A. Girbau

Risk factors for resistance to ceftriaxone and its impact on mortality in community, healthcare and nosocomial spontaneous bacterial peritonitis

BACKGROUND & AIMS The recent emergence of third-generation cephalosporin resistance in spontaneous bacterial peritonitis is of great concern, although neither the risk factors for resistance nor its real impact on mortality have been well defined. METHODS We conducted a retrospective study of all spontaneous bacterial peritonitis episodes with positive blood and/or ascitic culture at our center (2001-2009). Episodes were classified according to the place of acquisition: community, healthcare system, or nosocomial. RESULTS Two hundred and forty-six episodes were analyzed in 200 patients (150 males, 57.3 years): 34.6% community-acquired, 38.6% healthcare system-acquired, and 26.8% nosocomially-acquired. Third-generation cephalosporin resistance occurred in 21.5% (7.1% community-acquired, 21.1% healthcare system-acquired, 40.9% nosocomially-acquired). These resistant cases were categorized as extended-spectrum β-lactamase-producing Gram-negative bacilli, other resistant Gram-negative bacilli, and Enterococci. Risk factors for resistance were previous use of cephalosporins, diabetes mellitus, upper gastrointestinal bleeding, nosocomial acquisition, and a low polymorphonuclear count in ascites. Regarding third-generation cephalosporin resistance, adequate empirical treatment was 80.7%. Independent predictors of mortality were nosocomial acquisition, poor hepato-renal function, immunosuppressive therapy, a marked inflammatory response during the episode and either third-generation cephalosporin-resistance or low rates of adequate empirical treatment. CONCLUSIONS The risk of third-generation cephalosporin resistance was particularly high in nosocomially-acquired episodes of spontaneous bacterial peritonitis, but also occurred in healthcare system-acquired cases. The extent of resistance and the adequacy of empirical antibiotics had a significant effect on mortality along with the patients hepato-renal function. These data can help determine the most suitable empirical antimicrobial treatments in these patients.

Secondary bacterial peritonitis in cirrhosis: A retrospective study of clinical and analytical characteristics, diagnosis and management

BACKGROUND & AIMS Secondary bacterial peritonitis in cirrhotic patients is an uncommon entity that has been little reported. Our aim is to analyse the frequency, clinical characteristics, treatment and prognosis of patients with secondary peritonitis in comparison to those of patients with spontaneous bacterial peritonitis (SBP). METHODS Retrospective analysis of 24 cirrhotic patients with secondary peritonitis compared with 106 SBP episodes. RESULTS Secondary peritonitis represented 4.5% of all peritonitis in cirrhotic patients. Patients with secondary peritonitis showed a significantly more severe local inflammatory response than patients with SBP. Considering diagnosis of secondary peritonitis, the sensitivity of Runyons criteria was 66.6% and specificity 89.7%, Runyons criteria and/or polymicrobial ascitic fluid culture were present in 95.6%, and abdominal computed tomography was diagnostic in 85% of patients in whom diagnosis was confirmed by surgery or autopsy. Mortality during hospitalization was higher in patients with secondary peritonitis than in those with SBP (16/24, 66.6% vs. 28/106, 26.4%) (p<0.001). There was a trend to lower mortality in secondary peritonitis patients who underwent surgery (7/13, 53.8%) than in those who received medical treatment only (9/11, 81.8%) (p=0.21). Considering surgically treated patients, the time between diagnostic paracentesis and surgery was shorter in survivors than in non-survivors (3.2+/-2.4 vs. 7.2+/-6.1 days, p=0.31). CONCLUSIONS Secondary peritonitis is an infrequent complication in cirrhotic patients but mortality is high. A low threshold of suspicion on the basis of Runyons criteria and microbiological data, together with an aggressive approach that includes prompt abdominal computed tomography and early surgical evaluation, could improve prognosis in these patients.

Ertapenem failure as therapy for nosocomial spontaneous bacterial peritonitis.

A a C 1 E E i Nosocomial spontaneous bacterial peritonitis (SBP) accounts for one third of all SBP episodes and is caused by microorganisms resistant to third generation cephalosporins (3rdGC) up to 40% of cases, mainly due to extended-spectrum -lactamases (ESBL) Escherichia coli and Klebsiella pneumoniae producing strains, other Enterobacteriaceae spp. and some gram positive bacteria.1 In this setting, 3rdGC must not be used as empirical antibiotic therapy in nosocomial SBP. Carbapenems have been recommended based in bacteriological data reported in these cases.2,3 Ertapenem, a parenteral broad-spectrum 1-beta-methyl carbapenem was approved by FDA in US and in Europe for complicated intra-abdominal infections. We are treating nosocomial SBP with ertapenem provided that 93% of isolated bacteria in nosocomial SBP of our center were sensible in vitro to this carbapenem. We report three cases of nosocomial SBP caused by ertapenem-susceptible, ESBLproducing E. coli and K. pneumoniae with a microbiological and clinical failure to recommended standard doses of 1 g/24 h.