Aim of study: Spontaneous bacterial peritonitis (SBP) is the most frequent infectious complication of liver cirrhosis with serious consequences. Initially, SBP is always treated with empirical, not targeted, antibiotic therapy. Since a retrospective study performed in our department showed suboptimal effectiveness (only 40 %) of empirical antibiotic therapy in accordance with the EASL guidelines, a decision was made to change the protocol. The aims of this prospective study were to determine: (1) the incidence and characteristics of SBP in real clinical practice - in a liver unit of a tertiary hospital, (2) the effectiveness of new antibiotic therapy selected based on analysis of the spectrum of pathogens and their resistance to antibiotics as identified in a retrospective cohort study on SBP carried out in our department, (3) mortality, and to compare these findings with the literature data.
Material and methods: A prospective cohort observational pragmatic study.
Setting: Department of Hepatology, Gastroenterology and Liver Transplantation, 2nd Internal Clinic, Slovak Medical University and F. D. Roosevelt Teaching Hospital with Polyclinic in Banska Bystrica. Time interval: November 2012-August 2013.
Inclusion criteria: hospitalization for liver cirrhosis, ascites ≥ grade 2, informed consent. The study was approved by the local ethics committee.
Exclusion criteria: malignancy, secondary bacterial peritonitis.
Diagnosis: SBP was defined by the count of neutrophil leukocytes in ascites ≥ 250/mm3). Positive ascitic fluid culture was not a necessary condition for the diagnosis. From each patient, 10 mL of ascitic fluid were sampled into two blood culture bottles, anaerobic and aerobic. Therapeutic response: defined as a decrease in NeA to 25 % of the baseline value after 48-72 hours, in accordance with the EASL guidelines. The absence of response was indication for change of the antibiotic therapy strategy. Empirical antibiotic therapy: The drug of choice was piperacillin/tazobactam 4 g/0.5 g i.v. every 8 hours for 5 days. Additionally, 20% human albumin at doses of 1.5 g/kg of patient weight on day 1 and 1.0 g/kg of patient weight on day 3 from the diagnosis was administered. If there was no response, (a) second choice antibiotic therapy according to analysis of the spectrum of pathogens and their resistance as identified in the former retrospective study on SBP, that is, ertapenem 1g i.v. every 24 hours for 5 days, or (b) targeted antibiotic therapy according to analysis of ascitic fluid culture performed in the meantime was initiated.
Results: The inclusion criteria were met by 65 patients (99 episodes); the incidence of SBP was 9 out of 99 episodes (9.1 %); 5 out of the 9 cases had positive bacterial culture (56 %), with most of bacteria being Gram-positive (4 out of 5 cases, 89 %). Therapeutic response was documented in 7 out of the 9 cases (78 %). The in-hospital mortality of patients with SBP was 11 %.
Conclusions: SBP was detected in one out of ten patients with cirrhotic ascites. The selection of empirical therapy in accordance with the principles of antibiotic stewardship led to an increase in therapeutic response to more than 75 %. Effective treatment of SBP is a prerequisite for reduction of mortality.