Emergence of Gram-Positive Organisms Causing Spontaneous Bacterial Peritonitis (SBP) and Proton Pump Inhibitor (PPI)-Induced Increased Mortality

Introduction: Spontaneous bacterial peritonitis (SBP) is an infection of the ascitic fluid in patients with cirrhosis without a secondary intra-abdominal source. SBP is defined as an absolute polymorphonuclear leucocyte count ≥ 250 cells/mm3 or positive fluid culture. This study was done to determine the effects on how current therapies (antibiotics PPIs, and nonselective beta blockers (NSBB) affect the bacteria recovered and mortality in SBP. Methods: This is an IRB approved 18-year retrospective study from 2000 to 2017 conducted at the VA Loma Linda Healthcare system of veterans both inpatients and outpatients for treatment of SBP. Patients were selected using ICD code 9 and CPT Code 10. Patients were ≥ 18 years of age, with a diagnosis of SBP, culture negative neutrophilic ascites (CNNA), monomicrobial non-neutrocytic bacterascites (MNB) polymicrobial bacterascites (PMBA) and spontaneous fungal peritonitis (SFP). Secondary bacterial peritonitis was excluded. Medications used at the time of admission were collected and include PPI, nonselective beta blockers (NSBB), and antibiotics. Results: Fifty-two patients were collected with 72 episodes of SBP. Average age was 59, of which 96% were male. The etiology was 35% alcohol, and 56% hepatitis C infection. Twelve percent of patients had hepatocellular carcinoma, 60% had varices, and 11.5% had hepatic encephalopathy. MELD score averaged 21, with number of Child Pugh B patients of 23% and Child C patients of 77%. Forty-six percent of patients were taking PPIs, and 24% were on NSBB. Patients were treated with either Cefotaxime or Ceftriaxone. Organisms isolated from ascites fluid is listed in Table-1. Conclusion: More gram-positive organisms appear to be causing SBP with streptococcal species predominant. This contradicts the established cause of SBP as being gram negative organisms. We postulate that this change could be related to prior antibiotic use and PPIs. PPI use in SBP was also associated with increased statistically significant mortality (P=0.007), likely due to acid suppression altering gastrointestinal bacterial flora.Table 1.: Changes in reimbursements by Medicare for colonoscopy CPT codes from 2018 to 2021