Effect of atenolol pre-treatment in heart damage in a model of intestinal ischemia-reperfusion.

PURPOSE: To investigate the effects of atenolol in inflammatory mediator and oxidative stress in a myocardial injury by intestinal ischemia/reperfusion in rat model. METHODS: Adult Wistar male rats were randomly (n=8), anesthetized and divided in: Sham: submitted to operation only; group SS+IR: intravenous saline infusion following superior mesenteric artery occlusion during 60 minutes (ischemia) and open for 120 minutes (reperfusion); group AT+IR: intravenous atenolol infusion (2 mg/kg) following superior mesenteric artery occlusion during 60 minutes (ischemia) and open for 120 minutes (reperfusion); and group AT+I+AT+R: intravenous atenolol infusion following superior mesenteric artery occlusion during 60 minutes (ischemia) and in the time 45 minutes other atenolol doses were administrated and the artery was open for 120 minutes (reperfusion), all animals were submitted to muscular relaxation for mechanical ventilation. In the end of experiment the animals were euthanized and the hearts tissue were morphology analyzed by histology and malondialdehyde by ELISA, and the plasma were analyzed for tumor necrosis factor-alpha by ELISA. RESULTS: The group SS+IR demonstrated the higher malondialdehyde levels when compared with the atenolol treated-groups (p=0.001) in the heart tissue. The tumor necrosis factor-alpha level in plasma decrease in the treated groups when compared with SS+IR group (p=0.001). Histology analyses demonstrate pyknosis, edema, cellular vacuolization, presence of inflammatory infiltrate and band contraction in the heart tissue of the rats. CONCLUSION: Atenolol significantly reduce the degree of cardiac damage after intestinal ischemia-reperfusion.

Effect of atenolol pre-treatment in heart damage in a model of intestinal ischemia-reperfusion

Abstract Purpose: To investigate the effects of atenolol in inflammatory mediator and oxidative stress in a myocardial injury by intestinal ischemia/reperfusion in rat model. Methods: Adult Wistar male rats were randomly (n=8), anesthetized and divided in: Sham: submitted to operation only; group SS+IR: intravenous saline infusion following superior mesenteric artery occlusion during 60 minutes (ischemia) and open for 120 minutes (reperfusion); group AT+IR: intravenous atenolol infusion (2 mg/kg) following superior mesenteric artery occlusion during 60 minutes (ischemia) and open for 120 minutes (reperfusion); and group AT+I+AT+R: intravenous atenolol infusion following superior mesenteric artery occlusion during 60 minutes (ischemia) and in the time 45 minutes other atenolol doses were administrated and the artery was open for 120 minutes (reperfusion), all animals were submitted to muscular relaxation for mechanical ventilation. In the end of experiment the animals were euthanized and the hearts tissue were morphology analyzed by histology and malondialdehyde by ELISA, and the plasma were analyzed for tumor necrosis factor-alpha by ELISA. Results: The group SS+IR demonstrated the higher malondialdehyde levels when compared with the atenolol treated-groups (p=0.001) in the heart tissue. The tumor necrosis factor-alpha level in plasma decrease in the treated groups when compared with SS+IR group (p=0.001). Histology analyses demonstrate pyknosis, edema, cellular vacuolization, presence of inflammatory infiltrate and band contraction in the heart tissue of the rats. Conclusion: Atenolol significantly reduce the degree of cardiac damage after intestinal ischemia-reperfusion.

Intravenous clonidine administration and its ability to reduce pulmonary arterial pressure in patients undergoing heart surgery.

OBJECTIVE: Evaluate the ability of clonidine to reduce pulmonary arterial pressure in patients with pulmonary hypertension undergoing heart surgery, either by reducing the pressure values from the direct measurement of pulmonary arterial pressure or by reducing or eliminating the need for intraoperative dobutamine and nitroprusside. METHOD: Randomized, double-blind, placebo-controlled, comparative study conducted in 30 patients with pulmonary arterial hypertension type 2 undergoing cardiac surgery. Mean pulmonary arterial pressure and dosage of dobutamine and sodium nitroprusside were assessed four times: before intravenous administration of clonidine (2 µg/kg) or placebo (T0), 30 min after tested treatment and before cardiopulmonary bypass (T1), immediately after CPB (T2), 10 min after protamine injection (T3). RESULTS: There were no significant differences regarding mean pulmonary arterial pressure at any time of evaluation. There was no significant difference between groups regarding other variables, such as mean systemic arterial pressure, heart rate, total dose of dobutamine, total dose of sodium nitroprusside, and need for fentanyl. CONCLUSION: Data analysis from patients included in this study allows us to conclude that intravenous clonidine (2 µg/kg) was not able to reduce the mean pulmonary arterial pressure in patients with pulmonary hypertension in group 2 (pulmonary venous hypertension), undergoing heart surgery, or reduce or eliminate the need for intraoperative administration of dobutamine and sodium nitroprusside.

Administracao de clonidina intravenosa e sua capacidade de reduzir a pressao da arteria pulmonar em pacientes submetidos a cirurgia cardiaca / Intravenous clonidine administration and its ability to reduce pulmonary arterial pressure in patients undergoing heart surgery / Administracion de la clonidina intravenosa y su capacidad de reducir la presion de la arteria pulmonar en pacientes sometidos a cirugia cardiaca

Objetivo: Avaliar a capacidade da clonidina de reduzir a pressão arterial pulmonar de pacientes com hipertensão pulmonar, submetidos a cirurgia cardíaca, seja pela diminuição dos valores pressóricos a partir da aferição direta da pressão de artéria pulmonar, seja pela redução ouabolição da necessidade de dobutamina e nitroprussiato de sódio no intraoperatório. Método: Trata-se de estudo controlado, comparativo, randomizado e duplamente encoberto feito com 30 pacientes portadores de hipertensão arterial pulmonar tipo 2, submetidos a cirurgia cardíaca. Avaliaram-se a pressão média de artéria pulmonar e a posologia de dobutaminae nitroprussiato de sódio em quatro momentos: (M0) antes da administração de 2 µg/kg declonidina intravenosa ou placebo; (M1) decorridos 30 minutos do tratamento testado e antes da circulação extracorpórea; (M2) imediatamente após a circulação extracorpórea; e (M3)10 minutos após a injeção de protamina. Resultados: Não houve diferenças significativas em relação à pressão média de artéria pulmonarem nenhum dos momentos estudados. Entre os grupos não houve também diferença significativa entre as demais variáveis estudadas, como pressão arterial sistêmica média, frequência cardíaca, dosagem total de dobutamina, dosagem total de nitroprussiato de sódio e necessidade do hipnoanalgésico fentanil. Conclusão: A análise dos dados obtidos dos pacientes incluídos neste estudo permite concluir que a clonidina, na dose de 2 µg/kg administrada via intravenosa, não foi capaz de reduzir a pressão média de artéria pulmonar de pacientes com hipertensão pulmonar do grupo 2 (hipertensão venosa pulmonar), ...

Objective: Evaluate the ability of clonidine to reduce pulmonary arterial pressure in patients with pulmonary hypertension undergoing heart surgery, either by reducing the pressure values from the direct measurement of pulmonary arterial pressure or by reducing or eliminating the need for intraoperative dobutamine and nitroprusside. Method: Randomized, double-blind, placebo-controlled, comparative study conducted in 30 patients with pulmonary arterial hypertension type 2 undergoing cardiac surgery. Mean pulmonary arterial pressure and dosage of dobutamine and sodium nitroprusside were assessed four times: before intravenous administration of clonidine (2 µg/kg) or placebo (T0), 30 min after tested treatment and before cardiopulmonary bypass (T1), immediately after CPB (T2), 10 min after protamine injection (T3). Results: There were no significant differences regarding mean pulmonary arterial pressure at any time of evaluation. There was no significant difference between groups regarding other variables, such as mean systemic arterial pressure, heart rate, total dose of dobutamine, total dose of sodium nitroprusside, and need for fentanyl. Conclusion: Data analysis from patients included in this study allows us to conclude that intra-venous clonidine (2 µg/kg) was not able to reduce the mean pulmonary arterial pressure inpatients with pulmonary hypertension in group 2 (pulmonary venous hypertension), undergoing heart surgery, or reduce or eliminate the need for intraoperative administration of dobutamineand sodium nitroprusside. .

Objetivo: Evaluar la capacidad de la clonidina de reducir la presión arterial pulmonar de pacientes con hipertensión pulmonar sometidos a cirugía cardíaca, sea por la disminución de los valores tensionales a partir de la comprobación directa de la presión de la arteria pulmonar, o por la reducción o supresión de la necesidad de dobutamina y nitroprusiato de sodio en el intraoperatorio. Método: Se trata de un estudio controlado, comparativo, aleatorizado y doble ciego hecho con 30 pacientes con hipertensión arterial pulmonar tipo 2, sometidos a cirugía cardíaca. Fueron evaluados la presión promedio de la arteria pulmonar y la posología de dobutamina y nitroprusiato de sodio en 4 momentos: (M0) antes de la administración de 2 µg/kg de clonidina intravenosa o placebo; (M1) transcurridos 30 min del tratamiento testado y antes de la circulación extracorpórea; (M2) inmediatamente después de la circulación extracorpórea; y (M3) 10 min después de la inyección de protamina. Resultados: No fueron verificadas diferencias significativas con relación a la presión promedio de la arteria pulmonar en ninguno de los momentos estudiados. Entre los grupos tampoco hubo diferencia significativa entre las demás variables estudiadas, como presión arterial sistémica promedio, frecuencia cardíaca, dosificación total de dobutamina, dosificación total de nitroprusiato de sodio y la necesidad del hipnoanalgésico fentanilo. Conclusiones: El análisis de los datos obtenidos de los pacientes incluidos en este estudio permite concluir que la clonidina en una dosis de 2 µg/kg administrada por vía intravenosa no fue capaz de reducir la presión promedio de la arteria pulmonar de pacientes con hipertensión pulmonar del grupo 2 (hipertensión venosa pulmonar), sometidos ...

Pretreatment with pentoxifylline attenuates lung injury induced by intestinal ischemia/reperfusion in rats / Pré-tratamento com pentoxifilina atenua a lesão pulmonar induzida por isquemia/reperfusão intestinal em ratos

PURPOSE: To investigate the protective effect of pentoxifylline against the lung injury observed after intestinal ischemia (I) followed by a period of reperfusion (R). METHODS: Twenty-eight male Wistar rats were equally divided into 4 experimental groups and operated under ketamine-xylazine anesthesia. (1) Sham: falsely-operated animals; (2) SS+IR: intestinal ischemia was accomplished by clipping the superior mesenteric artery during 60 minutes, with an administration of a standard volume of saline solution (SS) 5 min before the end of the ischemia period; the clip was then releases or a 120-min period of reperfusion; (3) I+PTX+R: ischemia as above, PTX was administered (25 mg/kg) and the gut reperfused as above; (4) PTX+I+PTX+R: Five minutes before arterial occlusion PTX was administered; the superior mesenteric artery was then clipped for 60 minutes. After 55-min ischemia, an additional dosis of PTX was administered; the clip was removed for reperfusion as above. At the 60th min of reperfusion a third dosis of PTX was administered. RESULTS: PTX markedly attenuated lung injury as manifested by significant decreases (all P<0.001 as compared with the SS+IR group) of pulmonary wet/dry tissue weight ratio, total protein content, myeloperoxidase activity and tumor necrosis factor-alpha. Moreover, it was apparent that in the group PTX+I+PTX+R the improvements have been even more significant. CONCLUSION: PTX exerted a protective effect on the lung from the injuries caused by intestinal ischemia/reperfusion.

OBJETIVO: Avaliar os efeitos protetores da pentoxifilina (PTX) na lesão pulmonar observada após isquemia (I) seguida de reperfusão (R) intestinal. MÉTODOS: Vinte e oito ratos machos foram divididos aleatoriamente em quatro grupos experimentais e operados sobre anestesia quetamina-xilazina. (1) Sham: animais falsamente operados; (2) SS+IR: isquemia intestinal realizada pelo clampeamento da artéria mesentérica superior durante 60 minutos, com a administração de solução salina (SS) 5 minutos antes do período de isquemia, após a retirada do clamp houve a reperfusão por mais 120 minutos; (3) I+PTX+R: isquemia como mencionado anteriormente seguida da administração de PTX (25 mg/Kg) 5 minutos antes do final da isquemia (60 minutos) seguida de reperfusão por mais 120 minutos; (4) PTX+I+PTX+R: 5 minutos antes da isquemia foi administrado PTX, após 55 minutos de isquemia foi administrado outra dose de PTX e a reperfusão mantida por mais 120 minutos, sendo que aos 60 minutos da reperfusão outra dose de PTX foi administrada. RESULTADOS: A pentoxifilina reduziu os marcadores de lesão pulmonar (proteínas totais, malondialdeído, atividade da mieloperoxidase e fator de necrose tumoral) quando comparada com o grupo não tratado (P<0.001), contudo esta redução foi mais significante no grupo PTX+I+PTX+R. CONCLUSÃO: A pentoxifilina exerce efeito protetor no pulmão no trauma causado por isquemia/reperfusão intestinal.

Pretreatment with pentoxifylline attenuates lung injury induced by intestinal ischemia/reperfusion in rats.

PURPOSE: To investigate the protective effect of pentoxifylline against the lung injury observed after intestinal ischemia (I) followed by a period of reperfusion (R). METHODS: Twenty-eight male Wistar rats were equally divided into 4 experimental groups and operated under ketamine-xylazine anesthesia. (1) Sham: falsely-operated animals; (2) SS+IR: intestinal ischemia was accomplished by clipping the superior mesenteric artery during 60 minutes, with an administration of a standard volume of saline solution (SS) 5 min before the end of the ischemia period; the clip was then releases or a 120-min period of reperfusion; (3) I+PTX+R: ischemia as above, PTX was administered (25 mg/kg) and the gut reperfused as above; (4) PTX+I+PTX+R: Five minutes before arterial occlusion PTX was administered; the superior mesenteric artery was then clipped for 60 minutes. After 55-min ischemia, an additional dosis of PTX was administered; the clip was removed for reperfusion as above. At the 60th min of reperfusion a third dosis of PTX was administered. RESULTS: PTX markedly attenuated lung injury as manifested by significant decreases (all P<0.001 as compared with the SS+IR group) of pulmonary wet/dry tissue weight ratio, total protein content, myeloperoxidase activity and tumor necrosis factor-alpha. Moreover, it was apparent that in the group PTX+I+PTX+R the improvements have been even more significant. CONCLUSION: PTX exerted a protective effect on the lung from the injuries caused by intestinal ischemia/reperfusion.

Atualização das diretrizes de ressuscitação cardiopulmonar de interesse ao anestesiologista / Spinal myoclonus after subarachnoid anesthesia with bupivacaine

JUSTIFICATIVA E OBJETIVOS: As novas diretrizes de ressuscitação cardiopulmonar (RCP) enfatizam a importância das compressões torácicas de alta qualidade e modificam algumas rotinas. Este artigo tem por objetivo revisar as principais alterações na reanimação praticada pelo médico anestesiologista. CONTEÚDO: A ênfase para realização das compressões torácicas de alta qualidade, com frequência e profundidade adequadas, permitindo retorno total do tórax e com interrupção mínima nas compressões, assume posição de destaque nesta atualização. Não se deve levar mais de dez segundos verificando o pulso antes de iniciar a RCP. A relação universal de 30:2 é mantida, modificando-se sua ordem de realização, iniciando-se pelas compressões torácicas, para, em seguida, prosseguir para as vias aéreas e respiração (C-A-B, em vez de A-B-C). O procedimento "ver, ouvir e sentir se há respiração" foi removido do algoritmo e o uso de pressão cricoidea durante as ventilações, em geral, não é mais recomendado. A frequência das compressões foi modificada para um mínimo de cem por minuto, em vez de aproximadamente cem por minuto, sendo sua profundidade em adultos alterada para 5 cm, em lugar da faixa antes recomendada de 4 a 5 cm. Choque único é mantido, devendo ser de 120 a 200 J quando bifásico, ou 360 J quando monofásico. No suporte avançado de vida, o uso de capnografia e capnometria para confirmação da intubação e monitoração da qualidade da RCP é uma recomendação formal. A atropina não é mais recomendada para uso rotineiro no tratamento da atividade elétrica sem pulso ou assistolia. CONCLUSÕES: É importante a atualização quanto às novas diretrizes de RCP, sendo enfatizado o contínuo aprendizado. Isso irá melhorar a qualidade da reanimação e sobrevida de pacientes em parada cardíaca.

BACKGROUND AND OBJECTIVES: The new cardiopulmonary resuscitation (CPR) guidelines emphasize the importance of high-quality chest compressions and modify some routines. The objective of this report was to review the main changes in resuscitation practiced by anesthesiologists. CONTENTS: The emphasis on high-quality chest compressions with adequate rate and depth allowing full recoil of the chest and with minimal interruptions is highlighted in this update. One should not take more than ten seconds checking the pulse before starting CPR. The universal relationship of 30:2 is maintained, modifying its order, initiating with chest compressions, followed by airways and breathing (C-A-B instead of A-B-C). The procedure "look, listen, and feel whether the patient is breathing" was removed from the algorithm, and the use of cricoid pressure during ventilations is not recommended any more. The rate of chest compressions was changed for at least one hundred per minute instead of approximately one hundred per minute, and its depth in adults was changed to 5 cm instead of the prior recommendation of 4 to 5 cm. The single shock is maintained, and it should be of 120 to 200 J when it is biphasic; and 360 J when it is monophasic. In advanced cardiac life support, the use of capnography and capnometry to confirm intubation and monitoring the quality of CPR is a formal recommendation. Atropine is no longer recommended for routine use in the treatment of pulseless electrical activity or asystole. CONCLUSIONS: Updating the phases of the new CPR guidelines is important, and continuous learning is recommended. This will improve the quality of resuscitation and survival of patients in cardiac arrest.

JUSTIFICATIVA Y OBJETIVOS: Las nuevas directrices de resucitación cardiopulmonar (RCP), destacan la importancia de las compresiones torácicas de alta calidad y modifican algunas rutinas. Este artículo tiene el objetivo de revisar las principales alteraciones en la reanimación practicada por el médico anestesista. CONTENIDO: El énfasis para la realización de las compresiones torácicas de alta calidad, con la frecuencia y la profundidad adecuadas, permitiendo el retorno total del tórax y con interrupción mínima en las compresiones, asume una posición de destaque en esta actualización. No debemos llevar más de 10 segundos verificando el pulso antes de iniciar la RCP. La relación universal de 30:2 se mantiene, modificando su orden de realización, e iniciándose por las compresiones torácicas para, enseguida, proseguir hacia las vías aéreas y la respiración (C-A-B, en vez de A-B-C). El procedimiento "ver, oír y sentir si hay respiración", fue retirado del algoritmo, y el uso de presión cricoide durante las ventilaciones, en general no se recomienda más. La frecuencia de las compresiones fue modificada para un mínimo de 100 por minuto, en vez de aproximadamente 100 por minuto, siendo su profundidad en adultos alterada para 5 cm, en lugar de la franja antes recomendada de 4 a 5 cm. El choque único se mantiene y debe ser de 120 a 200 J, cuando es bifásico, o 360 J, cuando es monofásico. En el soporte avanzado de vida, el uso de capnografía y capnometría para la confirmación de la intubación y de la monitorización de la calidad de la RCP, es una recomendación formal. La atropina no se recomienda más para el uso de rutina en el tratamiento de la actividad eléctrica sin pulso o asistolia. CONCLUSIONES: Es importante la actualización sobre las nuevas directrices de RCP, destacando su continuo aprendizaje. Eso mejorará la calidad de la reanimación y la sobrevida de los pacientes en una parada cardíaca.

Update on cardiopulmonary resuscitation guidelines of interest to anesthesiologists.

BACKGROUND AND OBJECTIVES: The new cardiopulmonary resuscitation (CPR) guidelines emphasize the importance of high-quality chest compressions and modify some routines. The objective of this report was to review the main changes in resuscitation practiced by anesthesiologists. CONTENTS: The emphasis on high-quality chest compressions with adequate rate and depth allowing full recoil of the chest and with minimal interruptions is highlighted in this update. One should not take more than ten seconds checking the pulse before starting CPR. The universal relationship of 30:2 is maintained, modifying its order, initiating with chest compressions, followed by airways and breathing (C-A-B instead of A-B-C). The procedure "look, listen, and feel whether the patient is breathing" was removed from the algorithm, and the use of cricoid pressure during ventilations is not recommended any more. The rate of chest compressions was changed for at least one hundred per minute instead of approximately one hundred per minute, and its depth in adults was changed to 5 cm instead of the prior recommendation of 4 to 5 cm. The single shock is maintained, and it should be of 120 to 200 J when it is biphasic; and 360 J when it is monophasic. In advanced cardiac life support, the use of capnography and capnometry to confirm intubation and monitoring the quality of CPR is a formal recommendation. Atropine is no longer recommended for routine use in the treatment of pulseless electrical activity or asystole. CONCLUSIONS: Updating the phases of the new CPR guidelines is important, and continuous learning is recommended. This will improve the quality of resuscitation and survival of patients in cardiac arrest.

Reanimaçäo cárdio-respiratória e cerebral / Cardiopulmonary and cerebral resuscitation

É fundamental que todo intensivista tenha conhecimento atualizado sobre reanimaçao cardiopulmonar. Estes procedimentos têm por finalidade manter a ventilaçao pulmonar e a circulaçao de sangue oxigenado para o cérebro e outros órgaos vitais. A reanimaçao cerebral inclui medidas destinadas a prevenir ou atenuar a lesao neurológica associada à interrupçao do fluxo sangüíneo. Os autores discutem os fatores etiológicos, os principais aspectos da fisiopatologia e o tratamento atual da parada cárdio-respiratória. Uma vez que a proteçao cerebral é o principal objetivo do tratamento prolongado da vida, os recentes progressos do conhecimento acerca dos mecanismos da lesao neurológica secundária enseja reavaliar as intervençoes realizadas com este objetivo.