Aims: The standard diagnosis of spontaneous bacterial peritonitis (SBP) is an ascitic fluid polymorphonuclear (PMN) cell count of ≥ 250/mm3 and/or a positive ascitic fluid. However, result is usually not promptly available in the emergency situation. Automated cell count and reagent strip tests have been used for rapid diagnosis of urinary tract infection and meningitis. We evaluated their usefulness by testing the validity of automated cell count and various reagents strip tests for the diagnosis of SBP.
Materials & Methods:
Two hundred consecutive paracentesis in cirrhotic patients were performed. All ascitic fluid samples were analyzed with automated cell count and three reagent strips: Aution sticks, Combur 10. Test M and Multistix10SG. Manual cell count for PMN of ≥ 250/mm3 was referred as gold standard. The sensitivity,specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for the diagnosis of SBP by different techniques were compared.
SBP was diagnosed by manual cell counts in 24 specimens (12%). The sensitivity, specificity,PPV, NPV and accuracy of the 1+ cutoff scale of the strips were 88%, 93%, 62%, 96%, 92% for Aution sticks, 75%,93%, 60%, 97%, 91% for Multistix test, 88%, 92%, 58%, 98%, 91% for Combur test and 88%, 98%, 84%, 98%,97% for the automated cell count, respectively.
Automated cell count is as sensitive as many reagent strips for a rapid diagnosis of SBP.However, it provides better specificity, PPV , NPV and accuracy.