Review article: the utility of reagent strips in the diagnosis of infected ascites in cirrhotic patients

Abstract

Spontaneous bacterial peritonitis (SBP) can be diagnosed via leucocyte esterase reagent strips, although diagnostic performances vary. To perform critical review of literature on the use of reagent strips in SBP. Nineteen studies were analysed (Medline search), comparing reagent strips in cirrhotic ascites vs. cytobacteriological methods. Diagnostic grades (G) were: GO = 0 leucocytes/mm3; G1 = 15; G2 = 70; G3 = 125; G4 = 500 for Multistix, GO = 0; G1 = 25; G2 = 75; G3 = 500 for Nephur, Combur, UriScan, and GO = 0; G1 = 25; G2 = 75; G3 = 250; G4 = 500 for Aution. Medians per study were: 75 patients (range: 31-1041), 136 ascites (47-2123), 17 SBP (5-117). For Multistix (12 studies), the sensitivities fell within the ranges 64.7-100% (G > or = 1), 45.7-83% (G > or = 2) and 45.3-89% (G > or = 3). For Nephur (n = 2), Combur (n = 6), UriScan (n = 1), sensitivities ranged 80.4-100% (G > or = 1), 63-100% (G > or = 2) and 67.7-97% (G > or = 3). For Aution (n = 3), sensitivities ranged 93-96% (G > or = 2) and 89% (G > or = 3). Nephur, Combur, UriScan displayed higher sensitivities than Multistix. However, in larger studies, sensitivities dramatically fell at 45.3% for Multistix (G > or = 3) if ascites polymorphonuclear count <1000/mm3 and 22.2% for bacterascites or 16.7-25% for asymptomatic patients. Use of reagent strips for the diagnosis of SBP cannot be recommended, in view of low sensitivity and a high risk of false negatives, especially in patients with SBP and low polymorphonuclear count.