Assessment of respiratory mechanics in assisted spontaneous breathing by minimal variations of pressure support

Zielsetzung: Ziel der voriegenden Arbeit war es, eine Methode zu entwickeln, die durch minimale Variation des Unterstützungsdrucks (PS-Variationen) bei druckunterstützter Spontanatmung (PSV) eine nichtinvasive Messung der Atemmechanik und Atemarbeit von intubierten und PSV-beatmeten Patienten auf Intensivstationen ermöglicht. Methoden: Eine Machbarkeitsstudie wurde geplant und nach Zustimmung der Ethikkomission durchgeführt. Hierzu wurden nach schriftlicher Einwilligung durch den Patienten oder deren gesetzlichen Betreuer bei 20 intubierten und PSV-beatmeten intensivmedizinischen Patienten in Abständen von 5-10 Atemzügen für jeweils einen einzigen Atemzug PS-Variationen von ±1 und ±2 cmH2O durchgeführt. Die respiratorische Zeitkonstante wurde aus der Steigung aller annähernd linear verlaufenden 10%-Abschnitte der exspiratorischen Fluss-Volumenkurve bestimmt. Basierend auf der mittleren Änderung des Atemzugvolumens geteilt durch die mittlere inspiratorische Druckdifferenz wurde ein Schätzwert für die Compliance berechnet. Anschließend wurde durch Divison der respiratorischen Zeitkonstante durch die mittels PS-Variationen ermittelte Compliance die Resistance des respiratorischen Systems berechnet. Mit der derart ermittelten Compliance und Resistance wurde basierend auf der Bewegungsgleichung des respiratorischen Systems die Atemarbeit berechnet. Zur Ermittlung von Referenzwerten für die Atemmechanik wurden die Patienten zusätzlich während einer kurzen Phase kontrolliert beatmet und die Atemmechanik aus dem aufgezeichneten Ösophagusdruck berechnet. Als Referenzwert für die Atemarbeit wurde diese nach der Campbell-Methode mit Hilfe des aufgezeichneten Ösophagusdrucks berechnet. Ergebnisse: Die aus linearen 10%-Abschnitten der Exspiration berechnete Zeitkonstante zeigte eine akzeptable Korrelation mit den Referenzwerten. Es fand sich jedoch im Vergleich mit den Referenzwerten eine geringe systematische Abweichung von etwa 0,13 Sekunden nach oben. Die mittels PS-Variationen ermittelte Compliance korrelierte ebenfalls gut mit den Referenzwerten. Die PS-Variationen um ±2 cmH2O führten hierbei zu deutlich besseren Ergebnissen als die PS-Variationen um ±1 cmH2O. Bei der Compliance zeigte sich gegenüber den Referenzwerten eine geringfügige systematische Abweichung nach unten von 5 bis 9 ml/cmH2O. Die Resistance ließ sich durch Division der Zeitkonstante durch die Compliance nicht mit akzeptabler Genauigkeit berechnen. Dies führte dazu, dass auch die Berechnung der Atemarbeit mit Hilfe der durch PS-Variationen bestimmten Compliance und Resistance nicht mit klinisch akzeptabler Genauigkeit gelang. Schlussfolgerungen: Geringe Änderungen des Unterstützungsdrucks für einzelne Atemzüge sind zur Messung der Compliance unter assistierter Spontanatmung geeignet. Hierbei führen Änderungen um ±2 cmH2O zu genaueren Messergebnissen als Änderungen um ±1 cmH2O. Die Messung der Resistance und der Atemarbeit unter assistierter Beatmung sind mit der untersuchten Methode nicht mit akzeptabler Genauigkeit möglich. Das Verfahren könnte in automatisierter Form zur Verbesserung des Messwertes der Compliance bei Beatmungsgeräten oder, in Kombination mit einer verbesserten Methode zur Bestimmung der Resistance, zur kontinuierlichen Berechnung der Atemarbeit verwendet werden

Fiducial qTq_T resummation of color-singlet processes at N3^3LL+NNLO

We present a framework for $q_T$ resummation at N$^3$LL+NNLO accuracy for arbitrary color-singlet processes based on a factorization theorem in SCET. Our implementation CuTe-MCFM is fully differential in the Born kinematics and matches to large-$q_T$ fixed-order predictions at relative order $\alpha_s^2$. It provides an efficient way to estimate uncertainties from fixed-order truncation, resummation, and parton distribution functions. In addition to $W^\pm$, $Z$ and $H$ production, also the diboson processes $\gamma\gamma,Z\gamma,ZH$ and $W^\pm H$ are available, including decays. We discuss and exemplify the framework with several direct comparisons to experimental measurements as well as inclusive benchmark results. In particular, we present novel results for $\gamma\gamma$ and $Z\gamma$ at N$^3$LL+NNLO and discuss in detail the power corrections induced by photon isolation requirements.Comment: 56 pages, 26 figure

Two-stage, low noise quantum frequency conversion of single photons from silicon-vacancy centers in diamond to the telecom C-band

The silicon-vacancy center in diamond holds great promise as a qubit for quantum communication networks. However, since the optical transitions are located within the visible red spectral region, quantum frequency conversion to low-loss telecommunication wavelengths becomes a necessity for its use in long-range, fiber-linked networks. This work presents a highly efficient, low-noise quantum frequency conversion device for photons emitted by a silicon-vacancy (SiV) center in diamond to the telecom C-band. By using a two-stage difference-frequency mixing scheme SPDC noise is circumvented and Raman noise is minimized, resulting in a very low noise rate of $10.4 \pm 0.7$ photons per second as well as an overall device efficiency of $35.6\, \%$. By converting single photons from SiV centers we demonstrate the preservation of photon statistics upon conversion.Comment: 12 pages, 3 figure

The value of multimodality imaging for detection, characterisation and management of a wall adhering structure in the right atrium

The case presents a wall adherent structure in the right atrium in a young patient with peripheral tcell lymphoma followed by successful prolonged lysis therapy resulting in the resolution of the thrombus is presented. This case highlights the utility of multimodality imaging in an accurate assessment of the right atrium thrombus and the effectiveness of prolonged lysis therapy.peer-reviewe

Telecom quantum photonic interface for a 40Ca+ single-ion quantum memory

Entanglement-based quantum networks require quantum photonic interfaces between stationary quantum memories and photons, enabling entanglement distribution. Here we present such a photonic interface, designed for connecting a 40Ca+ singleion quantum memory to the telecom C-band. The interface combines a memory-resonant, cavity-enhanced spontaneous parametric down-conversion photon pair source with bi-directional polarization-conserving quantum frequency conversion. We demonstrate preservation of high-fidelity entanglement during conversion, fiber transmission over up to 40 km and backconversion to the memory wavelength. Even for the longest distance and bi-directional conversion the entanglement fidelity remains larger than 95% (98%) without (with) background correction

The effects of three mash separation systems on the isomerisation of hop alpha‐acids

This study investigates the effects of wort composition from three lautering systems on hop utilisation at different hop boiling and dosing times. A response surface methodology was applied with 60 single tests at a 5 litre scale. The parameters, which were varied, were lautering system, boiling time without hops, boiling time with hops and α‐acid dosage. It was shown that the wort composition from the different lautering systems requires different boiling times or enables the reduction in boiling time with hops. Although the pH and original gravity of the lauter tun and mash filter worts were similar, different boiling times were necessary to achieve the same concentration of iso‐α‐acids. Further, there were variations in fatty acid composition of the worts. In order to be able to assess the effects on a larger scale, six brews were performed in a 10 hL pilot brewery. The utilisation of hop bitter substances differed despite the same boiling time and the same α‐acid dosage in relation to the total quantity of wort. In addition, no significant losses of hop bitter substances were observed in the wort from a continuous mash filtration system due to the process related higher dosage of α‐acid. Both sets of experiments showed that the boiling times depend on the wort composition and increased as follows: novel continuous mash filtration system < mash filter < lauter tun. The results lay the foundation for calculating the optimal parameter settings for each brewery to optimise the hop isomerisation rate

SCET sum rules for B->P and B->V transition form factors

We investigate sum rules for heavy-to-light transition form factors at large recoil derived from correlation functions with interpolating currents for light pseudoscalar or vector fields in soft-collinear effective theory (SCET). We consider both, factorizable and non-factorizable contributions at leading power in the Lambda/m_b expansion and to first order in the strong coupling constant alpha_s, neglecting contributions from 3-particle distribution amplitudes in the B-meson. We pay particular attention to various sources of parametric and systematic uncertainties. We also discuss certain form factor ratios where part of the hadronic uncertainties related to the B-meson distribution amplitude and to logarithmically enhanced alpha_s corrections cancel.Comment: 27 pages, 19 figures, minor corrections, matches journal versio

Interaction of proteins and amino acids with iso-α-acids during wort preparation in the brewhouse

This paper investigates the binding behavior of iso-α-acids from hops on free wort amino acids and proteins concerning the wort production process in breweries. The studies were carried out with different amino acids, bovine serum albumin and wort. To identify the nature of reaction between iso-α-acids and these substances, analyses of free amino nitrogen, HPLC and isothermal titration calorimetry were performed. According to the results, the iso-α-acids do not form covalent bonds with free amino acids of wort. However, iso-α-acids, especially isohumulone and isoadhumulone, form ionic bonds with wort proteins. A distinction must be made between proteins that are present in the hot trub, and those that are still dissolved in the hot wort. Proteins that are already coagulated and precipitated no longer react with iso-α-acids. Future experiments will investigate whether the established ionic bonds between iso-α-acids and proteins from the wort preparation process are maintained during fermentation until the finished beer or beer foam. If this is the case, which is induced by the experiments, there is a measurable loss of iso-α-acids in the hot wort, but at the same time, a gain for the later beer foam retention, as the iso-α-acids will stabilize it.TU Berlin, Open-Access-Mittel – 202

Ventilatory Effects of Isoflurane Sedation via the Sedaconda ACD-S versus ACD-L : A Substudy of a Randomized Trial

Devices used to deliver inhaled sedation increase dead space ventilation. We therefore compared ventilatory effects among isoflurane sedation via the Sedaconda ACD-S (internal volume: 50 mL), isoflurane sedation via the Sedaconda ACD-L (100 mL), and propofol sedation with standard mechanical ventilation with heat and moisture exchangers (HME). This is a substudy of a randomized trial that compared inhaled isoflurane sedation via the ACD-S or ACD-L to intravenous propofol sedation in 301 intensive care patients. Data from the first 24 h after study inclusion were analyzed using linear mixed models. Primary outcome was minute ventilation. Secondary outcomes were tidal volume, respiratory rate, arterial carbon dioxide pressure, and isoflurane consumption. In total, 151 patients were randomized to propofol and 150 to isoflurane sedation; 64 patients received isoflurane via the ACD-S and 86 patients via the ACD-L. While use of the ACD-L was associated with higher minute ventilation (average difference (95% confidence interval): 1.3 (0.7, 1.8) L/min, p < 0.001), higher tidal volumes (44 (16, 72) mL, p = 0.002), higher respiratory rates (1.2 (0.1, 2.2) breaths/min, p = 0.025), and higher arterial carbon dioxide pressures (3.4 (1.2, 5.6) mmHg, p = 0.002), use of the ACD-S did not significantly affect ventilation compared to standard mechanical ventilation and sedation. Isoflurane consumption was slightly less with the ACD-L compared to the ACD-S (−0.7 (−1.3, 0.1) mL/h, p = 0.022). The Sedaconda ACD-S compared to the ACD-L is associated with reduced minute ventilation and does not significantly affect ventilation compared to a standard mechanical ventilation and sedation setting. The smaller ACD-S is therefore the device of choice to minimize impact on ventilation, especially in patients with a limited ability to compensate (e.g., COPD patients). Volatile anesthetic consumption is slightly higher with the ACD-S compared to the ACD-L

Peripheral Ventricular Assist Devices in Interventional Cardiology: The Impella® Micro-Axial Pump

Coronary artery disease (CAD) presents an ever-growing burden on health systems especially in the Western world. While percutaneous coronary intervention (PCI) is feasible in increasingly complex CAD, certain patient groups possess a high risk for major cardiac adverse events (MACE) during PCI. Poor outcome is associated with significantly depressed left ventricular function, complexity of relevant lesions, and increasing incidence of pre-existing cerebrovascular comorbidities and poor pre-interventional status. However, these risk factors also translate into a high peri-operative risk for coronary artery bypass graft (CABG) rendering some of these patients inoperable. Peripheral ventricular assist devices (pVADs) are temporarily inserted axial or centrifugal pumps that support ventricular output during PCI. The Impella® micro-axial device (Abiomed, Danvers, Massachusetts, USA) is an easily implantable pVAD that may improve patient outcome during PCI in high-risk patients (termed “protected PCI”) and in patients with cardiogenic shock (CS). pVADs in general and the Impella® system in particular play important roles in interventional cardiology and its indications and use will likely expand in the future. This chapter outlines in detail the indications, applications, and future trends concerning the Impella® system. Practical advice is given on the correct implantation of the device