Spontaneous Bacterial Peritonitis at University Hospitals of North Midlands NHS Trust: A Retrospective Study

Spontaneous bacterial peritonitis is an acute infection of ascitic fluid that is not related to an underlying intra-abdominal pathology.

This is a retrospective study of data on ascitic fluid samples taken during the period of January to December 2017 to assess the management of SBP patients and associated mortality. Kaplan-Meir method was used to estimate survival probability at 30 and 90 days. Cox proportional models were used to evaluate aetiology and causative organism in predicting mortality. Analyses were done using R: A language and environment for statistical computing.

Total of 53 patients were identified as having SBP based on ascitic fluid cultures. Sixteen of these also fulfilled the national criteria of ascitic neutrophil count of more than 250 or total cell count of more than 500.

Thirty-three (62.8%) samples grew pathogenic organisms. The most common pathogenic organisms were E coli (30.3%) followed by Enterococcus (21.2%) – in which four were ESBL tagged – Klebsiella (6%) and Staph Aureus (6%). In majority of the patients, the underlying aetiology of ascites was secondary to ALD (68.9%), Malignancy (11.8%) and NASH cirrhosis (11.8%). In this cohort, the overall 30-day survival was 64.2% and 90-day survival was 43.4%. About half mortality occurred during the same admission to hospital.

E coli was the most commonly isolated organism. Alcoholic Liver Disease was the most common underlying aetiology in SBP patients. SBP is associated with a high 30-day and 90-day mortality. Isolation of pathogenic organisms was associated with a four-fold higher mortality than non-pathogenic organisms.