Para determinar los intervalos de predicción del porcentaje de hemoglobina ligada a monóxido de carbono (CO-Hb) en los no fumadores y los fumadores pasivos y obtener una ecuación de la CO-Hb en ...función del número de cigarrillos fumados, estudiamos a 233 pacientes ambulantes enviados para gasometría arterial a un hospital universitario de un área urbana. No se incluyó a aquellos sujetos que estuviesen recibiendo cualquier modalidad de oxigenoterapia o hubiesen estado ingresados en los 2 meses previos. Se les clasificó en: a) no fumadores (57): b) fumadores pasivos (54); c) fumadores de < 11 cigarrillos (22); d) fumadores de 11-20 cigarrillos (41); e) fumadores de 21-40 cigarrillos (44), y f) fumadores de > 40 cigarrillos (15). A todos se les realizó un cuestionario sobre la exposición al humo del tabaco y a otras fuentes de CO, gasometría y cooximetría. La media de la CO-Hb en los no fumadores y los intervalos de predicción del 95% fueron del 1,53% (0,78-1,85%) y en los fumadores pasivos del 2,59% (1,89-3,29%). La relación lineal que mejor ajustaba, era: CO-Hb = 0,153 x número de cigarrillos + 1,1 exposición a otras fuentes (1 o 0) + 1,39 (0,84 DE)%. La Hb sanguínea fue significativamente mayor en los dos grupos de fumadores de > 21 cigarrillos que en los otros grupos. Concluimos que en los sujetos no fumadores, no expuestos a otras fuentes de CO, el límite superior del intervalo de predicción es del 1,9%. Los fumadores pasivos tienen concentraciones significativamente más altas de CO-Hb que los no fumadores, y los fumadores más intensos tienen policitemia.
To determine the carboxyhemoglobin (CO-Hb) predictive intervals in active and passive smokers and to obtain an equation expressing the relation of CO-Hb to number of cigarettes smoked, we studied 233 outpatients referred to an urban university hospital for arterial gas measurement. Patients were excluded if they were receiving oxygen therapy or had been hospitalized in the two months before the study. The patients were classified as non smokers (57), passive smokers (54), smokers of less than 11 cigarettes (22), smokers of 11 to 20 (41) smokers of 21 to 40 (44) and smokers of over 40 (15). All patients answered a questionnaire on exposure to tobacco smoke or other sources of CO. Blood gases and co-oximetry were measured in all patients. Mean CO-Hb and 95% confidence intervals were 1.53% (0.78-1.85%) in smokers and 2.59% (1.89-3.29%) in passive smokers. The linear equation that best expressed the relationship was CO-Hb = 0.153 x number of cigarettes + 1.1 exposure to other sources (1 or 0) + 1.39 (SD 0.84)%. Hemoglobin level was significantly higher in the two groups smoking more than 21 cigarettes. We conclude that the predictive intervals is 1.9% in non smokers who are not exposed to other sources of CO. Passive smokers have significantly higher levels of CO-Hb than non smokers. Heavy smokers have polycythemia.
Para analizar la utilidad de una forma de estimar la captación pico de oxígeno postoperatoria basada en la función ventilatoria perdida tras resección pulmonar (V.O2pico-PPO) y establecer las razones ...fisiológicas subyacentes a la relaciön entre ésta y el valor medido postoperatorio (V.O2pico-PO), estudiamos a 29 pacientes (26 varones) de 60 años (DE, 9), con limitación crónica al flujo aéreo, FEV1 = 66% (DE, 13), sometidos a lobectomía o mayor resección pulmonar por cáncer de pulmón. Los pacientes se dividieron en 2 grupos: aquellos cuya ergometría postoperatoria se consideró limitada por el agotamiento de la reserva ventilatoria (LV) y los demás (NLV). Una semana antes de la cirugía se evaluó la disnea y se realizaron pruebas de función ventilatoria, ergometría en tapiz rodante y gammagrafia de perfusión para estimar la función postoperatoria. Las mismas mediciones se repitieron aproximadamente 5 meses después de la cirugía, salvo la gammagrafía. La diferencia media entre V.O2pico-PPO y V.O2pico-PO fue de –0,034 (IC: 0,293 a 0,348) l/min-1 y el coeficiente de correlación intraclase de 0,76. La correlación entre V.O2pico-PPO y la disnea postoperatoria fue de –0,72. La correlación entre V.O2pico-PPO y V.O2pico-PO fue de 0,86 (EE, 0,1) (0,89 0,13 para los LV n = 14 y 0,85 0,16 para los NLV n = 15). Las correlaciones tras ajustar para la V.O2pico preoperatoria fueron 0,73 (0,2) en los LV y 0,35 (0,27) en los NLV. Concluimos que el V.O2pico-PPO es un estimador válido pero sólo moderadamente preciso del V.O2pico-PO. Únicamente en los pacientes con LV existe una verdadera relación entre la reducción del V.O2pico y la pérdida de función ventilatoria.
To assess the usefulness of a method for predicting postoperative peak oxygen uptake based on lost lung function after lung resection (V.O2peak-PPO) and to establish the underlying physiological foundation for the relation between V.O2peak-PPO and the measured postoperative value (V.O2peak-PO), we studied 29 patients (26 men) age 60 (SD9) with chronic airflow limitation FEV1 = 66 (SD13) % undergoing lobectomy or major pulmonary resection to treat lung cancer. The patients were assigned to groups according to whether postoperative exercise tolerance was considered to be limited by exhaustion of ventilatory reserve (LV) or not (NLV). Data to estimate postoperative pulmonary function was obtained one week before surgery: patients performed pulmonary function tests and exercise tests on a treadmill; dyspnea was also evaluated and perfusion scintigraphs were obtained. Pulmonary function, exercise tolerance and dyspnea were evaluated again approximately five months after surgery. The mean difference between V.O2peak-PPO and V.O2peak-PO was –0.034 (CI 0.293 to –0.348) l.min-1 and the between-group correlation coefficient was 0.76. The correlation between V.O2peak-PPO and V.O2peak-PO was 0.86 (SE 0.1) 0.89 (SE 0.13) for LV (n=14) patients and 0.85 (SE 0.16) for NLV (n=15) patients. The correlations after adjusting for preoperative V.O2peak-PPO were 0.73 (SE 0.2) and 0.35 (SE 0.27) for LV and NLV patients, respectively. We conclude that V.O2peak-PPO provides a valid but only moderately precise estimate of V.O2peak-PO. Only in LV patients is there a true relation between a decrease in V.O2peak and loss of lung function.
To determine the carboxyhemoglobin (CO-Hb) predictive intervals in active and passive smokers and to obtain an equation expressing the relation of CO-Hb to number of cigarettes smoked, we studied 233 ...outpatients referred to an urban university hospital for arterial gas measurement. Patients were excluded if they were receiving oxygen therapy or had been hospitalized in the two months before the study. The patients were classified as non smokers (57), passive smokers (54), smokers of less than 11 cigarettes (22), smokers of 11 to 20 (41) smokers of 21 to 40 (44) and smokers of over 40 (15). All patients answered a questionnaire on exposure to tobacco smoke or other sources of CO. Blood gases and co-oximetry were measured in all patients. Mean CO-Hb and 95% confidence intervals were 1.53% (0.78-1.85%) in smokers and 2.59% (1.89-3.29%) in passive smokers. The linear equation that best expressed the relationship was CO-Hb = 0.153 x number of cigarettes + 1.1 exposure to other sources (1 or 0) + 1.39 (SD 0.84)%. Hemoglobin level was significantly higher in the two groups smoking more than 21 cigarettes. We conclude that the predictive intervals is 1.9% in non smokers who are not exposed to other sources of CO. Passive smokers have significantly higher levels of CO-Hb than non smokers. Heavy smokers have polycythemia.
To assess the usefulness of a method for predicting postoperative peak oxygen uptake based on lost lung function after lung resection (VO2peak-PPO) and to establish the underlying physiological ...foundation for the relation between VO2peak-PPO and the measured postoperative value VO2peak-PO), we studied 29 patients (26 men) age 60 (SD9) with chronic airflow limitation FEV1 = 66 (SD13)% undergoing lobectomy or major pulmonary resection to treat lung cancer. The patients were assigned to groups according to whether postoperative exercise tolerance was considered to be limited by exhaustion of ventilatory reserve (LV) or not (NLV). Data to estimate postoperative pulmonary function was obtained one week before surgery: patients performed pulmonary function tests and exercise tests on a treadmill; dyspnea was also evaluated and perfusion scintigraphs were obtained. Pulmonary function, exercise tolerance and dyspnea were evaluated again approximately five months after surgery. The mean difference between VO2peak-PPO and VO2peak-PO was -0.034 (CI 0.293 to -0.348) l.min-1 and the between-group correlation coefficient was 0.76. The correlation between VO2peak-PPO and VO2peak-PO was 0.86 (SE 0.1) 0.89 (SE 0.13) for LV (n = 14) patients and 0.85 (SE 0.16) for NLV (n = 15) patients. The correlations after adjusting for preoperative VO2peak-PPO were 0.73 (SE 0.2) and 0.35 (SE 0.27) for LV and NLV patients, respectively. We conclude that VO2peak-PPO provides a valid but only moderately precise estimate of VO2peak-PO. Only in LV patients is there a true relation between a decrease in VO2peak and loss of lung function.
We sought to determine if predicted post-operative maximal oxygen uptake (VO2max/kg-PPO) was associated to the occurrence of respiratory or cardiac failure within the 60 days following lung surgery ...and to evaluate its validity as operability criterion. We studied 47 patients with chronic air-flow limitation (COPD) with FEV1 > 0.8 1 and without hypercapnia, that underwent lung surgery. Age was 56 (SD 11) years, FEV1 = 1.8 (SD 0.5) 1 (61% predicted (SD 13%) and FEV1/FVC = 55 (SD 7.5). Ten patients presented serious cardiac or respiratory complications (3 died). Significant correlation with complications was found for RV, TL-COsb-PPO, VO2max/kg, resection size and VO2max/kg-PPO. VO2max/kg-PPO correlation (-0.73) was significantly higher (p = 0.0016) than all the pulmonary function test (PFT) correlation and than VO2max/kg correlation (p = 0.049) as well. Cut-off points, positive and negative predictive values were respectively: 12.6 ml/min/kg, 0.75 y 0.90% for VO2max/kg-PPO; 17 ml/min/kg 0.83 and 0.87 for VO2max/kg and 148%, 0.67 and 0.82 for RV (the best of the pulmonary function tests). Multivariable models did not improve discriminant power. We conclude that, out of the studied variables, VO2max/kg-PPO showed higher correlation with the complications sought than PFT or VO2max/kg. As criterion to predict cardiac or respiratory failure, with the observed prevalence, its negative predictive values is good, but its positive predictive value is relatively low. None parameter was able to predict all the complications.
Nos planteamos determinar si la captación máxima de oxígeno estimado postoperatoria (VO2max/kg-PPO) se relaciona con la insuficiencia cardiorrespiratoria postoperatoria inmediata (60 días) tras ...cirugía de tórax y evaluar su validez como criterio de operabilidad. Estudiamos 47 pacientes con limitación crónica al flujo aéreo, FEV1 estimado postoperatorio > 0,8 1 y sin hipercapnia preoperatoria, sometidos a resección pulmonar por cáncer de pulmón. La edad fue 56 años (DE=11), FEV1=1,8 1 (DE=0,5), (61% DE=13) y FEV1/FVC=55% (DE=7,5). Diez pacientes presentaron insuficiencia respiratoria o cardíaca (tres murieron). El RV, TLCOsb-PPO, VO2max/kg, tamaño de resección y VO2max/kg-PPO mostraron correlación significativa con la aparición de complicaciones. VO2max/kg-PPO tenía una correlación (-0,73), significativamente mejor (p=0,0016) que las pruebas funcionales (PFB) y que VO2max/kg (p=0,049). Los puntos de corte y valores predictivos positivos y negativos fueron, respectivamente, 12,6ml/min/kg, 0,75 y 0,9 para VO2max/kg-PPO; 17 m1/min/kg 0,83 y 0,87 para el VO2max/kg y 148%, 0,67 y 0,82 para RV (la mejor de las pruebas funcionales). Los modelos multivariables no incrementaron el poder discriminativo. Concluimos que, de las variables estudiadas, VO2max/kg-PPO presentaba una correlación significativamente mayor que las PFB y que el VO2max/kg con la aparición de insuficiencia cardiorrespiratoria en los primeros 60 días postoperatorios. Como criterio para predecir dichas complicaciones, con la prevalencia observada, su valor predictivo negativo fue bueno, pero el valor predictivo positivo fue relativamente bajo. Ningún otro parámetro se comportó mejor.
We sought to determine if predicted post-operative maxi-mal oxygen uptake (VO2max/kg-PPO) was associated to the occurrence of respiratory or cardiac failure within the 60 days following lung surgery and to evaluate its validity as operability criterion. We studied 47 patients with chronic air-flow limitation (COPD) with FEV1> 0.8 1 and without hypercapnia, that underwent lung surgery. Age was 56 (SD 11) years, FEV1=1.8 (SD 0.5) 1 (61% predicted (SD 13%) and FEV1/FVC=55 (SD 7.5). Ten patients presented serious cardiac or repiratory complications (3 died). Significant correlation with complications was found for RV, TL-COsb-PPO, VO2max/kg, resection size and VO2max/kg-PPO. VO2max/kg-PPO correlation (-0.73) was significantly higher (p=0.0016) than all the pulmonary function test (PFT) correlation and than VO2max/kg correlation (p=0.049) as well. Cut-off points, positive and negative predictive values were respectively: 12.6ml/min/kg, 0.75 y 0.90% for VO2max/kg-PPO; 17ml/min/kg 0.83 and 0.87 for VO2max/kg and 148%, 0.67 and 0.82 for RV (the best of the pulmonary function tests). Multivariable models did not improve discriminant power. We conclude that, out of the studied variables, VO2max/kg-PPO showed higher correlation with the complications sought than PFT or VO2max/kg. As criterion to predict cardiac or respiratory failure, with the observed prevalence, its negative predictive values is good, but its positive predictive value is relatively low. None parameter was able to predict all the complications.
New Findings
•
What is the central question of this study?
We explored whether experimental cancer‐induced cachexia may alter mitochondrial respiratory chain (MRC) complexes and oxygen uptake in ...respiratory and peripheral muscles, and whether signalling pathways, proteasome and oxidative stress influence that process.
•
What is the main finding and what is its importance?
In cancer cachectic mice, MRC complexes and oxygen consumption were decreased in the diaphragm and gastrocnemius. Blockade of nuclear factor‐κB and mitogen‐activated protein kinase actions partly restored the muscle mass and force and corrected the MRC dysfunction, while concomitantly reducing tumour burden. Antioxidants improved mitochondrial oxygen consumption without eliciting effects on the loss of muscle mass and force or the tumour size, whereas bortezomib reduced tumour burden without influencing muscle mass and strength or MRC function.
Abnormalities in mitochondrial content, morphology and function have been reported in several muscle‐wasting conditions. We specifically explored whether experimental cancer‐induced cachexia may alter mitochondrial respiratory chain (MRC) complexes and oxygen uptake in respiratory and peripheral muscles, and whether signalling pathways, proteasomes and oxidative stress may influence that process. We evaluated complex I, II and IV enzyme activities (specific activity assays) and MRC oxygen consumption (polarographic measurements) in diaphragm and gastrocnemius of cachectic mice bearing the LP07 lung tumour, with and without treatment with N‐acetylcysteine, bortezomib and nuclear factor‐κB (sulfasalazine) and mitogen‐activated protein kinases (MAPK, U0126) inhibitors (n= 10 per group for all groups). Whole‐body and muscle weights and limb muscle force were also assessed in all rodents at baseline and after 1 month. Compared with control animals, cancer cachectic mice showed a significant reduction in body weight gain, smaller sizes of the diaphragm and gastrocnemius, lower muscle strength, decreased activity of complexes I, II and IV and decreased oxygen consumption in both muscles. Blockade of nuclear factor‐κB and MAPK actions restored muscle mass and force and corrected the MRC dysfunction in both muscles, while partly reducing tumour burden. Antioxidants improved mitochondrial oxygen uptake without eliciting significant effects on the loss of muscle mass and force or tumour size, whereas the proteasome inhibitor reduced tumour burden without significantly influencing muscle mass and strength or mitochondrial function. In conclusion, nuclear factor‐κB and MAPK signalling pathways modulate muscle mass and performance and MRC function of respiratory and limb muscles in this model of experimental cancer cachexia, thus offering targets for therapeutic intervention.
Dyspnea as the only symptom in a Krukenberg tumor Arnedillo Muñoz, A; Rodríguez De Guzmán, M C; Puente Maestu, L ...
Anales de medicina interna (Madrid, Spain : 1984)
13, Številka:
11
Journal Article
A elaboração deste documento pelo grupo de trabalho da European Respiratory Society tem como objectivo apresentar as recomendações sobre o uso clínico dos testes de exercício em doentes com patologia ...cardiorrespiratória, dando particular ênfase à avaliação funcional, à avaliação do prognóstico e à avaliação das intervenções terapêuticas.
A intolerância ao esforço físico é um dos sintomas mais frequentes, condicionando a perda de qualidade de vida do doente com patologia cardiorrespiratória crónica. Pode definir-se “intolerância ao exercício” numa perspectiva clínica à incapacidade que o doente apresenta para realizar tarefas que os indivíduos saudáveis considerariam toleráveis.
A intolerância ao exercício, considerada em termos do pico de consumo de oxigénio atingido no esforço máximo (V’O2pico) não pode ser prevista por parâmetros avaliados em repouso, como o volume expiratório máximo no primeiro segundo (FEV 1), a transferência alvéolo-capilar do monóxido de carbono (DLCO), a fracção de ejecção do ventrículo esquerdo ou o índice de massa corporal (IMC). A avaliação em exercício impõe alguns desafios técnicos: a aplicação de protocolos específicos de incremento de carga de forma precisa e reprodutível, com o recurso habitual a ergómetros, tais como a bicicleta ergométrica e o tapete rolante.
A prova de exercício cardiorrespiratória (CPET) é considerada o gold standard na avaliação das causas de intolerância ao exercício em doentes com doença cardíaca e pulmonar e é baseado no princípio de que a falência do sistema ocorre tipicamente quando o sistema (seja ele músculo-energético, cardiovascular ou pulmonar) se encontra sob stress. A CPET compreende a imposição de um exercício com cargas crescentes (ou seja, incremental) limitado por sintomas, enquanto se monitorizam as variáveis cardiopulmonares (exemplo: consumo de oxigénio (V’O2), produção de dióxido de carbono (V’CO2), ventilação minuto (V’E), frequência cardíaca (fC)), a percepção de sintomas (exemplo: a dispneia e o desconforto nos membros inferiores) e, quando necessárias, as avaliações da dessaturação arterial do oxigénio relacionada com o esforço, da hiperinsuflação dinâmica e da força muscular dos membros. Os sistemas são forçados até ao seu limite tolerável, de forma controlada, o que permite detectar respostas que identificam padrões de alteração e que podem ser relacionadas com padrões de referência previamente estudados e publicados pelas sociedades respiratórias europeia e americanas 1‒3.
Neste documento, é descrito o papel da CPET como auxiliar no diagnóstico e na avaliação funcional e prognóstica. A CPET pode:
– Fornecer uma medição objectiva da capacidade para o exercício;
– Identificar os mecanismos que limitam a tolerância ao exercício;
– Estabelecer índices de prognóstico;
– Monitorizar a progressão da doença e a resposta às intervenções terapêuticas.
– Auxiliar no diagnóstico, em situações de broncoconstrição induzida pelo exercício e de dessaturação arterial do oxigénio.
Na identificação das causas de intolerância ao exercício, a CPET pode detectar:
– Alterações na entrega de oxigénio (desde a sua entrada nas vias aéreas, passando pelo sistema de transporte cardiocirculatório, até à entrega às mitocôndrias das fibras musculares);
– Limitação ventilatória no exercício;
– Alteração do controlo ventilatório;
– Alteração das trocas gasosas pulmonares;
– Percepção excessiva de sintomas (exemplos: dispneia, precordialgia, fadiga muscular periférica);
– Disfunção metabólica muscular;
– Descondicionamento;
– Fraco esforço dispendido.
Com um bom esforço realizado, se o valor do pico do consumo de oxigénio atingido foi normal e o motivo para parar a prova foi dispneia ou fadiga muscular, então pode considerar-se que o indivíduo estudado tem uma normal tolerância ao exercício. Este cenário irá excluir doença pulmonar (DPOC, doença intersticial pulmonar, doença vascular pulmonar) ou cardíaca (insuficiência cardíaca congestiva) significativas como causa de intolerância.
A prova de exercício cardiopulmonar pode auxiliar no diagnóstico diferencial entre limitação no esforço de origem pulmonar ou cardiocirculatória. Pode fornecer um perfil de respostas que caracterizam determinadas doenças; exemplo: na DPOC são frequentes a limitação ventilatória, a hiperinsuflação dinâmica, a dessaturação arterial com o exercício, a dispneia, a disfunção dos músculos periféricos; na doença intersticial pulmonar são frequentes a dispneia, a restrição ventilatória mecânica e as alterações graves das trocas gasosas. Outros padrões de respostas podem ser encontrados na broncoconstrição induzida pelo exercício, na doença vascular pulmonar, na insuficiência cardíaca e em cardiopatias congénitas. A avaliação cardiorrespiratória no exercício fornece ainda indicadores prognósticos em várias doenças. Descrevem-se neste documento vários trabalhos que estudaram os parâmetros indicadores de prognóstico em doenças como a DPOC, a doença intersticial pulmonar, a hipertensão pulmonar primária, a fibrose quística e a insuficiência cardíaca.
Este documento demonstra ainda a utilidade dos testes de exercício na definição das respostas às intervenções terapêuticas, em avaliações seriadas.
O grupo de trabalho envolvido neste documento considerou importante apresentar as indicações baseadas na evidência para a realização dos testes de exercício na prática clínica. A evidência actual é clara quanto à utilidade da prova de exercício cardiopulmonar, das provas de marcha e das provas de carga constante na avaliação do grau de intolerância ao exercício, do prognóstico e dos efeitos das intervenções terapêuticas em doentes adultos com doença pulmonar crónica (DPOC, doença intersticial pulmonar, hipertensão pulmonar primária), em crianças e adultos com fibrose quística, em crianças e adultos com broncospasmo induzido pelo exercício, em adultos com insuficiência cardíaca congestiva e em crianças e adolescentes com cardiopatias congénitas.
Na elaboração deste documento, os autores pretenderam fornecer as respostas às perguntas que se colocam com frequência na prática clínica:
– Quando se deve pedir uma avaliação da intolerância ao esforço?
– Qual o teste mais adequado?
– Quais as variáveis a seleccionar na avaliação do prognóstico de determinada doença ou na avaliação do efeito de uma intervenção terapêutica particular?
O documento contém ainda um suplemento que pode ser obtido on-line e que descreve as bases fisiológicas subjacentes aos parâmetros avaliados nas provas de exercício cardiopulmonar.
We report 4 cases of idiopathic bronchiolitis obliterans with organizing pneumonia. With this motive, we asses the clinical and radiologic features, lung function tests and response to treatment of ...our cases. Our findings, in general, are coincident with other authors. It's an entity with nonspecific respiratory symptoms that one must suspect in presence of alveolar patchy opacities on chest roentgenogram that do not respond to antibiotics. The diagnosis is based on histopathologic findings with lung biopsy and the treatment on corticosteroids, with favorable evolution in the majority of the cases.
PDF
