Craneotomía en el paciente despierto / Awake craniotomy

Introducción: La craneotomía con el paciente despierto es útil para lograr resecciones cerebrales amplias de lesiones de áreas elocuentes. Objetivo: Presentar un caso al que se le realizó la técnica dormido- despierto. Método: Se realizó la inducción de la anestesia con propofol/fentanilo/rocuronio y se colocó una mascarilla laríngea. Después del bloqueo de escalpe se mantuvo la infusión de propofol/fentanilo y lidocaína hasta que se realizó la craneotomía. Se disminuyó la velocidad de infusión y se mantuvo de esta manera hasta finalizada la intervención. Resultados: Se logró el despertar del paciente a los 13 minutos de reducida la infusión. Se mantuvo buena estabilidad hemodinámica, sin depresión respiratoria ni otras complicaciones. El paciente se mantuvo colaborador, respondió preguntas y movilizó sus extremidades. No presentó complicaciones posoperatorias. Discusión: Dentro de las técnicas anestésicas utilizadas en el mundo la dormido- despierto-dormido es la más popular; sin embargo, constituye una alternativa no dormir nuevamente al paciente ni reinstrumentar la vía respiratoria. Los medicamentos más empleados son el propofol/remifentanilo, aunque la comparación con otros opioides no arrojan diferencias significativas; aunque sí supone un beneficio adicional la dexmedetomidina. Conclusiones: La craneotomía con el paciente despierto es posible de realizar en el entorno hospitalario siempre que exista un equipo multidisciplinario que consensue las mejores acciones médicas para el paciente(AU)

Introduction: Awake craniotomy is useful to achieve wide brain resections of lesions in eloquent areas. Objective: To present the case of a patient who was operated on with the asleep-awake-asleep technique. Method: Anesthesia was induced with propofol-fentanyl-rocuronium and a laryngeal mask was placed. After scalp block, the propofol-fentanyl and lidocaine infusion was maintained until craniotomy was performed. The infusion rate was decreased and remained this way until the end of the intervention. Results: The patient was awakened thirteen minutes after the infusion was reduced. Good hemodynamic stability was maintained, without respiratory depression or other complications. The patient remained collaborative, answered questions, and mobilized his limbs. He had no postoperative complications. Discussion: Among the anesthetic techniques used in the world, asleep-awake-asleep is the most popular. However, it is an alternative not to put the patient back to sleep or re-instrument the airway. The most commonly used drugs are propofol-remifentanil, although the comparison with other opioids does not show significant differences, except for dexmedetomidine, which does represent an additional benefit. Conclusions: Awake craniotomy is possible to be performed in the hospital setting as long as there is a multidisciplinary team that agrees on the best medical actions for the patient(AU)

Awareness and satisfaction with antenatal care services among pregnant women in Lagos state, Nigeria

Objectives: Despite the growing interest and efforts by government to make popular use of antenatal care (ANC) services in Nigeria as recommended by the World Health Organization, high level of infant and maternal mortality remains a major public health challenge facing the country. Dissatisfaction toward ANC services among pregnant women may be attributed to low level of awareness. This study assessed the level of awareness and satisfaction of ANC services among pregnant women in Lagos state, Nigeria. Material and Methods: The study adopted a survey research design. A multistage sampling technique was utilized to recruit participants for this study. A validated questionnaire was used for data collection and data were analyzed using both descriptive and inferential statistics. Ethical approval was obtained from Babcock University Health Research Ethics Committee with approval no: BUHREC543/17. Approval was also obtained from health service commission and in the six general hospitals used for the study. Informed consent was taken and respondents were reassured of the privacy and confidentiality of the information obtained. Results: The results showed that most of the respondents (85.6%) were in their reproductive years, that is, ages 23­37. The results showed that the level of awareness had a significant influence on pregnant women's satisfaction with the services (ß = 0.460, F(1,1313) = 351.499, R2 = 0.211, P < 0.05). The level of awareness of ANC services was high (M = 4.31, SD = 1.01) on a scale of 5. Conclusion: The study concluded that awareness of ANC services positively impacts pregnant women's satisfaction with the services in Lagos state. Efforts should be made to improve the level of awareness of pregnant mothers to achieve greater satisfaction with ANC services in Lagos state.

Variability of anesthetic depth in total intravenous anesthesia vs balanced anesthesia using entropy indices: a randomized, crossover, controlled clinical trial / Variabilidad de la profundidad anestésica en anestesia total intravenosa vs. anestesia general balanceada usando índices de entropía. Un ensayo clínico aleatorizado, cruzado y controlado

Abstract Introduction: Total intravenous anesthesia (TIVA) and balanced anesthesia (BA) are the most commonly used anesthetic techniques. The differences are the variability of the depth of anesthesia between these techniques that might predict which one is safer for patients and presents a lower risk of intraoperative awakening. Objective: To determine whether a difference exists in the variability of depth of anesthesia obtained by response entropy (RE). Methods: A crossover clinical trial was conducted on 20 healthy patients receiving upper or lower limb ambulatory orthopedic surgery. Patients were randomly assigned to (a) target-controlled infusion of propofol using the Schnider model at a target concentration of 2.5 µg/mL for 15 minutes and a 10-minute washout, followed by sevoflurane administration at 0.8 minimal alveolar concentration (MAC) for the reminder of the surgery, or (b) the reverse sequence. Differences in the variability of the depth of anesthesia using RE were evaluated using paired t-test. Results: The treatment effect showed no significant difference in the average values of RE, during TIVA = 97.23 vs BA 97.04 (P = 0.39). Carry Over (-4.98 vs 4.08) and Period (100.3 vs 94.68) effects were not significantly different. Conclusion: The present study suggests that both anesthetic techniques are equivalent in terms of the stability of the depth of anesthesia. It is important to keep testing the determinants of the efficacy of different populations because the individual behaviors of patients might ultimately tip the scale.

Resumen Introducción: La anestesia total intravenosa (TIVA, por sus siglas en inglés) y la anestesia balanceada (AB) son las técnicas anestésicas más comúnmente utilizadas. La diferencia está en la variabilidad de la profundidad de la anestesia entre estas dos técnicas, lo cual pudiera predecir cuál es más segura para los pacientes y representar un menor riesgo de despertar intraoperatorio. Objetivo: Determinar si existe alguna diferencia en la variabilidad de la profundidad de la anestesia obtenida según los índices de entropía de respuesta (ER). Métodos: Se llevó a cabo un estudio clínico cruzado en 20 pacientes sanos que se sometieron a cirugía ortopédica ambulatoria de miembros superiores o inferiores. Los pacientes se asignaron aleatoriamente así: a) infusión controlada por objetivo (TCI, por sus siglas en inglés) de propofol, utilizando el modelo Schnider a una concentración objetivo de 2,5 µg/mL durante 15 min y un período de lavado de 10 minutos, seguido de la administración de sevoflurano a 0,8 de concentración alveolar mínima (CAM) durante el tiempo restante de la cirugía; o b) la secuencia inversa. Las diferencias en la variabilidad de la profundidad de la anestesia utilizando entropía de respuesta se evaluaron utilizando la prueba t pareada. Resultados: El efecto del tratamiento no mostró ninguna diferencia significativa en los valores promedio de entropía de respuesta (ER) durante TIVA = 97,23 vs. AB 97,04 (P = 0,39). Los efectos de arrastre (-4,98 vs. 4,08) y período (100,3 vs. 94,68) no fueron significativamente diferentes. Conclusiones: El presente estudio sugiere que ambas técnicas anestésicas son equivalentes en términos de estabilidad de la profundidad de la anestesia. Es importante continuar probando los factores determinantes de eficacia en las distintas poblaciones, ya que el comportamiento individual de cada paciente pudiera finalmente inclinar la balanza.

The relation between preoperative anxiety and awareness during anesthesia: an observational study / Relação entre ansiedade pré-operatória e consciência durante a anestesia: estudo observacional

Abstract Background: Anxiety is a state of worry caused by the anticipation of external or internal danger. Awareness During Anesthesia (ADA) is an unexpected memory recall during anesthesia. In this study, we aimed to determine the factors that affect preoperative anxiety and observe the incidence of ADA, as well as to determine the anxiety levels of these patients with a history of ADA. Methods: This study was planned to be prospective, observational, and cross-sectional. Patients in whom septoplasty was planned, who was admitted to the anesthesiology outpatients between March 2018 and September 2018, were ASA I-II, and aged 18-70 years were included in the study. The demographic characteristics of patients were recorded. The State-Trait Anxiety Inventory (STAI) was used to determine anxiety during a preoperative evaluation. The modified Brice awareness score was used simultaneously to determine previous ADA. Results: The anxiety scores of patients who were conscious during anesthesia were higher than other patients. The mean STAI score was 40.85 ± 14.8 in the 799 patients who met the inclusion criteria of this study. When the anxiety scores were compared, the scores were higher in females than in males (p < 0.05). The mean STAI score was found as 40.3 ± 13.8 in patients who dreamed during anesthesia. Conclusion: It is important to determine the anxiety levels of patients in the preoperative period to prevent the associated complications. Preoperative anxiety, besides preventing ADA, should be dealt with in a multidisciplinary manner. ADA should be carefully questioned while evaluating previous anesthesia experiences.

Resumo Justificativa: A ansiedade é um estado de preocupação causado pela expectativa de perigo externo ou interno. Consciência durante a anestesia (CDA) é a evocação imprevista da memória de eventos intranestésicos. O objetivo deste estudo foi determinar os fatores que afetam a ansiedade pré-operatória, a incidência de CDA e os níveis de ansiedade nos pacientes com antecedente de CDA. Método: O estudo foi planificado como prospectivo, observacional e transversal. Foram incluídos no estudo pacientes programados para septoplastia eletiva, admitidos ao ambulatório de anestesiologia entre Março de 2018 e Setembro de 2018, com classe funcional ASA I-II e faixa etária entre 18 e 70 anos. As características demográficas dos pacientes foram registradas. O Inventário de Ansiedade Traço-Estado (IDATE) foi utilizado para determinar a ansiedade durante a avaliação pré-operatória. Simultaneamente, o escore de consciência de Brice modificado foi usado para determinar CDA anterior. Resultados: Os escores de ansiedade dos pacientes que apresentaram CDA foram mais elevados do que de outros pacientes. A pontuação média do IDATE foi 40,85±14,8 nos 799 pacientes que obedeceram aos critérios de inclusão do estudo. Quando os escores de ansiedade foram comparados, foram maiores no sexo feminino do que no masculino (p < 0,05). O escore médio do IDATE encontrado foi 40,3±13,8 nos pacientes que relataram sonhos durante a anestesia. Conclusão: É importante determinar no pré-operatório os níveis de ansiedade dos pacientes para evitar as complicações associadas. Ansiedade pré-operatória e a prevenção de CDA devem ser tratadas com abordagem multiprofissional. A CDA deve ser cuidadosamente investigada, avaliando-se as experiências vividas pelo paciente em anestesias pregressas.

Monitorización automática de estados de sedación en señales electroencefalográficas / Automatic monitoring of sedation states in electroencephalographic signals

La anestesia general proporciona al paciente estados de inconciencia, amnesia y analgesia, sin embargo, se reportan casos de despertar intraoperatorio. Debido a la incidencia de este fenómeno y sus efectos psicosomáticos, el Centro de Estudios de Neurociencias, Procesamiento de Imágenes y Señales en la Universidad de Oriente, y el Hospital General Juan Bruno Zayas Alfonso ambos en Santiago de Cuba, Cuba, implementan una metodología que permita detectar automáticamente estados de sedación anestésica aplicando Inteligencia Artificial. Para esto se emplearon las señales registradas por el canal electroencefalográfico F4, nueve parámetros espectrales, las Máquinas de Soporte Vectorial y los Sistemas Neuro-Difusos. En el reconocimiento automático de los estados de Sedación Profunda, Moderada y Ligera se logró una Exactitud de 96.12 por ciento, 90.06 por ciento y 90.24 por ciento respectivamente con las Máquinas de Soporte Vectorial, por lo que se propone el uso del canal electroencefalográfico F4 en la detección de estados anestésicos(AU)

General anesthesia provide the patient states of unconsciousness, amnesia and analgesia, however, cases of intraoperative awareness are reported. Due to the incidence of this phenomenon and the psychosomatic effects it causes, the Neuroscience Studies Center, Images and Signals Processing at the University of Oriente, and the General Hospital Juan Bruno Zayas Alfonso both in Santiago de Cuba, Cuba, implement a methodology that allows the automatic detection of anesthetic sedation states applying Artificial Intelligence. For this, the signals recorded by the electroencephalographic channel F4, nine spectral parameters, the Support Vector Machines and the Neuro-Fuzzy Systems were used. In the automatic recognition of the Sedation States: Profound, Moderate and Mild an Accuracy of 96.12 percent, 90.06 percent and 90.24 percent respectively was achieved with the Support Vector Machines, so the use of the electroencephalographic channel F4 is proposed in the detection of anesthetic states(AU)

Awareness during general anesthesia despite simultaneous bispectral index and end-tidal anesthetic gas concentration monitoring / 영남의대학술지

Awareness during general anesthesia occurs in approximately 0.1–0.2% of cases; nevertheless, particular attention is required because it can lead to critical complications including insomnia, depression, anxiety, and post-traumatic stress disorder. To prevent these complications, bispectral index (BIS) and end-tidal anesthetic gas (ETAG) concentration monitoring are commonly used to examine patient consciousness during surgery. In the present case, an 80-year-old man was scheduled for total gastrectomy. Anesthesia was maintained using desflurane 4.0–5.0% vol, oxygen, and nitrous oxide. The authors simultaneously monitored BIS, which was maintained between 37 and 43, and ETAG, which was maintained between 0.9 and 1.2 minimum alveolar concentration (MAC). After the operation, however, the authors were surprised to learn that the patient complained of awareness during anesthesia. Although BIS and ETAG concentration monitoring are useful in preventing awareness during anesthesia, they cannot be completely trusted. Even though BIS was maintained at approximately 40 and ETAG at 0.7–1.3 MAC, awareness during anesthesia occurred.

Awareness of the ward based outreach team and the services offered by the programme in the tshwane health district, South Africa

Background: The Ward Based Outreach Team (WBOT) is an organised team approach to a healthcare system based on theprinciples of epidemiology, primary health care, preventive medicine and health promotion. Globally, it has become a primary care response to many health challenges such as universal health coverage. The beneficiaries are community members, also referred to as households.Methods: The study assessed the awareness of the WBOT and the servicesoffered by the programme in the Tshwane health district of South Africa. This was a cross-sectional survey conducted in all seven sub-districts of the health district. The health district is further sub-divided into 150 health wards. Eighty-five health wards were randomly selected for the study. Using the sample size calculator, with a confidence interval of 5% and confidence level of 99%, the sample size of participants was 654. However, during the data collection process there was over-sampling of up to 764. Participants were recruited by convenience sampling. Data werecollected between October 12 and December 3, 2015, using a pre-piloted, structured questionnaire administered by 14 trained field workers. Results: The study obtained 6 288 responses from the 764 participants. The responses were grouped into two sections, 'Yes' and 'No'. A summary of the responses showed that the number of 'yes' responses, the number of participants who were aware of the WBOT and the services offered by the programme were higher than the number of participants who were unaware of the programme. The figures were 5 590 (88.8%) 'yes' responses and 698 (11.1%) 'no' responses.Conclusion: In summary, the awareness of the WBOT and the services offered by the programme in the Tshwane health district, South Africa is evaluated to be 88.8%

Do you believe that processed EEG helps to prevent intraoperative awareness? / 대한마취과학회지

No abstract available.

Investigation into memory formation according to the level of hypnotic depth using process dissociation

BACKGROUND: Process dissociation procedure has been used to evaluate explicit and implicit memories. Two process-dissociation measurement models are described. METHODS: This prospective study evaluated intraoperative memory formation in Korean patients undergoing elective surgery under general anesthesia and its relation to the depth of hypnotic state. A total of 270 patients enrolled were randomly assigned to three groups based on Bispectral Index (BIS) values in the following ranges: 30 to 40, BIS 40 to 50, and BIS 50 to 60 according to the level of hypnotic depth induced by propofol or sevoflurane during the presentation of wordlists. When the level of hypnotic depth was maintained at the target BIS range, words were played for 15 minutes via headphones to patients. Within 24 hours after the word presentation, memory was assessed using an auditory word stem completion test. The probability of explicit and implicit memory was calculated using original and extended measurement models. Brice interviews were performed within 1 and 24 hours after surgery. RESULTS: A total of 119 patients who did not deviate from the target BIS range were included in the analysis. The 95% confidence interval (CI) of the probability of occurrence of implicit memory evaluated by the original model did not include zero. However, when the extension model was used, 0 was included in the 95% CI. Explicit memory evaluated via Brice interviews did not occur in any group. CONCLUSIONS: When BIS was maintained in the range of 30 to 60 during surgery, no explicit or implicit memory was observed.

Intraoperative awareness as an example of the influence of cardiac output on anesthetic dosing: case report / Despertar intraoperatorio como ejemplo de la influencia del gasto cardíaco en la dosificación anestésica. Reporte de caso

Abstract A case of intraoperative awareness during ablation of pulmonary veins-one of the most widely used techniques in interventional cardiology-is discussed. An infusion of isoproterenol was administered following the ablation of ectopic foci. A few seconds after the infusion the patient experienced increased heart rate and intraoperative awareness manifested as an abrupt patient movement and bispectral index elevation. This has been described in similar procedures, following the administration of isoproterenol. In our opinion, the isoproterenol infusion caused the increased heart rate and subsequent abrupt rise in cardiac output. As an inversely proportional relationship between the propofol concentrations and cardiac output has been described, we believe that this rise in cardiac output could have favored the decline in the concentrations of propofol, leading to an intraoperative awareness episode.

Resumen Presentamos un caso de despertar intraoperatorio durante la ablación de venas pulmonares, una de las técnicas más empleadas por los cardiólogos intervencionistas. Tras la ablación de focos ectópicos se procede a la infusión de isoproterenol. Segundos después de la infusión se produce un aumento de la frecuencia cardíaca seguido de un despertar intraoperatorio traducido como un movimiento brusco del paciente y un aumento en el índice bi-espectral (BIS). Esto ha sido descrito en procedimientos similares tras la administración de isoproterenol. En nuestra opinión, la infusión de isoproterenol provocó un aumento de la frecuencia cardiaca y secundariamente del gasto cardíaco de forma brusca. Dado que se ha descrito una relación inversamente propocional entre las concentraciones de propofol y el gasto cardíaco, pensamos que este aumento del gasto cardíaco pudo condicionar un descenso de las concentraciones de propofol y esto causar el episodio de despertar intraoperatorio.

Anesthesia management by residents does not alter the incidence of recall of tracheal extubation: a teaching hospital-based propensity score analysis / A administração de anestesia por residentes não altera a incidência de memória da extubação traqueal: uma análise de pontuação de propensão baseada no ensino hospitalar

Abstract Background and objectives: The memory of emergence from anesthesia is recognized as one type of anesthesia awareness. Apart from planed awake extubation, unintentional recall of tracheal extubation is thought to be the results of inadequate anesthesia management; therefore, the incidence can be related with the experience of anesthetists. To assess whether the incidence of recall of tracheal extubation is related to anesthetists' experience, we compared the incidence of recall of tracheal extubation between patients managed by anesthesia residents or by experienced anesthetists. Methods: This is a retrospective review of an institutional registry containing 21,606 general anesthesia cases and was conducted with the board of ethical review approval. All resident tracheal extubations were performed under anesthetists' supervision. To avoid channeling bias, propensity score analysis was used to generate a set of matched cases (resident managements) and controls (anesthetist managements), yielding 3,475 matched patient pairs. The incidence of recall of tracheal extubation was compared as primary outcomes. Results: In the unmatched population, there was no difference in the incidences of recall of tracheal extubation between resident management and anesthetist management (6.5% vs. 7.1%, p = 0.275). After propensity score matching, there was still no difference in incidences of recall of tracheal extubation (7.1% vs. 7.0%, p = 0.853). Conclusion: In conclusion, when supervised by an anesthetist, resident extubations are no more likely to result in recall than anesthetist extubations.

Resumo Justificativa e objetivos: A recordação da emergência da anestesia é reconhecida como um dos tipos de memória da anestesia. Excluindo a extubação planejada com o paciente acordado, acredita-se que a memória não intencional durante a extubação traqueal seja o resultado de manejo inadequado da anestesia; portanto, a incidência pode estar relacionada com a experiência dos anestesistas. Para avaliar se a incidência de memória durante a extubação traqueal está relacionada com a experiência dos anestesistas, comparamos a incidência de memória durante a extubação traqueal entre pacientes tratados por residentes de anestesia ou por anestesistas experientes. Métodos: Estudo retrospectivo de revisão de um registo institucional com 21.606 casos de anestesia geral, conduzido com a aprovação do Comitê de Ética. Todas as extubações traqueais foram feitas por residentes sob a supervisão de anestesistas. Para evitar o viés de canalização, a análise do índice de propensão foi usada para gerar um grupo de casos pareados (manejo por residentes) e de controles (manejo por anestesistas), obtiveram-se 3.475 pares combinados de pacientes. A incidência de memória durante a extubação traqueal foi comparada com os desfechos primários. Resultados: Na população não pareada, não houve diferença na incidência de memória durante a extubação traqueal entre o manejo feito por residentes e anestesistas (6,5% vs. 7,1%, p = 0,275). Mesmo após parear os escores de propensão, não observamos diferença na incidência de memória durante a extubação traqueal (7,1% vs. 7,0%, p = 0,853). Conclusão: Em conclusão, quando supervisionadas por um anestesista, as extubações feitas por residentes não são mais propensas a resultar em memória do que as extubações feitas por anestesistas.

Unexpected anesthetic leakage from a damaged O-ring on the Selectatec back bar: A case report

The Selectatec mounting system was devised to provide easy and quick on-site fitting of various vaporizers for the anesthetic machine. However, a quick changing system for the vaporizer can also damage the O-ring due to friction between the vaporizer and the Selectatec back bar. We herein report a case of an unexpected anesthetic gas leakage from a damaged O-ring on the Selectatec back bar, which resulted from exchanging the vaporizers between two operations. In cases using the Datex Ohmeda machine, it is not easy to detect leakages from the vaporizers because of the location of the check valve near to the fresh gas outlet. This complicates the use of the positive pressure leakage test to detect a low pressure system leakage on the Selectatec back bar. We recommend the preanesthetic negative pressure or low-flow leakage test to detect a low pressure leakage when exchanging vaporizers on the Selectatec system.

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

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

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

Bispectral index monitoring in patients undergoing open heart surgery

Abstract Introduction: To obtain the optimal anesthesia depth is not easy in cardiovascular surgery patients where the haemodynamic reserve is limited, due to reasons such as not being able to give the desired dose of anesthetic agent, or the change in the pharmacokinetics of the agent in the heart-lung machine. This study was planned to assess the contribution of bispectral index (BIS) monitoring in the depth of anesthesia. Methods: The patients were divided into 2 groups, and BIS monitoring was used for each patient. Group 1 (G1 n=35): keeping the BIS monitor screen open, the anesthesia need was set. Group 2 (G2 n=35): BIS monitor was tied to the patient and the monitor screen was closed in such a way that the anaesthesist couldn't see the BIS value. When the recording time came, the data on the monitor was recorded. The need for the anesthetic agent was set according to the parameters such as haemodynamics or follow up of pupils, instead of BIS value, by titrating the anesthetic infusion doses. Results: BIS values were similar in both groups before the induction, BIS values in both groups showed a decrease, showing no significant statistical difference (P>0.05). One patient in each group said that he dreamt, and one patient in G2 said that he had heard a noise and felt that he was taken from one place to another. Conclusion: The management should be done with clinical evaluation, haemodynamics and other monitorization methods and BIS monitoring findings together.

Mechanisms underlying brain monitoring during anesthesia: limitations, possible improvements, and perspectives / 대한마취과학회지

Currently, anesthesiologists use clinical parameters to directly measure the depth of anesthesia (DoA). This clinical standard of monitoring is often combined with brain monitoring for better assessment of the hypnotic component of anesthesia. Brain monitoring devices provide indices allowing for an immediate assessment of the impact of anesthetics on consciousness. However, questions remain regarding the mechanisms underpinning these indices of hypnosis. By briefly describing current knowledge of the brain's electrical activity during general anesthesia, as well as the operating principles of DoA monitors, the aim of this work is to simplify our understanding of the mathematical processes that allow for translation of complex patterns of brain electrical activity into dimensionless indices. This is a challenging task because mathematical concepts appear remote from clinical practice. Moreover, most DoA algorithms are proprietary algorithms and the difficulty of exploring the inner workings of mathematical models represents an obstacle to accurate simplification. The limitations of current DoA monitors - and the possibility for improvement - as well as perspectives on brain monitoring derived from recent research on corticocortical connectivity and communication are also discussed.

Study on the Evaluation Index of Depth of Anesthesia Awareness Based on Sample Entropy and Decision Tree / 生物医学工程学杂志

Currently, monitoring system of awareness of the depth of anesthesia has been more and more widely used in clinical practices. The intelligent evaluation algorithm is the key technology of this type of equipment. On the basis of studies about changes of electroencephalography (EEG) features during anesthesia, a discussion about how to select reasonable EEG parameters and classification algorithm to monitor the depth of anesthesia has taken place. A scheme which combines time domain analysis, frequency domain analysis and the variability of EEG and decision tree as classifier and least squares to compute Depth of anesthesia Index (DOAI) is proposed in this paper. Using the EEG of 40 patients who underwent general anesthesia with propofol, and the classification and the score of the EEG annotated by anesthesiologist, we verified this scheme with experiments. Classification and scoring was based on a combination of modified observer assessment of alertness/sedation (MOAA/S), and the changes of EEG parameters of patients during anesthesia. Then we used the BIS index to testify the validation of the DOAI. Results showed that Pearson's correlation coefficient between the DOAI and the BIS over the test set was 0.89. It is demonstrated that the method is feasible and has good accuracy.

Anesthesia awareness. Can midazolam attenuate or prevent memory consolidation on intraoperative awakening during general anesthesia without increasing the risk of postoperative delirium? / 대한마취과학회지

No abstract available.

Effect of beach chair position on bispectral index values during arthroscopic shoulder surgery / 대한마취과학회지

BACKGROUND: Bispectral index (BIS) monitoring reduces the cases of intraoperative awareness. Several factors can alter BIS readings without affecting the depth of anesthesia. We conducted a study to assess the impact of beach chair position (sitting position) on BIS readings. METHODS: General anesthesia was administered to 30 patients undergoing arthroscopic shoulder surgery. Patients were kept in neutral position (supine) for 10 minutes and BIS readings, mean arterial blood pressure, heart rate, end-tidal carbon dioxide, and end-tidal sevoflurane were recorded. Patients were then shifted to beach chair position. After 15 minutes, data were recorded. RESULTS: A significant decrease in BIS values (P < 0.01) associated with a position change from neutral position to beach chair position was evident. CONCLUSIONS: BIS values are significantly decreased in the beach chair position compared with the neutral position and might affect interpretation of the depth of anesthesia.

Awareness and recall during general anesthesia / 대한마취과학회지

Anesthesia awareness is defined as both consciousness and recall of surgical events. New research has been conducted out to test this phenomenon. However, testing methods have not proven reliable, including those using devices based on electroencephalographic techniques to detect and prevent intraoperative awareness. The limitations of a standard intraoperative brain monitor reflect our insufficient understanding of consciousness. Moreover, patients who experience an intraoperative awareness can develop serious post-traumatic stress disorders that should not be overlooked. In this review, we introduce the incidence of intraoperative awareness during general anesthesia and discuss the mechanisms of consciousness, as well as risk factors, various monitoring methods, outcome and prevention of intraoperative awareness.

Evaluation of awareness during elective cesarean section in two models of general anesthesia

This prospective randomized comparative study conducts in Assiut women's health hospital to asses awareness during cesarean section in two models of general anesthesia ,120 pregnant women between 37-10 weeks gestational age who underwent elective cesarean section under general anesthesia were randomly allocated into two groups, propofol group [n =60] received propofol 2.5 mg/ kg for induction followed by a continuous infusion of propofol of 0.2mg/ kg/ min The sevoflurane group [n-60] received propofol 2.5 mg/ kg for induction followed by sevoflurane 1% for maintenance. All patients had rapid sequence induction using succinyl-choline and endotracheal intubation, after delivery of the fetus all patients were received, l00microg fentanyl and 0.25mg/kg atracurium. Heart rates, blood pressures and -AAI-index values during significant events of surgery and anesthesia till delivery, induction to skin incision, to delivery and Apgar scores were recorded. The patients in the propofol group had significantly lower levels of hemodynamics [heart rate and mean arterial blood pressure] and AAI index. In conclusion propofol infusion as 0.2 mg/k/min after induction of general anesthesia with blouse dose [2.5mg/ kg until the end of surgery is effective in reducing the incidence of awareness in patients undergoing cesarean section .the use of this regimen was not associated with side effect of fetal outcome or delayed recovery