Therapeutic strategies and emergence of multiresistant bacterial strains

Spontaneous bacterial peritonitis (SBP) is one of the most serious complications occurring in cirrhotic patients with ascites. Therefore, an effective therapy is always required starting immediately after diagnosis. There are three aims of therapy: (1) to eradicate the bacterial strain responsible of the infection; (2) to prevent renal failure; and (3) to prevent SBP recurrence. The first end point is achievable by means of a large-spectrum antibiotic therapy. Empirical antibiotic therapy can be started with a third-generation cephalosporin, amoxicillin–clavulanate or a quinolone. The effectiveness of antibiotics should be verified by determining the percent reduction of polymorphonuclear cells count in the ascitic fluid. If bacteria result to be resistant to the empirical therapy, a further antibiotic must be given according to the in vitro bacterial susceptibility. In most cases, a 5-day antibiotic therapy is enough to eradicate the bacterial strain. Severe renal failure occurs in about 30% of patients with SBP, independently of the response to antibiotics, and it is associated with elevated mortality. The early administration of large amount of human albumin showed to be able to reduce the episodes of renal failure and to improve survival. After the resolution of an episode of SBP, the recurrence is frequent. Therefore, an intestinal decontamination with oral norfloxacin has been shown to significantly reduce this risk and is widely practised. However, such a long-term prophylaxis, as well as the current increased use of invasive procedures, favours the increase of bacterial infections, including SBP, contracted during the hospitalization (nosocomial infections) and sustained by multi-resistant bacteria. This involves the necessity to use a different strategy of antibiotic prophylaxis as well as a more strict surveillance of patients at risk.