RESUMO
CONTEXT AND OBJECTIVE: Spontaneous bacterial peritonitis (SBP) is a frequent and severe complication of cirrhotic patients with ascites. It has been proposed that the reagent strip for leukocyte esterase designed for the testing of urine (Combur test UX) could be a useful tool for diagnosing SPB. The aim of this study was to assess the sensitivity and specificity of urine test strips for diagnosing SBP in cirrhotic patients with ascites. DESIGN AND SETTING: Prospective study, at a university hospital in northeastern Brazil. METHODS: Forty-two unselected consecutive cirrhotic patients (32 males; mean age: 51.7 +/- years) were included, and a total of 100 paracenteses were performed. All ascitic fluid samples were analyzed using the reagent strip and cytology, neutrophils, lymphocyte count, appropriate biochemical tests and culturing. The strips were considered positive if the color became purple on a colorimetric scale. RESULTS: Nine patients were diagnosed with SBP using cytology (> 250 neutrophils/mm(3)), and the strips were positive for all these nine patients with SBP. In one sample, the strip was positive but the neutrophil count was less than 250 cells/mm(3). For 86 samples, both the strips and cytology were negative. At the threshold of 250 neutrophils/mm(3) in ascitic fluid, the sensitivity, specificity, positive predictive value and negative predictive value for the strips were respectively 100%, 98.9%, 92.3% and 100%. CONCLUSION: The Combur test UX urine screening test is a very sensitive and specific method for diagnosing SBP in cirrhotic patients with ascites.
Assuntos
Infecções Bacterianas/diagnóstico , Cirrose Hepática/complicações , Peritonite/diagnóstico , Fitas Reagentes/normas , Ascite/complicações , Líquido Ascítico/enzimologia , Infecções Bacterianas/microbiologia , Técnicas Bacteriológicas , Brasil , Hidrolases de Éster Carboxílico/análise , Feminino , Humanos , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Paracentese , Peritonite/microbiologia , Estudos Prospectivos , Sensibilidade e EspecificidadeRESUMO
CONTEXT AND OBJECTIVE: Spontaneous bacterial peritonitis (SBP) is a frequent and severe complication of cirrhotic patients with ascites. It has been proposed that the reagent strip for leukocyte esterase designed for the testing of urine (Combur test® UX) could be a useful tool for diagnosing SPB. The aim of this study was to assess the sensitivity and specificity of urine test strips for diagnosing SBP in cirrhotic patients with ascites. DESIGN AND SETTING: Prospective study, at a university hospital in northeastern Brazil. METHODS: Forty-two unselected consecutive cirrhotic patients (32 males; mean age: 51.7 ± years) were included, and a total of 100 paracenteses were performed. All ascitic fluid samples were analyzed using the reagent strip and cytology, neutrophils, lymphocyte count, appropriate biochemical tests and culturing. The strips were considered positive if the color became purple on a colorimetric scale. RESULTS: Nine patients were diagnosed with SBP using cytology (> 250 neutrophils/mm³), and the strips were positive for all these nine patients with SBP. In one sample, the strip was positive but the neutrophil count was less than 250 cells/mm³. For 86 samples, both the strips and cytology were negative. At the threshold of 250 neutrophils/mm³ in ascitic fluid, the sensitivity, specificity, positive predictive value and negative predictive value for the strips were respectively 100 percent, 98.9 percent, 92.3 percent and 100 percent. CONCLUSION: The Combur test® UX urine screening test is a very sensitive and specific method for diagnosing SBP in cirrhotic patients with ascites.
CONTEXTO E OBJETIVO: Peritonite bacteriana espontânea (PBE) é uma freqüente e grave complicação em pacientes cirróticos com ascite. Vem sendo proposto o uso de fitas reagente para esterase leucocitária, utilizadas para diagnóstico de infecção urinária, como instrumento para diagnosticar PBE. O objetivo deste estudo é avaliar a sensibilidade e a especificidade da fita reagente Combur Test® UX no diagnóstico de PBE em pacientes cirróticos com ascite. TIPO DE ESTUDO E LOCAL: Estudo prospectivo, realizado no Hospital Universitário Walter Cantídio, Fortaleza, Ceará, Brasil. MÉTODOS: Quarenta e dois pacientes consecutivos, não selecionados (32 homens, com média de idade de 51,7 ± anos) foram incluídos e um total de 100 paracenteses foram realizadas. O líquido ascítico foi avaliado pela fita reagente (Combur Test® UX), citologia, contagem de neutrófilos, linfócitos, testes bioquímicos e cultura. As fitas reagentes foram consideradas positivas se havia mudança na cor para roxo na escala colorimétrica fornecida pelo fabricante. RESULTADOS: Foram diagnosticados nove pacientes com PBE pela citologia (> 250 neutrófilos/mm³), estando a fita Combur Test® UX positiva em todos os nove pacientes. Em uma amostra o teste da fita foi positivo, embora a contagem de neutrófilos fosse < 250 células/mm³. Nas outras 86 amostras ambos os testes foram negativos. Tendo-se como ponto de corte 250 PMN/mm³ no líquido ascítico, a sensibilidade, a especificidade, o valor preditivo positivo e o valor preditivo negativo foram respectivamente 100 por cento, 98,9 por cento, 92,3 por cento e 100 por cento. CONCLUSÕES: Combur Test® UX (fita reagente para urinanálise) é um método sensível e específico para o diagnóstico de PBE em pacientes cirróticos com ascite.