Predictors of mortality in patients with bloodstream infections caused by extended-spectrum-beta-lactamase-producing Enterobacteriaceae: importance of inadequate initial antimicrobial treatment.
Bloodstream infections (BSI) caused by extended-spectrum beta-lactamase (ESBL)-producing organisms markedly increase the rates of treatment failure and death. We conducted a retrospective cohort analysis to identify risk factors for mortality in adult in-patients with BSI caused by ESBL-producing Enterobacteriaceae (ESBL-BSI). Particular attention was focused on defining the impact on the mortality of inadequate initial antimicrobial therapy (defined as the initiation of treatment with active antimicrobial agents >72 h after collection of the first positive blood culture). A total of 186 patients with ESBL-BSI caused by Escherichia coli (n = 104), Klebsiella pneumoniae (n = 58), or Proteus mirabilis (n = 24) were identified by our microbiology laboratory from 1 January 1999 through 31 December 2004. The overall 21-day mortality rate was 38.2% (71 of 186). In multivariate analysis, significant predictors of mortality were inadequate initial antimicrobial therapy (odds ratio [OR] = 6.28; 95% confidence interval [CI] = 3.18 to 12.42; P < 0.001) and unidentified primary infection site (OR = 2.69; 95% CI = 1.38 to 5.27; P = 0.004). The inadequately treated patients (89 of 186 [47.8%]) had a threefold increase in mortality compared to the adequately treated group (59.5% versus 18.5%; OR = 2.38; 95% CI = 1.76 to 3.22; P < 0.001). The regimens most commonly classified as inadequate were based on oxyimino cephalosporin or fluoroquinolone therapy. Prompt initiation of effective antimicrobial treatment is essential in patients with ESBL-BSI, and empirical decisions must be based on a sound knowledge of the local distribution of pathogens and their susceptibility patterns.
Tumbarello
Mario
M
Istituto Malattie Infettive, Università Cattolica del Sacro Cuore, Largo A. Gemelli 8, 00168 Rome, Italy. tumbarello@rm.unicatt.it
Sanguinetti
Maurizio
M
Montuori
Eva
E
Trecarichi
Enrico M
EM
Posteraro
Brunella
B
Fiori
Barbara
B
Citton
Rita
R
D'Inzeo
Tiziana
T
Fadda
Giovanni
G
Cauda
Roberto
R
Spanu
Teresa
T
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality*; D003428:Cross Infection / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000201:enzymology*; D004756:Enterobacteriaceae Infections / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality*; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology; D005260:Female; D006801:Humans; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011237:Predictive Value of Tests; D011513:Proteus mirabilis / Q000187:drug effects / Q000201:enzymology; D012307:Risk Factors; D016019:Survival Analysis; D016896:Treatment Outcome; D001618:beta-Lactamases / Q000096:biosynthesis*
D000900:Anti-Bacterial Agents; D001618:beta-Lactamases