Giancarlo Marcondes

Comparação entre os efeitos hemodinâmicos da intoxicação aguda com bupivacaína racêmica e a mistura com excesso enatiomérico de 50% (S75-R25): estudo experimental em cães

JUSTIFICATIVA Y OBJETIVOS: La bupivacaina racemica ha sido ampliamente utilizada en bloqueos locorregionales por la calidad y duracion de la anestesia proporcionada. Su toxicidad cardiovascular, sin embargo ya hace mucho tiempo preocupa a los anestesiologos y nuevas opciones han sido buscadas. Una de ellas es la utilizacion de su isomero levogiro que por una menor afinidad con los receptores de los canales de sodio de la celula cardiaca que seria menos cardiotoxico. En nuestro medio existe la presentacion que contiene un 75% del isomero levogiro y 25% del isomero dextrogiro, denominada mezcla con exceso enantiomerico de 50% (S75-R25). El objetivo de este estudio fue comparar en animales los efectos hemodinamicos de la intoxicacion aguda con bupivacaina racemica y con la mezcla S75-R25. METODO: Cuarenta y cuatro perros fueron anestesiados con pentobarbital, entubados y ventilados mecanicamente, siendo en seguida instalada la monitorizacion hemodinamica con cateter de Swan-Ganz y presion invasiva. Despues del periodo de reposo fueron divididos aleatoriamente en dos grupos de estudio encubierto, segun la intoxicacion con uno u otro agente en la dosis de 5 mg.kg-1. Los resultados hemodinamicos se recolectaron durante 30 minutos, tratados estadisticamente permitiendo la comparacion de la accion de los dos agentes. RESULTADOS: La mezcla S75-R25 causo mayores repercusiones hemodinamicas, particularmente, con importante disminucion de la presion arterial promedio, del indice cardiaco y del indice de trabajo del ventriculo izquierdo. CONCLUSIONES: Esos resultados se contraponen con los encontrados en humanos, cuando se utiliza el isomero levogiro puro, pero estan de acuerdo con estudios recientes en animales. Rebasar datos obtenidos en animales para seres humanos exige mucha cautela. Nuevos estudios se hacen necesarios en muestras mas abarcadoras y en grupos mas homogeneos.BACKGROUND AND OBJECTIVES Racemic bupivacaine has been widely used in locoregional anesthesia due to the quality and duration of its anesthetic action. However, its cardiovascular toxicity has worried anesthesiologists for a long time, and new options have been sought. One of them is the use of its levorotatory isomer that, due to a lesser affinity for the sodium channel receptors in the cardiac cell, would be less toxic. The presentation containing 75% of the levorotatory isomer and 25% of the dextrorotatory isomer, named 50% enantiomeric excess mixture (S75-R25), is available in our country. The objective of this study was to compare the hemodynamic effects of the acute intoxication with racemic bupivacaine and with the S75-R25 mixture in animals. METHODS Forty-four dogs were anesthetized with pentobarbital, intubated and placed on mechanical ventilation. Hemodynamic monitorization was accomplished with a Swan-Ganz catheter and intra-arterial blood pressure measurements. After a period of rest, they were randomly and blindly divided in two groups, according to the intoxication with either agent at a dose of 5 mg.Kg-1. Hemodynamic data were collected during 30 minutes and analyzed statically to allow for the comparison of both agents. RESULTS The mixture S75-R25 had more hemodynamic repercussions causing, especially, a significant reduction of the mean arterial pressure, cardiac index, and the left ventricle work index. CONCLUSIONS These results contradict those found in human beings regarding the pure levorotatory isomer, but confirm recent animal studies. One must be very careful when extrapolating animal data to human beings. Further studies involving larger samples and more homogeneous groups are necessary.

Transporte de pacientes sem oxigenoterapia para a sala de recuperação pós-anestésica: repercussões na saturação de oxigênio e fatores de risco associados à hipoxemia

JUSTIFICATIVA E OBJETIVOS: O transporte de pacientes da sala de cirurgia para a sala de recuperacao pos-anestesica sem o uso de oxigenoterapia suplementar e pratica comum, sendo utilizada apenas em pacientes de alto risco para o desenvolvimento de hipoxemia. O objetivo deste estudo foi avaliar a incidencia das alteracoes na saturacao de oxigenio durante esse transporte e identificar os fatores de riscos associados ao desenvolvimento de hipoxemia. METODO: Avaliou-se uma amostra de 882 pacientes de ambos os sexos, estado fisico ASA I, II e III, submetidos a intervencoes cirurgicas eletivas de varias especialidades e sob quatro tecnicas anestesicas. A variavel de saturacao de oxigenio foi medida e registrada imediatamente antes da saida da sala de cirurgia e, de novo, na admissao na sala de recuperacao pos-anestesica. RESULTADOS: Houve maior incidencia de hipoxemia moderada/intensa durante o transporte de pacientes do sexo feminino (14,47%), nos pacientes estado fisico ASA II e III (14,74% e 16,46%, respectivamente) e naqueles submetidos a cirurgias cardiotoracicas (28,21%), gastroproctologicas (14,18%) e de cabeca-pescoco (18,18%). A anestesia geral, entre as tecnicas anestesicas empregadas, foi fator de risco associado ao desenvolvimento de hipoxemia. CONCLUSOES: Existem fatores associados a ocorrencia de hipoxemia durante o transporte da sala de cirurgia ate a sala de recuperacao pos-anestesica. A utilizacao seletiva de oxigenoterapia deve ser orientada pela presenca desses fatores de risco, ou pelo uso do oximetro de pulso, com o intuito de diminuir a morbimortalidade e a incidencia de hipoxemia no pos-operatorio imediato.BACKGROUND AND OBJECTIVES The transportation of patients from the operating room to the post-anesthetic recovery room without supplemental oxygen is a common practice, since oxygen supplementation is used only in patients at high risk of developing hypoxemia. The objective of this study was to evaluate the incidence of changes in oxygen saturation during this transportation and to identify the risk factors associated to the development of hypoxemia. METHODS A cohort of 882 patients of both genders, physical status ASA I, II, and III, who underwent elective surgeries of several subspecialties using four different anesthetic techniques, was evaluated. Oxygen saturation was measured and recorded just before the patients left the operating room and as soon as they arrived in the recovery room. RESULTS There was a greater incidence of moderate to severe hypoxia during the transport of female patients (14.47%), patients with physical status ASA II and III (14.74% and 16.46%, respectively), and those who underwent cardiothoracic (28.21%), gastroproctologic (14.18%), and head and neck (18.18%) surgeries. Among the anesthetic techniques used, general anesthesia was a risk factor associated with the development of hypoxia. CONCLUSIONS There are factors associated with the development of hypoxia during the transportation of patients from the operating room to the post-anesthetic recovery room. The selective use of supplemental oxygen should be guided by the presence of those risk factors or by the use of a pulse oxymeter, in order to reduce the morbidity, mortality, and the incidence of hypoxemia early in the post-operatory period.

Transportation of patients to the post-anesthetic recovery room without supplemental oxygen: repercutions on oxygen saturation and risk factors associated with hypoxemia

JUSTIFICATIVA E OBJETIVOS: O transporte de pacientes da sala de cirurgia para a sala de recuperacao pos-anestesica sem o uso de oxigenoterapia suplementar e pratica comum, sendo utilizada apenas em pacientes de alto risco para o desenvolvimento de hipoxemia. O objetivo deste estudo foi avaliar a incidencia das alteracoes na saturacao de oxigenio durante esse transporte e identificar os fatores de riscos associados ao desenvolvimento de hipoxemia. METODO: Avaliou-se uma amostra de 882 pacientes de ambos os sexos, estado fisico ASA I, II e III, submetidos a intervencoes cirurgicas eletivas de varias especialidades e sob quatro tecnicas anestesicas. A variavel de saturacao de oxigenio foi medida e registrada imediatamente antes da saida da sala de cirurgia e, de novo, na admissao na sala de recuperacao pos-anestesica. RESULTADOS: Houve maior incidencia de hipoxemia moderada/intensa durante o transporte de pacientes do sexo feminino (14,47%), nos pacientes estado fisico ASA II e III (14,74% e 16,46%, respectivamente) e naqueles submetidos a cirurgias cardiotoracicas (28,21%), gastroproctologicas (14,18%) e de cabeca-pescoco (18,18%). A anestesia geral, entre as tecnicas anestesicas empregadas, foi fator de risco associado ao desenvolvimento de hipoxemia. CONCLUSOES: Existem fatores associados a ocorrencia de hipoxemia durante o transporte da sala de cirurgia ate a sala de recuperacao pos-anestesica. A utilizacao seletiva de oxigenoterapia deve ser orientada pela presenca desses fatores de risco, ou pelo uso do oximetro de pulso, com o intuito de diminuir a morbimortalidade e a incidencia de hipoxemia no pos-operatorio imediato.BACKGROUND AND OBJECTIVES The transportation of patients from the operating room to the post-anesthetic recovery room without supplemental oxygen is a common practice, since oxygen supplementation is used only in patients at high risk of developing hypoxemia. The objective of this study was to evaluate the incidence of changes in oxygen saturation during this transportation and to identify the risk factors associated to the development of hypoxemia. METHODS A cohort of 882 patients of both genders, physical status ASA I, II, and III, who underwent elective surgeries of several subspecialties using four different anesthetic techniques, was evaluated. Oxygen saturation was measured and recorded just before the patients left the operating room and as soon as they arrived in the recovery room. RESULTS There was a greater incidence of moderate to severe hypoxia during the transport of female patients (14.47%), patients with physical status ASA II and III (14.74% and 16.46%, respectively), and those who underwent cardiothoracic (28.21%), gastroproctologic (14.18%), and head and neck (18.18%) surgeries. Among the anesthetic techniques used, general anesthesia was a risk factor associated with the development of hypoxia. CONCLUSIONS There are factors associated with the development of hypoxia during the transportation of patients from the operating room to the post-anesthetic recovery room. The selective use of supplemental oxygen should be guided by the presence of those risk factors or by the use of a pulse oxymeter, in order to reduce the morbidity, mortality, and the incidence of hypoxemia early in the post-operatory period.

Insulinoma e gestação: anestesia e manejo perioperatório

Insulinoma is a functional neuroendocrine tumor derived from beta cells of the pancreatic islets of Langerhans, usually solitary, benign, and curable with surgery (enucleation). It rarely occurs during pregnancy and is clinically manifested by hypoglycemia, particularly in the first trimester of pregnancy. During pregnancy, both conservative therapeutic measures (medication) and surgical treatment are challenging regarding the impossibility of studies on drug teratogenicity as well as the maternal-fetal repercussions during surgery, such as hypoglycemia and changes due to stress. CASE REPORT A 33-year primiparous woman, 86kg, 1.62m, BMI 32.7kg.m-2, at 15 weeks of gestation, physical status ASA III, investigated for a reduced level of consciousness. Laboratory tests showed: hypoglycemia (45mg.dL-1) associated with hyperinsulinemia (24 nUI.mL-1), glycosylated hemoglobin (4.1%); other laboratory findings and physical examination were normal. Magnetic resonance imaging showed a 1.1cm nodule in the pancreatic tail with suspected insulinoma. Due to the difficult glycemic control with bolus and continuous infusion of glucose, laparotomy was performed for tumor enucleation under total intravenous anesthesia combined with epidural block. Monitoring, central and peripheral venous access, radial artery catheterization, diuresis, and glucosimetry were recorded every 15minutes. Intraoperatively, there was severe hypoglycemia while handling the tumor and shortly before its enucleation, which was controlled through continuous infusion of 10% glucose balanced crystalloid solution (100-230ml.h-1). The patients postoperative evolution was uneventful, with resolution of hypoglycemia and total withdrawal of glucose intravenous infusion.

Comparación entre los efectos hemodinámicos de la intoxicación aguda con bupivacaína racémica y la mezcla con exceso enatiomérico de 50% (S75-R25): estudio experimental en perros

JUSTIFICATIVA Y OBJETIVOS: La bupivacaina racemica ha sido ampliamente utilizada en bloqueos locorregionales por la calidad y duracion de la anestesia proporcionada. Su toxicidad cardiovascular, sin embargo ya hace mucho tiempo preocupa a los anestesiologos y nuevas opciones han sido buscadas. Una de ellas es la utilizacion de su isomero levogiro que por una menor afinidad con los receptores de los canales de sodio de la celula cardiaca que seria menos cardiotoxico. En nuestro medio existe la presentacion que contiene un 75% del isomero levogiro y 25% del isomero dextrogiro, denominada mezcla con exceso enantiomerico de 50% (S75-R25). El objetivo de este estudio fue comparar en animales los efectos hemodinamicos de la intoxicacion aguda con bupivacaina racemica y con la mezcla S75-R25. METODO: Cuarenta y cuatro perros fueron anestesiados con pentobarbital, entubados y ventilados mecanicamente, siendo en seguida instalada la monitorizacion hemodinamica con cateter de Swan-Ganz y presion invasiva. Despues del periodo de reposo fueron divididos aleatoriamente en dos grupos de estudio encubierto, segun la intoxicacion con uno u otro agente en la dosis de 5 mg.kg-1. Los resultados hemodinamicos se recolectaron durante 30 minutos, tratados estadisticamente permitiendo la comparacion de la accion de los dos agentes. RESULTADOS: La mezcla S75-R25 causo mayores repercusiones hemodinamicas, particularmente, con importante disminucion de la presion arterial promedio, del indice cardiaco y del indice de trabajo del ventriculo izquierdo. CONCLUSIONES: Esos resultados se contraponen con los encontrados en humanos, cuando se utiliza el isomero levogiro puro, pero estan de acuerdo con estudios recientes en animales. Rebasar datos obtenidos en animales para seres humanos exige mucha cautela. Nuevos estudios se hacen necesarios en muestras mas abarcadoras y en grupos mas homogeneos.BACKGROUND AND OBJECTIVES Racemic bupivacaine has been widely used in locoregional anesthesia due to the quality and duration of its anesthetic action. However, its cardiovascular toxicity has worried anesthesiologists for a long time, and new options have been sought. One of them is the use of its levorotatory isomer that, due to a lesser affinity for the sodium channel receptors in the cardiac cell, would be less toxic. The presentation containing 75% of the levorotatory isomer and 25% of the dextrorotatory isomer, named 50% enantiomeric excess mixture (S75-R25), is available in our country. The objective of this study was to compare the hemodynamic effects of the acute intoxication with racemic bupivacaine and with the S75-R25 mixture in animals. METHODS Forty-four dogs were anesthetized with pentobarbital, intubated and placed on mechanical ventilation. Hemodynamic monitorization was accomplished with a Swan-Ganz catheter and intra-arterial blood pressure measurements. After a period of rest, they were randomly and blindly divided in two groups, according to the intoxication with either agent at a dose of 5 mg.Kg-1. Hemodynamic data were collected during 30 minutes and analyzed statically to allow for the comparison of both agents. RESULTS The mixture S75-R25 had more hemodynamic repercussions causing, especially, a significant reduction of the mean arterial pressure, cardiac index, and the left ventricle work index. CONCLUSIONS These results contradict those found in human beings regarding the pure levorotatory isomer, but confirm recent animal studies. One must be very careful when extrapolating animal data to human beings. Further studies involving larger samples and more homogeneous groups are necessary.

Comparison of the hemodynamic effects in acute intoxication with racemic bupivacaine and with 50% enantiomeric excess mixture (S75-R25): an experimental study in dogs

JUSTIFICATIVA Y OBJETIVOS: La bupivacaina racemica ha sido ampliamente utilizada en bloqueos locorregionales por la calidad y duracion de la anestesia proporcionada. Su toxicidad cardiovascular, sin embargo ya hace mucho tiempo preocupa a los anestesiologos y nuevas opciones han sido buscadas. Una de ellas es la utilizacion de su isomero levogiro que por una menor afinidad con los receptores de los canales de sodio de la celula cardiaca que seria menos cardiotoxico. En nuestro medio existe la presentacion que contiene un 75% del isomero levogiro y 25% del isomero dextrogiro, denominada mezcla con exceso enantiomerico de 50% (S75-R25). El objetivo de este estudio fue comparar en animales los efectos hemodinamicos de la intoxicacion aguda con bupivacaina racemica y con la mezcla S75-R25. METODO: Cuarenta y cuatro perros fueron anestesiados con pentobarbital, entubados y ventilados mecanicamente, siendo en seguida instalada la monitorizacion hemodinamica con cateter de Swan-Ganz y presion invasiva. Despues del periodo de reposo fueron divididos aleatoriamente en dos grupos de estudio encubierto, segun la intoxicacion con uno u otro agente en la dosis de 5 mg.kg-1. Los resultados hemodinamicos se recolectaron durante 30 minutos, tratados estadisticamente permitiendo la comparacion de la accion de los dos agentes. RESULTADOS: La mezcla S75-R25 causo mayores repercusiones hemodinamicas, particularmente, con importante disminucion de la presion arterial promedio, del indice cardiaco y del indice de trabajo del ventriculo izquierdo. CONCLUSIONES: Esos resultados se contraponen con los encontrados en humanos, cuando se utiliza el isomero levogiro puro, pero estan de acuerdo con estudios recientes en animales. Rebasar datos obtenidos en animales para seres humanos exige mucha cautela. Nuevos estudios se hacen necesarios en muestras mas abarcadoras y en grupos mas homogeneos.BACKGROUND AND OBJECTIVES Racemic bupivacaine has been widely used in locoregional anesthesia due to the quality and duration of its anesthetic action. However, its cardiovascular toxicity has worried anesthesiologists for a long time, and new options have been sought. One of them is the use of its levorotatory isomer that, due to a lesser affinity for the sodium channel receptors in the cardiac cell, would be less toxic. The presentation containing 75% of the levorotatory isomer and 25% of the dextrorotatory isomer, named 50% enantiomeric excess mixture (S75-R25), is available in our country. The objective of this study was to compare the hemodynamic effects of the acute intoxication with racemic bupivacaine and with the S75-R25 mixture in animals. METHODS Forty-four dogs were anesthetized with pentobarbital, intubated and placed on mechanical ventilation. Hemodynamic monitorization was accomplished with a Swan-Ganz catheter and intra-arterial blood pressure measurements. After a period of rest, they were randomly and blindly divided in two groups, according to the intoxication with either agent at a dose of 5 mg.Kg-1. Hemodynamic data were collected during 30 minutes and analyzed statically to allow for the comparison of both agents. RESULTS The mixture S75-R25 had more hemodynamic repercussions causing, especially, a significant reduction of the mean arterial pressure, cardiac index, and the left ventricle work index. CONCLUSIONS These results contradict those found in human beings regarding the pure levorotatory isomer, but confirm recent animal studies. One must be very careful when extrapolating animal data to human beings. Further studies involving larger samples and more homogeneous groups are necessary.

Transporte de pacientes sin oxigenoterapia para la sala de recuperación postanestésica: repercusiones en la saturación de oxígeno y factores de riesgo asociados a la hipoxemia

JUSTIFICATIVA E OBJETIVOS: O transporte de pacientes da sala de cirurgia para a sala de recuperacao pos-anestesica sem o uso de oxigenoterapia suplementar e pratica comum, sendo utilizada apenas em pacientes de alto risco para o desenvolvimento de hipoxemia. O objetivo deste estudo foi avaliar a incidencia das alteracoes na saturacao de oxigenio durante esse transporte e identificar os fatores de riscos associados ao desenvolvimento de hipoxemia. METODO: Avaliou-se uma amostra de 882 pacientes de ambos os sexos, estado fisico ASA I, II e III, submetidos a intervencoes cirurgicas eletivas de varias especialidades e sob quatro tecnicas anestesicas. A variavel de saturacao de oxigenio foi medida e registrada imediatamente antes da saida da sala de cirurgia e, de novo, na admissao na sala de recuperacao pos-anestesica. RESULTADOS: Houve maior incidencia de hipoxemia moderada/intensa durante o transporte de pacientes do sexo feminino (14,47%), nos pacientes estado fisico ASA II e III (14,74% e 16,46%, respectivamente) e naqueles submetidos a cirurgias cardiotoracicas (28,21%), gastroproctologicas (14,18%) e de cabeca-pescoco (18,18%). A anestesia geral, entre as tecnicas anestesicas empregadas, foi fator de risco associado ao desenvolvimento de hipoxemia. CONCLUSOES: Existem fatores associados a ocorrencia de hipoxemia durante o transporte da sala de cirurgia ate a sala de recuperacao pos-anestesica. A utilizacao seletiva de oxigenoterapia deve ser orientada pela presenca desses fatores de risco, ou pelo uso do oximetro de pulso, com o intuito de diminuir a morbimortalidade e a incidencia de hipoxemia no pos-operatorio imediato.BACKGROUND AND OBJECTIVES The transportation of patients from the operating room to the post-anesthetic recovery room without supplemental oxygen is a common practice, since oxygen supplementation is used only in patients at high risk of developing hypoxemia. The objective of this study was to evaluate the incidence of changes in oxygen saturation during this transportation and to identify the risk factors associated to the development of hypoxemia. METHODS A cohort of 882 patients of both genders, physical status ASA I, II, and III, who underwent elective surgeries of several subspecialties using four different anesthetic techniques, was evaluated. Oxygen saturation was measured and recorded just before the patients left the operating room and as soon as they arrived in the recovery room. RESULTS There was a greater incidence of moderate to severe hypoxia during the transport of female patients (14.47%), patients with physical status ASA II and III (14.74% and 16.46%, respectively), and those who underwent cardiothoracic (28.21%), gastroproctologic (14.18%), and head and neck (18.18%) surgeries. Among the anesthetic techniques used, general anesthesia was a risk factor associated with the development of hypoxia. CONCLUSIONS There are factors associated with the development of hypoxia during the transportation of patients from the operating room to the post-anesthetic recovery room. The selective use of supplemental oxygen should be guided by the presence of those risk factors or by the use of a pulse oxymeter, in order to reduce the morbidity, mortality, and the incidence of hypoxemia early in the post-operatory period.