Endocarditis infecciosa de válvula nativa: factores asociados a resultados adversos / Mortality predictors in patients with native valve infec tive endocarditis

Resumen Introducción : La mortalidad de la endocarditis infec ciosa (EI) en Argentina continúa siendo elevada. El obje tivo del trabajo fue describir las características clínicas e identificar factores asociados a mortalidad en pacientes con EI de válvula nativa. Métodos : Estudio de cohorte retrospectiva que inclu yó pacientes adultos con diagnóstico de EI de válvula nativa internados durante 2011-2021. Resultados : Se incluyeron 129 pacientes con una edad promedio de 66±17 años. El organismo responsa ble más frecuente (38.8%, n = 50) fue el Staphylococcus aureus (SA). El 63.6% presentó criterios de indicación quirúrgica. La mortalidad durante la internación fue del 22.5%. En el análisis multivariado que incluyó índice de comorbilidad Charlson, infección por SA y la presencia de criterios de indicación quirúrgica, se observó un OR ajustado de mortalidad de 1.32 (IC95% 1.10-1.57; p = 0.003), 2.75 (IC95% 1.11-6.8; p = 0.028) y 4.14 (IC95% 1.34-12; p = 0.013), respectivamente. En el análisis mul tivariado para mortalidad alejada que agregó el criterio quirúrgico y la realización de cirugía durante la inter nación, se observó un OR ajustado de 1.62 (IC95% 1.31- 2.00; p < 001), 0.77 (IC95% 0.31-1.93; p = 0.58), 7.49 (IC95% 2.07-27.07; p = 0.002) y 0.21 (IC95% 0.06-0.70; p = 0.01), respectivamente. Conclusiones : La mortalidad de la EI se asoció al grado de comorbilidad previa, a la forma de presenta ción y, en relación inversa, a la realización oportuna del tratamiento quirúrgico.

Abstract Introduction : Mortality of infective endocarditis (IE) in Argentina continues to be high. The aim objective was to describe the clinical characteristics and identify factors associated with in-hospital and long-term mortality in patients with native valve IE. Methods : Retrospective cohort study including adult patients with diagnosis of native valve IE, hospitalized during 2011-2021. Results : A total of 129 patients with a mean age of 66±17 years were included. The most frequent respon sible organism was Staphylococcus aureus (SA) (38.8%). Surgical indication criteria were present in 63.6% of the patients. Mortality during hospitalization was 22.5% .In the multivariate analysis that included Charlson comorbidity index, SA infection and the presence of surgical indication criteria, an adjusted OR of mor tality of 1.32 (95%CI 1.10-1.57; p = 0.003), 2.75 (95%CI 1.11-6.8; p = 0.028) and 4.14 (95%CI 1.34-12; p = 0.013), respectively, was observed. In the multivariate analysis for long term mortality, that added surgical indication criteria and the performance of surgery during hospitalization, an adjusted OR of 1.62 (CI95% 1.31-2.00; p<001), 0.77 (95%CI 0.31-1.93; p = 0.58), 7.49 (95%CI 2.07-27.07; p = 0.002) and 0.21 (95%CI 0.06-0.70; p = 0.01), respec tively, was observed. Conclusions : Mortality in IE was associated with the degree of previous comorbidity, with the presence of surgical indication criteria and, inversely, with the timely completion of surgical treatment.

Construção e validação de um instrumento de avaliação de cursos na modalidade a distância / Construction and validation of an evaluation instrument for distance learning courses / Construcción y validación de un instrumento de evaluación para cursos a distancia

Objetivos: construir, validar e aplicar um instrumento de avaliação de cursos de nível superior ofertados na modalidade a distância. Método: estudo metodológico. Para a elaboração do instrumento realizou-se revisão de literatura. A validação do pré-teste se deu pela triangulação de especialistas e a do conteúdo pelo Método Delphi. Para a análise da confiabilidade adotou-se a análise fatorial confirmatória e o coeficiente de Correlação de Spearman a partir da aplicação em dois cursos a distância. Resultados: a partir de onze referenciais (nacionais e internacionais) foram estratificados 70 critérios e agrupados em seis categorias que foram modificados na triangulação. Dois ciclos compuseram a Técnica Delphi com 17 especialistas inicialmente e alfa de Cronbach de 0,80 na segunda rodada. Na análise fatorial confirmatória, realizada com 221 participantes, inicialmente, não gerou índices satisfatórios, resultando na exclusão de questões. O novo modelo ajustado, produziu índices próximos aos ideais: CFI = 0,806; TLI = 0,770 e RMSEA = 0,088 com associação positiva entre as variáveis, e melhor média (p<5%) quanto à correlação entre os aspectos práticos e a indicação do curso pelos discentes. Conclusão: o estudo produziu um instrumento validado e com a confiabilidade aferida que pode ser aplicado em cursos com diferentes desenhos pedagógicos e não se limita a uma área específica, uma relevante contribuição para a educação superior.

Objectives: To construct, validate and apply an instrument of evaluation of higher education courses offered in distance learning modality. Method: Methodologi- cal study. For the elaboration of the instrument, a literature review was carried out. The pre-test was validated by expert triangulation and the content was validated by the Delphi Method. For the reliability analysis we adopted the confirmatory factor analysis and Spe- arman's Correlation coefficient from the application in two distance learning courses. Re- sults: from eleven references (national and international) 70 criteria were stratified and grouped into six categories that were modified in the triangulation. Two rounds compri- sed the Delphi Technique with 17 experts initially and Cronbach's alpha of 0.80 in the second round. The confirmatory factor analysis, performed with 221 participants, did not initially generate satisfactory indexes, resulting in the exclusion of questions. The new adjusted model produced close to ideal indexes: CFI = 0.806; TLI = 0.770 and RMSEA regarding the correlation between practical aspects and students' recommendation of the course. Conclusion: the study produced a validated instrument with gauged reliability that can be applied in courses with different pedagogical designs and is not limited to a spe- cific area, a relevant contribution to higher education.

Objetivos: Construir, validar y aplicar un instrumento de evaluación de cur- sos de educación superior ofrecidos en la modalidad a distancia. Método: Estudio meto- dológico. Para la elaboración del instrumento se realizó una revisión bibliográfica. El pre- test fue validado por triangulación de expertos y el contenido fue validado por el Método Delphi. Para el análisis de fiabilidad adoptamos el análisis factorial confirmatorio y el coeficiente de correlación de Spearman a partir de la aplicación en dos cursos a distancia. Resultados: a partir de once referencias (nacionales e internacionales) se estratificaron 70 criterios que se agruparon en seis categorías que se modificaron en la triangulación. Se realizaron dos rondas con la técnica Delphi con 17 expertos inicialmente y un alfa de Cronbach de 0,80 en la segunda ronda. El análisis factorial confirmatorio, realizado con 221 par-ticipantes, no generó inicialmente índices satisfactorios, lo que dio lugar a la ex- clusión de preguntas. El nuevo modelo ajustado produjo índices cercanos al ideal: CFI = 0,806; TLI = 0,770 y RMSEA = 0,088 con una asociación positiva entre las variables, y una media mejor (p<5%) en cuanto a la correlación entre los aspectos prácticos y la re- comendación del curso por parte de los alumnos. Conclusión: el estudio produjo un ins- trumento validado con confiabilidad medida, que puede ser aplicado en cursos con dife- rentes diseños pedagógicos y no se limita a un área específica, una contribución relevante para la educación superior.

Resultados de la anestesia total intra venosa (TIVA) con perfusión controlada por objetivo (TCI) en pacientes sometidos a trasplante renal / Outcomes of Total Intravenous Anesthesia (TIVA) with Goal Controlled Perfusion (TCI) in Kidney Transplant Patients

Introducción: La anestesia total intravenosa (TIVA) con perfusión controlada por objetivo (TCI) es una técnica de anestesia general que usa una combinación de fármacos administrados exclusivamente por vía intravenosa sin usar fármacos por vía inhalatoria. Objetivos: Determinar los resultados del uso de TIVA TCI en los pacientes sometidos a trasplante renal, donantes y receptores, entre noviembre de 2014 y julio de 2018, en el Hospital de Clínicas. Pacientes y métodos: Estudio observacional, analítico transversal, con muestreo no probabilístico a criterio. La serie se agrupó en donantes y receptores. Los datos se expresan en medias y proporciones, se analizó el Odds Rattio y el R2. Se consideró una p< 0,05 como significativa. Resultados: se incluyeron a 198 intervenciones anestésicas, 131 (66,2%) fueron receptores. El rango de edad fue de entre 5 y 66 años (35,8±13 años) y 114 (57%) fueron masculinos. En el post operatorio inmediato, el tiempo en despertar, la PAS, PAD, PAM, frecuencia cardiaca y saturación de oxígeno no tuvieron diferencias significativas, en la comparación de los grupos (donante y receptor). Se observó cefalea en 3 (1,5%) del grupo de donantes y ninguna en los receptores. La diuresis fue tardía en 18 (9,1%) pacientes (p= 0,084 R2=29). Conclusión: La TIVA TCI demostró ser una técnica muy efectiva en el trasplante renal, con pronta recuperación y despertar inmediato tras la extubación, con lucidez absoluta en todos los pacientes.

Introduction: Total intravenous anesthesia (TIVA) with goal-controlled perfusion (TCI) is a general anesthesia technique that uses a combination of drugs administered exclusively intravenously without using inhalational drugs. Objectives: To determine the results of the use of TIVA TCI in kidney transplant patients, donors and recipients, between November 2014 and July 2018, at the Hospital de Clínicas. Patients and methods: Observational, cross-sectional analytical study, with non-probabilistic sampling at the discretion. The series was grouped into donors and recipients. The data is expressed in means and proportions, the Odds Rattio and the R2 were analyzed. A p<0.05 was considered significant. Results: 198 anesthetic interventions were included, 131 (66.2%) were recipients. The age range was between 5 and 66 years (35.8±13 years) and 114 (57%) were male. In the immediate postoperative period, time to awakening, SBP, DBP, MAP, heart rate and oxygen saturation did not show significant differences when comparing the groups (donor and recipient). Headache was observed in 3 (1.5%) of the donor group and none in the recipients. Diuresis was late in 18 (9.1%) patients (p= 0.084 R2=29). Conclusion: TIVA TCI proved to be a very effective technique in kidney transplantation, with prompt recovery and immediate awakening after extubation, with absolute clarity in all patients.

Anestesia total intravenosa en pacientes con síndrome oclusivo intestinal / Total Intravenous anesthesia in patients with intestinal occlusive syndrome

Introducción: La anestesia total intravenosa es una técnica de anestesia general en la que se administran los fármacos exclusivamente por vía endovenosa, en ausencia de agentes inhalatorios. Objetivo: Describir los resultados que se observaron en el empleo de la anestesia total intravenosa en los pacientes con diagnóstico de síndrome oclusivo para tratamiento quirúrgico. Métodos: Se desarrolló una investigación observacional descriptiva, longitudinal en el Hospital General Docente "Abel Santamaría Cuadrado", de enero de 2014 a enero de 2017. De un universo de 417 pacientes, se seleccionó una muestra de 205 casos que cumplieron con los criterios de inclusión y exclusión. Las variables fueron presión arterial media, frecuencia cardíaca, saturación de oxígeno, complicaciones, tiempo de recuperación, nivel de sedación y respuesta analgésica. Resultados: El 95,61 por ciento de los casos se mantuvieron normotensos y el 96,10 por ciento con frecuencia cardíaca normal. Se constataron signos clínicos de superficialidad anestésica en el 1,46 por ciento de los individuos. La mayoría de los casos se recuperaron entre 10 y 20 min para un 92,19 por ciento. Se observó un nivel de sedación insuficiente en 189 pacientes (92,19 por ciento). No se evidenciaron complicaciones posoperatorias en el 96,58 por ciento. La respuesta analgésica fue adecuada en el 95,12 por ciento de los casos. Conclusiones: La aplicación de la anestesia total intravenosa para cirugía por oclusión intestinal demostró resultados satisfactorios como método anestésico(AU)

Introduction: Total intravenous anesthesia is a general anesthesia technique in which drugs are administered exclusively intravenously, in the absence of inhalation agents. Objective: To describe the outcomes observed in the use of total intravenous anesthesia in patients diagnosed with occlusive syndrome for surgical treatment. Methods: A descriptive, longitudinal and observational research was carried out in Abel Santamaría Cuadrado General Teaching Hospital of Pinar del Río, Cuba, from January 2014 to January 2017. From a universe of 417 patients, a sample of 205 cases that met the inclusion and exclusion criteria was selected. The variables were mean arterial pressure, heart rate, oxygen saturation, complications, recovery time, level of sedation, and analgesic response. Results: 95.61 percent of the cases remained normotensive and 96.10 percent kept a normal heart rate. Clinical signs of sedation were found in 1.46 percent of the individuals. Most of the cases recovered between 10 and 20 minutes, accounting for 92.19 percent. Insufficient sedation was observed in 189 patients (92.19 percent). No postoperative complications were observed in 96.58 %. Analgesic response was adequate in 95.12 percent of cases. Conclusions: The application of total intravenous anesthesia for intestinal occlusion surgery showed satisfactory outcomes as an anesthetic method(AU)

Why do We Use the Concepts of Adult Anesthesia Pharmacology in Developing Brains? Will It Have an Impact on Outcomes? Challenges in Neuromonitoring and Pharmacology in Pediatric Anesthesia.

BACKGROUND: Pediatric sedation and anesthesia techniques have plenty of difficulties and challenges. Data on the pharmacologic, electroencephalographic, and neurologic response to anesthesia at different brain development times are only partially known. New data in neuroscience, pharmacology, and intraoperative neuromonitoring will impact changing concepts and clinical practice. In this article, we develop a conversation to guide the debate and search for a view more attuned to the updated knowledge in neurodevelopment, electroencephalography, and clinical pharmacology for the anesthesiologic practice in the pediatric population.

Evaluation of anaesthetic depth and cardiopulmonary effects of propofol infusion rate in Sapajus apella previously chemically contained with dextroketamine-midazolam.

BACKGROUND: This study evaluated the cardiopulmonary effects and anaesthetic depth induced by a propofol infusion rate of 0.8 mg/kg/min in monkeys (Sapajus apella). MATERIALS AND METHODS: Five capuchin monkeys received dextroketamine-midazolam intramuscularly. After a maximum duration of 5 min, the values of the physiological parameters were recorded, and a venous catheter was placed. After recovery from chemical restraint, the animals were anaesthetized with propofol intravenously, which was maintained for 1 h. Physiological parameters, anaesthetic depth, the time and quality of anaesthetic recovery were evaluated. RESULTS: Heart and respiratory rates, systolic blood pressure and rectal temperature during propofol infusion were lower than those during anaesthesia induction with dextroketamine-midazolam. Unconsciousness, muscle relaxation and lack of response to tail clamping were observed during propofol infusion. No animals showed excitement or vocalization during anaesthetic recovery. CONCLUSION: Propofol infusion rate of 0.8 mg/kg/min promoted surgical general anaesthesia, with transient hypotension, which showed excellent anaesthetic recovery.

¿Anestesia halogenada o anestesia total endovenosa en neurocirugía? / Volatile or total intravenous anesthesia for neurosurgery?

Total intravenous anesthesia (TIVA) with propofol/remifentanil appears in the literatura as a good option for neurosurgical patients who have increased intracranial pressure (ICP),risk of postoperative nausea and vomiting (PONV), need for neuromonitoring, and in those with impaired brain self-regulation. On the other hand, in patients with normal neurological status, normal ICP, a technique with volatile (halogenated) agents plus an opiiid can be used. This review describes two anesthetic techniques available for use in neurosurgery, highlighting the neurophysiological changes, advantages and disadvantages of each technique. MATERIAL AND METHOD: PubMed search engine was used for bibliographic search. DISCUSSION: The search for an ideal anesthetic in neurosurgery is still a matter of debate. There are numerous investigations aimed at finding an optimal agent that ensure the coupling between cerebral flow (CBF) and metabolism, keeping self-regulation intact without increasing the CBF and intracerebral pressure (ICP). CONCLUSIONS: Both anesthetic techniques, TIVA and volatile agents (halogenated), can be used in neurosurgical procedures and should provide neuroprotection, brain relaxation and a rapid awakening.

La anestesia total endovenosa (TIVA) con propofol/remifentanilo aparece en la literatura como una buena opción para pacientes neuroquirúrgicos que tienen aumento de la presión intracraneana (PIC), riesgo de náuseas y vómitos posoperatorios (NVPO), necesidad de neuromonitoreo, y en aquellos con alteración de la autorregulación cerebral. Por otra parte, en pacientes con estado neurológico normal, PIC normal puede usarse una técnica con agentes volátiles (halogenados) más un opioide. Esta revisión describe dos técnicas anestésicas disponibles para su uso en neurocirugía, destaca los cambios neurofisiológicos, ventajas y desventajas de cada técnica. MATERIAL Y MÉTODO: Para búsqueda bibliográfica se usó buscador PubMed. DISCUSIÓN: La búsqueda de un anestésico ideal en neurocirugía sigue siendo tema de debate. Existen numerosas investigaciones destinadas a buscar un agente óptimo que asegure el acoplamiento entre flujo sanguíneo cerebral (FSC) y metabolismo, manteniendo la autorregulación intacta sin aumentar el FSC y presión intracerebral (PIC). CONCLUSIONES: Ambas técnicas anestésicas, TIVA y agentes volátiles (halogenados), pueden ser usadas en procedimientos neuroquirúrgicos y deben brindar neuroprotección, relajación cerebral y un despertar rápido.

Obstrução esofágica torácica por corpo estranho em cão: relato de caso

Corpos estranhos (CE) esofágicos são objetos inanimados que podem causar obstrução total ou parcial do lúmen esofágico, comumente causam disfagia, regurgitação e vômito. A casuísta de obstrução por CE esofágico é elevada na clínica de pequenos animais. O tratamento constitui na remoção do CE e correção de possíveis alterações secundárias. Dessa forma, o objetivo do presente trabalho foi relatar um caso de obstrução por CE em porção de esôfago torácico, tendo como fim aprofundar conhecimentos a respeito de obstrução esofágica de forma geral, desde as manifestações clínicas, achados aos exames complementares, diagnóstico e terapêutica.

Esophageal foreign bodies (FB) are inanimate objects that can cause total or partial obstruction of the esophageal lumen, commonly causing dysphagia, regurgitation and vomiting. The number of esophageal FB obstruction is high in the small animal clinic. Treatment consists of removing the FB and correcting secondary changes. Thus, the objective of the present study was to report a case of obstruction by a FB in a group of thoracic esophagus, with the purpose of deepening the knowledge about esophageal obstruction in general, from clinical manifestations, findings to complementary exams, diagnosis and technical.

Total intravenous anesthesia in domestic chicken (Gallus gallus domesticus) with propofol alone or in combination with methadone, nalbuphine or fentanyl for ulna osteotomy.

OBJECTIVE: To compare the propofol infusion rate and cardiopulmonary effects during total intravenous anesthesia with propofol alone and propofol combined with methadone, fentanyl or nalbuphine in domestic chickens undergoing ulna osteotomy. STUDY DESIGN: Prospective, randomized, experiment trial. ANIMALS: A total of 59 healthy Hissex Brown chickens weighing 1.5 ± 0.2 kg. METHODS: Anesthesia was induced with propofol (9 mg kg-1) administered intravenously (IV) and maintained with propofol (1.2 mg kg-1 minute-1) for 30 minutes. Birds were intubated and supplemented with 100% oxygen through a nonrebreathing circuit under spontaneous ventilation. Thereafter, each animal was randomly assigned to one of four groups: group P, no treatment; group PM, methadone (6 mg kg-1) intramuscularly (IM); group PN, nalbuphine IM (12.5 mg kg-1); and group PF, fentanyl IV (30 µg kg-1 loading dose, 30 µg kg-1 hour-1 constant rate infusion). During the osteotomy surgery, the propofol infusion rate was adjusted to avoid movement of birds and provide adequate anesthesia. Pulse rate, invasive blood pressure, respiratory frequency, end-tidal carbon dioxide partial pressure (Pe'CO2) and hemoglobin oxygen saturation (SpO2) were recorded. RESULTS: Data were available from 58 chickens. The mean ± standard deviation propofol infusion rate (mg kg-1 minute-1) for the duration of anesthesia was: group P, 0.81 ± 0.15; group PM, 0.66 ± 0.11; group PN, 0.60 ± 0.14; and group PF, 0.80 ± 0.07. Significant differences were P versus PM (p = 0.042), P versus PN (p = 0.002) and PF versus PN (p = 0.004). Pulse rate, blood pressure and SpO2 remained acceptable for anesthetized birds with minor differences among groups. Values of Pe'CO2 >60 mmHg (8 kPa) were observed in all groups. CONCLUSIONS AND CLINICAL RELEVANCE: Methadone and nalbuphine, but not fentanyl, decreased the propofol infusion rate required for anesthesia maintenance, but resulted in no obvious benefit in physiological variables.

Uso do propofol na anestesia intravenosa em equinos / Use of propofol in total intravenous anesthesia in horses

A anestesia equina apresenta elevada taxa de mortalidade em comparação com outras espécies animais e seres humanos, em parte devido à ampla utilização de agentes inalatórios como único agente anestésico, promovendo importante depressão cardiovascular e respiratória. A anestesia total intravenosa (TIVA), com uso de anestésicos e analgésicos exclusivamente pela via intravenosa, possui o propofol como principal agente e pode ser uma boa opção ao uso dos anestésicos voláteis. As propriedades farmacocinéticas do propofol permitem rápida recuperação após bolus intravenoso ou quando administrado em infusão contínua, com tentativas coordenadas e calmas para alcançar decúbito esternal, posição quadrupedal e com mínima ataxia. Contudo, é considerado um agente anestésico insuficiente quando utilizado de forma isolada, visto que apresenta efeito analgésico insatisfatório, moderada a acentuada depressão respiratória e hipotensão, imprevisibilidade na indução, como excitação, além dos altos volumes necessários para indução e manutenção. Dessa forma, a combinação de propofol com vários fármacos sedativos e analgésicos pode fornecer um método alternativo para melhorar a qualidade e a segurança da anestesia em equinos e, potencialmente, diminuir a dose total de fármaco necessária. Objetivou-se realizar essa revisão de literatura abordando o uso do propofol na anestesia intravenosa total em equinos, considerando a importância de um maior conhecimento acerca da técnica na referida espécie, visto que os dados na literatura ainda são poucos quando comparados a outras espécies animais.(AU)

Equine anesthesia has a high mortality rate compared to other animal species and human beings, partly due to the widespread use of inhalation agents as the only anesthetic agent, developing major cardiovascular and respiratory depression. Total intravenous anesthesia (TIVA), with the use of intravenous anesthetics and analgesics exclusively, has propofol as the main agent and may be a good option for the use of volatile anesthetics. The pharmacokinetic properties of propofol allow rapid recovery after intravenous bolus or when administered by continuous infusion, with coordinated and calm attempts to achieve sternal decubitus, quadrupedal position and minimal ataxia. However, it is considered an insufficient anesthetic agent when used alone, as it has an unsatisfactory analgesic effect, moderate to severe respiratory depression and hypotension, unpredictability in induction such as arousal, and the high volumes required for induction and maintenance. Thus, combining propofol with various sedative and analgesic drugs may provide an alternative method for improving the quality and safety of anesthesia in horses and potentially decreasing the total required drug dose. The aim of this literature review is to approach the use of propofol in total intravenous anesthesia in horses, considering the importance of a better knowledge of the technique in this species, since the data in the literature are still few when compared to other animal species.(AU)

Uso do propofol na anestesia intravenosa em equinos / Use of propofol in total intravenous anesthesia in horses

A anestesia equina apresenta elevada taxa de mortalidade em comparação com outras espécies animais e seres humanos, em parte devido à ampla utilização de agentes inalatórios como único agente anestésico, promovendo importante depressão cardiovascular e respiratória. A anestesia total intravenosa (TIVA), com uso de anestésicos e analgésicos exclusivamente pela via intravenosa, possui o propofol como principal agente e pode ser uma boa opção ao uso dos anestésicos voláteis. As propriedades farmacocinéticas do propofol permitem rápida recuperação após bolus intravenoso ou quando administrado em infusão contínua, com tentativas coordenadas e calmas para alcançar decúbito esternal, posição quadrupedal e com mínima ataxia. Contudo, é considerado um agente anestésico insuficiente quando utilizado de forma isolada, visto que apresenta efeito analgésico insatisfatório, moderada a acentuada depressão respiratória e hipotensão, imprevisibilidade na indução, como excitação, além dos altos volumes necessários para indução e manutenção. Dessa forma, a combinação de propofol com vários fármacos sedativos e analgésicos pode fornecer um método alternativo para melhorar a qualidade e a segurança da anestesia em equinos e, potencialmente, diminuir a dose total de fármaco necessária. Objetivou-se realizar essa revisão de literatura abordando o uso do propofol na anestesia intravenosa total em equinos, considerando a importância de um maior conhecimento acerca da técnica na referida espécie, visto que os dados na literatura ainda são poucos quando comparados a outras espécies animais.

Equine anesthesia has a high mortality rate compared to other animal species and human beings, partly due to the widespread use of inhalation agents as the only anesthetic agent, developing major cardiovascular and respiratory depression. Total intravenous anesthesia (TIVA), with the use of intravenous anesthetics and analgesics exclusively, has propofol as the main agent and may be a good option for the use of volatile anesthetics. The pharmacokinetic properties of propofol allow rapid recovery after intravenous bolus or when administered by continuous infusion, with coordinated and calm attempts to achieve sternal decubitus, quadrupedal position and minimal ataxia. However, it is considered an insufficient anesthetic agent when used alone, as it has an unsatisfactory analgesic effect, moderate to severe respiratory depression and hypotension, unpredictability in induction such as arousal, and the high volumes required for induction and maintenance. Thus, combining propofol with various sedative and analgesic drugs may provide an alternative method for improving the quality and safety of anesthesia in horses and potentially decreasing the total required drug dose. The aim of this literature review is to approach the use of propofol in total intravenous anesthesia in horses, considering the importance of a better knowledge of the technique in this species, since the data in the literature are still few when compared to other animal species.

Comparison between total intravenous anesthesia with propofol and intermittent bolus of tiletamine-zolazepam in capuchin monkey (Sapajus apella) / Comparação entre anestesia total intravenosa com propofol e bolus intermitente de tiletamina-zolazepam em macaco-prego (Sapajus apella)

Dissociative anesthesia results in stressful and long recovery periods in monkeys and use of injectable anesthetics in medical research has to be refined. Propofol has promoted more pleasure wake up from anesthesia. The objectives of this study were to investigate the use of intravenous anesthetic propofol, establishing the required infusion rate to maintain surgical anesthetic level and comparing it to tiletamine-zolazepam anesthesia in Sapajus apella. Eight healthy capuchin monkeys, premedicated with midazolam and meperidine, were anesthetized with propofol (PRO) or tiletamine-zolazepam (TZ) during 60 minutes. Propofol was infused continually and rate was titrated to effect and tiletamine-zolazepam was given at 5mg/kg IV bolus initially and repeated at 2.5mg/kg IV bolus as required. Cardiopulmonary parameters, arterial blood gases, cortisol, lactate and quality and times to recovery were determined. Recovery quality was superior in PRO. Ventral recumbency (PRO = 43.0±21.4 vs TZ = 219.3±139.7 min) and normal ambulation (PRO = 93±27.1 vs TZ = 493.7±47.8 min) were faster in PRO (p<0.05). Cardiopulmonary effects did not have marked differences between groups. Median for induction doses of propofol was 5.9mg/kg, varying from 4.7 to 6.7mg/kg, Mean infusion rate was 0.37±0.11mg/kg/min, varying during the one-hour period. In TZ, two animals required three and five extra doses. Compared to tiletamine-zolazepam, minor post-anesthetic adverse events should be expected with propofol anesthesia due to the faster and superior anesthetic recovery.(AU)

A anestesia dissociativa em primatas resulta em recuperação anestésica lenta e estressante, e, portanto, o uso de anestesia injetável em pesquisas médicas precisa ser refinado. Por outro lado, o propofol promove recuperação mais suave. Os objetivos desse estudo foram investigar o uso do anestésico intravenoso propofol, estabelecer a taxa de infusão contínua necessária para manter anestesia cirúrgica, e comparar tal técnica com a dissociativa tiletamina-zolazepam em Sapajus apella. Oito macacos-prego saudáveis foram pré-medicados com midazolam e meperidina, e posteriormente anestesiados com propofol (PRO) ou tiletamina-zolazepam (TZ) durante 60 minutos. O propofol foi administrado em infusão contínua, e a taxa foi titulada ao efeito, já a tiletamina-zolazepam foi administrada em 5mg/kg IV como bolus inicial, e repiques de 2,5mg/kg IV conforme necessário. Os parâmetros cardiopulmonares, hemogasometria arterial, cortisol, e lactato, além da qualidade e duração da recuperação anestésica foram determinados. A qualidade da recuperação anestésica foi superior em PRO. O tempo para atingir decúbito ventral (PRO = 43,0±21,4 vs TZ = 219,3±139,7 min) e ambulação normal (PRO = 93±27,1 vs TZ = 493,7±47,8 min) foram mais rápidos em PRO (p<0,05). As variáveis cardiopulmonares não diferiram entre os grupos. A mediana para dose de indução com propofol foi de 5,9mg/kg, variando de 4,7 a 6,7mg/kg. A taxa de infusão contínua média de propofol foi de 0,37±0,11mg/kg/min, variando ao longo dos 60 minutos. Em TZ, dois animais necessitaram de três e cinco repiques. Comparado à tiletamina-zolazepam, menos efeitos adversos pós-anestésicos devem ser esperados com o propofol, devido à recuperação mais suave e rápida.(AU)

Comparison between total intravenous anesthesia with propofol and intermittent bolus of tiletamine-zolazepam in capuchin monkey (Sapajus apella) / Comparação entre anestesia total intravenosa com propofol e bolus intermitente de tiletamina-zolazepam em macaco-prego (Sapajus apella)

Dissociative anesthesia results in stressful and long recovery periods in monkeys and use of injectable anesthetics in medical research has to be refined. Propofol has promoted more pleasure wake up from anesthesia. The objectives of this study were to investigate the use of intravenous anesthetic propofol, establishing the required infusion rate to maintain surgical anesthetic level and comparing it to tiletamine-zolazepam anesthesia in Sapajus apella. Eight healthy capuchin monkeys, premedicated with midazolam and meperidine, were anesthetized with propofol (PRO) or tiletamine-zolazepam (TZ) during 60 minutes. Propofol was infused continually and rate was titrated to effect and tiletamine-zolazepam was given at 5mg/kg IV bolus initially and repeated at 2.5mg/kg IV bolus as required. Cardiopulmonary parameters, arterial blood gases, cortisol, lactate and quality and times to recovery were determined. Recovery quality was superior in PRO. Ventral recumbency (PRO = 43.0±21.4 vs TZ = 219.3±139.7 min) and normal ambulation (PRO = 93±27.1 vs TZ = 493.7±47.8 min) were faster in PRO (p<0.05). Cardiopulmonary effects did not have marked differences between groups. Median for induction doses of propofol was 5.9mg/kg, varying from 4.7 to 6.7mg/kg, Mean infusion rate was 0.37±0.11mg/kg/min, varying during the one-hour period. In TZ, two animals required three and five extra doses. Compared to tiletamine-zolazepam, minor post-anesthetic adverse events should be expected with propofol anesthesia due to the faster and superior anesthetic recovery. (AU)

A anestesia dissociativa em primatas resulta em recuperação anestésica lenta e estressante, e, portanto, o uso de anestesia injetável em pesquisas médicas precisa ser refinado. Por outro lado, o propofol promove recuperação mais suave. Os objetivos desse estudo foram investigar o uso do anestésico intravenoso propofol, estabelecer a taxa de infusão contínua necessária para manter anestesia cirúrgica, e comparar tal técnica com a dissociativa tiletamina-zolazepam em Sapajus apella. Oito macacos-prego saudáveis foram pré-medicados com midazolam e meperidina, e posteriormente anestesiados com propofol (PRO) ou tiletamina-zolazepam (TZ) durante 60 minutos. O propofol foi administrado em infusão contínua, e a taxa foi titulada ao efeito, já a tiletamina-zolazepam foi administrada em 5mg/kg IV como bolus inicial, e repiques de 2,5mg/kg IV conforme necessário. Os parâmetros cardiopulmonares, hemogasometria arterial, cortisol, e lactato, além da qualidade e duração da recuperação anestésica foram determinados. A qualidade da recuperação anestésica foi superior em PRO. O tempo para atingir decúbito ventral (PRO = 43,0±21,4 vs TZ = 219,3±139,7 min) e ambulação normal (PRO = 93±27,1 vs TZ = 493,7±47,8 min) foram mais rápidos em PRO (p<0,05). As variáveis cardiopulmonares não diferiram entre os grupos. A mediana para dose de indução com propofol foi de 5,9mg/kg, variando de 4,7 a 6,7mg/kg. A taxa de infusão contínua média de propofol foi de 0,37±0,11mg/kg/min, variando ao longo dos 60 minutos. Em TZ, dois animais necessitaram de três e cinco repiques. Comparado à tiletamina-zolazepam, menos efeitos adversos pós-anestésicos devem ser esperados com o propofol, devido à recuperação mais suave e rápida.(AU)

Neural inertia and differences between loss of and recovery from consciousness during total intravenous anaesthesia: a narrative review.

Most anaesthetists using target-controlled infusion systems will have observed that the calculated effect-site concentration at loss of consciousness is usually higher than the concentration at emergence. Inertia is the ability of biological systems to keep a functional state at rest or in activity and is an active process of resistance to change in state. Hysteresis is a phenomenon whereby the value of a physical property lags behind changes in the effect that is causing it and this is also seen in anaesthesia pharmacology. Recently, a phenomenon called neuronal inertia has been proposed when trying to explain the resistance observed to changes in consciousness induced by general anaesthesia, independent of drug kinetics. This review discusses the existence of this phenomenon and the conceptual and practical impact it may have on induction and recovery from general anaesthesia.

Variante de cálculo de infusión de ketamina en la TIVA manual / A Variant for calculating ketamine infusion in manual total intravenous anesthesia

Introducción: Un requisito en la conducción de la anestesia intravenosa total, en modo manual, radica en la necesidad de realizar ajustes de dosificación temporales para evitar la acumulación plasmática del fármaco. Desde hace algunos años existe el interés de emplear otros fármacos como la ketamina. Objetivos: Comparar la variación temporal de la concentración plasmática de ketamina al aplicar una variante de cálculo de decrecimiento de la velocidad de infusión (Vinf) con una velocidad de infusión invariable. Métodos: Se realizó un estudio analítico que describe el cálculo de dosificación para TIVA manual, la simulación farmacocinética del comportamiento de la concentración plasmática de la ketamina en caso de administrarse invariablemente con esos regímenes de dosificación, en un paciente virtual, de 70 Kg, según el modelo de Domino y el análisis de la variante de cálculo de decrecimiento de la Vinf del medicamento. Se estimó una significación estadística de un 95 por ciento (p<0.05). Resultados: la variante de cálculo de decrecimientode la velocidad de infusión: Vinf (tn) = Vinf (tn-1) _ [(Vinf (tn-1) x e(1 + 1/t)t)/100] = Vinf (t n-1) x 0,85 permitió valores más estables de la concentración plasmática, aproximadas a la del modelo ideal (p>0,05), por espacio de 6 h. Conclusiones: es probable que el decrecimiento de la dosis de ketamina, establecido por la variante de cálculo e infusión propuesta, posibilite una mejor estabilidad de la concentración plasmática(AU)

Introduction: A requirement in the manual conduction of total intravenous anesthesia is the need to make temporary dosage adjustments to avoid drug accumulation in plasma. For some years there has been interest in using other drugs such as ketamine. Objectives: To compare the temporal variation of ketamine concentration in plasma when applying a variant for calculating the decrease in the infusion rate (Vinf) with an invariable infusion rate. Methods: An analytical study was carried out describing the dosage calculation for manual total intravenous anesthesia, the pharmacokinetic simulation of the behavior of ketamine concentration in plasma in case of being invariably administered with these dosing regimens, in a virtual patient, of 70 kg, according to the Domino model and the analysis of the variant for calculating the decrease of ketamine infusion rate. A statistical significance of 95 percent was estimated (p<0.05). Results: The variant for calculating the decrease of the infusion rate: Vinf (tn) = Vinf (tn-1) _ [(Vinf (tn-1) x e (1+1/t) t)/100] = Vinf (tn -1) x 0.85 allowed more stable values of plasma concentration, which approximate that of the ideal model (p>0.05), for a time of 6 hours. Conclusions: Probably, the decrease of the ketamine dose, established by the proposed calculation and infusion variant, allows better stability of plasma concentration(AU)

Analgesia Nociception Index for perioperative analgesia monitoring in spinal surgery / Índice de analgesia/nocicepção para monitorização da analgesia perioperatória na cirurgia da coluna vertebral

Abstract Background and objectives: The Analgesia Nociception Index is an index used to measure the levels of pain, sympathetic system activity and heart rate variability during general anesthesia. In our study, Analgesia Nociception Index monitoring in two groups who had undergone spinal stabilization surgery and were administered propofol-remifentanil (Total Intravenous Anesthesia) and sevoflurane-remifentanyl anesthesia was compared regarding its significance for prediction of postoperative early pain. Methods: BIS and Analgesia Nociception Index monitoring were conducted in the patients together with standard monitoring. During induction, fentanyl 2 µg.kg-1, propofol 2.5 mg.kg-1 and rocuronium 0.6 mg.kg-1 were administered. During maintenance, 1.0 MAC sevoflurane + remifentanil 0.05-0.3 µg.kg-1.min-1 and propofol 50-150 µg.kg-1.min-1 + remifentanil 0.05-0.3 µg.kg-1.min-1 were administered in Group S and Group T, respectively. Hemodynamic parameters, BIS and Analgesia Nociception Index values were recorded during surgery and 30 min postoperatively. Postoperative visual analog scale (VAS) values at 30 minutes were recorded. Results: While no difference was found between mean Analgesia Nociception Index at all times of measurement in both groups, Analgesia Nociception Index measurements after administration of perioperative analgesic drug were recorded to be significantly higher compared to baseline values in both groups. There was correlation between mean values of Analgesia Nociception Index and VAS after anesthesia. Conclusion: Analgesia Nociception Index is a valuable parameter for monitoring of perioperative and postoperative analgesia. In spine surgery, similar analgesia can be provided in both Total Intravenous Anesthesia with remifentanil and sevoflurane administration. Analgesia Nociception Index is efficient for prediction of the need for analgesia during the early postoperative period, and therefore is the provision of patient comfort.

Resumo Justificativa e objetivos: O índice de analgesia/nocicepção (ANI) é usado para medir os níveis de dor, a atividade do sistema simpático e a variabilidade da frequência cardíaca durante a anestesia geral. Em nosso estudo, a monitoração do ANI em dois grupos que foram submetidos à cirurgia de estabilização da coluna vertebral e receberam propofol-remifentanil (Total Intravenous Anesthesia - TIVA) e sevoflurano-remifentanil foram comparados para identificar sua importância na previsão precoce de dor no pós-operatório. Métodos: Os pacientes foram monitorados com o uso de BIS e ANI juntamente com a monitoração padrão. Durante a indução, fentanil (2 µg.kg-1), propofol (2,5 mg.kg-1) e rocurônio (0,6 mg.kg-1) foram administrados. Durante a manutenção, 1 CAM de sevoflurano + remifentanil (0,05-0,3 µg.kg-1.min-1) e propofol (50-150 µg.kg-1.min-1) + remifentanil (0,05-0,3 µg.kg-1.min-1) foram administrados aos grupos S e T, respectivamente. Parâmetros hemodinâmicos, valores de BIS e ANI foram registrados durante a cirurgia e aos 30 minutos de pós-operatório. Os valores escala visual analógica (EVA) aos 30 minutos de pós-operatório foram registrados. Resultados: Enquanto não observamos diferença entre as médias do ANI em todos os tempos de mensuração de ambos os grupos, as mensurações do ANI após a administração do analgésico no perioperatório foram significativamente maiores do que os valores basais de ambos os grupos. Houve correlação entre as médias dos valores de ANI e EVA após a anestesia. Conclusão: ANI é um parâmetro importante para o monitoração de analgesia nos períodos perioperatório e pós-operatório. Na cirurgia da coluna vertebral, analgesia semelhante pode ser obtida com anestesia intravenosa total com remifentanil e com a administração de sevoflurano. O ANI é eficiente para prever a necessidade de analgesia durante o período pós-operatório imediato e, portanto, para proporcionar conforto ao paciente.

Estimation of the Optimal CA-CFAR Threshold Multiplier in Pareto Clutter with Known Parameters

The performance of the CA-CFAR processor is affected by certain clutter variations. Although problems caused by sudden clutter changes have already been corrected in multiple CFAR proposals, the influence of slow statistical variations in the background signal is often ignored. To solve this problem, the authors estimated the optimal CA-CFAR threshold multiplier values necessary to adapt the processor to the clutter slow statistical changes. The application of the results guarantees that the operational false alarm probability of the processor will only exhibit a small deviation from the value conceived in the design. The clutter was simulated with a Pareto distribution with a known fluctuating shape parameter according to recent papers that strongly suggest the use of this distribution. The current research completes an important step in the design of an adaptive detector that operates without a priori knowledge of the shape parameter In addition, the authors provide mathematical expressions that allow the direct application of the results in the design of radar detectors.

El desempeño del procesador CA-CFAR es afectado por ciertas variaciones del clutter Mientras que los problemas causados por los cambios repentinos del clutter han sido corregidos por múltiples propuestas CFAR, se ignora frecuentemente la influencia de las variaciones estadísticas lentas de la señal de fondo. Para resolver este problema, los autores estimaron los valores óptimos del multiplicador del umbral CA-CFAR necesarios para adaptar el procesador a los cambios estadísticos lentos, garantizando por tanto que la probabilidad de falsa alarma del detector exhibirá solamente una ligera desviación con respecto al valor concebido en el diseño. El clutter fue simulado con una distribución Pareto con parámetro de forma conocido de antemano, de acuerdo a publicaciones recientes que sugieren fuertemente el uso de esta distribución. La investigación actual completa un paso importante en el diseño de detectores adaptativos que operan sin el conocimiento a priori del parámetro de forma. Adicionalmente, los autores proporcionan expresiones matemáticas que permiten la aplicación directa de los resultados en el diseño de detectores de radar.

O desempenho do processador CA-CFAR está afectada por certas variações da desordem. Enquanto os problemas causados por mudanças bruscas de lixo foram corrigidos para múltiplas propostas CFAR, é muitas vezes ignorado a influ-ência de variações estatísticas lento do sinal de fundo. Para resolver esse problema, os autores estimaram os valores ideais do limiar necessário multiplicador CA-CFAR para adaptar o processador para retardar alterações estatísticas, garantizando, portanto, a probabilidade de falsa detector de alarme apenas um ligeiro desvio da valor concebido no design. A desordem foi simulado com um parâmetro de distribuição de Pareto conhecidos na maneira previamente, de acordo com publicações recentes que sugerem fortemente a utilização desta distribuição. A investigação actual complete um passo importante na concepção de detectores adaptativas que operam sem conhecimento a priori do parâmetro de forma. Addi-cionalmente, os autores fornecem expressões matemáticas que permitem a aplicação direta dos resultados do projeto de detectores de radar.

[Analgesia Nociception Index for perioperative analgesia monitoring in spinal surgery]. / Índice de analgesia/nocicepção para monitorização da analgesia perioperatória na cirurgia da coluna vertebral.

BACKGROUND AND OBJECTIVES: The Analgesia Nociception Index is an index used to measure the levels of pain, sympathetic system activity and heart rate variability during general anesthesia. In our study, Analgesia Nociception Index monitoring in two groups who had undergone spinal stabilization surgery and were administered propofol-remifentanil (Total Intravenous Anesthesia) and sevoflurane-remifentanyl anesthesia was compared regarding its significance for prediction of postoperative early pain. METHODS: BIS and Analgesia Nociception Index monitoring were conducted in the patients together with standard monitoring. During induction, fentanyl 2µg.kg-1, propofol 2.5mg.kg-1 and rocuronium 0.6mg.kg-1 were administered. During maintenance, 1.0 MAC sevoflurane+remifentanil 0.05-0.3µg.kg-1.min-1 and propofol 50-150µg.kg-1.min+remifentanil 0.05-0.3µg.kg-1.min-1 were administered in Group S and Group T, respectively. Hemodynamic parameters, BIS and Analgesia Nociception Index values were recorded during surgery and 30min postoperatively. Postoperative visual analog scale (VAS) values at 30minutes were recorded. RESULTS: While no difference was found between mean Analgesia Nociception Index at all times of measurement in both groups, Analgesia Nociception Index measurements after administration of perioperative analgesic drug were recorded to be significantly higher compared to baseline values in both groups. There was correlation between mean values of Analgesia Nociception Index and VAS after anesthesia. CONCLUSION: Analgesia Nociception Index is a valuable parameter for monitoring of perioperative and postoperative analgesia. In spine surgery, similar analgesia can be provided in both Total Intravenous Anesthesia with remifentanil and sevoflurane administration. Analgesia Nociception Index is efficient for prediction of the need for analgesia during the early postoperative period, and therefore is the provision of patient comfort.

Uso de la Dexmedetomidina en la Neurocirugía con el paciente despierto. A propósito de un caso clínico / Use of Dexmedetomidine in Neurosurgery with the patient awake. About a clinical case

Presentamos el caso de un paciente de 58 años, coordinado para resección de tumor temporo insular izquierdo mediante una craneotomía despierto. Se analiza en este trabajo, a partir de la descripción del caso clínico, las ventajas de la resección de este tipo de lesiones con el paciente despierto. La posibilidades de abordaje, despierto durante todo el procedimiento (awake), dormido-despierto-dormido (asleep-awake-asleep), dormido-despierto (asleep-awake). A su vez se analiza la técnica anestésica, la combinación de fármacos y especialmente las características de la Dexmedetomidina. Conclusiones: la neurocirugía con el paciente despierto, determina una serie de características y desafíos para el equipo anestésico tratante y la interacción con un equipo mulitidisciplinario (neurocirujanos, neurofisiologos, anestesiologos). Existen diferentes combinaciones de fármacos; siendo la Dexmedetomidina una opción que mejorar la satisfacción de los pacientes durante la etapa de despertar, así como las condiciones quirúrgicas con mínimas interferencia en la monitorización neurofisiológica.

We present the case of a 58-year-old patient, scheduled to resection of left insular tumor by an awake craniotomy. In this paper, from the description of the clinical case, we analyzed the advantages of a resection of this type of lesion with an awake patient. We discuss the surgical approach, and options of an awake patient all throughout the procedure, asleep-awake-asleep and asleep-awake. Also, the anesthetic technique, the combination of drugs and especially the characteristics of Dexmedetomidine are analyzed. Conclusions: neurosurgery with an awake patient, determines a series of characteristics and challenges for the anesthetic and multidisciplinary team (neurosurgeons, neurophysiologists, anesthesiologists). There are different combinations of drugs, with Dexmedetomidine being an option that would improve patient satisfaction during the awakening stage, as well as surgical conditions with minimal interference in neurophysiological monitoring.