Towards automation in anaesthesia: a review

Simpósio Internacional MeMeA, realizado em 2014.Surgeries represent a risk for patients and a big cost for the hospital. Anaesthesia represents a complex part of surgery also carries risks for patients. The most known are awareness (with deep psychological consequences); increased risk of morbidity and mortality; adverse reactions and long post-op recovery. The complexity of anaesthesia management can be reduced by studying the patients' responses and developing indicators of the patient state. To assess the level of depth of anaesthesia, the anaesthetist needs to be aware of the patient physiological responses to the drugs and to surgical stimuli. A system that could advise on the patient state considering all clinical signs being measured, the patient individual response and the amount of drugs, will have a big impact on patient overall safety and future health, post-op recovery and hospital resources. This paper does a review of different systems and methods applied to several aspects of the anaesthesia field. All with the goal of working towards automation in this very complex area, that involves high risks for patients. This paper covers advisor systems; signal processing; new monitors and devices; mathematical modelling; and control algorithms; all focused on practical clinical implementation. The objective is to have an overview of the work done so far and the steps taken towards automation in anaesthesia.ISPA - System Integration and Process Automation Unit - Part of the LAETA (Associated Laboratory of Energy, Transports and Aeronautics) a I&D Unit of the Foundation for Science and Technology (FCT), Portugal. FCT support under project PEst-OE/EME/LA0022/2013.info:eu-repo/semantics/publishedVersio

Cerebral and cardiovascular effects of analgesic doses of ketamine during a target controlled general anesthesia: a prospective randomized study

Introduction: Ketamine is increasingly being used in various pain settings. The purpose of this study was to assess the effect of an analgesic dose of ketamine in the bispectral index (BIS), spectral edge frequency (SEF-95), density spectral array (DSA), cerebral oximetry (rSO2) and mean arterial pressure (MAP) during general anaesthesia with a target controlled infusion. Methods: A prospective, single-blinded and randomized study on adult patients scheduled for elective spine surgery was carried out. After anaesthesia induction with propofol, remifentanil and rocuronium, when a stable BIS value (45-55) was achieved, an automatic recording of BIS, SEF-95, rSO2 and MAP values during 9 min was performed to establish patients baseline values. Subsequently, patients were randomly assigned to receive a ketamine bolus dose of 0.2 mg/kg, 0.5 mg/kg or 1 mg/kg; all variables were recorded for additional 9 min after the ketamine bolus, in the absence of any surgical stimulus. A p-value <0.05 was considered significant in the statistical analysis. Results and discussion: Thirty-nine patients were enrolled in the study. Our results show a dose-related increase of SEF-95 and BIS values. DSA demonstrate a shift in the frequency range and power distribution towards higher frequencies. Our results do not show significant differences in MAP and rSO2 values. Conclusion: When ketamine is used intraoperatively in analgesic doses, the anaesthetist should anticipate an increase in SEF-95 and BIS values which will not be associated with the level of anaesthesia.info:eu-repo/semantics/publishedVersio

Garch models for drug effects on patient heart rate, during general anaesthesia

A model that can describe the effect of anaesthetic drugs on patient’s heart rate (HR) is of great importance when considering haemodynamic stability under surgery. A Generalized Autoregressive Conditional Heteroscedasticity (GARCH) model was used to model HR considering the effect concentrations of the anaesthetic propofol and the analgesic remifentanil, using the clinical data of 16 patients. The model was able to capture the HR trend in all 16 patients with very small errors throughout the surgical time. A correlation was found between the GARCH parameters and patient baseline characteristics, leading to the possibility a patient adjusted adaptive model.info:eu-repo/semantics/publishedVersio

Modelos de lógica difusa para descrever o efeito de fármacos

Jornadas de Estatística e Computação, realizadas no CLA de Porto de Mós em 7 de maio de 2014A lógica difusa tenta reproduzir o raciocínio humano utilizando graus de certeza. Nesta palestra será apresentado o conceito de lógica difusa e a sua implementação na modelação do efeito de fármacos anestésicos nos sinais vitais dos doentes submetidos a anestesia geral (sob cirurgia)

Metodologias no ensino-aprendizagem a distância da estatística: desenvolvimento e reflexão

A estatística é encarada como um desafio dentro de cursos fora da área da matemática. Este aspecto ganha particular relevância num ambiente de ensino-aprendizagem a distância e eLearning, onde existe um risco acrescido de que os aspectos teóricos se sobreponham aos práticos. Neste artigo é explorada a estrutura de uma unidade curricular de estatística, inserida num curso de informática. A estrutura da unidade curricular e respectivas metodologias de aprendizagem, são apresentadas paralelamente com uma reflexão sobre o impacto no percurso de aprendizagem do estudante. A especificidade da estatística é explorada num ambiente virtual recorrendo a ferramentas audiovisuais e incentivando o processo construtivo de aprendizagem. A interacção dos estudantes ao longo do semestre é analisada, sendo aparente que a participação diminui com o decorrer do tempo. Os recursos audiovisuais são uma clara mais-valia para os estudantes, tal como a presença constante do docente. Neste contexto é de especial importância a integração de diferentes metodologias no processo pedagógico. Sendo necessário continuar com a incorporação de cenários mais relevantes para a área profissional dos estudantes. O objectivo é caminhar no sentido do ensino-aprendizagem no contexto da própria experiência do estudante.Statistics is seen as a challenge in courses outside the mathematics area. This is of particular relevance in a distance learning and eLearning environment, where there is an increased risk that theory overtakes practice. In this article, the structure of statistics curricular unit from a computer science course is explored. The structure of the curricular unit and its learning methodologies are presented in parallel with a reflection on its effect on the students learning path. The specificity of statistics is explored in a virtual environment taking advantage of audio-visual tools and encouraging a constructive learning process. The students’ interaction during the semester is analysed, with an apparent decreased during time. The audio-visual tools are a clear positive point for the students, so is the constant online presence of the lecturer. In this context, it is of special importance the integration in the pedagogical process of different methodologies. It is necessary to continue with the inclusion of scenarios relevant to the students’ professional area. The objective is to move towards a learning and teaching environment in the context of the students’ own experience.info:eu-repo/semantics/publishedVersio

Analgesic interpatient variability of remifentanil assessed through pupillary dilation reflex

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Intrapatient variability of the pupillary pain index to remifentanil

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Mode of delivery and labour analgesia: a study of preference in portuguese pregnant women

Background: Portugal has had one of the highest cesarean rates in Europe, possibly influenced by patient preferences. A reduction in the prevalence of these rates due to safety, quality, and concern with costs is one of the current goals of obstetric care. Fear of pain, often associated with vaginal delivery, is one of the reasons why pregnant women might prefer a cesarean section. Objective: The aim of this study was to identify the type of delivery and anaesthesia/analgesia preferred, as well as the reasons and factors associated with this preference, in a representative sample in order to identify possible modifiable factors possibly involved in increased rates. Methods: A descriptive cross-sectional study was carried out by an anonymous questionnaire to 245 pregnant women from February to April 2018. Respondents were also asked about their preference for peripartum anaesthesia/analgesia and on the sources of information that helped decide their preferences. Results: 22% of respondents would prefer an elective cesarean section. This preference was higher in women with a previous cesarean section. The preference for vaginal delivery was higher in women with more advanced pregnancies. The main reasons that led participants to prefer a vaginal delivery were the quicker postpartum recovery and not wanting to miss the first hours of their child's life. Regarding the preference for an elective cesarean section, the main reasons were fear and convenience. Most pregnant women preferred epidural analgesia. Respondents who selected their doctor (most common source) were more likely to prefer vaginal delivery. Conclusion: A minority of women showed a preference for cesarean delivery. A majority would prefer to have epidural anaesthesia. Despite the high cesarean rates, maternal desire for cesarean section is low, suggesting that this number is due to factors other than the preference of pregnant women.info:eu-repo/semantics/publishedVersio

Pupillary pain index correlates with postoperative pain scores in neurosurgical patients

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Propofol administration in the induction phase of general anesthesia in Portugal

Introdução: A administração adequada de propofol por via intravenosa durante a indução da anestesia geral implica um bom conhecimento da farmacocinética e da farmacodinâmica, um bom entendimento de como a anestesia altera a consciência e a habilidade de interpretar corretamente a monitorização dos sinais vitais. Este trabalho pretende avaliar a prática usual dos anestesiologistas em Portugal no que diz respeito à administração de propofol por via intravenosa durante a indução da anestesia geral. Material e Métodos: Estudo observacional transversal, descritivo e analítico realizado através de um questionário enviado por correio eletrónico a todos os médicos internos e especialistas em Anestesiologia de vários hospitais portugueses. O questionário apresentava um cenário convencional (Sujeito do sexo masculino, 50 anos, 60 kg, 160 cm, ASA I, submetido a anestesia geral com propofol a 1%) e incluía 10 questões relacionadas com a administração de propofol durante a indução. Foi realizada análise descritiva dos dados obtidos através do programa SPSS 23.0®. Resultados: Responderam ao inquérito 118 médicos, sendo que, a maioria eram especialistas há mais de 5 anos (56,9%). Baseados no cenário apresentado, a maioria dos anestesiologistas administraria uma dose de 60 mg de propofol na indução, a uma velocidade superior a 1200 mL/horas, avaliariam a perda de consciência através da perda do reflexo palpebral, o que se refletiria num índica BIS de 60. A maioria dos participantes medem a pressão arterial do doente a cada 5 minutos e nunca utilizaram sistemas de infusão alvo-controlada. Discussão: Os resultados do inquérito mostraram que existe uma grande variedade de métodos para avaliar a perda de consciência, uma diversidade no manuseamento e doses de propofol na indução, uma falta de experiência no uso de sistemas de infusão alvo-controlada e na avaliação da relação entre a dose, a velocidade e a concentração de propofol. Neste trabalho apresentaram-se também algumas sugestões para os anestesiologistas ponderarem implementar nas suas práticas clínicas. Conclusão: Parece haver uma diversidade na quantidade e na forma como os anestesiologistas portugueses utilizam o propofol na indução da anestesia geral.Introduction: Administering propofol intravenously adequately during induction of general anesthesia implies a good knowledge of pharmacokinetics and pharmacodynamics, a good understanding of how anesthesia alters consciousness and the ability to correctly interpret vital signs monitoring. The purpose of this study was to assess the usual practice of anesthesiologists in Portugal regarding the administration of propofol during the induction of general anesthesia. Methods: A transversal observational analytical and descriptive study, conducted through a questionnaire sent by e-mail to all anesthesiologists of several Portuguese hospitals. The questionnaire presented a conventional scenario (male subject, 50 years, 60 kg, 160 cm, ASA I, submitted to general anesthesia with 1% propofol) and has 10 questions directed to the administration of propofol during induction phase of general anesthesia. A descriptive analysis of the data was performed through SPSS 23.0®. Results: A total of 118 physicians responded to the survey, most of whom were experts for more than 5 years (56.9%). Based on the presented scenario, most anesthesiologists would administer mL/hours, and would assess loss of consciousness by evaluating loss of the eyelid reflex, which, in BIS index, would be reflected in a 60 value. Most participants measure the patient's blood pressure every 5 minutes and have never used target-controlled infusion systems. Discussion: The survey showed that there is a wide variety of methods to assess the loss of consciousness, a diversity in handling propofol in induction, a lack of experience in the use of targetcontrolled infusion systems and in the evaluation of the relationship between dose, velocity and concentration of propofol. In this work, some suggestions were also made for anesthesiologists to consider implementing in their clinical practices. Conclusion: There seems to be a diversity in the amount and in the way propofol is used by the Portuguese anesthesiologists to induce general anesthesia.Foundation for Science and Technology ((FCT), Portugal, for the PhD Scholarship SFRH/BD/98915/2013 and for the project UID/ SEM/50022/2013.info:eu-repo/semantics/publishedVersio