Teste de Valsalva ortostático no refluxo venoso / Upright Valsalva's test in venous reflux

OBJETIVO: Determinar se a modificação proposta pelos autores no teste de Valsalva proporcionou ganho de sensibilidade, especificidade e acurácia no diagnóstico do refluxo em relação ao teste realizado na posição supina, quando comparados com a flebografia, utilizada como padrão-ouro. MÉTODO: Cento e sessenta e um pacientes com insuficiência venosa crônica (C4, 5 ou 6E P A SDP P R ) foram examinados prospectivamente. Os pacientes foram submetidos à avaliação hemodinâmica, incluindo o teste de Valsalva supino padrão e o novo teste de Valsalva ortostático. A flebografia descendente foi utilizada como padrão-ouro, com a qual os testes foram comparados. Foi criada uma curva ROC (Receiver Operator Characteristic) para determinação do limite superior da normalidade do novo teste. Os valores obtidos para sensibilidade, especificidade e acurácia de cada um dos testes foram comparados entre si, utilizando o teste de comparação de porcentagens de Dunn. Foi adotado o nível de significância de 5 por cento. RESULTADOS: O teste de Valsalva supino padrão atingiu uma sensibilidade de 65 por cento, especificidade de 81 por cento e acurácia de 66 por cento, enquanto o teste de Valsalva ortostático atingiu uma sensibilidade de 80 por cento (P < 0,01), especificidade de 63 por cento (P = 0,43) e acurácia de 78 por cento (P < 0,05). CONCLUSÃO: A modificação no teste de Valsalva proposta pelos autores determinou melhor sensibilidade e acurácia, sem decréscimo significante na especificidade, provando ser útil na avaliação do refluxo da insuficiência venosa crônica.

OBJECTIVE: To test sensitivity, specificity and accuracy of the modified upright Valsalva's test described by the authors for diagnosing the reflux, when compared to phlebography, which is used as gold standard. METHOD: One hundred sixty one patients with chronic venous insufficiency (C4, 5 or 6E P A SDP P R) were prospectively examined. The patients were submitted to hemodynamic evaluation, including the standard supine Valsalva's test and the new modified upright Valsalva's test. Descending phlebography was used as a gold standard, to which the hemodynamic tests were compared. A ROC curve (Receiver Operator Characteristic) was plotted to determine the upper limit of normality for the new test. The observed sensitivity, specificity and accuracy values of each test were compared using Dunn's test. The significance level of 5 percent was adopted. RESULTS: The standard supine Valsalva's test reached a sensitivity of 65 percent, specificity of 81 percent and accuracy of 66 percent, whereas the upright Valsalva's test reached a sensitivity of 80 percent (P < 0.01), specificity of 63 percent (P = 0.43) and accuracy of 78 percent (P < 0.05). CONCLUSION: The modification in the Valsalva's test proposed by the authors seems to determine better sensitivity and accuracy without significant decrease in specificity, proving to be useful in reflux evaluation of chronic venous insufficiency.

Stimulation of lipid peroxidation in vitro in rat brain by the metabolites accumulating in maple syrup urine disease.

In this study we investigated the in vitro effects of the metabolites accumulating in maple syrup urine disease on lipid peroxidation in brain of young rats. Chemiluminescence and thiobarbituric acid-reactive substances were measured in brain homogenates from 7- and 30-day-old rats in the presence of 10 mM of the branched-chain amino acids L-leucine, L-isoleucine, or L-valine; their keto acids L-2-ketoisocaproic acid, L-2-keto-3-methylvaleric acid, or L-2-ketoisovaleric acid; or the hydroxy derivatives L-2-hydroxyisocaproic acid, L-2-hydroxy-3-methylvaleric acid, or L-2-hydroxyisovaleric acid separately added to the incubation medium. We observed that all amino acids, keto acids, and hydroxy acids accumulating in this disease stimulate to a variable degree the in vitro parameters of lipid peroxidation tested in homogenates of rat brain. The results indicate a possible participation of oxidative stress in the neuropathology of maple syrup urine disease patients, especially during a crisis, when the metabolites are highly increased, and point to the use of antioxidant drugs as a possible adjuvant therapy in such situations to improve the neurological status of the patients and to prevent sequelae.