Evaluation of Reagent Strips for Ascitic Fluid Leukocyte Determination: Is It a Possible Alternative for Spontaneous Bacterial Peritonitis Rapid Diagnosis?

In order to evaluate the accuracy of a urine reagent dipstick (Multistix 10SG®) to determine ascitic fluid leukocyte count, we prospectively studied 106 cirrhotic patients from April 2003 to December 2004, in two different centers (Federal University of São Paulo – UNIFESP-EPM and Federal University of Juiz de Fora – HU-UFJF) for the rapid bedside diagnosis of spontaneous bacterial peritonitis. The mean age 54 ± 12 years, there was a predominance of males (eighty-two patients, 77%), and alcohol was the most frequent etiology (43%). Forty-four percent of patients were classified as Child B and fifty-one as Child C (51%). Abdominal paracentesis was performed both in outpatient and inpatient settings and the Multistix 10SG ® was tested. Eleven cases of spontaneous bacterial peritonitis were identified by means of polymorphonuclear count. If we considered the positive Multistix 10SG ® result of 3 or more, the sensitivity, specificity, positive and negative predictive value were respectively 71%, 99%, 91 % and 98%. With a positive reagent strip result taken as grade 2 (traces) or more, sensitivity was 86 % and specificity was 96 % with positive and negative predictive values of 60 % and 99%, respectively. Diagnostic accuracy was 95%. We concluded that the use of a urine reagent dipstick (Multistix 10SG®) could be considered a quick, easy and cheap method for ascitic fluid cellularity determination in SBP diagnosis. Key-Words: Ascitic fluid, rapid diagnosis, dipstick, bacterial peritonitis