The Incidence of Spontaneous Bacterial Peritonitis in Patients With Cirrhosis-Related Ascites Undergoing Elective Outpatient Large-Volume Paracentesis.

Background and aims Large-volume paracentesis (LVP) is a common practice for diuretic-refractory ascites in patients with cirrhosis. Spontaneous bacterial peritonitis (SBP) is reportedly low in asymptomatic patients presenting for elective outpatient LVP. The benefits and cost-effectiveness of routine testing for SBP in these patients are yet to be established. We aimed to investigate the incidence of SBP in outpatients who underwent elective LVP and the diagnostic yield of routine ascitic fluid testing, specifically fluid culture, and to assess the cost-effectiveness of these tests. Methods This is a retrospective study of adult patients undergoing outpatient LVP at Wollongong Hospital over three years. Symptomatic patients and patients with non-cirrhosis-related ascites were excluded. The ascitic fluid results were reviewed to determine if the polymorphonuclear (PMN) cell count was above 250 x 106 /L and whether this was associated with positive fluid culture and clinical outcomes. The primary outcome was the incidence of SBP. The secondary outcome was the incidence of bacterascites. Results There were 26 patients with 122 elective ascitic taps. Two of 122 taps (1.6%) had ascitic PMN count above 250 x 106 /L, indicating SBP. Four out of 122 taps (3.2%) had positive ascitic fluid cultures with a normal PMN count. All patients did not have significant clinical outcomes, did not receive antibiotic treatment, and remained asymptomatic over three years of follow-up. Conclusions Routine testing of ascitic fluid cell count and culture in asymptomatic patients with cirrhosis presenting for outpatient LVP yielded a low incidence of SBP and bacterascites, which were not clinically significant. Routine testing is costly and potentially exposes patients to antibiotics unnecessarily.