Efecto de los anestésicos en la electroencefalografía. Parte 2 / Effect of anesthetics on electroencephalography. Part 2

Resumen: La anestesiología cuenta con una nueva generación de monitores de la profundidad anestésica como Narcotrend, SedLine y el índice biespectral; con un procesador del electroencefalograma llamado espectrograma o espectrografía. Tras la obtención del electroencefalograma, se procesa para graficar en tres dimensiones: la frecuencia, el tiempo y la potencia en una escala de colores, con lo que se obtiene la matriz de densidad espectral (DSA, por sus siglas en inglés). El objetivo de esta revisión narrativa es ilustrar los efectos de los anestésicos más comunes en el espectrograma y hacer una breve revisión de su huella en el electroencefalograma.

Abstract: Anesthesiology has a new generation of anesthetic depth monitors such as Narcotrend, SedLine and Bispectral Index; with an electroencephalogram processor called a spectrogram or spectrograph. After obtaining the electroencephalogram, it is processed to graph three dimensions: frequency, time, and power on a color scale, obtaining the DSA (density spectral array). The objective of this narrative review is to illustrate the effects of the most common anesthetics on the spectrogram and to briefly review their signature on the electroencephalogram.

Índice biespectral y tasa de supresión tras parada cardiaca: ¿son útiles para individualizar planes de escalada terapéutica? / Bispectral index and suppression ratio after cardiac arrest: are they useful as bedside tools for rational treatment escalation plans?

Introducción y objetivos: La disfunción miocárdica contribuye a la mortalidad precoz (24-72 horas) de los supervivientes de parada cardiaca (PC). Actualmente, la decisión de implantar un dispositivo de soporte circulatorio en este contexto se toma con información limitada acerca del potencial de recuperación neurológica (PRN) del paciente, lo que en muchas ocasiones termina en infratratamiento. Por tanto, requerimos de herramientas accesibles y fiables que añadan información sobre el PRN y ayuden a establecer planes individualizados de escalada terapéutica. Métodos: Se recogieron valores de índice biespectral (BIS) y tasa de supresión (TS) en supervivientes de una PC sometidos a control de la temperatura corporal. La función neurológica se evaluó con la escala Cerebral Performance Category (CPC). Resultados: Se incluyeron 340 pacientes. En la primera evaluación neurológica completa, 211 (62,1%) alcanzaron buen pronóstico (CPC 1-2). Los valores de BIS fueron significativamente mayores y los de TS menores, en pacientes con CPC 1-2. Un BIS promedio> 26 en las primeras 12 horas predijo buena evolución neurológica (sensibilidad 89,5%; especificidad 75,8%; AUC=0,869), mientras que una TS promedio> 24 en las primeras 12 horas predijo mala evolución o CPC 3-5 (sensibilidad 91,5%; especificidad 81,8%; AUC=0,906). Los valores horarios de BIS/TS mostraron buena capacidad predictiva (AUC> 0,85) desde la 2.a hora para TS y 4.a para BIS. Conclusiones: El BIS/TS permiten estimar el PRN tras una PC. Este hallazgo puede contribuir a crear conciencia con respecto a evitar la limitación de escalada terapéutica en pacientes potencialmente recuperables.(AU)

Introduction and objectives: Myocardial dysfunction contributes to early mortality (24-72 hours) among survivors of a cardiac arrest (CA). The benefits of mechanical support in refractory shock should be balanced against the patient's potential for neurological recovery. To date, these early treatment decisions have been taken based on limited information leading mainly to undertreatment. Therefore, there is a need for early, reliable, accessible, and simple tools that offer information on the possibilities of neurological improvement. Methods: We collected data from bispectral index (BIS) and suppression ratio (SR) monitoring of adult comatose survivors of CA managed with targeted temperature management (TTM). Neurological status was assessed according to the Cerebral Performance Category (CPC) scale. Results: We included 340 patients. At the first full neurological evaluation, 211 patients (62.1%) achieved good outcome or CPC 1-2. Mean BIS values were significantly higher and median SR lower in patients with CPC 1-2. An average BIS> 26 during first 12hours of TTM predicted good outcome with 89.5% sensitivity and 75.8% specificity (AUC of 0.869), while average SR values> 24 during the first 12hours of TTM predicted poor outcome (CPC 3-5) with 91.5% sensitivity and 81.8% specificity (AUC, 0.906). Hourly BIS and SR values exhibited good predictive performance (AUC> 0.85), as soon as hour 2 for SR and hour 4 for BIS. Conclusions: BIS/SR are associated with patients’ potential for neurological recovery after CA. This finding could help to create awareness of the possibility of a better outcome in patients who might otherwise be wrongly considered as nonviable and to establish personalized treatment escalation plans.(AU)

Bispectral index and suppression ratio after cardiac arrest: are they useful as bedside tools for rational treatment escalation plans?

INTRODUCTION AND OBJECTIVES: Myocardial dysfunction contributes to early mortality (24-72 hours) among survivors of a cardiac arrest (CA). The benefits of mechanical support in refractory shock should be balanced against the patient's potential for neurological recovery. To date, these early treatment decisions have been taken based on limited information leading mainly to undertreatment. Therefore, there is a need for early, reliable, accessible, and simple tools that offer information on the possibilities of neurological improvement. METHODS: We collected data from bispectral index (BIS) and suppression ratio (SR) monitoring of adult comatose survivors of CA managed with targeted temperature management (TTM). Neurological status was assessed according to the Cerebral Performance Category (CPC) scale. RESULTS: We included 340 patients. At the first full neurological evaluation, 211 patients (62.1%) achieved good outcome or CPC 1-2. Mean BIS values were significantly higher and median SR lower in patients with CPC 1-2. An average BIS> 26 during first 12 hours of TTM predicted good outcome with 89.5% sensitivity and 75.8% specificity (AUC of 0.869), while average SR values> 24 during the first 12 hours of TTM predicted poor outcome (CPC 3-5) with 91.5% sensitivity and 81.8% specificity (AUC, 0.906). Hourly BIS and SR values exhibited good predictive performance (AUC> 0.85), as soon as hour 2 for SR and hour 4 for BIS. CONCLUSIONS: BIS/SR are associated with patients' potential for neurological recovery after CA. This finding could help to create awareness of the possibility of a better outcome in patients who might otherwise be wrongly considered as nonviable and to establish personalized treatment escalation plans.

Viabilidade e validade do índice bispectral para mensurar o sono de pacientes na unidade de terapia intensiva / Viability and validity of the bispectral index to measure sleep in patients in the intensive care unit

RESUMO Objetivo: Investigar a viabilidade do índice bispectral na avaliação do sono de pacientes criticamente enfermos lúcidos e a associação entre os parâmetros do sono aferidos por esse índice, pelo Questionário de Sono de Richards-Campbell e pelo ruído ambiental. Métodos: Estudo observacional transversal que avaliou indivíduos adultos criticamente enfermos com doenças de gravidades baixa ou moderada. Foram aferidos: volume e tempo total de sono, volume e tempo de sono profundo, volume e tempo de sono contínuo, latência para o início do sono e pressão sonora ambiental. A percepção subjetiva do sono foi registrada com o Questionário de Sono de Richards-Campbell nas manhãs subsequentes às noites de observação. Resultados: Os pacientes apresentaram tempo total de sono reduzido (234 minutos), predominância dos estágios superficiais e pouco sono profundo (1,7 minutos). Os volumes de sono total, profundo e contínuo foram 3.679, 9,4 e 3.143 índice bispectral versus minutos, respectivamente. A latência para o sono foi de 94 minutos. O escore médio do Questionário de Sono de Richards-Campbell foi 57,9. Foram observadas correlações de magnitudes fracas entre volume total, tempo total, volume contínuo e os domínios do Questionário de Sono de Richards-Campbell profundidade do sono, qualidade geral de sono e escore total; e correlações de magnitudes moderadas entre volume total, tempo total, volume contínuo e o domínio ocorrência de despertares. Conclusão: O índice bispectral é um instrumento com viabilidade limitada para monitorar o sono de pacientes lúcidos e com enfermidades de gravidades baixa e moderada na unidade de terapia intensiva, e pacientes que apresentaram maior volume, tempo total e volume de sono contínuo tiveram melhor percepção global do sono.

Abstract Objective: To investigate the viability of the bispectral index in the sleep evaluation of critically ill patients and to quantify the associations of sleep parameters measured by this index with the Richards-Campbell Sleep Questionnaire and environmental noise. Methods: This was a cross-sectional observational study that evaluated critically ill adults with diseases of low or moderate severity. The following were measured: total sleep volume and time, deep sleep volume and time, continuous sleep volume and time, sleep onset latency, and environmental sound pressure level. The subjective perception of sleep was evaluated with the Richards-Campbell Sleep Questionnaire the morning after each night of observation. Results: Patients had a low total sleep time (234 minutes), a predominance of superficial sleep stages, and little deep sleep (1.7 minutes). The total, deep, and continuous sleep volumes were 3,679, 9.4, and 3,143 (bispectral index units × minutes), respectively. The sleep latency was 94 minutes. The mean score of the Richards-Campbell Sleep Questionnaire was 57.9. Total sleep volume, total sleep time, and continuous sleep volume were weakly correlated with the Richards-Campbell Sleep Questionnaire depth of sleep domain score, overall sleep quality domain score, and total score. Total volume, total time, and continuous volume were moderately correlated with the occurrence of awakenings domain score. Conclusion: The bispectral index is an instrument with limited viability to monitor the sleep of lucid patients and patients with low to moderate disease severity in the intensive care unit. Patients with higher total sleep volume, total sleep time, and continuous sleep volume had better overall sleep perception.

Idiopathic decreased bispectral index during anaesthesia emergence: Possible causes for the phenomenon of paradoxical arousal. / Disminución idiopática del índice biespectral durante la educción anestésica: posibles causas del fenómeno delta paradójico.

In a small percentage of patients, sound, touch and even nociceptive stimulation in the presence of a light anaesthetic depth does not cause an electroencephalogram wave pattern of cortical activation (α, ß waves) as would be expected, but leads to a slowed electroencephalogram pattern instead. We report the case of a patient who on emerging from anaesthesia showed very slowed brain activity on the electroencephalogram and reduced algorithmic value, that lasted approximately 5min coinciding with sound and tactile stimulation. After keeping her under observation for 24h during the postoperative period she did not present any brain disorder that could justify that event.

Avaliação do nível de consciência de recém-nascidos com asfixia neonatal. Proposta para unidades de tratamentos intensivos neonatais / Level consciousness?s assessment of newborn with neonatal asphyxia: a proposal for neonatal intensive care units

A asfixia perinatal se constitui em uma das três principais causas de mortalidade neonatal. A encefalopatia hipóxico-isquêmica (EHI) é causada pela associação entre a hipóxia sanguínea e a isquemia tecidual. Esta associação, acompanhada de alterações metabólicas, resulta em manifestações clínicas secundárias ao comprometimento fisiológico ou estrutural, com disfunção múltipla de órgãos e presença de lesão cerebral grave. Acomete cerca de 50% a 60% dos recém-nascidos com asfixia perinatal. O objetivo do trabalho foi realizar uma revisão da literatura sobre asfixia neonatal. Foi realizada busca de artigos científicos através das bases de dados Lilacs, SciELO e Medline, utilizando as palavras-chave do trabalho, além de pesquisa adicional em bancos de dados de dissertações, teses e livros texto, em publicações do período de 1974 a 2013. Uma atuação preventiva, através da identificação e do tratamento precoce da lesão cerebral, constitui-se em estratégia efetiva para minimizar sequelas e promover melhor qualidade de vida em longo prazo...