60 research outputs found

    Clinician miscalibration of survival estimate in hypothermic cardiac arrest: HOPE-estimated survival probabilities in extreme cases.

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    Patients with hypothermic cardiac arrest may survive with an excellent outcome after extracorporeal life support rewarming (ECLSR). The HOPE (Hypothermia Outcome Prediction after ECLS) score is recommended to guide the in-hospital decision on whether or not to initiate ECLSR in patients in cardiac arrest following accidental hypothermia. We aimed to assess the HOPE-estimated survival probabilities for a set of survivors of hypothermic cardiac arrest who had extreme values for the variables included in the HOPE score. Survivors were identified and selected through a systematic literature review including case reports. We calculated the HOPE score for each patient who presented extraordinary clinical parameters. We identified 12 such survivors. The HOPE-estimated survival probability was ≥10% for all (n = 11) patients for whom we were able to calculate the HOPE score. Our study confirms the robustness of the HOPE score for outliers and thus further confirms its external validity. These cases also confirm that hypothermic cardiac arrest is a fundamentally different entity than normothermic cardiac arrest. Using HOPE for extreme cases may support the proper calibration of a clinician's prognosis and therapeutic decision based on the survival chances of patients with accidental hypothermic cardiac arrest

    The Efficacy of Renal Replacement Therapy for Rewarming of Patients in Severe Accidental Hypothermia-Systematic Review of the Literature.

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    Renal replacement therapy (RRT) can be used to rewarm patients in deep hypothermia. However, there is still no clear evidence for the effectiveness of RRT in this group of patients. This systematic review aims to summarize the rewarming rates during RRT in patients in severe hypothermia, below or equal to 32 °C. This systematic review was registered in the PROSPERO International Prospective Register of Systematic Reviews (identifier CRD42021232821). We searched Embase, Medline, and Cochrane databases using the keywords hypothermia, renal replacement therapy, hemodialysis, hemofiltration, hemodiafiltration, and their abbreviations. The search included only articles in English with no time limit, up until 30 June 2021. From the 795 revised articles, 18 studies including 21 patients, were selected for the final assessment and data extraction. The mean rate of rewarming calculated for all studies combined was 1.9 °C/h (95% CI 1.5-2.3) and did not differ between continuous (2.0 °C/h; 95% CI 0.9-3.0) and intermittent (1.9 °C/h; 95% CI 1.5-2.3) methods (p > 0.9). Based on the reviewed literature, it is currently not possible to provide high-quality recommendations for RRT use in specific groups of patients in accidental hypothermia. While RRT appears to be a viable rewarming strategy, the choice of rewarming method should always be determined by the specific clinical circumstances, the available resources, and the current resuscitation guidelines

    Prognosis of Hypothermic Patients Undergoing ECLS Rewarming-Do Alterations in Biochemical Parameters Matter?

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    While ECLS is a highly invasive procedure, the identification of patients with a potentially good prognosis is of high importance. The aim of this study was to analyse changes in the acid-base balance parameters and lactate kinetics during the early stages of ECLS rewarming to determine predictors of clinical outcome. This single-centre retrospective study was conducted at the Severe Hypothermia Treatment Centre at John Paul II Hospital in Krakow, Poland. Patients ≥18 years old who had a core temperature (Tc) < 30 °C and were rewarmed with ECLS between December 2013 and August 2018 were included. Acid-base balance parameters were measured at ECLS implantation, at Tc 30 °C, and at 2 and 4 h after Tc 30 °C. The alteration in blood lactate kinetics was calculated as the percent change in serum lactate concentration relative to the baseline. We included 50 patients, of which 36 (72%) were in cardiac arrest. The mean age was 56 ± 15 years old, and the mean Tc was 24.5 ± 12.6 °C. Twenty-one patients (42%) died. Lactate concentrations in the survivors group were significantly lower than in the non-survivors at all time points. In the survivors group, the mean lactate concentration decreased -2.42 ± 4.49 mmol/L from time of ECLS implantation until 4 h after reaching Tc 30 °C, while in the non-survivors' group (p = 0.024), it increased 1.44 ± 6.41 mmol/L. Our results indicate that high lactate concentration is associated with a poor prognosis for hypothermic patients undergoing ECLS rewarming. A decreased value of lactate kinetics at 4 h after reaching 30 °C is also associated with a poor prognosis

    Pressure-induced collapse of H-bonded structures

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    Study of the effect of the adhesion promoter on the Coefficient of Friction, COF, of PET film

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    Coefficient of Friction, COF, is a very important parameter in the process of Flexo printing technique. For all films are very important both COF: static and dynamic. For film of PET undertaken a study to determine the impact of an adhesion promoter on the COF

    THE USE IN PRINTING OF THE PHOTONIC BAND GAP AS A PARTICULAR FEATURE OF PHOTONIC CRYSTALS

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    The photonic crystals are macroscopic structures. They exhibit many properties over which numerous tests are conducted. These crystals, thanks to the presence of so-called photonic band gap, cause conscious control of the course of electromagnetic waves. This property allows the conscious design of colors, because the color is not created by additive or subtractive synthesis, such as RGB or CMY, but through photonic changes taking place in the structure. The change in color may change due to changes in the viewing angle of the print or other external stimuli applied to the printed substrate.Photonic crystals, thanks to their introduction to pigments, are used in printing mainly as a kind of security for documents or product brand. It is difficult to fake such documents because they can not be scanned or copied. After some time, the possibility of producing photonic paper, which would solve the problem of environmental pollution, was also considered. The recorded image would disappear after some time and the paper could be re-used.Conducting experiments related to acquiring knowledge about the properties of photonic crystals is very expensive. The conditions for mass production have not yet been developed. It is expected that the structure of these crystals provides a new approach to light issues

    Properties of photonic crystals that enable their use in polygraphy

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    Photonic crystals are an innovative material and have recently been used in printing. They consist of dielectric layers of a variable refractive index. The change of this value may occur in one, two or three directions. Thanks to it, photonic crystals give the possibility of conscious control of the electromagnetic wave in the structure, which leads to the creation of photonic band gap, and this allows the conscious creation of color. It turns out therefore that the color is created not only as a result of the mixture of additive or subtractive basic colors, but also due to photonic changes as in the case of photonic crystals. Photonic crystals are used in printing as a method of securing documents. The deliberately designed width of the photonic band gap creates any color that can change under the influence of certain factors, such as the application of a magnetic field or a change in the angle of observation. Pigments containing photonic crystals make the item difficult to forge. So far, research has been conducted on the use of cognition of new properties of these crystals and on the use of those already known. Conducting experiments is expensive, however, the premonition of scientists allow to conclude that photonic crystals are a valuable material on which to focus more attention

    Numerical simulation of coupled quantum dots

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    In the work we present self-consistent solutions of Poisson and Schrödinger equations which describe electron states in coupled quantum dots. Results for two neighbouring quantum dots formed in an electrostatic way are discussed. Zero-dimensional electron gas is investigated in the structure proposed by Kastner [1] and presented in our earlier works [2-4]. In the work results of simulations performed in three- and two-dimensional space are shown. We included Hartree potential for modeling Coulomb interactions among electrons in the system. We also considered the exchange and correlation potentials which ensured that each discrete energy level was occupied by only one electron. The exchange and correlation potentials were taken into account with the help of the Local Density Approximation (LDA)

    The effect of level of soil hydratation on the content ofnitrogen compounds in the yield of New Zealand spinach

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    Doświadczenia polowe przeprowadzono w Stacji doświadczalnej Akademii Rolniczej w Szczecinie. Zróżnicowany poziom uwilgotnienia gleby wpłynął istotnie na plonowanie szpinaku nowozelandzkiego. Zawartość azotu w roślinach była zależna od części rośliny. Ulistnione wierzchołki pędów powyżej 15 cm, zawierały istotnie więcej suchej masy, azotu ogólnego, białka, azotanów i azotynów niż same liście.The field experiment was carried out in the Experimental Station of Agricultural University of Szczecin in 2003. Different levels of soil hydratation did not have a significant effect on the yielding of New Zealand spinach. The content of nitrogen compounds in the plants was significantly dependant on the usable parts of spinach plant. It was proved that stems with leaves up to 15 cm in length contained significantly more dry matter, total nitrogen, total protein, nitrates and nitrites than leaf blades alone
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