Efficacy of leukocyte esterase dipstick test as a rapid test in diagnosis of spontaneous bacterial peritonitis.

Aim: To evaluate the efficacy of dipstick test in diagnosis of spontaneous bacterial peritonitis (SBP) in cirrhotic patients who underwent abdominal paracentesis based on the locally available dipstick test.

Methods: There were 200 consecutive samples from cirrhotic patients who underwent abdominal paracentesis. Urine dipstick (Combur10 TestM, Roche, Mannheim, Germany) was used as a screening test. A manual cell count with differential study was done in all samples by experienced technicians. The polymorphonuclear (PMN) cell count more than 250 cells/mm3 was used as a diagnostic cut off level. One to three plus dipstick results were used as cut off levels for a positive result. The dipstick test results had to be agreed by three experienced readers. The sensitivity, specificity, positive and negative predictive values and accuracy of two different colorimetric cut off scales (1+ and 2+) were calculated and compared.

Results: The prevalence of SBP diagnosed by manual cell count was 21.0%. There were 128 specimens that had a true negative result by dipstick. The sensitivity, specificity, positive and negative predictive values and accuracy of 1+ and 2+ cut off scale to diagnose SBP were 88%, 81%, 55%, 96% and 83% respectively, and 63%, 96%, 82%, 81% and 89% respectively.

Conclusion: Dipstick test can be used as a rapid test for screening of SBP. The higher cut off colorimetric scale has a better specificity and positive predictive value but a lower sensitivity.