¿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.

Anestesia total intravenosa con remifentanilo vs fentanilo como base analgésica en cirugía torácica electiva / Intravenous total anesthesia with remifentanil and fentanyl as analgesic base in elective thoracic surgery

Introducción: Mantener una oxigenación adecuada durante la ventilación a un solo pulmón es el problema fundamental al que se enfrenta el anestesiólogo durante la cirugía torácica, es por ello que se mantiene una constante búsqueda del método anestésico ideal que ayude a lograr dicho objetivo. Objetivos: Evaluar los resultados de dos técnicas de anestesia total intravenosa con remifentanilo y fentanilo como base analgésica e identificar la aparición de complicaciones durante la intervención quirúrgica. Métodos: Se realizó un estudio causiexperimental prospectivo, en el Hospital Docente Clínico Quirúrgico Dr. Salvador Allende, entre enero 2013 a diciembre 2015 en 40 pacientes ASA II o III que requirieron procedimientos intratorácicos. Estos se dividieron en dos grupos. A (remifentanilo-propofol) y B (fentanilo-propofol). Se estudiaron variables hemodinámicas, de oxigenación durante la ventilación unipulmonar, el tiempo de recuperación anestésica (ventilación espontánea, apertura ocular, extubación) y la analgesia posoperatoria. Resultados: No existieron variaciones significativas en la hemodinamia, ni en la oxigenación de los enfermos con el empleo de ambas técnicas anestésicas; sin embargo, el despertar y recuperación posoperatoria a corto plazo fue mejor en el grupo A. La intensidad del dolor posoperatorio según la escala visual análoga fue menor en el grupo B. Conclusiones: Ambas técnicas son efectivas para procedimientos quirúrgicos torácicos. Con mínima interferencia en la hemodinámia y parámetros de oxigenación(AU)

Introduction: Maintaining adequate oxygenation during single-lung ventilation is a fundamental concern faced by the anesthesiologist during thoracic surgery; therefore, a constant search is maintained for the ideal anesthetic method that helps achieve this goal is maintained. Objectives: To evaluate the outcomes of two total intravenous anesthesia techniques with remifentanil and fentanyl as analgesic base and to identify the onset of complications during surgery. Methods: A prospective and quasi-experimental study was carried out at Dr. Salvador Allende Clinical-Surgical Hospital, between January 2013 and December, with 40 ASA II or III patients who required intrathoracic procedures. These were divided into two groups: A (remifentanil-propofol) and B (fentanyl-propofol). Hemodynamic variables and others of oxygenation during one-lung ventilation were studied, together with anesthetic recovery time (spontaneous ventilation, ocular opening, extubation) and postoperative analgesia. Results: There were no significant variations in the hemodynamics or oxygenation of patients with the use of both anesthetic techniques; however, awakening and short-term postoperative recovery was better in group A. Postoperative pain intensity, based on the analogue-visual scale, was lower in group B. Conclusion: Both techniques are effective for thoracic surgical procedures, with minimal effect in hemodynamics and oxygenation parameters(AU)

Conducción anestésica de un paciente pediátrico con micro esferocitosis hereditaria / Anesthetic approach on a pediatric patient with hereditary microspherocytosis

Introducción: La esferocitosis hereditaria (ESH) es una anemia hemolítica de observación frecuente, en la cual existen defectos cualitativos o cuantitativos de algunas proteínas de la membrana eritrocitaria que llevan a la formación de hematíes de forma esférica, osmóticamente frágiles, que son atrapados de formas selectiva y destruidos en el bazo, con incidencia variable y más frecuente en pacientes con descendencia europea. Objetivo: Describir la conducta clínica y anestesiológica de un paciente pediátrico con diagnóstico de micro esferocitosis hereditaria programado de forma electiva para procedimiento quirúrgico. Desarrollo: Se presenta un caso clínico de un paciente escolar con diagnóstico de micro esferocitosis hereditaria al cual se le realizó esplenectomía total electiva convencional. Con principal signo dolor a la palpación en hipocondrio izquierdo. Se condujo con anestesia total intravenosa con buenos resultados clínicos quirúrgicos, utilizando propofol a razón de 3 mcg/mL y ketamina a 0,2 mg/mL. La estrategia estuvo basada en cinco aspectos claves: evitar la hipoxia, la hipotermia, la acidosis, reducir la pérdida de sangre, así como un correcto control del dolor postoperatorio. Asociado a lo anterior es indispensable una estrecha vigilancia ya que estos pacientes pueden manifestar crisis hemolítica y aplásica. Conclusiones: El manejo perioperatorio del paciente con esferocitosis hereditaria depende de la severidad del cuadro clínico, de la anemia y su repercusión y del grado de hemólisis. La anestesia total intravenosa es una técnica segura para el tratamiento de pacientes con esferocitosis hereditaria(AU)

Introduction: Hereditary spherocytosis (HS) is a hemolytic anemia of frequent occurrence, in which there are qualitative or quantitative defects of some erythrocyte membrane proteins that lead to the formation of sphere-shaped red blood cells, which are osmotically fragile, and that are selectively trapped and destroyed in the spleen, with variable and more frequent incidence in patients with European descent. Objective: To describe the clinical and anesthesiological behavior of a pediatric patient with a diagnosis of hereditary microspherocytosis electively programmed for a surgical procedure. Development: A clinical case of a school-age patient with a diagnosis of hereditary microspherocytosis was presented. The patient underwent conventional elective total splenectomy. Pain was as the main sign on palpation to the left hypochondrium. The case was conducted with total intravenous anesthesia, with good surgical clinical results, using propofol at a rate of 3 mcg/mL and ketamine at 0.2 mg/mL. The strategy was based on five key aspects: avoid hypoxia, hypothermia, acidosis, reduce blood loss, as well as proper control of postoperative pain. Associated with the above-mentioned, close monitoring is essential, as these patients may manifest hemolytic and aplastic crisis. Conclusions: The perioperative management of the patient with hereditary spherocytosis depends on the severity of the clinical status, the anemia and its repercussion, and the degree of hemolysis. Total intravenous anesthesia is a safe technique for the treatment of patients with hereditary spherocytosis(AU)

Anestesia intravenosa total: Propofol/remifentanil vs. midazolam/remifentanil en cirugía torácica / Total intravenous anesthesia: propofol/remifentanil vs midazolam/remifentanil in thoracic surgery

Introducción: Las técnicas de administración de anestesia en cirugía torácica han experimentado gran evolución y mayor fundamento científico. La anestesia intravenosa total basada en la analgesia favorece a que el período perioperatorio transcurra sin dolor y la recuperación sin complicaciones. Objetivo: Comparar la efectividad y seguridad de dos técnicas de anestesia intravenosa total en cirugía torácica electiva con remifentanilo como base analgésica. Métodos: Estudio causiexperimental, prospectivo realizado en el Hospital Docente Clínico Quirúrgico Dr. Salvador Allende, en el período comprendido entre enero de 2013 a enero de 2015, en 45 pacientes, programados para cirugía torácica electiva, divididos en dos grupos según hipnótico utilizado. Grupo A: Propofol/Remifentanil y Grupo B: Midazolam/Remifentanil. Se evaluaron variables hemodinámicas en diferentes momentos del período intraoperatorio. Variables de oxigenación (PaO2 y SaO2) durante la ventilación unipulmonar y los tiempos de recuperación anestésica. Resultados: Predominaron los pacientes mayores de 60 años en los dos grupos, con estado físico ASA III. No hubo diferencias en la oxigenación arterial entre los grupos. Hubo disminución de la tensión arterial sistólica en el grupo A sin diferencias significativas. La recuperación de la anestesia fue significativamente más demorada en el grupo B. Conclusiones: La técnica de anestesia intravenosa total con remifentanil como base analgésica asociado a propofol resultó segura y efectiva en pacientes operados de cirugía torácica(AU)

Introduction: Anesthesia administration techniques in thoracic surgery have undergone great evolution and greater scientific foundation. Total intravenous anesthesia based on analgesia favors the perioperative period without pain and recovery without complications. Objective: To compare the effectiveness and safety of two techniques of total intravenous anesthesia in elective thoracic surgery with remifentanil as an analgesic base. Methods: Prospective and causiexperimental study carried out at Dr. Salvador Allende Clinical-Surgical Teaching Hospital, in the period from January 2013 to January 2015, with 45 patients scheduled for elective thoracic surgery, who were divided into two groups according to the hypnotic drug used. Group A: propofol/remifentanil, and group B: midazolam/remifentanil. Hemodynamic variables were evaluated at different times during the intraoperative period. Oxygenation variables (PaO2 and SaO2) during unipulmonary ventilation and anesthetic recovery times. Results: Patients older than 60 years predominated in the two groups, with a physical status of ASA III. There were no differences in arterial oxygenation between the groups. There was a decrease in systolic blood pressure in group A without significant differences. The recovery of anesthesia was significantly more delayed in group B. Conclusions: The total intravenous anesthesia technique with remifentanil as an analgesic base associated with propofol was safe and effective in patients undergoing thoracic surgery(AU)

Anestesia total intravenosa en cirugía oncológica de mama / Total intravenous anesthesia in breast oncology surgery

Introducción: La anestesia total intravenosa se caracteriza por estabilidad hemodinámica, profundidad anestésica, recuperación rápida y predecible, menor cantidad de medicamentos y menor toxicidad. Objetivo: Describir los resultados de la anestesia total intravenosa en cirugía oncológica de mama. Método: Se realizó un estudio descriptivo, longitudinal en el Hospital Clínico Quirúrgico Hermanos Ameijeiras, entre enero de 2016 a diciembre 2016, en 100 pacientes a las que se les administró anestesia total intravenosa con midazolam y fentanilo para proceder quirúrgico oncológico de mama. En ellas se determinó la repercusión hemodinámica, el nivel de sedación, analgesia, la recuperación y complicaciones. Resultados: La media de la edad de las pacientes fue 58,99 ± 12,5 años. De las pacientes en estudio 92 por ciento no presentó signos clínicos de superficialidad. Solo 21 pacientes presentaron complicaciones. Las variaciones de la tensión arterial fueron las más frecuentes (16 por ciento), seguidas de la bradicardia o taquicardia en solo cuatro casos. De forma inmediata se recuperó 74 por ciento de los casos y 26 por ciento restante lo hizo de manera mediata. El nivel de sedación fue adecuado en 50 por ciento y excesivo en 4 por ciento. Del total de los casos, 99 por ciento experimentaron respuesta analgésica sin dolor. Conclusiones: Los resultados del uso de anestesia total intravenosa fueron buenos, con adecuada respuesta analgésica y escasas complicaciones(AU)

Introduction: Total intravenous anesthesia is characterized by hemodynamic stability, anesthetic depth, rapid and predictable recovery, less medication and less toxicity. Objective: To describe the outcomes of total intravenous anesthesia in breast cancer surgery. Method: A descriptive, longitudinal study was carried out in Hermanos Ameijeiras Clinical-Surgical Hospital, from January 2016 to December 2016, in 100 patients who were administered total intravenous anesthesia with midazolam and fentanyl for breast oncology surgery. The patients were determined hemodynamic repercussion, the level of sedation, analgesia, recovery and complications. Results: The mean age of the patients was 58.99±12.5 years. Among the patients under study, 92 percent did not present clinical signs of superficiality. Only 21 patients presented complications. Variations in blood pressure were the most frequent (16 percent), followed by bradycardia or tachycardia in only four cases. Immediately, 74 percent of the cases were recovered and the remaining 26 percent did so timely. The level of sedation was adequate in 50 percent and excessive in 4 percent. Among the total number of cases, 99 percent experienced analgesic response without pain. Conclusions: The outcomes of total intravenous anesthesia usage were good, with adequate analgesic response and few complications(AU)

Sufentanil during anesthetic induction of remifentanil-based total intravenous anesthesia: a randomized controlled trial / Sufentanil durante a indução da anestesia intravenosa total à base de remifentanil: ensaio clínico randômico

Abstract Background Postoperative pain represents an important concern when remifentanil is used for total intravenous anesthesia because of its ultrashort half-life. Longer acting opioids, such as sufentanil, have been used during induction of remifentanil-based total intravenous anesthesia as a means to overcome this shortcoming. However, the effectiveness and safety of such strategy still lacks evidence from randomized clinical trials. Hence, we aimed to assess the postoperative analgesic efficacy and safety of a single dose of sufentanil administered during the induction of remifentanil-based total intravenous anesthesia. Methods Forty patients, scheduled for elective open abdominal surgery, were randomized to receive remifentanil-based total intravenous anesthesia with or without a single dose of sufentanil upon induction. We assessed the postoperative morphine consumption administered through a patient-controlled analgesia pump. Self-reported pain scores and the occurrence of nausea, vomiting, pruritus, agitation, somnolence and respiratory depression were also assessed up to 2 days after surgery. Results The mean difference between the sufentanil and control groups regarding morphine consumption in the post-anesthetic care unit and at 12, 24 and 48 h after surgery were -7.2 mg (95%CI: -12.5 to -2.1, p < 0.001), -3.9 mg (95%CI: -11.9 to 4.7, p = 0.26), -0.6 mg (95%CI: (-12.7 to 12.7, p = 0.80), and -1.8 mg (95%CI: (-11.6 to 15.6, p = 0.94), respectively. Neither self-reported pain nor the incidence of adverse events were significantly different between groups at any time point. Conclusion Our findings suggest that the administration of sufentanil during induction of remifentanil-based total intravenous anesthesia is associated with decreased early postoperative opioid consumption.

Resumo Justificativa A dor pós-operatória é uma grande preocupação quando o remifentanil é usado para anestesia intravenosa total devido à sua meia-vida ultracurta. Os opioides de ação mais longa, como o sufentanil, têm sido usados durante a indução de anestesia intravenosa total à base de remifentanil como um meio de superar essa deficiência. Porém, a eficácia e segurança de tal estratégia ainda precisam de evidências advindas de ensaios clínicos randômicos. Portanto, objetivamos avaliar a eficácia analgésica e a segurança pós-operatória de uma dose única de sufentanil administrada durante a indução de anestesia intravenosa total à base de remifentanil. Métodos Quarenta pacientes eletivamente agendados para cirurgia abdominal aberta foram randomizados para receber anestesia intravenosa total à base de remifentanil, com ou sem uma dose única de sufentanil, após a indução da anestesia. Avaliamos o consumo de morfina no pós-operatório, administrado através de uma bomba de analgesia controlada pelo paciente. Os escores de dor autorrelatados e a ocorrência de náusea, vômito, prurido, agitação, sonolência e depressão respiratória também foram avaliados até dois dias após a cirurgia. Resultados A diferença média entre os grupos sufentanil e controle em relação ao consumo de morfina em sala de recuperação pós-anestesia e após 12, 24 e 48 horas da cirurgia foi de -7,2 mg (IC 95%: -12,5 a -2,1, p < 0,001), -3,9 mg (IC 95%: -11,9 a 4,7, p = 0,26), -0,6 mg (IC 95%: (-12,7 a 12,7, p = 0,80) e -1,8 mg (IC 95%: -11,6 para 15,6, p = 0,94), respectivamente. Não houve diferença significativa tanto nos escores de dor autorrelatados, quanto na incidência de eventos adversos entre os grupos. Conclusão Nossos achados sugerem que a administração de sufentanil durante a indução de anestesia intravenosa total à base de remifentanil está associada à redução do consumo de opioides no pós-operatório imediato.

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)

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)

Regulation of hypnosis in Propofol anesthesia administration based on non-linear control strategy / Controle da hipnose na administração de propofol com base na estratégia de controle não linear

Abstract Continuous adjustment of Propofol in manual delivery of anesthesia for conducting a surgical procedure overburdens the workload of an anesthetist who is working in a multi-tasking scenario. Going beyond manual administration and Target Controlled Infusion, closed-loop control of Propofol infusion has the potential to offer several benefits in terms of handling perturbations and reducing the effect of inter-patient variability. This paper proposes a closed-loop automated drug administration approach to control Depth Of Hypnosis in anesthesia. In contrast with most of the existing research on anesthesia control which makes use of linear control strategies or their improved variants, the novelty of the present research lies in applying robust control strategy i.e. Sliding Mode Control to accurately control drug infusion. Based on the derived patient's model, the designed controller uses measurements from EEG to regulate DOH on Bispectral Index by controlling infusion rate of Propofol. The performance of the controller is investigated and characterized with real dataset of 8 patients undergoing surgery. Results of this in silico study indicate that for all the patients, with 0% overshoot observed, the steady state error lies in between ±5. Clinically, this implies that in all the cases, without any overdose, the controller maintains the desired DOH level for smooth conduction of surgical procedures.

Resumo O ajuste contínuo de propofol na administração manual de anestesia para um procedimento cirúrgico onera a carga de trabalho de anestesistas que trabalham em ambiente multitarefa. Indo além da administração manual e da infusão alvo-controlada (IAC), o controle de circuito fechado da infusão de propofol tem o potencial de oferecer vários benefícios em termos de manejo das perturbações e reduzir o efeito da variabilidade interpaciente. Este artigo propõe uma abordagem para a administração automatizada de drogas em circuito fechado para controlar a profundidade da hipnose (PDH) em anestesia. Em contraste com a maioria das pesquisas existentes sobre o controle da anestesia que usam estratégias de controle linear ou de suas variantes melhoradas, a novidade da presente pesquisa reside na aplicação de uma estratégia de controle consistente; isto é, o Controle por Modos Deslizantes (CMD) para controlar com precisão a infusão da droga. Com base no modelo derivado do paciente, o controlador projetado usa as medições do EEG para regular a PDH no Bispectral Index (BIS), controla a taxa de infusão de propofol. O desempenho do controlador é investigado e caracterizado com um conjunto de dados reais de oito pacientes submetidos à cirurgia. Os resultados deste estudo in silico indicam que, para todos os pacientes, com 0% de excesso observado, o erro de estado estacionário fica entre ± 5. Clinicamente, isso implica que em todos os casos, sem qualquer sobredosagem, o controlador mantém o nível desejado de PDH para a condução tranquila dos procedimentos cirúrgicos.

Anesthesia in a patient with Stiff Person Syndrome / Anestesia em paciente com síndrome da pessoa rígida

Abstract Stiff Person Syndrome (SPS), typified by rigidity in muscles of the torso and extremities and painful episodic spasms, is a rare autoimmune-based neurological disease. Here we present the successful endotracheal intubation and application of TIVA without muscle relaxants on an SPS patient. A 46 years old male patient was operated with ASA-II physical status because of lumber vertebral compression fracture. After induction of anesthesia using lidocaine, propofol and remifentanil tracheal intubation was completed easily without neuromuscular blockage. Anesthesia was maintained with propofol, remifentanil and O2/air mixture. After a problem-free intraoperative period the patient was extubated and seven days later was discharged walking with aid. Though the mechanism is not clear neuromuscular blockers and volatile anesthetics may cause prolonged hypotonia in patients with SPS. We think the TIVA technique, a general anesthetic practice which does not require neuromuscular blockage, is suitable for these patients.

Resumo A síndrome da pessoa rígida (SPR), caracterizada pela rigidez dos músculos do tronco e das extremidades e por episódios de espasmos dolorosos, é uma doença neurológica autoimune rara. Apresentamos o ocaso de intubação endotraqueal bem-sucedida e aplicação de AVT sem relaxantes musculares em um paciente com SPR. Paciente do sexo masculino, 46 anos, estado físico ASA-II, submetido à cirurgia devido à fratura por compressão da coluna lombar. Após a indução da anestesia com lidocaína, propofol e remifentanil, a intubação traqueal foi concluída com facilidade, sem bloqueio neuromuscular. A anestesia foi mantida com propofol, remifentanil e mistura de ar/O2. Após o período intraoperatório, que transcorreu sem intercorrências, o paciente foi extubado e, sete dias depois, recebeu alta, deambulando com ajuda. Embora o mecanismo não esteja claro, bloqueadores neuromusculares e anestésicos voláteis podem causar hipotonia prolongada em pacientes com SPR. Acreditamos que a técnica de AVT, uma prática de anestesia geral que não requer bloqueio neuromuscular, é adequada para esses pacientes.

Effect of preoperative gabapentin on pain intensity and development of chronic pain after carpal tunnel syndrome surgical treatment in women: randomized, double-blind, placebo-controlled study / Efeito da gabapentina pré-operatória na intensidade da dor e desenvolvimento de dor crônica após o tratamento cirúrgico da síndrome do túnel do carpo em mulheres: estudo randomizado duplo-cego controlado com placebo

ABSTRACT CONTEXT AND OBJECTIVES: Effective postoperative analgesia is important for reducing the incidence of chronic pain. This study evaluated the effect of preoperative gabapentin on postoperative analgesia and the incidence of chronic pain among patients undergoing carpal tunnel syndrome surgical treatment. DESIGN AND SETTINGS: Randomized, double-blind controlled trial, Federal University of São Paulo Pain Clinic. METHODS: Forty patients aged 18 years or over were randomized into two groups: Gabapentin Group received 600 mg of gabapentin preoperatively, one hour prior to surgery, and Control Group received placebo. All the patients received intravenous regional anesthesia comprising 1% lidocaine. Midazolam was used for sedation if needed. Paracetamol was administered for postoperative analgesia as needed. Codeine was used additionally if the paracetamol was insufficient. The following were evaluated: postoperative pain intensity (over a six-month period), incidence of postoperative neuropathic pain (over a six-month period), need for intraoperative sedation, and use of postoperative paracetamol and codeine. The presence of neuropathic pain was established using the DN4 (Douleur Neuropathique 4) questionnaire. Complex regional pain syndrome was diagnosed using the Budapest questionnaire. RESULTS: No differences in the need for sedation, control over postoperative pain or incidence of chronic pain syndromes (neuropathic or complex regional pain syndrome) were observed. No differences in postoperative paracetamol and codeine consumption were observed. CONCLUSIONS: Preoperative gabapentin (600 mg) did not improve postoperative pain control, and did not reduce the incidence of chronic pain among patients undergoing carpal tunnel syndrome surgery.

RESUMO CONTEXTO E OBJETIVOS: Analgesia pós-operatória eficaz é importante para reduzir a incidência de dor crônica. Este estudo avaliou o efeito da gabapentina pré-operatória na analgesia pós-operatória e na incidência de dor crônica em pacientes submetidos à cirurgia para tratamento da síndrome do túnel do carpo. DESENHO E LOCAL: Randomizado, duplo cego, Universidade Federal de São Paulo. MÉTODOS: Os 40 pacientes com 18 anos ou mais de idade foram distribuídos aleatoriamente em dois grupos: o Grupo Gabapentina recebeu 600 mg de gabapentina no pré-operatório uma hora antes da cirurgia, e o Grupo Controle recebeu placebo. Todos os pacientes receberam anestesia regional intravenosa com lidocaína a 1%. Midazolam foi utilizado para sedação, se necessário. Paracetamol foi administrado para analgesia pós-operatória, conforme necessário, e codeína, se o paracetamol fosse insuficiente. Foram avaliados: a intensidade da dor pós-operatória (durante seis meses), a incidência de dor neuropática pós-operatória (durante seis meses), a necessidade de sedação intra-operatória e o uso de paracetamol e codeína no pós-operatório. A presença de dor neuropática foi estabelecida utilizando-se o questionário DN4 (dor neuropática 4). Síndrome de dor regional complexa foi diagnosticada através do questionário Budapeste. RESULTADOS: Não foram observadas diferenças na necessidade de sedação, no controle da dor pós-operatória e na incidência de síndromes dolorosas crônicas (neuropáticas ou síndrome de dor regional complexa). Não foram observadas diferenças no consumo de paracetamol e codeína. CONCLUSÕES: Gabapentina pré-operatória (600 mg) não melhorou o controle da dor pós-operatória e não reduziu a incidência de dor crônica em pacientes submetidos à cirurgia para tratamento da síndrome do túnel do carpo.

Dexmedetomidine decreases the inflammatory response to myocardial surgery under mini-cardiopulmonary bypass

Cardiopulmonary bypass (CPB) with extracorporeal circulation produces changes in the immune system accompanied by an increase in proinflammatory cytokines and a decrease in anti-inflammatory cytokines. We hypothesize that dexmedetomidine (DEX) as an anesthetic adjuvant modulates the inflammatory response after coronary artery bypass graft surgery with mini-CPB. In a prospective, randomized, blind study, 12 patients (4 females and 8 males, age range 42-72) were assigned to DEX group and compared with a conventional total intravenous anesthesia (TIVA) group of 11 patients (4 females and 7 males). The endpoints used to assess inflammatory and biochemical responses to mini-CPB were plasma interleukin (IL)-1, IL-6, IL-10, interferon (INF)-γ, tumor necrosis factor (TNF)-α, C-reactive protein, creatine phosphokinase, creatine phosphokinase-MB, cardiac troponin I, cortisol, and glucose levels. These variables were determined before anesthesia, 90 min after beginning CPB, 5 h after beginning CPB, and 24 h after the end of surgery. Endpoints of oxidative stress, including thiobarbituric acid reactive species and delta-aminolevulinate dehydratase activity in erythrocytes were also determined. DEX+TIVA use was associated with a significant reduction in IL-1, IL-6, TNF-α, and INF-γ (P<0.0001) levels compared with TIVA (two-way ANOVA). In contrast, the surgery-induced increase in thiobarbituric acid reactive species was higher in the DEX+TIVA group than in the TIVA group (P<0.01; two-way ANOVA). Delta-aminolevulinate dehydratase activity was decreased after CPB (P<0.001), but there was no difference between the two groups. DEX as an adjuvant in anesthesia reduced circulating IL-1, IL-6, TNF-α, and INF-γ levels after mini-CPB. These findings indicate an interesting anti-inflammatory effect of DEX, which should be studied in different types of surgical interventions.

A influência do índice bispectral no tempo de alta hospitalar de pacientes submetidos a procedimentos oftalmológicos / The influence of the bispectral index in hospital time of patients undergoing ophthalmic procedures

Objetivo do estudo: avaliar se a titulação de drogas guiada pelo índice bispectral em pacientes submetidos à cirurgia oftalmológica ambulatorial está associada a uma redução no tempo de alta. Método: foram selecionados 111 pacientes submetidos a procedimentos oftalmológicos realizados sob sedação intravenosa associada ao bloqueio peribulbar. Ospacientes foram randomizados em dois grupos. Nos pacientes do grupo controle, o anestesista responsável administrou a sedação de acordo com parâmetros clínicos: manter o paciente entre 2 a 4 pontos na escala de sedação de Ramsay. No outro grupo, o índice bispectral foi monitorizado e a sedação foi administrada para manter os valores entre 70 e 85. Foram comparados entre os grupos os dados demográficos, a dosagem de drogas, a duração dos procedimentos, as complicações pós-operatórias e o tempo de alta. Resultados: os grupos não apresentaram diferenças estatísticas em relação aos dados demográficos, à dosagem das drogas intravenosas e à dose administrada de anestésico local. Não se observou diferença entre os grupos em relação à duração dos procedimentos e ao tempo de alta para casa. As complicações pós-operatórias detectadas foram náuseas e vômitos e dor pós-operatória, no entanto, sem diferença estatística significante entre os grupos. Conclusões: a monitorização com o índice bispectral não foi mais eficaz que à monitorização clínica, em reduzir o tempo de alta para casa de pacientes submetidos a cirurgias oftalmológicas ambulatoriais sob sedação e bloqueio peribulbar.

Study objective: assessing whether drug titration guided by the bispectral index in patients submitted to outpatient ophthalmological surgeries is associated with a decreased time of hospital discharge. Method: one hundred and eleven patients submitted to outpatient ophthalmological procedures performed under intravenous sedation associated with peribulbar block were selected for this study. Patients were randomized in two groups. In the control group, the anesthetist in charge administered sedation according to clinical parameters: maintaining the patient between 2 and 4 points in the Ramsay?s sedation scale. In the other group, the bispectral index was monitored and sedation was performed with the purpose of maintaining its values between 70 and 85. Demographic data, drug dosage, length of procedures, post-surgical complications and time of hospital discharge were compared between the two groups. Results: groups have not shown statistical differences regarding demographic data, dosage of intravenous drugs and the dosage of local anesthetic administered. No difference was observed between groups regarding the length of the procedures, and the time of hospital discharge. The post-surgical complications detected were nausea and vomiting and post-surgical pain, however, with no statistically significant difference between groups. Conclusions: bispectral index monitoring has not been more effective than clinical monitoring to reduce the time of hospital discharge of patients submitted to outpatient ophthalmological surgeries under sedation and peribulbar block.

A randomized, double blind comparison of pethidine and ketoprofen as adjuvants for lignocaine in intravenous regional anaesthesia / Estudo comparativo, randômico e duplo-cego de petidina e cetoprofeno como adjuvantes de lidocaína em anestesia regional intravenosa / Estudio comparativo, aleatorizado y doble ciego, de la petidina y del ketoprofeno como adyuvantes de la lidocaína en la anestesia regional intravenosa

BACKGROUND AND OBJECTIVES: A review of all the adjuncts for intravenous regional anaesthesia concluded that there is good evidence to recommend NonSteroidal Anti-Inflammatory agents and pethidine in the dose of 30 mg dose as adjuncts to intravenous regional anaesthesia. But there are no studies to compare pethidine of 30 mg dose to any of the NonSteroidal Anti-Inflammatory agents. METHODS: In a prospective, randomized, double blind study, 45 patients were given intravenous regional anaesthesia with either lignocaine alone or lignocaine with pethidine 30 mg or lignocaine with ketprofen 100 mg. Fentanyl was used as rescue analgesic during surgery. For the first 6 h of postoperative period analgesia was provided by fentanyl injection and between 6 and 24 h analgesia was provided by diclofenac tablets. Visual analogue scores for pain and consumption of fentanyl and diclofenac were compared. RESULTS: The block was inadequate for one case each in lignocaine group and pethidine group, so general anaesthesia was provided. Time for the first dose of fentanyl required for postoperative analgesia was significantly more in pethidine and ketoprofen groups compared to lignocaine group (156.7 ± 148.8 and 153.0 ± 106.0 vs. 52.1 ± 52.4 min respectively). Total fentanyl consumption in first 6 h of postoperative period was less in pethidine and ketoprofen groups compared to lignocaine group (37.5 ± 29.0 mcg, 38.3 ± 20.8 mcg vs. 64.2 ± 27.2 mcg respectively). Consumption of diclofenac tablets was 2.4 ± 0.7, 2.5 ± 0.5 and 2.0 ± 0.7 in the control, pethidine and ketoprofen group respectively, which was statistically not significant. Side effects were not significantly different between the groups. CONCLUSION: Both pethidine and ketoprofen are equally effective in providing postoperative analgesia up to 6 h, without significant difference in the side effects and none of the adjuncts provide significant ...

JUSTIFICATIVA E OBJETIVOS: uma revisão de todos os adjuvantes para anestesia regional intravenosa concluiu que há boas evidências para recomendar os agentes anti-inflamatórios não esteroides e petidina em dose de 30 mg como adjuvantes para anestesia regional intravenosa. Porém, não há estudos que comparem petidina (30 mg) com quaisquer dos agentes anti-inflamatórios não esteroides. MÉTODOS: em um estudo prospectivo, randômico e duplo-cego, 45 pacientes receberam anestesia regional intravenosa com apenas lidocaína ou lidocaína com petidina (30 mg) ou lidocaína com cetoprofeno (100 mg). Fentanil foi usado como analgésico de resgate durante a cirurgia. Durante as seis primeiras horas de pós-operatório, analgesia foi fornecida via injeção de fentanil e, entre seis e 24 horas, analgesia foi fornecida via comprimidos de diclofenaco. Os escores visuais analógicos para dor e do consumo de fentanil e diclofenaco foram comparados. RESULTADOS: o bloqueio foi inadequado para um caso tanto do grupo lidocaína quanto do grupo petidina; portanto, anestesia geral foi administrada. O tempo para a primeira dose necessária de fentanil para analgesia pós-operatória foi significativamente maior nos grupos petidina e cetoprofeno em comparação com o grupo lidocaína (156,7 ± 148,8 e 153,0 ± 106,0 vs. 52,1 ± 52,4 minutos, respectivamente). O consumo total de fentanil nas primeiras seis horas de pós-operatório foi menor nos grupos petidina e cetoprofeno em comparação com o grupo lidocaína (37,5 ± 29,0 mcg, 38,3 ± 20,8 mcg vs. 64,2 ± 27,2 mcg, respectivamente). O consumo de comprimidos de diclofenaco foi de 2,4 ± 0,7, 2,5 ± 0,5 e 2,0 ± 0,7 no grupo controle, petidina e cetoprofeno, respectivamente, o que não foi estatisticamente significante. ...

JUSTIFICACIÓN Y OBJETIVOS: una revisión sobre todos los adyuvantes para la anestesia regional intravenosa concluyó que hay buenas evidencias para recomendar los agentes antiinflamatorios no esteroideos y la petidina en dosis de 30 mg como adyuvantes para la anestesia regional intravenosa. Sin embargo, no hay estudios comparando la petidina (30 mg) con cualesquiera de los agentes antiinflamatorios no-esteroideos. MÉTODOS: en un estudio prospectivo, aleatorizado y doble ciego, 45 pacientes recibieron anestesia regional intravenosa con solamente lidocaína o lidocaína con petidina (30 mg) o lidocaína con ketoprofeno (100 mg). El fentanilo fue usado como analgésico de rescate durante la cirugía. Durante las 6 primeras horas del postoperatorio, la analgesia fue suministrada vía inyección de fentanilo y entre 6 y 24 h, la analgesia fue suministrada vía comprimidos de diclofenaco. Se compararon las puntuaciones visuales analógicas para el dolor y el consumo de fentanilo y diclofenaco. RESULTADOS: el bloqueo fue inadecuado para un caso tanto del grupo lidocaína como del grupo petidina; por tanto, se administró anestesia general. El tiempo para la primera dosis necesaria de fentanilo para analgesia postoperatoria fue significativamente mayor en los grupos petidina y ketoprofeno en comparación con el grupo lidocaína (156,7 ± 148,8 y 153,0 ± 106,0 vs. 52,1 ± 52,4 min, respectivamente). El consumo total de fentanilo en las primeras 6 h del postoperatorio fue menor en los grupos petidina y ketoprofeno en comparación con el grupo lidocaína (37,5 ± 29,0 mcg; 38,3 ± 20,8 mcg vs. 64,2 ± 27,2 mcg, respectivamente). El consumo de comprimidos de diclofenaco fue de 2,4 ± 0,7; 2,5 ± 0,5; y 2 ± 0,7 en el grupo control, petidina y ketoprofeno, respectivamente, lo que no fue estadísticamente significativo. Los ...

Bloqueo continuo del plexo braquial en el posoperatorio inmediato / Continuous brachial plexus block in immediate postoperative

OBJETIVO: evaluar el período posoperatorio inmediato en pacientes con lesiones traumáticas quirúrgicas del miembro superior que han recibido dos métodos de anestesia-analgesia. MÉTODOS: se estudiaron 240 pacientes, todos ASA I-II-III según la clasificación del estado físico de la Sociedad Americana de Anestesiología. Se dividieron en dos grupos iguales, grupo G: anestesia general endotraqueal más fentanil y analgesia con dipirona 1,2 g IM cada 6 h, y grupo B: anestesia regional por técnicas continuas de bloqueo del plexo braquial con 100 mg de bupivacaína y analgesia regional con igual anestésico local cada 6 h. RESULTADOS: las complicaciones respiratorias se presentaron solamente en el grupo G (p= 0,01), mientras que las cardiovasculares se observaron 5,3 veces más en el grupo G (p= 0,000). Las náuseas y vómitos se manifestaron en más de la mitad de los pacientes (55 %) del grupo G y solo en seis (5 %) del grupo B (p= 0,000). La retención de orina y la oliguria se observó en tres y cuatro pacientes respectivamente, todos masculinos y del grupo G (p= 0,000). La tendencia a la hiperglucemia apareció en el grupo G en 27 pacientes (22,5 %) y solo en cinco (4,2 %) del grupo B (p= 0,000). Las molestias por la manipulación de la vía aérea superior, se presentaron en 79 pacientes (65,8 %) del grupo G; mientras que las molestias por el catéter solo se refirió en 16 pacientes (13,3 %) del grupo B. El grupo G a las 24 h llegó a tener 69 pacientes (57,5 %) en el nivel de analgesia no satisfactoria (p= 0,01). CONCLUSIONES: el método de anestesia-analgesia regional por bloqueo continuo del plexo braquial tuvo menor incidencia de complicaciones en el posoperatorio inmediato y mejor calidad de analgesia.

OBJECTIVE: to evaluate the immediate postoperative period in surgical patients with traumatic injuries of the upper limb who have undertaken two methods of anesthesia-analgesia. METHODS: 240 patients were studied, all ASA I-II-III according to the classification of the American Society of Anesthesiologists for physical state. They were divided into two equal groups. Group G had general endotracheal anesthesia and analgesia with fentanyl plus dipyrone 1.2 g IM every 6 h, and group B who had regional anesthesia techniques for continuous brachial plexus block with 100 mg of bupivacaine and regional analgesia with equal local anesthetic every 6 h. RESULTS: respiratory complications occurred only in group G (p= 0.01), cardiovascular complications were observed 5.3 times more in G group (p= 0.000). Nausea and vomiting were expressed in more than half of patients (55 %) in group G and only in six (5 %) from group B (p= 0.000). Urine retention and oliguria were observed in three and four patients respectively, all male from group G (p= 0.000). Hyperglycemia tendency appeared in group G in 27 patients (22.5 %) and in only five (4.2 %) from group B (p= 0.000). Discomfort by manipulating the upper airway occurred in 79 patients (65.8 %) from group G; nuisance due to the catheter was only referred in 16 patients (13.3 %) from group B. 24 hours after surgery, Group G had 69 patients (57.5 %) in unsatisfactory analgesia level (p= 0.01). CONCLUSIONS: the method of regional anesthesia-analgesia by continuous brachial plexus block had lower incidence of complications in the immediate postoperative period and better quality of analgesia.

Remifentanil-based total intravenous anesthesia for pediatric rigid bronchoscopy: comparison of adjuvant propofol and ketamine

OBJECTIVE: Laryngoscopy and stimuli inside the trachea cause an intense sympatho-adrenal response. Remifentanil seems to be the optimal opioid for rigid bronchoscopy due to its potent and short-acting properties. The purpose of this study was to compare bolus propofol and ketamine as an adjuvant to remifentanil-based total intravenous anesthesia for pediatric rigid bronchoscopy. MATERIALS AND METHODS: Forty children under 12 years of age who had been scheduled for a rigid bronchoscopy were included in this study. After midazolam premedication, a 1 µg/kg/min remifentanil infusion was started, and patients were randomly allocated to receive either propofol (Group P) or ketamine (Group K) as well as mivacurium for muscle relaxation. Anesthesia was maintained with a 1 µg/kg/min remifentanil infusion and bolus doses of propofol or ketamine. After the rigid bronchoscopy, 0.05 µg/kg/min of remifentanil was maintained until extubation. Hemodynamic parameters, emergence characteristics, and adverse events were evaluated. RESULTS: The demographic variables were comparable between the two groups. The decrease in mean arterial pressure from baseline values to the lowest values during rigid bronchoscopy was greater in Group P (p = 0.049), while the reduction in the other parameters and the incidence of adverse events were comparable between the two groups. The need for assisted or controlled mask ventilation after extubation was higher in Group K. CONCLUSION: Remifentanil-based total intravenous anesthesia with propofol or ketamine as an adjuvant drug along with controlled ventilation is a viable technique for pediatric rigid bronchoscopy. Ketamine does not provide a definite advantage over propofol with respect to hemodynamic stability during rigid bronchoscopy, while propofol seems more suitable during the recovery period. .

Perfusión intravenosa de remifentanilo controlada por ordenador: efectos, consumo, concentración efectiva / Intravenous infusion of remifentanil computer controlled: effects, consumption, effective concentration

Introducción: El objetivo fue comprobar si los sistemas de perfusión guiados por ordenador TCI (Target Control Infusion) estimando concentraciones plasmáticas (Cp), modulan condiciones hemodinámicas, consumo de remifentanil y concentraciones sitio efecto (Ce), en colecistectomía videolaparoscópica (CVL). Material y Métodos: Estudio clínico prospectivo, aleatorizado en pacientes ASA I, dos grupos: GRUPO PC (n = 12) remifentanil 0.5 mcg x kg-1 x min-1 y GRUPO TCI (n = 12) TCI remifentanil Cp 4 ng x ml-1 (Modelo Minto, Ke sub 0 0,595/min). Ambas perfusiones disminuidas 50% posintubación. Se registraron Tensión Arterial Sistólica (TAS), Tensión Arterial Diastólica (TAD) y Frecuencia Cardíaca (FC), remifentanil consumido y Ce, basal, posintubación, posincisión y finalización cirugía. Resultados: Sin diferencias entre grupos variables antropométricas, tiempos quirúrgico y de anestesia. Se halló diferencia G PC vs G TCI en FC (X ± de) posintubación 63,2 ± 12,2 vs 76,6 ± 13 (p = 0,014). Dentro grupos, G PC posintubación TAS 96,9 ± 18,5 (p = 0,0009), TAD 57,7 ± 15,2 (p = 0,0006) y FC 63,2 ± 12,2 (p = 0,010). Consumo de remifentanil G PC vs G TCI posintubación 216,2 ± 91,6 vs 102,4 ± 14,8 (p < 0,0001), posincisión 381,4 ± 185,4 vs 184,1 ± 39,6 (p = 0,0002) y fin de cirugía 2310 ± 912,8 vs 1642,4 ± 607,8 (p = ,028). Ce remifentanil posintubación 7,4 ± 1,6 vs 3,6 ± 0,2 (p < 0,0001), posincisión 6,1 ± 1,7 vs 2,2 ± 0,3 (p < 0,0001). Hipotensión G PC posintubación (50% p < 0,007), posincisión (33,3% p < 0,047), necesidad de efedrina dos pacientes G PC. Conclusión: La perfusión de remifentanil controlada por ordenador Cp de 4 ng/ml produjo en nuestro grupo de pacientes mejores condiciones hemodinámicas durante el intraoperatorio, comparada con perfusión continua de 0.5 mcg x kg-1 x min-1, en CVL. La mejoría se atribuiría a la adecuada concentración de remifentanil en sitio de efecto, permitiendo además disminuir el consumo de la droga.

The analgesic effect of nitroglycerin added to lidocaine on quality of intravenous regional anesthesia in patients undergoing elective forearm and hand surgery

PURPOSE: To evaluate the effect of nitroglycerine (NTG) on sensory and motor block onset and recovery time as well as the quality of tourniquet pain relief, when added to lidocaine (LID) for intravenous regional anesthesia in elective forearm and hand surgery. METHODS: A randomized double-blinded clinical trial was performed on 40 patients that were randomly allocated into two groups received lidocaine 3 mg/kg with NTG 200 µg or received only lidocaine 3 mg/kg as the control. RESULTS: There was no difference between the two study groups in hemodynamic parameters before tourniquet inflation, at any time after inflation and after its deflation. There was no difference in the mean of pain score over time between the two groups. The onset time of sensory and motor blockades was shorter in the group received both LID and NTG. The mean recovery time of sensory blockade was longer in the former group. The frequency of opioid injections was significantly lower in those who administered LID and NTG. CONCLUSION: The adjuvant drug of NTG when added to LID is effective in improving the overall quality of anesthesia, shortening onset time of both sensory and motor blockades, and stabling homodynamic parameters in hand and forearm surgery.

Comparison of 7.2% hypertonic saline - 6% hydroxyethyl starch solution and 6% hydroxyethyl starch solution after the induction of anesthesia in patients undergoing elective neurosurgical procedures

OBJECTIVE: The ideal solution for fluid management during neurosurgical procedures remains controversial. The aim of this study was to compare the effects of a 7.2% hypertonic saline - 6% hydroxyethyl starch (HS-HES) solution and a 6% hydroxyethyl starch (HES) solution on clinical, hemodynamic and laboratory variables during elective neurosurgical procedures. METHODS: Forty patients scheduled for elective neurosurgical procedures were randomly assigned to the HS-HES group orthe HES group. Afterthe induction of anesthesia, patients in the HS-HES group received 250 mL of HS-HES (500 mL/h), whereas the patients in the HES group received 1,000 mL of HES (1000 mL/h). The monitored variables included clinical, hemodynamic and laboratory parameters. Chictr.org: ChiCTR-TRC-12002357 RESULTS: The patients who received the HS-HES solution had a significant decrease in the intraoperative total fluid input (p<0.01), the volume of Ringer's solution required (p<0.05), the fluid balance (p<0.01) and their dural tension scores (p<0.05). The total urine output, blood loss, bleeding severity scores, operation duration and hemodynamic variables were similar in both groups (p>0.05). Moreover, compared with the HES group, the HS-HES group had significantly higher plasma concentrations of sodium and chloride, increasing the osmolality (p<0.01). CONCLUSION: Our results suggest that HS-HES reduced the volume of intraoperative fluid required to maintain the patients undergoing surgery and led to a decrease in the intraoperative fluid balance. Moreover, HS-HES improved the dural tension scores and provided satisfactory brain relaxation. Our results indicate that HS-HES may represent a new avenue for volume therapy during elective neurosurgical procedures.