1,720,992 research outputs found
Anästhesie und perioperative Betreuung bei Patienten mit Morbus Parkinson
Idiopathic Parkinson's syndrome is associated with the loss of dopaminergic cells. It is defined by the presence of akinesia together with one of the cardinal symptoms: rigor, tremor, or postural instability. As the perioperative management of these patients can be challenging and they have an increased perioperative risk, every anaesthesiologist should know some special features. If a patient with Parkinson's disease does not receive the required amount of dopa, akinetic crisis may occur. Moreover, the administration of dopamine-antagonistic drugs can trigger a malignant neuroleptic syndrome. These are life-threatening clinical pictures that require intensive medical treatment. Therefore, patients with Parkinson's disease should be enabled to keep the period without the intake of the specific medication as short as possible. General anaesthesia should be performed with short acting anaesthetics and a regional anaesthesia might be beneficial. Besides, all dopamine antagonists sometimes used for prophylaxis or therapy of delirium or PONV (haloperidol, metoclopramide) are contraindicated. Alternatives are short-acting benzodiazepines, atypical neuroleptics and domperidone
Dolasetron and shivering. A prospective randomized placebo-controlled pharmaco-economic evaluation
Background and goal: Forced by the current economical situation, German hospitals have to reconsider their clinical productivity. When caregivers introduce new therapeutic concepts medical quality should either be improved without increasing costs or when reducing costs medical quality should be maintained. In the surgical field postoperative shivering reduces both patient comfort and medical quality. We therefore investigated the clinical pathway prevention of shivering with dolasetron in a prospective, randomized, placebo-controlled analysis of cost-effectiveness. Material and methods. After written informed consent we randomized 40 patients scheduled for lumbar disc hernia repair or head and neck surgery into two groups: patients of group D received dolasetron 1 mg/kg body weight during surgery whereas patients of group K received 100 ml saline as placebo. Primary endpoints were the incidence of shivering, the length of stay in the postanesthesia care unit and process-associated costs. Secondary endpoint was the influence on perioperative thermoregulation. Results. We observed postanesthetic shivering in 5 patients belonging to group D in comparison to 15 patients receiving the placebo (p < 0.05). The length of stay in the postanesthesia care unit was shorter in patients allocated to dolasetron (mean +/- SD; group D: 43 +/- 16 min, group K 62 +/- 18 min, p < 0.05). There was a significant saving in process-associated personnel costs (personnel costs in group D EUR 41.26 +/- 14, personnel costs in group K EUR 53.15 +/- 15) but in contrast the process-associated material costs were significantly increased (group D EUR 17.16 +/- 3, group K EUR 0.73 +/- 1, p < 0.05). Conclusions. The optimization of the clinical process and medical quality induced by a prophylaxis against shivering and postoperative nausea and vomiting compensates for the increased use of pharmaceutical resources in our setting
Myotoxicity of local anaesthetics. Experimental myth or clinical truth?
Intramuscular injections of local anaesthetic agents regularly result in reversible muscle damage, with a dose-dependent extent of the lesions. All local anaesthetic agents that have been examined are myotoxic, whereby procaine produces the least and bupivacaine the most severe muscle injury. The histological pattern and the time course of skeletal muscle injury appear relatively uniform: hypercontracted myofibrils become evident directly after injection, followed by lytic degeneration of striated muscle sarcoplasmic reticulum myocyte edema and necrosis. Intriguingly, in most cases myoblasts, basal laminae and connective tissue elements remain intact which subsequently ensures complete muscular regeneration. Subcellular pathomechanisms of local anaesthetic myotoxicity are still not understood in detail. Increased intracellular Ca2+ levels are suggested to be the most important element in myocyte injury, since denervation, inhibition of sarcolemmal Na+ channels and direct toxic effects on myofibrils have been excluded as sites of action. Although experimental myotoxic effects are impressively intense and reproducible, only few case reports of myotoxic complications in patients after local anaesthetic administration have been published. In particular, the occurrence of clinically relevant myopathy and myonecrosis has been described after continuous peripheral blockades, infiltration of wound margins, trigger point injections, peribulbar and retrobulbar blocks
Simulation as an additional tool for investigating the performance of standard operating procedures in anaesthesia
Background. In medicine, the use of standard operating procedures (SOPs) is often evaluated using questionnaires (QUES). However, QUES can have limitations with regard to method, thus leading to errors. Simulation (SIM) offers another opportunity for evaluation. We hypothesized that medical errors in the evaluation of SOPs using QUES could be detected by SIM, and that SIM is better qualified to demonstrate applied medicine. Methods. We investigated the use of SOPs in anaesthesia, rapid sequence induction (RSI), by means of a QUES (n=42) or SIM (n=42) among 84 anaesthesiologists. Seven measures for preventing aspiration during induction of anaesthesia were examined and evaluated according to a predetermined points system. Results. The average number of times that precautionary measures to prevent aspiration were mentioned in the QUES [4.8 (0.9)] or performed during SIM [5.0 (1.1)] did not differ between the two groups. Pre-oxygenation was the most frequently described or performed measure (95% vs 93%). However, other measures, such as avoidance of positive pressure ventilation (45% vs 85%), differed significantly between the two groups. Conclusions. QUES and SIM are powerful instruments for evaluating the implementation of SOPs such as RSI. SIM demonstrates automated behaviours and thus more clearly represents behaviours used in clinical practice than is possible to demonstrate using QUES. Using a combination of these two instruments, method errors resulting from the individual instruments can be reduced
GABAmimetic intravenous anaesthetics inhibit spontaneous Ca2+-oscillations in cultured hippocampal neurons
Background: Spontaneous Ca2+-oscillations are a possible mechanism of Ca2+-mediated signal transduction in neurons. They develop by a periodical interplay of Ca2+, which enters the neuron from the extracellular medium and triggers Ca2+ release from the endoplasmic reticulum (ER). Ca2+-oscillations are terminated by reuptake into the ER or plasmalemmal extrusion. Spontaneous Ca2+-oscillations are glutamate dependent and appear to be responsible for neuronal plasticity and integration of information. Here, we examined the role of the gamma-aminobutyric acid (GABA,) receptor on spontaneous Ca2+-oscillations and studied the effects of the anaesthetics miclazolam, thiopental and the non-anesthetic barbituric acid on spontaneous Ca2+-oscillations. Methods: Hippocampal neuronal cell cultures of 19-day-old embryonic Wistar rats 17-18 days in culture were loaded with the Ca2+-sensitive dye Fura-2AM. Experiments were performed using dual wave-length excitation fluorescence microscopy and calibration constants were obtained from in situ calibration. Results: Spontaneous Ca2+-oscillations are influenced by the GABA(A) receptor. The intravenous anaesthetics midazolam and thiopental suppressed the amplitude and frequency reversibly in a dose-dependent manner with EC50 in clinically relevant concentrations. This effect was mediated via the GABA(A) receptor as it could be reversed by the GABA(A) receptor antagonist bicuculline. In contrast, the application of barbituric acid had no effects on the spontaneous Ca2+-oscillations. Conclusion: Spontaneous Ca2+-oscillations are influenced by the GABAA receptor. Spontaneous Ca2+-oscillations might represent an interesting model system to study anaesthetic mechanisms on neuronal information processing
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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