1,720,974 research outputs found
An innovative technique to improve safety of volatile anesthetics suction from the cardiopulmonary bypass circuit
No full textContext: Myocardial injury during cardiac surgery on cardiopulmonary bypass (CPB) is a major determinant of morbidity and mortality. Preclinical and clinical evidence of dose- and time-related cardioprotective effects of volatile anesthetic drugs exist and their use during the whole surgery duration could improve perioperative cardiac protection. Even if administering volatile agents during CPB are relatively easy, technical problems, such as waste gas scavenging, may prevent safe and manageable administration of halogenated vapors during CPB. Aims: The aim of this study is to improve the safe administration of volatile anesthesia during CPB. Settings and Design: Tertiary teaching hospital. Subjects and Methods: We describe an original device that collects and disposes of any volatile anesthetic vapors present in the exit stream of the oxygenator, hence preventing its dispersal into the operating theatre environment and adaptively regulates pressure of oxygenator chamber in the CPB circuit. Results: We have so far applied a prototype of this device in more than 1300 adult cardiac surgery patients who received volatile anesthetics during the CPB phase. Conclusions: Widespread implementation of scavenging system like the one we designed may facilitate the perfusionist and the anesthesiologist in delivering these cardioprotective drugs with beneficial impact on patients' outcome without compromising on safety
Minimum alveolar concentration of sevoflurane for maintaining BIS below 50 in patients undergoing coronary artery bypass grafting during normothermic cardiopulmonary bypass phase
No full textIntrodução: A concentração alveolar mínima (CAM) de anestésico inalatório em que 50% dos pacientes mantêm o valor do índice bispectral (BIS) abaixo de 50 é denominada CAMBIS50. A CAMBIS50 foi determinada em pacientes de diferentes idades e condições clinicas, mas não em cirurgia cardíaca. Objetivo: Determinar a concentração alveolar mínima do sevoflurano para índice bispectral abaixo de 50 durante o reaquecimento na circulação extracorpórea, em pacientes submetidos à revascularização do miocárdio. Métodos: Pacientes com estado físico III ou IV da American Society of Anestesiology, com idade entre 40 e 70 anos e submetidos à revascularização do miocárdio foram recrutados para este estudo. Na fase final de reaquecimento da circulação extracorpórea, durante o estado de equilíbrio, uma concentração expirada final alvo pré-determinada do sevoflurano foi mantida por pelo menos dez minutos. Seguido imediatamente por uma avaliação durante 1 minuto do valor do BIS, consistindo de 6 registros feitos em intervalos de 10 segundos. O vaporizador foi ajustado para atingir uma concentração final do sevoflurano de 1% no primeiro paciente. Se um dado paciente apresentasse uma média de valor do BIS abaixo de 50, a concentração expirada final do sevoflurano era reduzida em 0,1% no paciente subsequente. Enquanto, se o paciente apresentasse uma média de valor do BIS 50, a concentração expirada final do sevoflurano era aumentada em 0,1% no paciente subsequente. A CAMBIS50 foi calculada pela média dos pontos médios de cada par cruzado através da sequência Up-and-Down de Dixon. Esta sequência foi avaliada também pelo Probit test, que nos permitiu obter as probabilidades 50% e 95% do sevoflurano para manter um valor do BIS < 50. Resultado: Dos 18 pacientes que foram recrutados para este estudo, 15 efetivamente continuaram no estudo (9 tiveram valores de BIS < 50 e 6 tiveram valores de BIS 50). A CAMBIS50 do sevoflurano durante o reaquecimento na circulação extracorpórea, em adultos com idade entre 40 e 70 anos submetidos à revascularização do miocárdio, calculada pelo método Up-and-Down de Dixon foi de 0,82% [intervalo de confiança de 95% (IC 95%): 0,47-1,16]. As probabilidades 50% e 95% calculadas pelo Probit test para o mesmo contexto foram respectivamente, 0,73% (IC 95%: 0,45-1,00) e 1,39% (IC 95%: 0,42-2,37). Conclusão: A CAMBIS50 do sevoflurano durante o reaquecimento na circulação extracorpórea, em adultos com idade entre 40 e 70 anos submetidos à revascularização do miocárdio, calculada pelo método Up-and-Down de Dixon foi de 0,82% (IC 95%: 0,47-1,16).Introduction: The minimum alveolar concentration (MAC) of inhalational anesthetic for maintaining bispectral index (BIS) below 50 in 50% of patients is defined MACBIS50. MACBIS50 was determined in different ages groups and clinical conditions of patients, however not in cardiac surgery. Objective: This study aims to determine the minimum alveolar concentration of sevoflurane for maintaining bispectral index below 50 in patients undergoing coronary artery bypass grafting during normothermic cardiopulmonary bypass phase. Method: Patients with physical status III or IV of the American Society of Anestesiology, aged between 40 and 70 years and undergoing myocardial revascularization were enrolled in our study. The predetermined target expired concentration of sevoflurane was maintained for at least ten minutes during normothermic cardiopulmonary bypass phase. BIS values were then recorded at an interval of 10 seconds for 1 minute in the state of equilibio. The dial settings were adjusted to attain an end-tidal sevoflurane concentration of 1% in the first patient. If a given patient had an average BIS of < 50, the sevoflurane concentration was reduced by 0.1% in the subsequent patient, whereas if a given patient had a BIS 50, the sevoflurane concentration was increased by 0.1% in the next patient. MACBIS50 was calculated using the midpoint concentration of patients involving a crossover according to the Dixons Up-and-Down sequence. The Up-and-Down sequences were also analyzed by the probit test, which enabled us to derive the sevoflurane concentration to obtain the 50% and 95% probabilities to maintain a BIS value < 50. Result: Of the 18 patients who were recruited for this study, 15 effectively continued in the study (9 had BIS values < 50 and 6 had BIS values 50). MACBIS50 of sevoflurane was 0.82% (CI 95%: 0.47-1.16) in patients undergoing coronary artery bypass grafting during normothermic cardiopulmonary bypass phase. The 50% and 95% probabilities calculated by the Probit test for the same context were, respectively, 0.73% (95% CI: 0.45-1.00) and 1.39% (95% CI: 0.42-2.37). Conclusion: MACBIS50 of sevoflurane was 0.82% (CI 95%: 0.47-1.16) in patients undergoing coronary artery bypass grafting during normothermic cardiopulmonary bypass phase
Evaluation of the systemic inflammatory response with the use of sevoflurane during cardiopulmonary bypass in myocardial revascularization surgery
No full textIntrodução: Atualmente, a anestesia para cirurgia de revascularização do miocárdio segue uma abordagem que visa combater os processos de lesões causados pela isquemia e reperfusão, por meio do pré-condicionamento cardíaco isquêmico remoto e farmacológico, como o proporcionado pelos anestésicos inalatórios, o que pode gerar uma redução nos processos inflamatórios associados à circulação extracorpóra, conforme modelo experimental. Objetivo: Avaliar o efeito anti-inflamatório do Sevoflurano nos pacientes submetidos a revascularização do miocárdio com CEC. Métodos: Foram incluídos total de 100 pacientes, submetidos a revascularização do miocárdio eletiva com CEC, e foram alocados aleatoriamente em 2 grupos: Grupo SEVO (n=50) e Grupo CONTROLE (n=50), com e sem uso de Sevoflurano durante a CEC, respectivamente. Foram anotadas informações biodemográficas e clínicas do pré e pós-operatório e coletadas também as amostras de sangue periférico para dosagens bioquímicas e análise da biologia molecular. Foram avaliados; PMN-elastase IL-1b, IL-4, IL-6, IL-8, IL-10, TNFa e TGFb, além da expressão gênica e dos microRNAs envolvidos no processo inflamatório. A análise estatística foi feita comparando os dois grupos. Resultados: Os parâmetros biodemográficos e clínicos préoperatórios foram homogêneos entre os grupos. As medicações em uso préoperatório mostraram uma diferença significativa para o uso do inibidor da enzima conversora de angiotensina no grupo SEVO (p=0,046). Os dados pósoperatórios mostraram um tempo de intubação maior no grupo SEVO (p=0,049), no entanto, sem diferença nas complicações e na mortalidade. A maioria das expressões gênicas nos leucócitos não mostraram diferença. As citocinas próinflamatórias circulantes IL-1B (p=0,004) e IL-8 (p=0,029) a IL-6 (p=0,009) estavam diminuídas no grupo SEVO. As citocinas anti-inflamatórias IL-4 (p=0,021) estava diminuída no grupo SEVO e IL10 (p=0,004) aumentada no grupo CONTROLE. Os microRNAs que atuam na regulação destas citocinas foram menos expressos no grupo SEVO. Conclusão: No contexto da cirurgia de revascularização do miocárdio com CEC, o sevoflurano pode diminuir o processo inflamatório, regulando os mecanismos pós-transcricionais mediados pelos microRNAs na síntese de citocinas pró e anti-inflamatórias.Introduction: Currently, anesthesia for myocardial revascularization surgery follows an approach that aims to combat the processes of injuries caused by ischemia and reperfusion, through remote ischemic and pharmacological cardiac preconditioning, such as that provided by inhaled anesthetics, which can generate a reduction in the inflammatory processes associated with extracorporeal circulation, according to the experimental model. Objective: To evaluate the antiinflammatory effect of Sevoflurane in patients undergoing coronary artery bypass graft with CPB. Methods: A total of 100 patients who underwent elective myocardial revascularization with CPB were included, and were randomly allocated to 2 groups: SEVO Group (n = 50) and CONTROL Group (n = 50), with and without the use of Sevoflurane during CEC, respectively. Pre-and postoperative bio-demographic and clinical information were recorded and peripheral blood samples were also collected for biochemical measurements and analysis of molecular biology. Were evaluated; PMN-elastase IL-1b, IL-4, IL-6, IL-8, IL-10, TNFa and TGFb, in addition to gene expression and microRNAs involved in the inflammatory process. Statistical analysis was performed comparing the two groups. Results: The preoperative bioemographic and clinical parameters were homogeneous between the groups. Preoperative medications showed a significant difference for the use of the angiotensin-converting enzyme inhibitor in the SEVO group (p = 0.046). Postoperative data showed a longer intubation time in the SEVO group (p = 0.049), however, with no difference in complications and mortality. Most leukocyte gene expressions showed no difference. Circulating pro-inflammatory cytokines IL-1B (p = 0.004) and IL-8 (p = 0.029) to IL-6 (p = 0.009) were decreased in the SEVO group. The anti-inflammatory cytokines IL- 4 (p = 0.021) was decreased in the SEVO group and IL10 (p = 0.004) increased in the CONTROL group. The microRNAs that act in the regulation of these cytokines were less expressed in the SEVO group. Conclusion: In the context of myocardial revascularization surgery with CPB, sevoflurane can decrease the inflammatory process, regulating microRNA-mediated post-transcriptional mechanisms in the synthesis of pro and anti-inflammatory cytokines
The effects of adding intrathecal sufentanil to general anesthesia in patients undergoing coronary artery bypass grafting
No full textObjetivo: Avaliar os efeitos da associacao de sufentanil intratecal a anestesia geral com relacao as alteracoes hemodinamicas no intraoperatorio, em pacientes submetidos a cirurgia de revascularizacao do miocardio com circulacao extracorporea. Tambem avaliados seus possiveis impactos em resultados pos-operatorios, como tempo para a retirada da canula endotraqueal, analgesia e tempo de permanencia na unidade de terapia intensiva e hospitalar. Metodos: Estudo randomizado e prospectivo, nao encoberto ao regime anestesico utilizado, realizado no Instituto Dante Pazzanese de Cardiologia apos aprovacao pelo Comite de Etica em pesquisa local. Incluidos 40 pacientes de ambos os sexos, divididos em dois grupos, S e N, na dependencia de receberem ou nao 1 μg.kg-1 de sufentanil intratecal, respectivamente. A inducao e manutencao da anestesia , incluindo a CEC, foram feitas com sevoflurano, pancuronio e infusao continua de remifentanil. Obtidas variaveis hemodinamicas, niveis sericos de troponina cardiaca I e peptideo natriuretico tipo B (avaliando cardioprotecao), interleucina 6 e fator de necrose tumoral alfa (avaliando resposta inflamatoria), dados coletados no intra e no pos-operatorio. Na analise estatistica os dados obtidos foram expressos em numero (porcentagem), media (±desvio padrao), ou mediana (variacao interquartil). Os testes compararam os grupos com relacao aos dados demograficos; necessidade do uso de drogas vasoativas; consumo de agentes anestesicos; dados bioquimicos e dados hemodinamicos. Resultados: Os grupos foram comparaveis quanto aos dados demograficos. Os pacientes do grupo S necessitaram de menor suporte inotropico com dopamina quando comparados aos pacientes do grupo N (9,5% vs 58%; p=0,001) e tambem menor consumo de remifentanil (62% vs 100%; p=0,004). Nao houve diferenca estatistica significativa quanto aos dados bioquimicos avaliados. Conclusoes: Os pacientes que receberam sufentanil intratecal apresentaram maior estabilidade hemodinamica quando comparados ao grupo controle. Tal resultado foi demonstrado por um menor suporte inotropico e menor necessidade nas doses de opiodes venosos utilizadas. Estes efeitos nao parecem terem sidos decorrentes de menor resposta inflamatoria, como tambem por maior cardioprotecaoBV UNIFESP: Teses e dissertaçõe
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
Dispelling 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
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