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Transesophageal echocardiography for verification of the position of the electrocardiographically-placed central venous catheter
No full textOBJECTIVE: Compare changes in P-wave amplitude of the intra-atrial electrocardiogram (ECG) and its corresponding transesophageal echocardiography (TEE)-controlled position to verify the exact localization of a central venous catheter (CVC) tip. DESIGN: A prospective study. SETTING: University, single-institutional setting. PARTICIPANTS: Two hundred patients undergoing elective cardiac surgery. INTERVENTIONS: CVC placement via the right internal jugular vein with ECG control using the guidewire technique and TEE control in 4 different phases: phase 1: CVC placement with normalized P wave and measurement of distance from the crista terminalis to the CVC tip; phase 2: TEE-controlled placement of the CVC tip; parallel to the superior vena cava (SVC) and measurements of P-wave amplitude; phase 3: influence of head positioning on CVC migration; and phase 4: evaluation of positioning of the CVC postoperatively using a chest x-ray. MEASUREMENTS AND MAIN RESULTS: The CVC tip could only be visualized in 67 patients on TEE with a normalized P wave. In 198 patients with the CVC parallel to the SVC wall controlled by TEE (phase 2), an elevated P wave was observed. Different head movements led to no significant migration of the CVC (phase 3). On a postoperative chest-x-ray, the CVC position was correct in 87.6% (phase 4). CONCLUSION: The study suggests that the position of the CVC tip is located parallel to the SVC and 1.5 cm above the crista terminalis if the P wave starts to decrease during withdrawal of the catheter. The authors recommend that ECG control as per their study should be routinely used for placement of central venous catheters via the right internal jugular vein
Verhalten elektroenzephalographischer (Bispectral Index™) und hämodynamischer (Herzfrequenz, Blutdruck) Parameter in Abhängigkeit vom Verfahren und der Qualität der Narkoseinduktion im Kindesalter
Get PDFIn der vorliegenden Arbeit wurden elektroenzephalographische und hämodynami-sche Parameter zur Überwachung der Narkoseinduktion bei Kindern, sowie das Auftreten von Exzitationen, Hustenereignissen und Intubationsreaktionen untersucht. In die Studie wurden insgesamt 54 Kinder (4 - 14 Jahre) eingeschlossen, die randomisiert drei Induktionsverfahren (schrittweise Einleitung mit Sevofluran, „single breath-Technik“, total intravenöse Anästhesie mit Propofol) zugewiesen wurden.
In allen drei Gruppen reflektierte das Verhalten des Bispectral Index die dynamischen Veränderungen des hypnotischen Niveaus. Das Zustandsbild „Wach“ ließ sich in allen drei Gruppen zuverlässig von den Zuständen „Verlust des Lidreflexes“, „Tonusverlust“ und „Intubation“ trennen (Pk ≥ 0,9). Unabhängig von der Narkoseinduktion zeigte der Bispectral Index in allen drei Gruppen eine ausreichende Hypnosetiefe zum Zeitpunkt der Intubation ([SEV-S] = 30±14; [SEV-V] = 24±10; [PROP] = 32±11). Dennoch wurden nach Sevofluran vermehrt Exzitationen (21 vs. 4; p ≤ 0,008) und nach Propofol verstärkt Hustenereignisse (11 vs. 3; p ≤ 0,011) und Intubationsreaktionen (3 vs. 0) registriert. Es war nicht möglich mit Hilfe des Bispectral Index diese Ereignisse vorherzusagen. Dies liegt wahrscheinlich an der fehlenden Erfassung spinal vermittelter Reaktionen. Problematisch ist weiterhin die Heterogenität der Einzelmesswerte aufgrund der breiten Altersverteilung.
Somit unterstreicht diese Arbeit die Notwendigkeit einer Weiterentwicklung der EEG-gestützten Monitorsysteme insbesondere hinsichtlich alterspezifischer Besonderheiten. Die Qualität der Narkoseinduktion unterscheidet sich rein klinisch, nicht aber hinsichtlich des Erreichens spezieller prozessierter EEG-Werte.:1 Einleitung 7
2 Methodik 12
2.1 Elektroenzephalographie 12
2.1.1 Grundlagen der Elektroenzephalographie 12
2.1.2 Wirkungen von Anästhetika auf das Elektroenzephalogramm 14
2.1.3 Bispectral Index 15
2.1.4 Interindividuelle Unterschiede und Einfluss des Lebensalters 17
2.1.5 Verwendete Geräte und Elektroden 18
2.2 Klinische Pharmakologie 20
2.2.1 Propofol (Disoprivan®) 20
2.2.2 Sevofluran (Sevorane®) 20
2.2.3 Alfentanil (Rapifen®) 21
2.3 Versuchsablauf 22
2.3.1 Studiendesign, Fallzahl, Studiendauer, Studienabbruch 22
2.3.2 Probanden, Aufklärung und Einwilligung, Randomisation 23
2.3.3 Einschluss- und Ausschlusskriterien 23
2.3.4 Standardisierung der drei Einleitungsverfahren 24
2.3.5 Datenerfassung 26
2.3.6 Flussdiagramm 27
2.3.7 Definition der klinischen Korrelate 28
2.4 Zielvariablen 29
2.4.1 Bispektral Index 29
2.4.2 Hämodynamik 29
2.4.3 Einleitungszeiten 29
2.4.4 Anästhesiequalität 30
2.5 Statistische Auswertung 31
3 Ergebnisse 32
3.1 Biometrische Daten 32
3.2 BIS 33
3.2.1 Verlauf des BIS zu den klinischen Korrelaten 33
3.2.2 Trennschärfe des BIS für ausgewählte klinische Korrelate 38
3.3 Hämodynamik 39
3.3.1 Herzfrequenz 39
3.3.2 Blutdruck 40
3.4 Zeitanalysen 43
3.5 Qualität der Narkoseinduktion 43
3.5.1 Intubationsreaktion 43
3.5.2 Exzitation 44
3.5.3 Hustenereignis 45
4 Diskussion 47
4.1 Ziel der Arbeit, Methodenkritik, biometrische Daten und Zeitanalysen 47
4.2 Die Veränderungen von BIS und Kreislaufparametern zu den klinischen Korrelaten 51
5 Zusammenfassung der Arbeit 67
6 Anhang 72
6.1 Versuchsprotokolle 72
7 Literaturverzeichnis 7
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Arzneimittelanwendungen in der Anästhesie klinische Pharmakologie und ärztliches Handeln ; 101 Tabellen
No full textDispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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