Persistent spontaneous bacterial peritonitis: a common complication in patients with spontaneous bacterial peritonitis and a high score in the model for end-stage liver disease.

Objectives: Spontaneous bacterial peritonitis (SBP) is associated with a high mortality rate. After antibiotic therapy, improvement in fluid polymorphonuclear (PMN) cell count is expected within 2 days. However, our institution recognized cases unresponsive to standard treatment.

Methods: To study these recalcitrant cases, we completed a retrospective chart review of patients admitted for SBP to the University of Chicago from 2002 to 2007. SBP was defined by an ascitic PMN cell count ≥250/ml.

Results: Of 55 patients with SBP, 15 did not show improvement in fluid PMN cell count to below 250/ml with standard treatment, leading to a prevalence of 27%. The patients with persistent SBP were younger than those with nonpersistent SBP [mean (SD) 51.80 (9.84) compared with 58.13 (8.79); p = 0.0253]. Persistent SBP had a higher serum ascites albumin gradient (SAAG) [median (Q1, Q3) 1.85 (1.50, 2.41) compared with 1.10 (0.60, 1.60)] and a higher score in the model for end-stage liver disease (MELD) [mean (SD) 27.98 (8.09) compared with 22.22 (8.10)] than nonpersistent SBP patients; p = 0.027 and p = 0.023, respectively. In addition, persistent SBP patients were more likely to have a positive ascitic fluid culture than nonpersistent SBP patients [odds ratio (OR) (95% CI) 4.33 (1.21, 15.47); p = 0.024]. Importantly, in-hospital mortality in the persistent SBP group was 40%, compared with 22.5% in the nonpersistent SBP group [OR = 2.30 (0.64, 8.19); p = 0.20].

Conclusions: The risk of persistent SBP is nearly 40% in patients with MELD score >25, SAAG >1.5 or positive ascitic fluid culture. Furthermore, patients who develop persistent SBP tend to experience a higher mortality rate. This study underscores the importance of further examination of this vulnerable population.