common carotid artery occlusion (BCCAO) model of global ischemia we subjected NCX3 knockout and wild-type mice to 17 and 15 minutes of ischemia. Following the 17 minute period of ischemia, wild-type mice exhibited approximately 80% CA1 neuronal loss and approximately 40% CA2 neuronal loss. In contrast, NCX3 knockout mice displayed >95% CA1 neuronal loss and approximately 95% CA2 neuronal loss. Following the 15 minute period of ischemia, wild-type mice did not exhibit any significant hippocampal neuronal loss. In contrast, NCX3 knockout mice displayed approximately 45% CA1 neuronal loss and approximately 25% CA2 neuronal loss. The results clearly demonstrate that mice deficient in the NCX3 protein are more susceptible to global cerebral ischemia than wild-type mice. Our findings suggest NCX3 has a positive role in maintaining neuronal intracellular calcium homeostasis following ischemia, and that when exchanger function is compromised neurons are more susceptible to calcium deregulation and cell death [less ▲]