RESUMO
Abstract We present the case of an adult with an extensive left frontal meningioma. He was scheduled for resection by craniotomy. During the surgery we used the density spectral array (DSA) and asymmetry obtained from Bispectral Index VISTA Monitoring System Bilateral. We observed a power increase in low frequency (0.1-1 Hz) and alpha bands (8-12 Hz) in the left hemisphere, where the meningioma was located. In this case, DSA was useful during and after the surgery because it provided information about the hemisphere with maximum brain activity and its subsequent normalization, which may reflect the effectiveness of the surgery.
Resumen Presentamos el caso de un paciente adulto con diagnóstico de un meningioma extenso a nivel frontal izquierdo, que fue programado para exéresis mediante craneotomía. Durante la cirugía se utilizó la Matriz de Densidad Espectral (MDE) y la asimetría obtenida del Sistema de Monitorización VISTATM del Índice Biespectral Bilateral (BVMS). Se observó un aumento de potencia en las bandas de baja frecuencia (0.1-1Hz) y en las bandas alfa (812 Hz) del hemisferio cerebral izquierdo, donde se encontraba el meningioma. En este caso la MDE demostró su utilidad durante y después de la cirugía, al proporcionar información sobre el hemisferio con registro de máxima actividad cerebral y su posterior normalización, reflejando así la efectividad de la cirugía.
Assuntos
Humanos , Masculino , Idoso de 80 Anos ou mais , Cuidados Pós-Operatórios , Craniotomia , Meningioma , Procedimentos Neurocirúrgicos , Eletroencefalografia , Monitores de ConsciênciaRESUMO
BACKGROUND AND OBJECTIVES: According to the manufacturer, the Bispectral Index (BIS) has a processing time delay of 5-10s. Studies addressing this have suggested longer delays. We evaluated the time delay in the Bispectral Index response. METHODS: Based on clinical data from 45 patients, using the difference between the predicted and the real BIS, calculated during a fixed 3minutes period after the moment the Bispectral Index dropped below 80 during the induction of general anesthesia with propofol and remifentanil. RESULTS: The difference between the predicted and the real BIS was in average 30.09±18.73s. CONCLUSION: Our results may be another indication that the delay in BIS processing may be much longer than stated by the manufacture, a fact with clinical implications.
Assuntos
Anestesia Geral/métodos , Monitores de Consciência , Propofol/administração & dosagem , Remifentanil/administração & dosagem , Adulto , Idoso , Anestésicos Intravenosos/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Intraoperatória/métodos , Fatores de Tempo , Adulto JovemRESUMO
Abstract Background and objectives According to the manufacturer, the Bispectral Index (BIS) has a processing time delay of 5-10 s. Studies addressing this have suggested longer delays. We evaluated the time delay in the Bispectral Index response. Methods Based on clinical data from 45 patients, using the difference between the predicted and the real BIS, calculated during a fixed 3 minutes period after the moment the Bispectral Index dropped below 80 during the induction of general anesthesia with propofol and remifentanil. Results The difference between the predicted and the real BIS was in average 30.09 ± 18.73 s. Conclusion Our results may be another indication that the delay in BIS processing may be much longer than stated by the manufacture, a fact with clinical implications.
Resumo Justificativa e objetivos De acordo com o fabricante, o índice bispectral (BIS) tem um tempo de processamento de cinco a dez segundos. Estudos que avaliaram esse tempo de processamento sugeriram atrasos mais longos. Nós avaliamos o tempo de atraso na resposta do BIS. Métodos Com base em dados clínicos de 45 pacientes, calculamos a diferença entre o tempo de atraso previsto e real do índice bispectral durante um período fixo de três minutos após o momento em que o BIS caiu abaixo de 80 durante a indução da anestesia geral com propofol e remifentanil. Resultados A diferença entre o BIS previsto e real foi em média 30,09 ± 18,73 segundos. Conclusão Nossos resultados sugerem que o atraso no processamento do índice bispectral pode ser muito maior do que o declarado pelo fabricante, um fato com implicações clínicas.
Assuntos
Humanos , Masculino , Feminino , Adulto , Idoso , Adulto Jovem , Propofol/administração & dosagem , Monitores de Consciência , Remifentanil/administração & dosagem , Anestesia Geral/métodos , Fatores de Tempo , Monitorização Intraoperatória/métodos , Anestésicos Intravenosos/administração & dosagem , Pessoa de Meia-IdadeRESUMO
Abstract Introduction: Intravenous general anesthesia is an anesthetic technique that can be administered with TCI (target-controlled infusion) or closed-loop systems. The authors designed an automatic delivery system using clinical variables such as bispectral index (BIS), heart rate, and blood pressure. Objective: To evaluate the clinical and technical performance of this controller by comparing it to a TCI system. Methods: This was a single-blind, randomized, controlled clinical trial in which 150 patients were recruited: 75 for the TCI group and 75 for the closed loop with BIS. Clinical performance was determined according to the mean percentage of time spent in the BIS range of 40 to 60 during anesthetic maintenance. In addition, adequate intraoperative analgesia, technical performance, intraoperative awakening, and intraoperative recall were evaluated. Results: The primary outcome showed a mean BIS time between 40 and 60 for the closed loop of 75.24% (± 15.78) versus 59.5% (± 20.3) for the TCI system, with an absolute difference of 15.8%, 95% confidence interval (CI): 9.9 to 21.65, P < 0.0001. The mean time in intraoperative analgesia was 82.4% (25.1) in closed loop and 70.77% (± 32.8) in TCI, with a difference of 4.76 (95% CI: 2.23-21.06), P = 0.016. There was no difference in intraoperative recall. Conclusion: The closed-loop system was better at maintaining a BIS in the range of 40 to 60 during a general anesthetic than the open system or TCI.
Resumen Introducción: La anestesia total endovenosa es una técnica anestésica que puede administrarse con sistemas de TCI (Target Controlled Infusión) o de lazo cerrado. Los autores diseñaron un sistema de administración automática empleando variables clínicas como índice biespectral (BIS), frecuencia cardiaca y presión arterial. Objetivo: Evaluar el desempeño clínico y técnico de este controlador, comparándolo con un sistema de TCI. Métodos: Este fue un ensayo clínico controlado, aleatorizado y de ciego único, en el cual se reclutaron 150 pacientes: 75 en el grupo de TCI y 75 en lazo cerrado con BIS. El desempeño clínico fue determinado de acuerdo al porcentaje promedio de tiempo de permanencia en el rango de BIS entre 40-60 durante el mantenimiento anestésico. Adicionalmente se evaluó analgesia intraoperatoria adecuada, desempeño técnico, despertar intraoperatorio y recuerdo intraoperatorio. Resultados: Para el desenlace primario se encontró un tiempo promedio de BIS entre 40-60 para el lazo cerrado de un 75.24% (+/-15.78) vs. 59.5% (+/- 20.3) para el sistema TCI, con una diferencia del 15.8%, IC del 95%: 9.9 a 21.65, p < 0.0001. El promedio de tiempo en analgesia intraoperatoria adecuada fue del 82.4% (25.1) en lazo cerrado y 70.77% (+/- 32.8) en TCI, con una diferencia de 4.76 (IC del 95%: 2.23 a 21.06), p=0.016. No hubo diferencias en recuerdo intraoperatorio. Conclusión: El sistema de lazo cerrado fue mejor para mantener un BIS en rango de 40-60 durante un acto anestésico que el sistema abierto o TCI.
Assuntos
Humanos , Masculino , Feminino , Gravidez , Adulto , Pessoa de Meia-Idade , Anestésicos Intravenosos , Propofol , Ensaio Clínico Controlado , Monitores de Consciência , Analgesia , Anestesia Geral , AnestésicosRESUMO
Abstract Background and objectives: Propofol is commonly employed as a hypnotic agent to perform electroconvulsive therapy, but it exhibits also anticonvulsant properties. The main objective was to study the effect of the weight-adjusted dose of propofol on duration of the electrical seizure. Secondary objectives were to study the effect of absolute dose of propofol on duration of electrical seizure, the effect of both absolute and weight-adjusted doses on values of bispectral index, and the influence of blood chemistry on anticonvulsant effect. Methods: After approval of the Institutional Review Board, a retrospective chart review was performed of all patients who underwent at least one electroconvulsive therapy session. Multiple lineal regression analysis adjusted for potential confounders was employed to explore the effect of propofol dosage on values of bispectral index and on duration of seizure; bivariate correlation analyses were previously performed to identify variables fulfilling confounding criteria, specifically values of Spearman's rho >0.10. Results of regression analysis were expressed as B coefficient with its 95% confident interval. Results: 76 patients received 631 acute phase sessions. Propofol showed a statistically significant negative effect on duration of seizure (specifically a reduction of 4.081 s for every mg.kg−1 of propofol; CI95%: −7906 to −0.255, p = 0.037) but not on bispectral index values. Slight anemia and hypoalbuminemia were very infrequent conditions, and the anticonvulsant effect was not influenced by these parameters. Conclusions: Propofol weight-adjusted dose is negatively related to duration of seizures. It should be carefully titrated when employed to perform electroconvulsive therapy.
Resumo Justificativa e objetivos: O propofol é comumente usado como agente hipnótico na terapia eletroconvulsiva, mas apresenta também propriedades anticonvulsivantes. O objetivo principal foi avaliar o efeito da dose de propofol ajustada ao peso na duração da convulsão elétrica. Os objetivos secundários foram avaliar o efeito da dose total de propofol na duração da convulsão elétrica, o efeito da dose tanto total quanto ajustada ao peso nos valores do índice bispectral e a influência da bioquímica do sangue no efeito anticonvulsivante. Métodos: Após aprovação do Comitê de Ética em Pesquisa, foi feita uma revisão retrospectiva dos prontuários de todos os pacientes que fizeram pelo menos uma sessão de eletroconvulsoterapia. Análise de regressão linear múltipla ajustada para potenciais confundidores foi feita para explorar o efeito da dosagem de propofol sobre os valores do índice bispectral e a duração da convulsão; análises de correlação bivariada foram previamente feitas para identificar as variáveis que atendem aos critérios de confusão, especificamente valores de r de Spearman > 0,10. Os resultados da análise de regressão foram expressos como coeficiente B com intervalo de confiança de 95%. Resultados: Setenta e seis pacientes receberam 631 sessões de fase aguda. Propofol mostrou um efeito negativo estatisticamente significativo sobre a duração da convulsão (especificamente uma redução de 4,081 segundos para cada mg.kg−1 de propofol; IC de 95%: -7906 para -0,255, p = 0,037), mas não para os valores do índice bispectral. Anemia leve e hipoalbuminemia foram condições muito raras e o efeito anticonvulsivante não foi influenciado por esses parâmetros. Conclusões: A dose de propofol ajustada ao peso está negativamente relacionada com a duração das crises convulsivas, deve ser cuidadosamente titulada quando usada na terapia eletroconvulsiva.
Assuntos
Humanos , Masculino , Feminino , Adulto , Idoso , Propofol/administração & dosagem , Eletroconvulsoterapia , Hipnóticos e Sedativos/administração & dosagem , Convulsões , Fatores de Tempo , Análise Química do Sangue , Peso Corporal , Estudos Retrospectivos , Monitores de Consciência , Pessoa de Meia-IdadeRESUMO
BACKGROUND AND OBJECTIVES: Propofol is commonly employed as a hypnotic agent to perform electroconvulsive therapy, but it exhibits also anticonvulsant properties. The main objective was to study the effect of the weight-adjusted dose of propofol on duration of the electrical seizure. Secondary objectives were to study the effect of absolute dose of propofol on duration of electrical seizure, the effect of both absolute and weight-adjusted doses on values of bispectral index, and the influence of blood chemistry on anticonvulsant effect. METHODS: After approval of the Institutional Review Board, a retrospective chart review was performed of all patients who underwent at least one electroconvulsive therapy session. Multiple lineal regression analysis adjusted for potential confounders was employed to explore the effect of propofol dosage on values of bispectral index and on duration of seizure; bivariate correlation analyses were previously performed to identify variables fulfilling confounding criteria, specifically values of Spearman's rho >0.10. Results of regression analysis were expressed as B coefficient with its 95% confident interval. RESULTS: 76 patients received 631 acute phase sessions. Propofol showed a statistically significant negative effect on duration of seizure (specifically a reduction of 4.081s for every mg.kg-1 of propofol; CI95%: -7906 to -0.255, p=0.037) but not on bispectral index values. Slight anemia and hypoalbuminemia were very infrequent conditions, and the anticonvulsant effect was not influenced by these parameters. CONCLUSIONS: Propofol weight-adjusted dose is negatively related to duration of seizures. It should be carefully titrated when employed to perform electroconvulsive therapy.
Assuntos
Eletroconvulsoterapia , Hipnóticos e Sedativos/administração & dosagem , Propofol/administração & dosagem , Adulto , Idoso , Análise Química do Sangue , Peso Corporal , Monitores de Consciência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Convulsões , Fatores de TempoRESUMO
OBJECTIVES: The objective of this study was to apply a pharmacokinetics-pharmacodynamics approach to investigate the free propofol plasma levels in patients undergoing coronary artery bypass grafting under hypothermic conditions compared with the off-pump procedure. METHODS: Nineteen patients scheduled for on-pump coronary artery bypass grafting under hypothermic conditions (n=10) or the equivalent off-pump surgery (n=9) were anesthetized with sufentanil and propofol target-controlled infusion (2 µg/mL) during surgery. The propofol concentration was then reduced to 1 µg/mL, and a pharmacokinetics-pharmacodynamics analysis using the maximum-effect-sigmoid model obtained by plotting the bispectral index values against the free propofol plasma levels was performed. RESULTS: Significant increases (two- to five-fold) in the free propofol plasma levels were observed in the patients subjected to coronary artery bypass grafting under hypothermic conditions. The pharmacokinetics of propofol varied according to the free drug levels in the hypothermic on-pump group versus the off-pump group. After hypothermic coronary artery bypass was initiated, the distribution volume increased, and the distribution half-life was prolonged. Propofol target-controlled infusion was discontinued when orotracheal extubation was indicated, and the time to patient extubation was significantly higher in the hypothermic on-pump group than in the off-pump group (459 versus 273 min, p=0.0048). CONCLUSIONS: The orotracheal intubation time was significantly longer in the hypothermic on-pump group than in the off-pump group. Additionally, residual hypnosis was identified through the pharmacokinetics-pharmacodynamics approach based on decreases in drug plasma protein binding in the hypothermic on-pump group, which could explain the increased hypnosis observed with this drug in this group of patients.
Assuntos
Anestésicos Intravenosos/farmacocinética , Ponte Cardiopulmonar/métodos , Ponte de Artéria Coronária/métodos , Hipotermia Induzida , Propofol/farmacocinética , Idoso , Anestésicos Intravenosos/sangue , Monitores de Consciência , Ponte de Artéria Coronária sem Circulação Extracorpórea/métodos , Feminino , Humanos , Hipnose Anestésica/normas , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Propofol/sangueRESUMO
BACKGROUND: The aim of this study is to derive a propofol pharmacokinetic (PK) pharmacodynamic (PD) model to perform effect-site target-controlled infusion (TCI) in obese patients, and to analyze its performance along with that of other available PK models. METHODS: In the first step of the study, a 3-compartment PK model linked to a sigmoidal inhibitory Emax PD model by a first-order rate constant (keo) was used to fit propofol concentration-bispectral index (BIS) data. Population modeling analysis was performed by nonlinear mixed effects regression in NONMEM (ICON, Dublin, Ireland). PK data from 3 previous studies in obese adult patients (n = 47), including PD (BIS) data from 1 of these studies (n = 20), were pooled and simultaneously analyzed. A decrease in NONMEM objective function (ΔOBJ) of 3.84 points, for an added parameter, was considered significant at the 0.05 level. In the second step of the study, we analyzed the predictive performance (median predictive errors [MDPE] and median absolute predictive errors [MDAPE]) of the current model and of other available models using an independent data set (n = 14). RESULTS: Step 1: The selected PKPD model produced an adequate fit of the data. Total body weight resulted in the best size scalar for volumes and clearances (ΔOBJ, -18.173). Empirical allometric total body weight relationships did not improve model fit (ΔOBJ, 0.309). A lag time parameter for BIS response improved the fit (ΔOBJ, 89.593). No effect of age or gender was observed. Step 2: Current model MDPE and MDAPE were 11.5% (3.7-25.0) and 26.8% (20.7-32.6) in the PK part and 0.4% (-10.39 to 3.85) and 11.9% (20.7-32.6) in the PD part. The PK model developed by Eleveld et al resulted in the lowest PK predictive errors (MDPE = <10% and MDAPE = <25%). CONCLUSIONS: We derived and validated a propofol PKPD model to perform effect-site TCI in obese patients. This model, derived exclusively from obese patient's data, is not recommended for TCI in lean patients because it carries the risk of underdosing.
Assuntos
Anestésicos Intravenosos/administração & dosagem , Anestésicos Intravenosos/farmacocinética , Estado de Consciência/efeitos dos fármacos , Cálculos da Dosagem de Medicamento , Modelos Biológicos , Obesidade Mórbida/metabolismo , Propofol/administração & dosagem , Propofol/farmacocinética , Adulto , Idoso , Anestésicos Intravenosos/efeitos adversos , Índice de Massa Corporal , Peso Corporal , Monitores de Consciência , Feminino , Humanos , Infusões Intravenosas , Monitorização Neurofisiológica Intraoperatória/instrumentação , Masculino , Pessoa de Meia-Idade , Dinâmica não Linear , Obesidade Mórbida/diagnóstico , Obesidade Mórbida/fisiopatologia , Propofol/efeitos adversos , Estudos Prospectivos , Reprodutibilidade dos TestesRESUMO
OBJECTIVES: The objective of this study was to apply a pharmacokinetics-pharmacodynamics approach to investigate the free propofol plasma levels in patients undergoing coronary artery bypass grafting under hypothermic conditions compared with the off-pump procedure. METHODS: Nineteen patients scheduled for on-pump coronary artery bypass grafting under hypothermic conditions (n=10) or the equivalent off-pump surgery (n=9) were anesthetized with sufentanil and propofol target-controlled infusion (2 μg/mL) during surgery. The propofol concentration was then reduced to 1 μg/mL, and a pharmacokinetics-pharmacodynamics analysis using the maximum-effect-sigmoid model obtained by plotting the bispectral index values against the free propofol plasma levels was performed. RESULTS: Significant increases (two- to five-fold) in the free propofol plasma levels were observed in the patients subjected to coronary artery bypass grafting under hypothermic conditions. The pharmacokinetics of propofol varied according to the free drug levels in the hypothermic on-pump group versus the off-pump group. After hypothermic coronary artery bypass was initiated, the distribution volume increased, and the distribution half-life was prolonged. Propofol target-controlled infusion was discontinued when orotracheal extubation was indicated, and the time to patient extubation was significantly higher in the hypothermic on-pump group than in the off-pump group (459 versus 273 min, p=0.0048). CONCLUSIONS: The orotracheal intubation time was significantly longer in the hypothermic on-pump group than in the off-pump group. Additionally, residual hypnosis was identified through the pharmacokinetics-pharmacodynamics approach based on decreases in drug plasma protein binding in the hypothermic on-pump group, which could explain the increased hypnosis observed with this drug in this group of patients.
Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Ponte Cardiopulmonar/métodos , Propofol/farmacocinética , Ponte de Artéria Coronária/métodos , Anestésicos Intravenosos/farmacocinética , Hipotermia Induzida , Propofol/sangue , Anestésicos Intravenosos/sangue , Ponte de Artéria Coronária sem Circulação Extracorpórea/métodos , Monitores de Consciência , Duração da Cirurgia , Hipnose Anestésica/normasRESUMO
Abstract Background and objectives There is a strong demand for fast and predictable anesthesia recovery with few side effects. Choice of the hypnotic agent could impact on that. This study investigated the differences between recoveries after remifentanil-propofol and remifentanil-desflurane anesthesias guided by bispectral index (BIS®). Methods Forty patients were randomly assigned into 2 groups according to the anesthesia technique applied: remifentanil-propofol (REM-PRO) and remifentanil-desflurane (REM-DES). After the discontinuation of the anesthetics, the times to extubation, to obey commands and to recover the airway protection reflex were recorted. In the post-anesthetic recovery room (PACU) it was recorded the occurrence of nausea and vomiting (PONV), scores of Ramsay sedation scale and of numeric pain scale (NPS), morphine dose and length of stay in the unit. Results Data from 38 patients were analyzed: 18 from REM-PRO and 20 from REM-DES group. Anesthesia times were similar (REM-PRO = 193 min, SD 79.9 vs. 175.7 min, SD 87.9 REM-DES; p = 0.5). REM-DES had shorter times than REM-PRO group: time to follow command (8.5 min; SD 3.0 vs. 5.6 min; SD 2.5; p = 0.0) and extubation time (6.2 min; 3.1-8.5 vs. 9.5 min; 4.9-14.4; p = 0.0). Times to recover airway protective reflex were similar: 16 patients from REM-PRO (88.9%) restored the airway protective reflex 2 min after extubation vs. 17 from REM-DES (89.5%); and 2 patients from REM-PRO (11.1%) vs. 2 from REM-DES (10.5%) 6 min after extubation, p = 1. Ramsay sedation score, NPS, PONV incidents, morphine dose and PACU stay of length PACU were also similar. Conclusion Remifentanil-desflurane-based anesthesia has a faster extubation time and to follow command than remifentanil-propofol-based anesthesia when both guided by BIS®.
Resumo Justificativa e objetivos Há uma forte demanda por recuperação pós-anestésica rápida e previsível com poucos efeitos adversos. A escolha do agente hipnótico pode influenciar isso. Este estudo investigou as diferenças da recuperação no pós-operatório entre as técnicas anestésicas com remifentanil-propofol e com remifentanil-desflurano ambas com monitoração guiada pelo índice bispectral (BIS ®). Métodos Foram randomicamente distribuídos 40 pacientes em dois grupos de acordo com a técnica anestésica aplicada: remifentanil-propofol (REM-PRO) e remifentanil-desflurano (REM-DES). Após a descontinuação dos anestésicos foram registrados os tempos para extubação, obedecer a comandos e recuperar o reflexo de proteção das vias aéreas. Na sala de recuperação pós-anestésica (SRPA) foi registrado a ocorrência de náuseas e vômitos (NVPO), os escores na escala de sedação de Ramsay e na escala numérica de dor (END), a dose de morfina utilizada e o tempo de permanência nesta unidade. Resultados Os dados de 38 pacientes foram analisados: 18 do grupo REM-PRO e 20 do grupo REM-DES. Os tempos de anestesia foram semelhantes (REM-PRO = 193 minutos, DP 79,9 vs. 175,7 minutos, DP 87,9 REM-DES; p = 0,5). O grupo REM-DES apresentou tempos mais curtos do que o grupo REM-PRO: tempo para obedecer a comandos (8,5 minutos; DP 3,0 vs. 5,6 minutos; DP 2,5; p = 0,0) e tempo de extubação (6,2 minutos; 3,1-8,5 vs. 9,5 minutos; 4,9-14,4; p = 0,0). Os tempos para recuperação do reflexo de proteção das vias aéreas foram semelhantes: 16 pacientes do grupo REM-PRO (88,9%) recuperaram o reflexo de proteção das vias aéreas dois minutos após a extubação vs. 17 do grupo REM-DES (89,5%) e dois pacientes do grupo REM-PRO (11,1%) vs. dois do REM-DES (10,5%) seis minutos após a extubação, p = 1. Os escores de Ramsay, NPS, a incidência de NVPO, a dose de morfina e o tempo de permanência na SRPA também foram semelhantes. Conclusão A anestesia com remifentanil-desflurano tem um perfil de recuperação da anestesia pós-anestésica mais rápido do que o da anestesia com remifentanil-propofol quando ambas guiadas pelo BIS®.