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PURPOSE: In this study, we evaluated the effectiveness of intubations by way of "Gum Elastic Bougie" and "Intubating Laryngeal Mask Airway" in endotracheal intubation of patients with simulated cervical trauma. METHOD: 134 patients were included in the study. All patients were placed cervical collar for a simulated cervical trauma. Patients were allocated randomly into three groups: Group NI (n=45) intubation with Macintosh laryngoscopy, Group GEB (n=45) intubation with Gum Elastic Bougie, and Group ILMA (n=44) intubation with Intubating Laryngeal Mask Airway. The number of intubation attempts, success of intubation, duration of complete visualization of the larynx, duration of intubation, user's performance score, hemodynamic changes and the observed complications were recorded. RESULTS: Success of intubation in the first attempt was highest in Group GEB while it was lowest in Group ILMA. Regarding the intubation success, rates of successful intubation were 95.6%, 84.4% and 65.9% in Groups GEB, NI, and ILMA, respectively. Durations of visualization of larynx and intubation were shorter in Groups NI and GEB than in Group ILMA. This difference was statistically significant (p<0.05) while there was no significant difference between Groups NI and GEB. The number of patients with "good" intubation performance was significantly higher in Group GEB while the number of patients with "poor" intubation performance was significantly higher in Group ILMA (p<0.05). CONCLUSIONS: We conclude that GEB, which is cheap and easily accessible, should be an advantageous choice in cervical trauma patients for both the easeness of intubation and patient morbidity and mortality.

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BACKGROUND AND OBJECTIVES: residual paralysis following the use of neuromuscular blocking drugs (NMBDs) without neuromuscular monitoring remains a clinical problem, even when NMBDs are used. This study surveys postoperative residual curarization and critical respiratory events in the recovery room, as well as the clinical approach to PORC of anesthesiologists in our institution. METHODS: This observational study included 415 patients who received general anesthesia with intermediate-acting NMBDs. Anesthesia was maintained by non-participating anesthesiologists who were blinded to the study. Neuromuscular monitoring was performed upon arrival in the recovery room. A CRE was defined as requiring airway support, peripheral oxygen saturation <90% and 90-93% despite receiving 3 L/min nasal O2, respiratory rate >20 breaths/min, accessory muscle usage, difficulty with swallowing or speaking, and requiring reintubation. The clinical approach of our anesthesiologists toward reversal agents was examined using an 8-question mini-survey shortly after the study. RESULTS: The incidence of PORC was 43% (n = 179) for TOFR <0.9, and 15% (n = 61) for TOFR <0.7. The incidence of TOFR <0.9 was significantly higher in women, in those with ASA physical status 3, and with anesthesia of short duration (p < 0.05). In addition, 66% (n = 272) of the 415 patients arriving at the recovery room had received neostigmine. A TOFR <0.9 was found in 46% (n = 126) of the patients receiving neostigmine. CONCLUSIONS: When routine objective neuromuscular monitoring is not available, PORC remains a clinical problem despite the use of NMBDs. The timing and optimal antagonism of the neuromuscular blockade, and routine objective neuromuscular monitoring is recommended to enhance patient safety.

JUSTIFICATIVA E OBJETIVOS: A paralisia residual após o uso de bloqueadores neuromusculares (BNMs) sem monitoração neuromuscular continua sendo um problema clínico, mesmo quando BNMs são usados. Este estudo pesquisou a curarização residual pós-operatória e os eventos respiratórios críticos em sala de recuperação, bem como a abordagem clínica da CRPO feita pelos anestesiologistas em nossa instituição. MÉTODOS: Este estudo observacional incluiu 415 pacientes que receberam anestesia geral com BNMs de ação intermediária. A manutenção da anestesia foi feita por anestesiologistas não participantes, "cegos" para o estudo. A monitoração neuromuscular foi realizada no momento da chegada à sala de recuperação. Um ERC foi definido como necessidade de suporte ventilatório; saturação periférica de oxigênio <90% e 90-93%, a despeito de receber 3 L/min de O2 via cânula nasal; frequência respiratória >20 bpm; uso de musculatura acessória; dificuldade de engolir ou falar e necessidade de reintubação. A abordagem clínica de nossos anestesiologistas, em relação aos agentes de reversão, foi avaliada usando um miniquestionário de oito perguntas logo após o estudo. RESULTADOS: A incidência de CRPO foi de 43% (n = 179) para a SQE <0 e 15% (n = 61) para a SQE <0,7. A incidência de SQE <0,9 foi significativamente maior em mulheres, pacientes com estado físico ASA III e com anestesia de curta duração (p < 0,05). Além disso, 66% (n = 272) dos 415 pacientes que chegam à sala de recuperação haviam recebido neostigmina. Uma SQE <0,9 foi encontrada em 46% (n = 126) dos pacientes que receberam neostigmina. CONCLUSÃO: Quando a monitoração neuromuscular objetiva de rotina não está disponível, a CRPO continua sendo um problema clínico, a despeito do uso de BNMs. O momento e o antagonismo ideais do bloqueio neuromuscular e a monitoração neuromuscular objetiva de rotina são recomendados para aumentar a segurança do paciente.

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BACKGROUND AND OBJECTIVES: residual paralysis following the use of neuromuscular blocking drugs (NMBDs) without neuromuscular monitoring remains a clinical problem, even when NMBDs are used. This study surveys postoperative residual curarization and critical respiratory events in the recovery room, as well as the clinical approach to PORC of anesthesiologists in our institution. METHODS: This observational study included 415 patients who received general anesthesia with intermediate-acting NMBDs. Anesthesia was maintained by non-participating anesthesiologists who were blinded to the study. Neuromuscular monitoring was performed upon arrival in the recovery room. A CRE was defined as requiring airway support, peripheral oxygen saturation <90% and 90-93% despite receiving 3 L/min nasal O2, respiratory rate > 20 breaths/min, accessory muscle usage, difficulty with swallowing or speaking, and requiring reintubation. The clinical approach of our anesthesiologists toward reversal agents was examined using an 8-question mini-survey shortly after the study. RESULTS: The incidence of PORC was 43% (n = 179) for TOFR < 0.9, and 15% (n = 61) for TOFR < 0.7. The incidence of TOFR < 0.9 was significantly higher in women, in those with ASA physical status 3, and with anesthesia of short duration (p < 0.05). In addition, 66% (n = 272) of the 415 patients arriving at the recovery room had received neostigmine. A TOFR < 0.9 was found in 46% (n = 126) of the patients receiving neostigmine. CONCLUSIONS: When routine objective neuromuscular monitoring is not available, PORC remains a clinical problem despite the use of NMBDs. The timing and optimal antagonism of the neuromuscular blockade, and routine objective neuromuscular monitoring is recommended to enhance patient safety.

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OBJECTIVE: This study investigated interleukin-10 and nitric oxide plasma levels following surgery to determine whether there is a correlation between these two variables and if different desflurane anesthesia flow rates influence nitric oxide and interleukin-10 concentrations in circulation. MATERIALS AND METHODS: Forty patients between 18 and 70 years and ASA I-II physical status who were scheduled to undergo thyroidectomy were enrolled in the study. INTERVENTIONS: Patients were allocated into two groups to receive two different desflurane anesthesia flow rates: high flow (Group HF) and low flow (Group LF). MEASUREMENTS: Blood samples were drawn at the beginning (t0) and end (t1) of the operation and after 24h (t2). Plasma interleukin-10 and nitric oxide levels were measured using an enzyme-linked-immunosorbent assay and a Griess reagents kit, respectively. Hemodynamic and respiratory parameters were assessed. RESULTS: There was no statistically significant difference between the two groups with regard to interleukin-10 levels at the times of measurement. Interleukin-10 levels were increased equally in both groups at times t1 and t2 compared with preoperative concentrations. For both groups, nitric oxide circulating concentrations were significantly reduced at times t1 and t2 compared with preoperative concentrations. However, the nitric oxide value was lower for Group HF compared to Group LF at t2. No correlation was found between the IL-10 and nitric oxide levels. CONCLUSION: Clinical usage of two different flow anesthesia forms with desflurane may increase interleukin-10 levels both in Group HF and Group LF; nitric oxide levels circulating concentrations were significantly reduced at times t1 and t2 compared with preoperative concentrations; however, at 24h postoperatively they were higher in Group LF compared to Group HF. No correlation was detected between interleukin-10 and nitric oxide levels.

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OBJECTIVE: This study investigated interleukin-10 and nitric oxide plasma levels following surgery to determine whether there is a correlation between these two variables and if different desflurane anesthesia flow rates influence nitric oxide and interleukin-10 concentrations in circulation. MATERIALS AND METHODS: Forty patients between 18 and 70 years and ASA I-II physical status who were scheduled to undergo thyroidectomy were enrolled in the study. INTERVENTIONS: Patients were allocated into two groups to receive two different desflurane anesthesia flow rates: high flow (Group HF) and low flow (Group LF). MEASUREMENTS: Blood samples were drawn at the beginning (t0) and end (t1) of the operation and after 24h (t2). Plasma interleukin-10 and nitric oxide levels were measured using an enzyme-linked-immunosorbent assay and a Griess reagents kit, respectively. Hemodynamic and respiratory parameters were assessed. RESULTS: There was no statistically significant difference between the two groups with regard to interleukin-10 levels at the times of measurement. Interleukin-10 levels were increased equally in both groups at times t1 and t2 compared with preoperative concentrations. For both groups, nitric oxide circulating concentrations were significantly reduced at times t1 and t2 compared with preoperative concentrations. However, the nitric oxide value was lower for Group HF compared to Group LF at t2. No correlation was found between the IL-10 and nitric oxide levels. CONCLUSION: Clinical usage of two different flow anesthesia forms with desflurane may increase interleukin-10 levels both in Group HF and Group LF; nitric oxide levels circulating concentrations were significantly reduced at times t1 and t2 compared with preoperative concentrations; however, at 24h postoperatively they were higher in Group LF compared to Group HF. No correlation was detected between interleukin-10 and nitric oxide levels.

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OBJECTIVE: This study investigated interleukin-10 and nitric oxide plasma levels following surgery to determine whether there is a correlation between these two variables and if different desflurane anesthesia flow rates influence nitric oxide and interleukin-10 concentrations in circulation. MATERIALS AND METHODS: Forty patients between 18 and 70 years and ASA I-II physical status who were scheduled to undergo thyroidectomy were enrolled in the study. INTERVENTIONS: Patients were allocated into two groups to receive two different desflurane anesthesia flow rates: high flow (Group HF) and low flow (Group LF). MEASUREMENTS: Blood samples were drawn at the beginning (t 0) and end (t 1) of the operation and after 24 h (t 2). Plasma interleukin-10 and nitric oxide levels were measured using an enzyme-linked-immunosorbent assay and a Griess reagents kit, respectively. Hemodynamic and respiratory parameters were assessed. RESULTS: There was no statistically significant difference between the two groups with regard to interleukin-10 levels at the times of measurement. Interleukin-10 levels were increased equally in both groups at times t 1 and t 2 compared with preoperative concentrations. For both groups, nitric oxide circulating concentrations were significantly reduced at times t 1 and t 2 compared with preoperative concentrations. However, the nitric oxide value was lower for Group HF compared to Group LF at t 2. No correlation was found between the IL-10 and nitric oxide levels. CONCLUSION: Clinical usage of two different flow anesthesia forms with desflurane may increase interleukin-10 levels both in Group HF and Group LF; nitric oxide levels circulating concentrations were significantly reduced at times t 1 and t 2 compared with preoperative concentrations; however, at 24 h postoperatively they were higher in Group LF compared to Group HF. No correlation was detected between interleukin-10 and nitric oxide levels. .

OBJETIVO: este estudo investigou os níveis plasmáticos de interleucina-10 e óxido nítrico após cirurgia para determinar se há correlação entre essas duas variáveis e se diferentes taxas de fluxo de anestesia com desflurano influenciam as concentrações de interleucina-10 e óxido nítrico na circulação. MATERIAIS E MÉTODOS: quarenta pacientes, entre 18 e 70 anos de idade, estado físico ASA I-II, programados para tireoidectomia foram incluídos no estudo. INTERVENÇÕES: os pacientes foram divididos em dois grupos para receber dois fluxos diferentes de anestesia com desflurano: fluxo alto (Grupo FA) e fluxo baixo (Grupo FB). MENSURAÇÕES: amostras de sangue foram colhidas no início (t 0 ) e final (t 1 ) da cirurgia e após 24 h (t 2 ). Os níveis plasmáticos de interleucina-10 e óxido nítrico foram medidos usando um ensaio imunossorvente ligado à enzima um estojo de reagentes de Griess, respectivamente. Os parâmetros hemodinâmicos e respiratórios foram avaliados. RESULTADOS: não houve diferença estatisticamente significante entre os dois grupos em relação aos níveis de interleucina-10 níveis nos tempos de medição. Os níveis de interleucina-10 aumentaram igualmente em ambos os grupos nos tempos t 1 e t 2 em comparação com as concentrações no pré-operatório. Em ambos os grupos, as concentrações circulantes de óxido nítrico estavam significativamente reduzidas nos tempos t 1 e t 2 em comparação com as concentrações no pré-operatório. No entanto, o valor de óxido nítrico foi menor no Grupo FA que no Grupo FB no t 2 . Não houve correlação entre os níveis de IL-10 e óxido nítrico. CONCLUSÃO: o ...

OBJETIVO: este estudio investigó los niveles plasmáticos de interleucina-10 y óxido nítrico después de la cirugía para determinar si hay alguna correlación entre esas 2 variables y si diferentes tasas de flujo de anestesia con desflurano influyen en las concentraciones de interleucina-10 y óxido nítrico en la circulación. MATERIALES Y MÉTODOS: cuarenta pacientes, entre 18 y 70 años de edad, estado físico ASA I-II, programados para tiroidectomía se incluyeron en el estudio. INTERVENCIONES: los pacientes se dividieron en 2 grupos para recibir 2 flujos diferentes de anestesia con desflurano: flujo alto (grupo FA) y flujo bajo (grupo FB). MEDICIONES: se extrajeron muestras de sangre al inicio (t 0 ) y al final (t 1 ) de la cirugía y después de 24 h (t 2 ). Los niveles plasmáticos de interleucina-10 y óxido nítrico fueron medidos usando un ensayo de inmunoabsorción conectando un kit de reactivos de Griess, respectivamente. Se evaluaron los parámetros hemodinámicos y respiratorios. RESULTADOS: no hubo diferencia estadísticamente significativa entre los 2 grupos con relación a los niveles de interleucina-10 en los tiempos de medición. Los niveles de interleucina-10 aumentaron igualmente en ambos grupos en los tiempos t 1 y t 2 en comparación con las concentraciones en el preoperatorio. En ambos grupos, las concentraciones circulantes de óxido nítrico estaban significativamente reducidas en los tiempos t 1 y t 2 en comparación con las concentraciones en el preoperatorio. Sin embargo, el valor de óxido nítrico fue menor en el grupo FA que en el grupo FB en el t 2 . No hubo correlación entre los niveles de interleucina-10 y óxido nítrico. CONCLUSIÓN: el uso clínico de 2 flujos diferentes en anestesia con desflurano puede aumentar los ...

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BACKGROUND AND OBJECTIVES: Regional anesthesia is a commonly used technique in orthopedic procedures. Sedation should reduce the patient's anxiety and fear while increasing regional anesthesia quality. This study evaluated the hemodynamic changes, level of sedation, both patients' and surgeons' levels of satisfaction and potential side effects in patient-controlled sedation using propofol. METHODS: This randomized clinical trial studied sixty ASA physical class I-III patients scheduled for total knee replacement surgery under combined spinal-epidural anesthesia. Patients in Group P (n = 30) received propofol via a patient-controlled analgesia device with the following settings: intravenous propofol bolus dose 400 µg.kg(-1), 5-minute lockout interval and no basal infusion. In Group S, we infused saline 150 using the same settings. To determine the level of sedation, we used BIS and Observer's Assessment of Alertness/ Sedation Scale. For all patients, we recorded the number of requests. As the fi nal evaluation, we scored surgeons' and patients' satisfaction on 4-point scales. RESULTS: Both BIS values and OAA/S scores were lower in Group P than in Group S. Patients' satisfaction was higher in Group P, although there was no significant difference with respect to surgeons' satisfaction between the groups. The number of requests for sedation was significantly higher in Group S. However, most requests were considered unsuccessful. CONCLUSION: This study suggests that patient-controlled sedation with propofol can be used efficiently in orthopedic procedures.

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JUSTIFICATIVA E OBJETIVOS: Anestesia regional é uma técnica de uso comum em procedimentos ortopédicos. A sedação deve reduzir a ansiedade e o medo do paciente e aumentar a qualidade da anestesia regional. Este estudo avaliou as alterações hemodinâmicas, o nível de sedação e de satisfação tanto dos pacientes quanto dos cirurgiões e os potencias efeitos colaterais da sedação controlada pelo paciente com o uso de propofol. MÉTODOS: Selecionamos 60 pacientes, estado físico Asa I-III e agendados para artroplastia total do joelho sob anestesia combinada raqui-peridural. Os pacientes do Grupo P (n = 30) receberam propofol por meio de um dispositivo de analgesia controlada pelo paciente com as seguintes configurações: dose de propofol em bolus de 400 µg.kg-1 por via intravenosa (IV), com intervalo de bloqueio de cinco minutos e sem infusão basal. Os pacientes do Grupo S receberam infusão de solução salina (150 mL), com as mesmas configurações. Para determinar o nível de sedação, o índice bispectral (BIS) e a Escala de Avaliação de Alerta e Sedação dos Observadores (OAA/S) foram usados. O número de solicitações foi registrado para todos os pacientes. Como avaliação final, a satisfação dos cirurgiões e dos pacientes foi registrada em escala de 4 pontos. RESULTADOS: Os valores de BIS e da OAA/S foram menores no Grupo P que no Grupo S. A satisfação dos pacientes foi maior no Grupo P, embora não tenha havido diferença significativa em relação à satisfação dos cirurgiões entre os grupos. O número de solitações de sedação foi significativamente maior no Grupo S. Contudo, a maioria das solicitações não foi considerada bem-sucedida. CONCLUSÃO: Este estudo sugere que a analgesia controlada pelo paciente com o uso de propofol pode ser usada com resultados eficazes em procedimentos ortopédicos.

BACKGROUND AND OBJECTIVES: Regional anesthesia is a commonly used technique in orthopedic procedures. Sedation should reduce the patient's anxiety and fear while increasing regional anesthesia quality. This study evaluated the hemodynamic changes, level of sedation, both patients' and surgeons' levels of satisfaction and potential side effects in patient-controlled sedation using propofol. METHODS: This randomized clinical trial studied sixty ASA physical class I-III patients scheduled for total knee replacement surgery under combined spinal-epidural anesthesia. Patients in Group P (n = 30) received propofol via a patient-controlled analgesia device with the following settings: intravenous propofol bolus dose 400 µg.kg_1, 5-minute lockout interval and no basal infusion. In Group S, we infused saline 150 using the same settings. To determine the level of sedation, we used BIS and Observer's Assessment of Alertness/ Sedation Scale. For all patients, we recorded the number of requests. As the final evaluation, we scored surgeons' and patients' satisfaction on 4-point scales. RESULTS: Both BIS values and OAA/S scores were lower in Group P than in Group S. Patients' satisfaction was higher in Group P, although there was no significant difference with respect to surgeons' satisfaction between the groups. The number of requests for sedation was significantly higher in Group S. However, most requests were considered unsuccessful. CONCLUSION: This study suggests that patient-controlled sedation with propofol can be used efficiently in orthopedic procedures.

JUSTIFICATIVA Y OBJETIVOS: La anestesia regional es una técnica de uso común en los procedimientos ortopédicos. La sedación debe reducir la ansiedad y el miedo del paciente y aumentar la calidad de la anestesia regional. Este estudio evaluó las alteraciones hemodinámicas, el nivel de sedación, los niveles de satisfacción tanto de los pacientes como de los cirujanos y los potencias efectos colaterales de la sedación controlada por el paciente con el uso de propofol. MÉTODOS: Seleccionamos 60 pacientes, estado físico Asa I-III programados para la artroplastia total de la rodilla bajo anestesia combinada raquiepidural. Los pacientes del Grupo P (n = 30) recibieron propofol por medio de un dispositivo de analgesia controlada por el paciente con las siguientes configuraciones: dosis de propofol en bolo de 400 µg.kg-1 vía intravenosa (IV), con un intervalo de bloqueo de cinco minutos y sin infusión basal. Los pacientes del Grupo S recibieron infusión de solución salina (150 mL), con las mismas configuraciones. Para determinar el nivel de sedación, usamos el índice bispectral (BIS) y la Escala de Evaluación del Índice de Alerta y Sedación del Observador (EAIASO). El número de solicitaciones fue registrado para todos los pacientes. Como evaluación final, la satisfacción de los cirujanos y de los pacientes fue registrada en escala de 4 puntos. RESULTADOS: Los valores de BIS y de la Evaluación del Observador de Guardia (OAA/S) fueron menores en el Grupo P que en el Grupo S. La satisfacción de los pacientes fue mayor en el Grupo P, aunque no haya habido diferencia significativa con relación a la satisfacción de los cirujanos entre los grupos. El número de solicitaciones de sedación fue significativamente mayor en el Grupo S. Sin embargo, la mayoría de las solicitaciones no fue considerada exitosa. CONCLUSIONES: Este estudio sugiere que la analgesia controlada por el paciente con el uso de propofol puede ser usada con resultados eficaces en procedimientos ortopédicos.

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BACKGROUND AND OBJECTIVES: We investigated the effect of Nitrous Oxide (N2O) on controlled hypotension in low-flow isoflurane-dexmedetomidine anesthesia in terms of hemodynamics, anesthetic consumption, and costs. METHODS: We allocated forty patients randomly into two equal groups. We then maintained dexmedetomidine infusion (0.1 µg.kg(-1).min(-1)) for 10 minutes. Next, we continued it until the last 30 minutes of the operation at a dose of 0.7 µg.kg(-1).hour(-1). We administered thiopental (4-6 mg. kg(-1)) and 0.08-0.12 mg.kg(-1) vecuronium bromide at induction for both groups. We used isoflurane (2%) for anesthesia maintenance. Group N received a 50% O2-N2O mixture and Group A received 50% O2-air mixture as carrier gas. We started low-flow anesthesia (1L.min(-1)) after a 10-minute period of initial high flow (4.4L.min(-1)). We recorded values for blood pressure, heart rate, peripheral O2 saturation, inspiratory isoflurane, expiratory isoflurane, inspiratory O2, expiratory O2, inspiratory N2O, expiratory N2O, inspiratory CO2, CO2 concentration after expiration, Minimum Alveolar Concentration. In addition, we determined the total consumption rate of fentanyl, dexmedetomidine and isoflurane as well as bleeding. RESULTS: In each group the heart rate decreased after dexmedetomidine loading. After intubation, values were higher for Group A at one, three, five, 10, and 15 minutes. After intubation, the patients reached desired hypotension values at minute five for Group N and at minute 20 for group A. MAC values were higher for Group N at minute one, three, five, 10, and 15 (p<0.05). FiO2 values were high between minute five and 60 for Group A, while at minute 90 Group N values were higher (p<0.05). FiIso (inspiratuvar isofluran) values were lower in Group N at minute 15 and 30 (p<0.05). CONCLUSION: By using dexmedetomidine instead of nitrous oxide in low flow isoflurane anesthesia, we attained desired MAP levels, sufficient anesthesia depth, hemodynamic stability and safe inspiration parameters. Dexmedetomidine infusion with medical air-oxygen as a carrier gas represents an alternative anesthetic technique.

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JUSTIFICATIVA E OBJETIVOS: Investigamos o efeito do óxido nitroso (N2O) em hipotensão controlada durante anestesia com baixo fluxo (isoflurano-dexmedetomidina) em termos de hemodinâmica, consumo de anestésico e custos. MÉTODOS: Quarenta pacientes foram randomicamente alocados em dois grupos. Infusão de dexmedetomidina (0,1 µg.kg-1.min-1) foi mantida por 10 minutos. Subsequentemente, essa infusão foi mantida até os últimos 30 minutos de operação a uma dose de 0,7 µg.kg-1.hora-1. Tiopental (4-6 mg.kg-1) e brometo de vecurônio (0,08 0,12 mg.kg-1) foram administrados na indução de ambos os grupos. Isoflurano (2%) foi administrado para manutenção da anestesia. O Grupo N recebeu uma mistura de 50% de O2-N2O e o Grupo A recebeu uma mistura de 50% de O2-ar como gás de transporte. Anestesia com baixo fluxo (1 L.min-1) foi iniciada após um período de 10 minutos de alto fluxo inicial (4,4 L.min-1). Os valores de pressão arterial, frequência cardíaca, saturação periférica de O2, isoflurano inspiratório e expiratório, O2 inspiratório e expiratório, N2O inspiratório e expiratório, CO2 inspiratório, concentração de CO2 após expiração e concentração alveolar mínima foram registrados. Além disso, as taxas de consumo total de fentanil, dexmedetomidina e isoflurano, bem como de hemorragia, foram determinadas. RESULTADOS: A frequência cardíaca diminuiu em ambos os grupos após a carga de dexmedetomidina. Após a intubação, os valores do Grupo A foram maiores nos minutos um, três, cinco, 10 e 15. Após a intubação, os valores de hipotensão desejados foram alcançados em 5 minutos no Grupo N e em 20 minutos no grupo A. Os valores da CAM foram mais altos no Grupo N nos minutos um, três, cinco, 10 e 15 (p < 0,05). Os valores da FiO2 foram mais altos entre 5 e 60 minutos no Grupo A, enquanto foram mais altos no Grupo N aos 90 minutos (p < 0,05). Os valores de Fi Iso (isoflurano inspiratório) foram menores no Grupo N nos minutos 15 e 30 (p < 0,05). CONCLUSÃO: O uso de dexmedetomidina em vez de óxido nitroso em anestesia com isoflurano pela técnica de baixo fluxo atingiu os níveis desejados de pressão arterial média (PAM), profundidade suficiente da anestesia, estabilidade hemodinâmica e parâmetros de inspiração seguros. A infusão de dexmedetomidina com oxigênio-ar medicinal como gás de transporte é uma técnica anestésica opcional.

BACKGROUND AND OBJECTIVES: We investigated the effect of Nitrous Oxide (N2O) on controlled hypotension in low-flow isoflurane-dexmedetomidine anesthesia in terms of hemodynamics, anesthetic consumption, and costs. METHODS: We allocated forty patients randomly into two equal groups. We then maintained dexmedetomidine infusion (0.1 µg.kg-1.min-1) for 10 minutes. Next, we continued it until the last 30 minutes of the operation at a dose of 0.7 µg.kg-1.hour-1. We administered thiopental (4-6 mg. kg-1) and 0.08-0.12 mg.kg-1 vecuronium bromide at induction for both groups. We used isoflurane (2%) for anesthesia maintenance. Group N received a 50% O2-N2O mixture and Group A received 50% O2-air mixture as carrier gas. We started low-flow anesthesia (1 L.min-1) after a 10-minute period of initial high flow (4.4 L.min-1). We recorded values for blood pressure, heart rate, peripheral O2 saturation, inspiratory isoflurane, expiratory isoflurane, inspiratory O2, expiratory O2, inspiratory N2O, expiratory N2O, inspiratory CO2, CO2 concentration after expiration, Minimum Alveolar Concentration. In addition, we determined the total consumption rate of fentanyl, dexmedetomidine and isoflurane as well as bleeding. RESULTS: In each group the heart rate decreased after dexmedetomidine loading. After intubation, values were higher for Group A at one, three, five, 10, and 15 minutes. After intubation, the patients reached desired hypotension values at minute five for Group N and at minute 20 for group A. MAC values were higher for Group N at minute one, three, five, 10, and 15 (p < 0.05). FiO2 values were high between minute five and 60 for Group A, while at minute 90 Group N values were higher (p < 0.05). Fi Iso (inspiratuvar isofluran) values were lower in Group N at minute 15 and 30 (p < 0.05). CONCLUSION: By using dexmedetomidine instead of nitrous oxide in low flow isoflurane anesthesia, we attained desired MAP levels, sufficient anesthesia depth, hemodynamic stability and safe inspiration parameters. Dexmedetomidine infusion with medical air-oxygen as a carrier gas represents an alternative anesthetic technique.

JUSTIFICATIVA Y OBJETIVOS: Investigamos el efecto del óxido nitroso (N2O) en hipotensión controlada durante anestesia con bajo flujo (isoflurano-dexmedetomidina) en términos de hemodinámica, consumo de anestésico y costes. MÉTODOS: Cuarenta pacientes fueron aleatoriamente divididos en dos grupos iguales. La infusión de dexmedetomidina (0,1 µg.kg-1.min-1) se mantuvo entonces por 10 minutos. En secuencia, esa infusión se mantuvo hasta los últimos 30 minutos de operación en una dosis de 0,7 µg.kg-1.hour-1. El tiopental (4-6 mg.kg-1) y el bromuro de vecuronio (0,08 0,12 mg.kg-1) fueron administrados en la inducción de ambos grupos. El Isofluorano (2%) fue administrado para el mantenimiento de la anestesia. El Grupo N recibió una mezcla de un 50% de O2-N2O y el Grupo A recibió una mezcla de un 50% de O2-ar como gas de transporte. La anestesia con bajo flujo (1 L.min-1) fue iniciada después de un período de 10 minutos de alto flujo inicial (4,4 L.min-1). Se registraron los valores de la presión arterial, frecuencia cardíaca, saturación periférica de O2, isoflurano inspiratorio, isoflurano espiratorio, O2 inspiratorio, O2 espiratorio, N2O inspiratorio, N2O espiratorio, CO2 inspiratorio, concentración de CO2 después de la espiración y concentración alveolar mínima. Además, de determinaron las tasas de consumo total de fentanil, dexmedetomidina e isoflurano, como también la de hemorragia. RESULTADOS: La frecuencia cardíaca disminuyó en ambos grupos después de la carga de dexmedetomidina. Después de la intubación, los valores del Grupo A fueron mayores en los minutos 1, 3, 5, 10 y 15. Después de la intubación, los valores de hipotensión deseados se alcanzaron en 5 minutos en el Grupo N y en 20 minutos en el grupo A. Los valores de la CAM fueron más altos en el Grupo N en los minutos 1, 3, 5, 10 y 15 (p < 0,05). Los valores de la FiO2 fueron más altos entre 5 y 60 minutos en el Grupo A, mientras que fueron más altos en el Grupo N a los 90 minutos (p < 0,05). Los valores de Fi Iso (isoflurano espiratorio) fueron menores en el Grupo N en los minutos 15 y 30 (p < 0,05). CONCLUSIONES: El uso de la dexmedetomidina en vez del óxido nitroso en la anestesia con el isoflurano por la técnica de bajo flujo, alcanzó los niveles deseados de presión arterial promedio (PAP), profundidad suficiente de la anestesia, estabilidad hemodinámica y parámetros de inspiración seguros. La infusión de dexmedetomidina con oxígeno / aire medicinal como gas de transporte es una técnica anestésica opcional.

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