Accuracy of closed-loop and open-loop propofol delivery systems by bispectral index monitoring in breast surgery patients: a prospective randomized trial.

BACKGROUND: This randomized and controlled prospective study tested the hypothesis that closed-loop Target-Controlled Infusion (TCI) of propofol would be associated with better system performance when compared with open-loop controlled delivery of propofol. METHODS: Patients scheduled for elective breast surgery were randomly assigned to two groups: a closed-loop group, in which propofol infusion was performed by a closed-loop TCI system that used the Bispectral Index (BIS) as a feedback parameter to titrate the rate of propofol infusion, and an open-loop group, in which propofol infusion was performed manually and guided by the bispectral index. RESULTS: A total of 156 patients were recruited for this study (closed-loop group n = 79; open-loop group n = 77). The Global Score (GS) of the closed-loop group was lower than that of the open-loop group (34.3 and 42.2) (p = 0.044). The proportions of time with a BIS value between 40 and 60 were almost identical in the closed-loop group and the open-loop group (68.7 ± 10.6% and 66.7 ± 13.3%) (p = 0.318). The individuals in the closed-loop group consumed more propofol compared with those in the open-loop group (7.20 ± 1.65 mg.kg-1.h-1 vs. 6.03 ± 1.31 mg.kg-1.h-1, p < 0.001). No intraoperative recall, somatic events or adverse events occurred. No significant difference in heart rate was observed between the two groups (p = 0.169). CONCLUSION: The closed-loop protocol was associated with lower BIS variability and lower out-of-range BIS values, at the cost of a greater consumption of propofol when compared to the open loop group. REGISTER NUMBER: ChiCTR-INR-17010399.

Accuracy of closed-loop and open-loop propofol delivery systems by bispectral index monitoring in breast surgery patients: a prospective randomized trial

Abstract Background: This randomized and controlled prospective study tested the hypothesis that closed-loop Target-Controlled Infusion (TCI) of propofol would be associated with better system performance when compared with open-loop controlled delivery of propofol. Methods: Patients scheduled for elective breast surgery were randomly assigned to two groups: a closed-loop group, in which propofol infusion was performed by a closed-loop TCI system that used the Bispectral Index (BIS) as a feedback parameter to titrate the rate of propofol infusion, and an open-loop group, in which propofol infusion was performed manually and guided by the bispectral index. Results: A total of 156 patients were recruited for this study (closed-loop group n = 79; open-loop group n = 77). The Global Score (GS) of the closed-loop group was lower than that of the open-loop group (34.3 and 42.2) (p = 0.044). The proportions of time with a BIS value between 40 and 60 were almost identical in the closed-loop group and the open-loop group (68.7 ± 10.6% and 66.7 ± 13.3%) (p = 0.318). The individuals in the closed-loop group consumed more propofol compared with those in the open-loop group (7.20 ± 1.65 mg.kg−1.h−1 vs. 6.03 ± 1.31 mg.kg−1.h−1, p < 0.001). No intraoperative recall, somatic events or adverse events occurred. No significant difference in heart rate was observed between the two groups (p = 0.169). Conclusion: The closed-loop protocol was associated with lower BIS variability and lower out-of-range BIS values, at the cost of a greater consumption of propofol when compared to the open loop group. Register number:ChiCTR-INR-17010399.

Homogenised and pasteurised human milk: lipid profile and effect as a supplement in the enteral diet of Wistar rats.

The retention of human milk (HM) fat in nasogastric probes of infusion pumps can be observed during the feed of infants unable to suck at the mother's breast. The lack of homogenisation of HM could contribute to the fat holding. Therefore, the present study evaluated (i) the influence of homogenisation on milk fat retaining in infant feeding probes and (ii) the in vivo effect of the homogenisation on lipid absorption by Wistar rats. The animals were fed with HM treated following two processing conditions, that is, pasteurised and homogenised-pasteurised. The animals were randomly subdivided into four experimental groups: water-fed (control), pasteurised milk, homogenised-pasteurised milk and pasteurised-skimmed milk. The results of food consumption, mass body gain, corporate metrics and plasma blood levels of total cholesterol did not show any difference (P < 0·05) among the three types of HM used in the experiments. The liver, intestine and intra-abdominal adipose tissue of the four groups of animals presented normal and healthy histology. The composition of fatty acids in the brain tissue of animals fed with homogenised HM increased when compared with the groups fed with non-homogenised HM. These values were 11·08 % higher for arachidonic acids, 6·59 % for DAH and 47·92 % for nervous acids. The ingestion of homogenised HM promoted higher absorption of milk nutrients. Therefore, the addition of the homogenisation stage in HM processing could be an alternative to reduce fat retention in probes and to improve the lipids' absorption in the body.

Accuracy of a Low-Cost Continuous Subcutaneous Insulin Infusion Pump Prototype: In Vitro Study Using Combined Methodologies.

Considering that infusion devices are safety-critical systems, the main goal of this paper is to evaluate the infusion accuracy and precision of a low-cost insulin infusion pump prototype, using two different methodologies. The first one used a microgravimetric method adapted from IEC60601-2-24, and the second estimated the displacement of the syringe plunger in response to programmed infusions. The low-cost prototype resulted in a compact and functional device with good accuracy. The prototype infused the programmed fluid doses with an average error of 2.2%. The percentage of infusions within ± 5% accuracy was 42.50 and of 84.17% for the ± 15% limit. The developed miniaturized mechanical system presented functionality, precision, and accuracy when coupled to the electronic system, responded well to repeatability tests. Additionally, the results from in vitro tests demonstrated that the performance of the device is satisfactory and comparable to commercial continuous insulin infusion pumps. This study presents a low-cost prototype as a candidate to be used by type 1 diabetic patients in Brazil and developing countries, especially in the context of public health.

Desenlaces maternos, fetales y perinatales de las gestantes con diabetes en manejo con bomba de insulina en el Hospital Universitario San Ignacio / Maternal, fetal and perinatal outcomes of pregnant women with diabetes on insulin pump management at the Hospital Universitario San Ignacio

Antecedentes: La diabetes en el embarazo se asocia a un incremento considerable en la morbimortalidad materna, fetal y perinatal. Objetivo: Determinar los desenlaces maternos, fetales y perinatales de las gestantes con diagnóstico de diabetes pre gestacional en manejo con bomba de insulina en el Hospital Universitario San Ignacio. Método: Estudio de corte transversal en 24 gestantes con diagnóstico de diabetes en manejo con bomba de insulina quienes asistieron a control por Endocrinología y Alto Riesgo Obstétrico en el Hospital Universitario San Ignacio, entre Septiembre de 2009 y Diciembre de 2015. Resultados: La complicación materna más frecuente fue la hipoglicemia sintomática (50%), en segundo lugar los trastornos hipertensivos asociados al embarazo (45,8%). Las complicaciones neonatales más frecuentes fueron el síndrome de dificultad respiratoria del recién nacido (37,5%) y la hiperbilirrubinemia (37,5%). La hemoglobina glicosilada mayor del 6% se relacionó con el 71% de pacientes con macrosomía fetal. Conclusiones: La bomba de infusión de insulina representa una estrategia relativamente nueva dentro de los protocolos de manejo de diabetes pre gestacional y embarazo. Representaría una opción de manejo segura y fácil para el control de la glicemia en pacientes con indicaciones precisas.

Background: Diabetes in pregnancy is associated to a considerable increase in the maternal, fetal and perinatal morbidity and mortality. Objective: Determine the maternal, fetal and perinatal outcomes of patients with pre gestational diabetes being treated with insulin pump at Hospital San Ignacio. Methods: Cross-sectional study of 24 patients diagnosed with diabetes being treated with insulin pump who assisted to controls made by Endocrinology and Obstetrical High-Risk units at Hospital San Ignacio from September 2009 to December 2015. Results: The most common maternal complication was symptomatic hypoglycemia (50%) followed by hypertensive disorders of pregnancy (45.8%). Most common neonatal complications were respiratory distress syndrome (37.5%) and hyperbilirubinemia (37.5%). Glycosylated hemoglobin higher than 6% was related with 71% of patients who developed fetal macrosomia. Conclusions: The insulin infusion pump is a relatively new strategy management of pre gestational diabetes and pregnancy. Representing a safe and easy option for glycemic control in patients with precise indications.

Sedação controlada pelo paciente em cirurgia ortopédica sob anestesia regional: uma nova abordagem em sedação / Patient-controlled sedation in orthopedic surgery under regional anesthesia: a new approach in procedural sedation / Analgesia controlada por el paciente en cirugía ortopédica bajo anestesia regional: un nuevo abordaje en sedación

JUSTIFICATIVA E OBJETIVOS: Anestesia regional é uma técnica de uso comum em procedimentos ortopédicos. A sedação deve reduzir a ansiedade e o medo do paciente e aumentar a qualidade da anestesia regional. Este estudo avaliou as alterações hemodinâmicas, o nível de sedação e de satisfação tanto dos pacientes quanto dos cirurgiões e os potencias efeitos colaterais da sedação controlada pelo paciente com o uso de propofol. MÉTODOS: Selecionamos 60 pacientes, estado físico Asa I-III e agendados para artroplastia total do joelho sob anestesia combinada raqui-peridural. Os pacientes do Grupo P (n = 30) receberam propofol por meio de um dispositivo de analgesia controlada pelo paciente com as seguintes configurações: dose de propofol em bolus de 400 µg.kg-1 por via intravenosa (IV), com intervalo de bloqueio de cinco minutos e sem infusão basal. Os pacientes do Grupo S receberam infusão de solução salina (150 mL), com as mesmas configurações. Para determinar o nível de sedação, o índice bispectral (BIS) e a Escala de Avaliação de Alerta e Sedação dos Observadores (OAA/S) foram usados. O número de solicitações foi registrado para todos os pacientes. Como avaliação final, a satisfação dos cirurgiões e dos pacientes foi registrada em escala de 4 pontos. RESULTADOS: Os valores de BIS e da OAA/S foram menores no Grupo P que no Grupo S. A satisfação dos pacientes foi maior no Grupo P, embora não tenha havido diferença significativa em relação à satisfação dos cirurgiões entre os grupos. O número de solitações de sedação foi significativamente maior no Grupo S. Contudo, a maioria das solicitações não foi considerada bem-sucedida. CONCLUSÃO: Este estudo sugere que a analgesia controlada pelo paciente com o uso de propofol pode ser usada com resultados eficazes em procedimentos ortopédicos.

BACKGROUND AND OBJECTIVES: Regional anesthesia is a commonly used technique in orthopedic procedures. Sedation should reduce the patient's anxiety and fear while increasing regional anesthesia quality. This study evaluated the hemodynamic changes, level of sedation, both patients' and surgeons' levels of satisfaction and potential side effects in patient-controlled sedation using propofol. METHODS: This randomized clinical trial studied sixty ASA physical class I-III patients scheduled for total knee replacement surgery under combined spinal-epidural anesthesia. Patients in Group P (n = 30) received propofol via a patient-controlled analgesia device with the following settings: intravenous propofol bolus dose 400 µg.kg_1, 5-minute lockout interval and no basal infusion. In Group S, we infused saline 150 using the same settings. To determine the level of sedation, we used BIS and Observer's Assessment of Alertness/ Sedation Scale. For all patients, we recorded the number of requests. As the final evaluation, we scored surgeons' and patients' satisfaction on 4-point scales. RESULTS: Both BIS values and OAA/S scores were lower in Group P than in Group S. Patients' satisfaction was higher in Group P, although there was no significant difference with respect to surgeons' satisfaction between the groups. The number of requests for sedation was significantly higher in Group S. However, most requests were considered unsuccessful. CONCLUSION: This study suggests that patient-controlled sedation with propofol can be used efficiently in orthopedic procedures.

JUSTIFICATIVA Y OBJETIVOS: La anestesia regional es una técnica de uso común en los procedimientos ortopédicos. La sedación debe reducir la ansiedad y el miedo del paciente y aumentar la calidad de la anestesia regional. Este estudio evaluó las alteraciones hemodinámicas, el nivel de sedación, los niveles de satisfacción tanto de los pacientes como de los cirujanos y los potencias efectos colaterales de la sedación controlada por el paciente con el uso de propofol. MÉTODOS: Seleccionamos 60 pacientes, estado físico Asa I-III programados para la artroplastia total de la rodilla bajo anestesia combinada raquiepidural. Los pacientes del Grupo P (n = 30) recibieron propofol por medio de un dispositivo de analgesia controlada por el paciente con las siguientes configuraciones: dosis de propofol en bolo de 400 µg.kg-1 vía intravenosa (IV), con un intervalo de bloqueo de cinco minutos y sin infusión basal. Los pacientes del Grupo S recibieron infusión de solución salina (150 mL), con las mismas configuraciones. Para determinar el nivel de sedación, usamos el índice bispectral (BIS) y la Escala de Evaluación del Índice de Alerta y Sedación del Observador (EAIASO). El número de solicitaciones fue registrado para todos los pacientes. Como evaluación final, la satisfacción de los cirujanos y de los pacientes fue registrada en escala de 4 puntos. RESULTADOS: Los valores de BIS y de la Evaluación del Observador de Guardia (OAA/S) fueron menores en el Grupo P que en el Grupo S. La satisfacción de los pacientes fue mayor en el Grupo P, aunque no haya habido diferencia significativa con relación a la satisfacción de los cirujanos entre los grupos. El número de solicitaciones de sedación fue significativamente mayor en el Grupo S. Sin embargo, la mayoría de las solicitaciones no fue considerada exitosa. CONCLUSIONES: Este estudio sugiere que la analgesia controlada por el paciente con el uso de propofol puede ser usada con resultados eficaces en procedimientos ortopédicos.

MODELADO Y SIMULACIÓN DE UN ROBOT PARA CIRUGÍA ENDOSCÓPICA TRANSLUMINAL / EVALUATION METHOD OF THE USE OF MEDICAL DEVICES IN THE HOMECARE ENVIRONMENT

El uso de dispositivos médicos en el hogar, originalmente diseñados para uso hospitalario, ha aumentado. Su uso es complejo e inseguro debido a la inexperiencia del usuario y el entorno no controlado. El objetivo de este estudio es evaluar la seguridad en el uso de este tipo de dispositivos a través de la creación de un modelo conceptual que identifica los riesgos que podrían surgir para un grupo de usuarios inexpertos que los operan. A través de un estudio de usabilidad y siguiendo la metodología Grounded Theory se identificaron problemas y errores que emergen a través del uso en el hogar de dos dispositivos médicos distintos con la finalidad de crear un modelo conceptual. El modelo conceptual obtenido es representado en una herramienta de evaluación, que permite a los interesados identificar el dispositivo médico más apropiado para un usuario específico, detectando las debilidades que pueden llevar a un uso inseguro. La herramienta creada efectivamente permite detectar las características de riesgo, considerando cada situación particular de uso.

The use of medical devices in the home environment, originally designed for hospital use has increased. Its use is complex and uncertain because of the inexperience of the lay user and the uncontrolled environment. The objective of this study is to evaluate the safety in the use of these devices through the creation of a conceptual model that identifies the risks that could arise for a group of lay users who operate them. Through a usability study and following the Grounded Theory methodology problems and errors were identified emerging through the home use of two different medical devices in order to create a conceptual model. The conceptual model obtained is reified as an evaluation tool that allows stakeholders to identify the most suitable medical device for a specific user, detecting the weaknesses that may lead to an unsafe use. The evaluation tool created effectively allows detecting risky characteristics, considering the particular situation of use.

Anestesia total intravenosa: de la farmacéutica a la farmacocinética / Total intravenous anesthesia: from pharmaceutics to pharmacokinetics

Introducción. En la actualidad, la disponibilidad de medicamentos como el remifentanilo y el propofol, ha creado la necesidad en los anestesiólogos de tener conceptos básicos sobre la anestesia total intravenosa. Más allá de conocer cómo se construye un modelo farmacocinético, es fundamental entender la diferencia entre administrar un medicamento de forma farmacéutica, farmacocinética o farmacodinámica. Objetivo. Reflexionar sobre los conceptos básicos que le permitan al anestesiólogo moderno la administración de los medicamentos utilizados en la anestesia intravenosa de una forma farmacocinética. Metodología. Se realizó una búsqueda en la literatura indexada para obtener artículos didácticos e ilustrativos en los conceptos de anestesia total intravenosa y farmacocinética. Se seleccionaron aquellos que se consideraron más relevantes y se complementaron con textos guía en anestesia en lo concerniente a farmacocinética y anestesia total intravenosa. Resultados. Se obtuvieron 51 artículos y 5 capítulos de texto guía en anestesia. Independientemente de cuál de estos instrumentos utilicemos o qué tan exactos sean, lo realmente importante es saber que contamos con herramientas que nos permiten adecuar, con base en la estimación de los niveles plasmáticos, la anestesia en los diferentes momentos de la cirugía y, en el caso del remifentanilo, a condiciones particulares como la edad. Se trata de la evolución del anestesiólogo a la par con la de los fármacos cada vez más predecibles con los que contamos en la actualidad y de la posibilidad de obtener una anestesia más segura, más predecible, más costo-eficiente y con mayor control por parte del profesional.

Introduction. The availability of medications such as remifentanyl and propofol has made anesthesiologists feel the need to understand the basics of total intravenous anesthesia (TIVA). In fact. beyond knowing how to develop a pharmacokinetic model, it is essential to differentiate among the pharmaceutical, pharmacokinetic and pharmacodynamic approach for administering a particular drug. Objective. To review the basic concepts the modern anesthesiologist needs for the pharmacokinetic administration of the drugs used for intravenous anesthesia. Methodology. A search of the indexed literature was done to identify educational and illustrative articles about total intravenous anesthesia concepts and pharmacokinetics. The most relevant articles were selected for this review and it was supplemented with anesthesia textbooks in the gueareaof pharmacokinetics and total intravenous anesthesia. Results. 51 articles and 5 chapters from textbooks on anesthesia were selected. Regardless of the instruments used or how accurate they may be, what is really important is knowing that we have the tools available and based on the estimated plasma levels, we can adjust the anesthesia to the different stages of the surgical procedure; in the case of remifentanyl, it can be adjusted to the specific conditions such as the age of the patient. The point is that the anesthesiologist has to evolve keeping pace with the increasingly more predictable drugs now available and with the possibility of achieving a safer, more predictable and cost-effective anesthesia with greater control both by the experienced professional and the trainee.

Anestesia venosa total com infusão alvo-controlada de remifentanil e propofol para ablação de fibrilação atrial / Anestesia venosa total con infusión objeto-controlada de remifentanil y propofol para ablación de la fibrilación atrial / Total intravenous anesthesia with target-controlled infusion of remifetanil and propofol for ablation of atrial fibrillation

Justificativa e objetivos: A ablação de fibrilação atrial (FA) é um procedimento novo em nosso meio, embora seja comum em outros centros. A escolha da anestesia, monitores e cuidados anestesiológicos para esse procedimento, realizado fora do bloco cirúrgico, não tem sido descrita. O objetivo deste relato foi descrever uma técnica de anestesia para a realização..

Background and objectives: Although ablation of atrial fibrillation (AF) is common in other centers, among us it is a new procedure. The choice of anesthesia, monitors, and anesthesiologic care for this procedure performed outside the surgical center has not been described. The objective of this report was to describe an anesthesia technique...

Justificativa y objetivos: La ablación de fibrilación atrial (FA) es un procedimiento nuevo en nuestro medio, aunque sea común en otros centros. No han sido descritos la elección de la anestesia, los monitores y los cuidados anestesiológicos para ese procedimiento realizado fuera del bloque quirúrgico. El objetivo de este relato fue describir una técnica de anestesia...