Objective: Spontaneous bacterial peritonitis (SBP) is one of the potentially life-threatening complications in ascitic cirrhotic patients with a mortality rate ranging between 30 and 50%. The improved survival might be explained by a more rapid diagnosis and treatment. The aim of our study was to assess the utility of two reagent strips, the Multistix test and the Combur(2) test LN, for the rapid diagnosis of SBP.
Methods: Thirty-one unselected consecutive cirrhotic patients with ascites were included and a total of 100 paracenteses were performed. All ascitic fluid was analysed with the two reagent strips, leucocyte and polymorphonuclear (PMN) leucocyte cell count and blood-bottle culture if the strips were positive. The strips were considered positive if the colour turned to purple: i.e. grade 3 or 4 for the Multistix test and 2 or 3 for the Combur(2) test LN on a colorimetric scale.
Results: We diagnosed nine infections of which four were SBP defined by PMN > or = 250 cells/mm(3) and a positive culture in ascitic fluid and five were culture negative neutrocytic ascites (PMN > or = 250 cells/mm(3) and a negative culture). The results of the two strips were concordant and were negative in only one SBP. The sensitivity, specificity, positive and negative predictive values of these two strips were 89%, 100%, 100% and 99%, respectively.
Conclusions: These reagent strips are very sensitive and specific for the diagnosis of SBP, allowing immediate commencement of empirical antibiotic therapy. These strips should be used for the diagnosis of SBP, especially on an emergency basis.