Use of CPAP as an alternative to the apnea test during the determination of brain death in hypoxemic patients. Report of two cases. / Uso da CPAP como alternativa para realização do teste de apneia durante determinação da morte encefálica em pacientes hipoxêmicos. Relato de dois casos.

The apnea test, which involves disconnection from the mechanical ventilator, presents risks during the determination of brain death, especially in hypoxemic patients. We describe the performance of the apnea test without disconnection from the mechanical ventilator in two patients. The first case involved an 8-year-old boy admitted with severe hypoxemia due to pneumonia. He presented with cardiorespiratory arrest, followed by unresponsive coma due to hypoxic-ischemic encephalopathy. Two clinical exams revealed the absence of brainstem reflexes, and transcranial Doppler ultrasound revealed brain circulatory arrest. Three attempts were made to perform the apnea test, which were interrupted by hypoxemia; therefore, the apnea test was performed without disconnection from the mechanical ventilator, adjusting the continuous airway pressure to 10cmH2O and the inspired fraction of oxygen to 100%. The oxygen saturation was maintained at 100% for 10 minutes. Posttest blood gas analysis results were as follows: pH, 6.90; partial pressure of oxygen, 284.0mmHg; partial pressure of carbon dioxide, 94.0mmHg; and oxygen saturation, 100%. The second case involved a 43-year-old woman admitted with subarachnoid hemorrhage (Hunt-Hess V and Fisher IV). Two clinical exams revealed unresponsive coma and absence of all brainstem reflexes. Brain scintigraphy showed no radioisotope uptake into the brain parenchyma. The first attempt at the apnea test was stopped after 5 minutes due to hypothermia (34.9°C). After rewarming, the apnea test was repeated without disconnection from the mechanical ventilator, showing maintenance of the functional residual volume with electrical bioimpedance. Posttest blood gas analysis results were as follows: pH, 7.01; partial pressure of oxygen, 232.0mmHg; partial pressure of carbon dioxide, 66.9mmHg; and oxygen saturation, 99.0%. The apnea test without disconnection from the mechanical ventilator allowed the preservation of oxygenation in both cases. The use of continuous airway pressure during the apnea test seems to be a safe alternative in order to maintain alveolar recruitment and oxygenation during brain death determination.

Uso da CPAP como alternativa para realização do teste de apneia durante determinação da morte encefálica em pacientes hipoxêmicos. Relato de dois casos / Use of CPAP as an alternative to the apnea test during the determination of brain death in hypoxemic patients. Report of two cases

RESUMO O teste de apneia com desconexão do ventilador mecânico representa riscos durante a determinação da morte encefálica, especialmente em pacientes hipoxêmicos. Descrevemos a realização do teste de apneia sem desconexão do ventilador mecânico em dois pacientes. O primeiro caso é o de um menino de 8 anos, admitido com hipoxemia grave por pneumonia. Apresentou parada cardiorrespiratória, seguida de coma não responsivo por encefalopatia hipóxico-isquêmica. Dois exames clínicos constataram ausência de reflexos de tronco, e o Doppler transcraniano revelou parada circulatória encefálica. Realizaram-se três tentativas de teste de apneia, que foram interrompidas por hipoxemia, sendo então realizado teste de apneia sem desconexão do ventilador mecânico, ajustando a pressão contínua nas vias aéreas em 10cmH2O e fração inspirada de oxigênio em 100%. A saturação de oxigênio manteve-se em 100% por 10 minutos. A gasometria pós-teste foi a seguinte: pH de 6,90, pressão parcial de oxigênio em 284,0mmHg, pressão parcial de dióxido de carbono em 94,0mmHg e saturação de oxigênio em 100%. O segundo caso é de uma mulher de 43 anos, admitida com hemorragia subaracnóidea (Hunt-Hess V e Fisher IV). Dois exames clínicos constataram coma não responsivo e ausência de todos os reflexos de tronco. A cintilografia cerebral evidenciou ausência de captação de radioisótopos no parênquima cerebral. A primeira tentativa do teste de apneia foi interrompida após 5 minutos por hipotermia (34,9oC). Após reaquecimento, o teste de apneia foi repetido sem desconexão do ventilador mecânico, evidenciando-se manutenção do volume residual funcional com tomografia de bioimpedância elétrica. Gasometria pós-teste de apneia apresentava pH em 7,01, pressão parcial de oxigênio em 232,0mmHg, pressão parcial de dióxido de carbono 66,9mmHg e saturação de oxigênio em 99,0%. O teste de apneia sem desconexão do ventilador mecânico permitiu a preservação da oxigenação em ambos os casos. O uso de pressão contínua nas vias aéreas durante o teste de apneia parece ser uma alternativa segura para manter o recrutamento alveolar e a oxigenação durante determinação da morte encefálica.

ABSTRACT The apnea test, which involves disconnection from the mechanical ventilator, presents risks during the determination of brain death, especially in hypoxemic patients. We describe the performance of the apnea test without disconnection from the mechanical ventilator in two patients. The first case involved an 8-year-old boy admitted with severe hypoxemia due to pneumonia. He presented with cardiorespiratory arrest, followed by unresponsive coma due to hypoxic-ischemic encephalopathy. Two clinical exams revealed the absence of brainstem reflexes, and transcranial Doppler ultrasound revealed brain circulatory arrest. Three attempts were made to perform the apnea test, which were interrupted by hypoxemia; therefore, the apnea test was performed without disconnection from the mechanical ventilator, adjusting the continuous airway pressure to 10cmH2O and the inspired fraction of oxygen to 100%. The oxygen saturation was maintained at 100% for 10 minutes. Posttest blood gas analysis results were as follows: pH, 6.90; partial pressure of oxygen, 284.0mmHg; partial pressure of carbon dioxide, 94.0mmHg; and oxygen saturation, 100%. The second case involved a 43-year-old woman admitted with subarachnoid hemorrhage (Hunt-Hess V and Fisher IV). Two clinical exams revealed unresponsive coma and absence of all brainstem reflexes. Brain scintigraphy showed no radioisotope uptake into the brain parenchyma. The first attempt at the apnea test was stopped after 5 minutes due to hypothermia (34.9°C). After rewarming, the apnea test was repeated without disconnection from the mechanical ventilator, showing maintenance of the functional residual volume with electrical bioimpedance. Posttest blood gas analysis results were as follows: pH, 7.01; partial pressure of oxygen, 232.0mmHg; partial pressure of carbon dioxide, 66.9mmHg; and oxygen saturation, 99.0%. The apnea test without disconnection from the mechanical ventilator allowed the preservation of oxygenation in both cases. The use of continuous airway pressure during the apnea test seems to be a safe alternative in order to maintain alveolar recruitment and oxygenation during brain death determination.

A pragmatic multi-center trial of goal-directed fluid management based on pulse pressure variation monitoring during high-risk surgery.

BACKGROUND: Intraoperative fluid therapy guided by mechanical ventilation-induced pulse-pressure variation (PPV) may improve outcomes after major surgery. We tested this hypothesis in a multi-center study. METHODS: The patients were included in two periods: a first control period (control group; n = 147) in which intraoperative fluids were given according to clinical judgment. After a training period, intraoperative fluid management was titrated to maintain PPV < 10% in 109 surgical patients (PPV group). We performed 1:1 propensity score matching to ensure the groups were comparable with regard to age, weight, duration of surgery, and type of operation. The primary endpoint was postoperative hospital length of stay. RESULTS: After matching, 84 patients remained in each group. Baseline characteristics, surgical procedure duration and physiological parameters evaluated at the start of surgery were similar between the groups. The volume of crystalloids (4500 mL [3200-6500 mL] versus 5000 mL [3750-8862 mL]; P = 0.01), the number of blood units infused during the surgery (1.7 U [0.9-2.0 U] versus 2.0 U [1.7-2.6 U]; P = 0.01), the fraction of patients transfused (13.1% versus 32.1%; P = 0.003) and the number of patients receiving mechanical ventilation at 24 h (3.2% versus 9.7%; P = 0.027) were smaller postoperatively in PPV group. Intraoperative PPV-based improved the composite outcome of postoperative complications OR 0.59 [95% CI 0.35-0.99] and reduced the postoperative hospital length of stay (8 days [6-14 days] versus 11 days [7-18 days]; P = 0.01). CONCLUSIONS: In high-risk surgeries, PPV-directed volume loading improved postoperative outcomes and decreased the postoperative hospital length of stay. TRIAL REGISTRATION: ClinicalTrials.gov Identifier; retrospectively registered- NCT03128190.

Brazilian recommendations of mechanical ventilation 2013. Part 2.

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Recomendações brasileiras de ventilação mecânica 2013. Parte 2 / Brazilian recommendations of mechanical ventilation 2013. Part 2

O suporte ventilatório artificial invasivo e não invasivo ao paciente grave tem evoluído e inúmeras evidências têm surgido, podendo ter impacto na melhora da sobrevida e da qualidade do atendimento oferecido nas unidades de terapia intensiva no Brasil. Isto posto, a Associação de Medicina Intensiva Brasileira (AMIB) e a Sociedade Brasileira de Pneumologia e Tisiologia (SBPT) - representadas por seu Comitê de Ventilação Mecânica e sua Comissão de Terapia Intensiva, respectivamente, decidiram revisar a literatura e preparar recomendações sobre ventilação mecânica, objetivando oferecer aos associados um documento orientador das melhores práticas da ventilação mecânica na beira do leito, com base nas evidências existentes, sobre os 29 subtemas selecionados como mais relevantes no assunto. O projeto envolveu etapas que visaram distribuir os subtemas relevantes ao assunto entre experts indicados por ambas as sociedades, que tivessem publicações recentes no assunto e/ou atividades relevantes em ensino e pesquisa no Brasil, na área de ventilação mecânica. Esses profissionais, divididos por subtemas em duplas, responsabilizaram-se por fazer uma extensa revisão da literatura mundial. Reuniram-se todos no Fórum de Ventilação Mecânica, na sede da AMIB, na cidade de São Paulo (SP), em 3 e 4 de agosto de 2013, para finalização conjunta do texto de cada subtema e apresentação, apreciação, discussão e aprovação em plenária pelos 58 participantes, permitindo a elaboração de um documento final.

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Brazilian recommendations of mechanical ventilation 2013. Part I.

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumonia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Recomendações brasileiras de ventilação mecânica 2013. Parte I / Brazilian recommendations of mechanical ventilation 2013. Part I

O suporte ventilatório artificial invasivo e não invasivo ao paciente crítico tem evoluído e inúmeras evidências têm surgido, podendo ter impacto na melhora da sobrevida e da qualidade do atendimento oferecido nas unidades de terapia intensiva no Brasil. Isto posto, a Associação de Medicina Intensiva Brasileira (AMIB) e a Sociedade Brasileira de Pneumonia e Tisiologia (SBPT) - representadas pelo seus Comitê de Ventilação Mecânica e Comissão de Terapia Intensiva, respectivamente, decidiram revisar a literatura e preparar recomendações sobre ventilação mecânica objetivando oferecer aos associados um documento orientador das melhores práticas da ventilação mecânica na beira do leito, baseado nas evidencias existentes, sobre os 29 subtemas selecionados como mais relevantes no assunto. O projeto envolveu etapas visando distribuir os subtemas relevantes ao assunto entre experts indicados por ambas as sociedades que tivessem publicações recentes no assunto e/ou atividades relevantes em ensino e pesquisa no Brasil na área de ventilação mecânica. Esses profissionais, divididos por subtemas em duplas, responsabilizaram-se por fazer revisão extensa da literatura mundial sobre cada subtema. Reuniram-se todos no Forum de Ventilação Mecânica na sede da AMIB em São Paulo, em 03 e 04 de agosto de 2013 para finalização conjunta do texto de cada subtema e apresentação, apreciação, discussão e aprovação em plenária pelos 58 participantes, permitindo a elaboração de um documento final.

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumonia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Evaluation of gasometric parameters in trauma patients during mobile prehospital care.

OBJECTIVE: To evaluate gasometric differences of severe trauma patients requiring intubation in prehospital care. METHODS: Patients requiring airway management were submitted to collection of arterial blood samples at the beginning of pre-hospital care and at arrival at the Emergency Room. We analyzed: Glasgow Coma Scale, respiratory rate, arterial pH, arterial partial pressure of CO2 (PaCO2), arterial partial pressure of O2 (PaO2), base excess (BE), hemoglobin O2 saturation (SpO2) and the relation of PaO2 and inspired O2 (PaO2/FiO2). RESULTS: There was statistical significance of the mean differences between the data collected at the site of the accident and at the entrance of the ER as for respiratory rate (p = 0.0181), Glasgow Coma Scale (p = 0.0084), PaO2 (p <0.0001) and SpO2 (p = 0.0018). CONCLUSION: tracheal intubation changes the parameters PaO2 and SpO2. There was no difference in metabolic parameters (pH, bicarbonate and base excess). In the analysis of blood gas parameters between survivors and non-survivors there was statistical difference between PaO2, hemoglobin oxygen saturation and base excess.

Avaliação dos parâmetros gasométricos dos traumatizados durante o atendimento pré-hospitalar móvel / Evaluation of gasometric parameters in trauma patients during mobile prehospital care

OBJETIVO: avaliar diferenças gasométricas dos pacientes traumatizados graves que necessitaram de intubação orotraqueal no atendimento pré-hospitalar. MÉTODOS: foram colhidas amostras de sangue dos pacientes que necessitaram de manejo de via aérea no início do atendimento pré-hospitalar e ao dar entrada na Unidade de Urgência. Foram analisados: pH, pressão arterial de CO2 (PaCO2), pressão arterial de O2 (PaO2), excesso de base (BE), saturação da hemoglobina por O2 (satO2) e a relação PaO2 e a fração inspirada de O2 (PaO2/FiO2). RESULTADOS: houve significância estatística entre as diferenças das médias entre os dados coletados no local do sinistro e na entrada da UUE na Frequência respiratória (p=0,0181), na Escala de Coma de Glasgow (p=0,0084), na pressão parcial arterial de oxigênio (PaO2; p<0,0001) e na saturação da hemoglobina pelo oxigênio (p=0,0018). CONCLUSÃO: a intubação orotraqueal altera os parâmetros PaO2 e saturação de oxigênio pela hemoglobina. Não houve diferença nos parâmetros metabólicos (pH, Bicarbonato e excesso de base). Na análise dos parâmetros hemogasométricos dos sobreviventes e não sobreviventes observou-se diferença estatística entre o PaO2, saturação de oxigênio pela hemoglobina e excesso de base.

OBJECTIVE: To evaluate gasometric differences of severe trauma patients requiring intubation in prehospital care. METHODS: Patients requiring airway management were submitted to collection of arterial blood samples at the beginning of pre-hospital care and at arrival at the Emergency Room. We analyzed: Glasgow Coma Scale, respiratory rate, arterial pH, arterial partial pressure of CO2 (PaCO2), arterial partial pressure of O2 (PaO2), base excess (BE), hemoglobin O2 saturation (SpO2) and the relation of PaO2 and inspired O2 (PaO2/FiO2). RESULTS: There was statistical significance of the mean differences between the data collected at the site of the accident and at the entrance of the ER as for respiratory rate (p = 0.0181), Glasgow Coma Scale (p = 0.0084), PaO2 (p <0.0001) and SpO2 (p = 0.0018). CONCLUSION: tracheal intubation changes the parameters PaO2 and SpO2. There was no difference in metabolic parameters (pH, bicarbonate and base excess). In the analysis of blood gas parameters between survivors and non-survivors there was statistical difference between PaO2, hemoglobin oxygen saturation and base excess.

Diretrizes para o manejo do tétano acidental em pacientes adultos / Guidelines for the management of accidental tetanus in adult patients

O tétano acidental, a despeito de ser uma doença prevenível por imunização, ainda é frequente nos países subdesenvolvidos e em desenvolvimento. Sua letalidade ainda é elevada e os estudos sobre a melhor forma de tratamento são escassos. Tendo em vista esta escassez e a importância clínica dessa doença, um grupo de especialistas reunidos pela Associação de Medicina Intensiva Brasileira (AMIB), desenvolveu recomendações baseadas na melhor evidencia disponível para o manejo do tétano no paciente necessitando cuidados intensivos. As recomendações incluem aspectos relativos à admissão do paciente tetânico na unidade de terapia intensiva, tratamento com imunoglobulinas, tratamento antibiótico, manejo da analgossedação e bloqueio neuromuscular, manejo da disautonomia e especificidades na ventilação mecânica e fisioterapia nesta população especial.

Although tetanus can be prevented by appropriate immunization, accidental tetanus continues to occur frequently in underdeveloped and developing countries. Tetanus mortality rates remain high in these areas, and studies regarding the best therapy for tetanus are scarce. Because of the paucity of data on accidental tetanus and the clinical relevance of this condition, the Associação de Medicina Intensiva Brasileira (AMIB) organized a group of experts to develop these guidelines, which are based on the best available evidence for the management of tetanus in patients requiring admission to the intensive care unit. The guidelines discuss the management of tetanus patients in the intensive care unit, including the use of immunoglobulin therapy, antibiotic therapy, management of analgesics, sedation and neuromuscular blockade, management of dysautonomia and specific issues related to mechanical ventilation and physiotherapy in this population.

Guidelines for the management of accidental tetanus in adult patients. / Diretrizes para o manejo do tétano acidental em pacientes adultos.

Although tetanus can be prevented by appropriate immunization, accidental tetanus continues to occur frequently in underdeveloped and developing countries. Tetanus mortality rates remain high in these areas, and studies regarding the best therapy for tetanus are scarce. Because of the paucity of data on accidental tetanus and the clinical relevance of this condition, the Associação de Medicina Intensiva Brasileira (AMIB) organized a group of experts to develop these guidelines, which are based on the best available evidence for the management of tetanus in patients requiring admission to the intensive care unit. The guidelines discuss the management of tetanus patients in the intensive care unit, including the use of immunoglobulin therapy, antibiotic therapy, management of analgesics, sedation and neuromuscular blockade, management of dysautonomia and specific issues related to mechanical ventilation and physiotherapy in this population.

[Comparison between two methods for hemodynamic measurement: thermodilution and oesophageal doppler]. / Comparação dos valores de débito cardíaco obtidos por termodiluição e dopplerfluxometria transesofágica.

OBJECTIVES: Thermodilution (TD) is the "gold standard method" for hemodynamic monitoring. Some parameters can be measured by Oesophageal Doppler (OD), which is simpler and less invasive. To evaluate the accuracy of OD, we compared this method with TD in measurement of cardiac output (CO). METHODS: One hundred and ninety two simultaneous measurements were made in 10 patients (5 male and 5 female) with different clinical situations, 8 with sepsis using vasoactive drugs and 2 monitored for laryngectomy and liver transplantation. Measurements were taken during 4 hours at 30 minute intervals. The two oesophageal dopplers used DeltexR and ArrowR, were introduced between 35 and 45 cm from the nose and located at the point of largest diameter of the descending aorta. In TD, we used the pulmonary artery catheter (Swan Ganz BaxterR) and the DX- 2001 monitorR positioning was confirmed with support of radiology and of pressures curves. Measurements of CO carried out by means of TD were achieved using an iced saline solution considering the mean of four measurements with less than a 5% difference. The statistical method used was the Bland-Altman scatter plot and dispersion graphic. RESULTS: No statistically significant difference was found between the two methods for hemodyamic measurement with a correlation coefficient of 0.8 for CO (Deltex DopplerR and Baxter Swan GanzR) and a correlation coefficient of 0.99 for CO (Arrow DopplerR and Baxter Swan GanzR). CONCLUSION: Homodynamic measurements with OD have the same accuracy as those with TD and were easily obtained in the 10 patients.

Comparação dos valores de débito cardíaco obtidos por termodiluição e dopplerfluxometria transesofágica / Comparison between two methods for hemodynamic measurement: thermodilution and oesophageal doppler

OBJETIVO: A termodiluição (TD) é padrão de monitorização hemodinâmica. Alguns parâmetros hemodinâmicos podem ser medidos através do Doppler Transesofágico (DTE). Método simples, menos invasivo. Com o objetivo de avaliar a acurácia do DTE foram comparados TD e DTE na determinação de medidas de débito cardíaco (DC). MÉTODOS: Foram determinadas 192 medidas simultâneas, em diferentes situações clínicas em dez pacientes com idade entre 21 85 anos (cinco do gênero masculino e cinco do feminino), oito internados sépticos em uso de drogas vasoativas e dois monitorizados para laringectomia e transplante hepático; todas avaliadas ao longo de quatro horas, em intervalos de 30 minutos. Foram utilizados dois tipos de doppler: o DeltexR, e o ArrowR, introduzidos entre 35 e 45 cm da fossa nasal e localizados no ponto de maior diâmetro da aorta descendente. Na TD, foi utilizado cateter de artéria pulmonar (Swan Ganz BaxterR) e monitor DX-2001R, confirmado o posicionamento radiologicamente e através das curvas pressóricas geradas. As medidas do DC realizadas através da TD foram obtidas com soro fisiológico gelado, sendo considerada a média de quatro medidas não diferentes de 5 por cento. Foi aplicado o método estatístico de Bland e Altman, com utilização de gráfico de regressão linear. RESULTADOS: Não houve diferença estatisticamente significante entre esses dois métodos de medida hemodinâmica, com coeficiente de correlação de 0,88 para o DC (Doppler DeltexR X Swan Ganz BaxterR) e coeficiente de correlação de 0,99 DC (Doppler Arrow rR X Swan Ganz BaxterR) respectivamente, observando-se correlação. CONCLUSÃO: A medida das variáveis hemodinâmicas ao DTE foi obtida com facilidade nos dez pacientes estudados e revelou ter este dispositivo acurácia compatível à TD.

OBJECTIVES: Thermodilution (TD) is the "gold standard method" for hemodynamic monitoring. Some parameters can be measured by Oesophageal Doppler (OD), which is simpler and less invasive. To evaluate the accuracy of OD, we compared this method with TD in measurement of cardiac output (CO). METHODS: One hundred and ninety two simultaneous measurements were made in 10 patients (5 male and 5 female) with different clinical situations, 8 with sepsis using vasoactive drugs and 2 monitored for laryngectomy and liver transplantation. Measurements were taken during 4 hours at 30 minute intervals. The two oesophageal dopplers used DeltexR and ArrowR, were introduced between 35 and 45 cm from the nose and located at the point of largest diameter of the descending aorta. In TD, we used the pulmonary artery catheter (Swan Ganz BaxterR) and the DX- 2001 monitorR positioning was confirmed with support of radiology and of pressures curves. Measurements of CO carried out by means of TD were achieved using an iced saline solution considering the mean of four measurements with less than a 5 percent difference. The statistical method used was the Bland-Altman scatter plot and dispersion graphic. RESULTS: No statistically significant difference was found between the two methods for hemodyamic measurement with a correlation coefficient of 0.8 for CO (Deltex DopplerR and Baxter Swan GanzR) and a correlation coefficient of 0.99 for CO (Arrow DopplerR and Baxter Swan GanzR). CONCLUSION: Homodynamic measurements with OD have the same accuracy as those with TD and were easily obtained in the 10 patients.

Comparison between cardiac output values measured by thermodilution and partial carbon dioxide rebreathing in patients with acute lung injury

CONTEXTO: A termodiluição, considerada técnica padrão para medida do débito cardíaco em pacientes graves, não é isenta de riscos relevantes. Faz-se necessário encontrar métodos alternativos não invasivos, automáticos, simples e acurados para monitorar o débito cardíaco à beira do leito. OBJETIVO: Comparar as medidas do débito cardíaco obtido com os métodos termodiluição e reinalação parcial de gás carbônico em pacientes com lesão pulmonar aguda em dois níveis de gravidade (índice de lesão pulmonar - LIS abaixo de 2,5 grupo A; e acima de 2,5, grupo B). TIPO DO ESTUDO: Comparativo, prospectivo, controlado. LOCAL: Unidades de Terapia Intensiva de dois hospitais-escola. MÉTODOS: Vinte pacientes acometidos de insuficiência respiratória aguda (PaO2/FiO2 < 300), sob ventilação pulmonar artificial, nos quais foram realizadas 294 medidas, 164 medidas no grupo A (n = 11) e 130 no grupo B (n = 9),variando de 14 a 15 medidas por paciente, foram estudados. Débito cardíaco foi medido com termodiluição e reinalação parcial de gás carbônico. RESULTADOS: A correlação entre os métodos estudados foi fraca no grupos A (r = 0,52, p < 0,001*) e no B: r = 0,47, p < 0,001*). A aplicação do teste de Bland-Altman permitiu evidenciar a discordância entre os métodos (grupo A: -0,9 ± 2,71 l/min; IC 95% = - 1,14 a -0,48; e grupo B: -1,75 ± 2,05 l/min (IC 95% = -2,11 a -1,4). A comparação dos resultados (testes t para grupos emparelhados e Mann-Whitney) obtidos nos grupos e entre os grupos de estudo revelou diferenças ( p = 0,00*, p < 0,05). DISCUSSAO: Erros em estimar o CaCO2 (conteúdo arterial de CO2) através da ETCO2 (CO2 de final de corrente) e situações de circulação hiperdinâmica associados a espaço morto e/ou shunt possivelmente expliquem nossos resultados. CONCLUSAO: Em pacientes com lesão pulmonar aguda, o débito cardíaco determinado pela reinalação parcial de gás carbônico difere dos valores medidos com termodiluição. Esta diferença se acentua com a maior gravidade da lesão pulmonar.

Comparison between cardiac output values measured by thermodilution and partial carbon dioxide rebreathing in patients with acute lung injury.

CONTEXT: Thermodilution, which is considered to be a standard technique for measuring the cardiac output in critically ill patients, is not free from relevant risks. There is a need to find alternative, noninvasive, automatic, simple and accurate methods for monitoring cardiac output at the bedside. OBJECTIVE: To compare cardiac output measurements by thermodilution and partial carbon dioxide rebreathing in patients with acute lung injury at two levels of severity (lung injury score, LIS: below 2.5, group A; and above 2.5, group B). TYPE OF STUDY: Comparative, prospective and controlled study. SETTING: Intensive Care Units of two university hospitals. METHODS: Cardiac output was measured by thermodilution and partial carbon dioxide rebreathing. Twenty patients with acute lung failure (PaO2/FiO2 < 300) who were under mechanical ventilation and from whom 294 measurements were taken: 164 measurements in group A (n = 11) and 130 in group B (n = 9), ranging from 14 to 15 determinations per patient. RESULTS: There was a poor positive correlation between the methods studied for the patients from groups A (r = 0.52, p < 0.001) and B (r = 0.47, p < 0.001). The application of the Bland-Altman test made it possible to expose the lack of agreement between the methods (group A: -0.9 +/- 2.71 l/min; 95% CI = -1.14 to -0.48; and group B: -1.75 +/- 2.05 l/min; 95% CI = -2.11 to -1.4). The comparison of the results (Student t and Mann-Whitney tests) within each group and between the groups showed significant difference (p = 0.000, p < 0.05). DISCUSSION: Errors in estimating CaCO2 (arterial CO2 content) from ETCO2 (end-tidal CO2) and situations of hyperdynamic circulation associated with dead space and/or increased shunt possibly explain our results. CONCLUSION: Under the conditions of this study, the results obtained allow us to conclude that, in patients with acute lung injury, the cardiac output determined by partial rebreathing of CO2 differs from the measurements obtained by thermodilution. This difference becomes greater, the more critical the lung injury is.

Síndrome da angústia respiratória do adulto (S.A.R.A.): consideraçöes gerais; relato de caso / Acute respiratory distress syndrome (A.R.D.S.): general considerations; case report

Os autores descrevem de uma maneira suscienta o quadro de S.A.R.A., tecendo cosideraçöes gerais sobre a patologia, incluindo os fatores precipitantes e/ou desencadeantes, critérios diagnósticos e fisiopatológicos. Apresentam um caso típico da síndrome e comentam a evoluçäo clínica e laboratorial