Predictors of in-hospital mortality for bloodstream infections caused by Enterobacter species or Citrobacter freundii.
OBJECTIVE
To identify predictors of in-hospital mortality among patients with bacteremia caused by Enterobacter cloacae, Enterobacter aerogenes, or Citrobacter freundii.


METHODS
Retrospective cohort study.


METHODS
1300-bed tertiary academic medical center.


METHODS
One hundred twenty-four patients who had bloodstream infections caused by E. cloacae (3), E. aerogenes (71), or C. freundii (50) between 1998 and 2004.


RESULTS
Data from patients with bloodstream infections caused by Enterobacter sp or C. freundii were retrospectively segregated according to hospital survival (98 survivors, 26 nonsurvivors). Multiple patient characteristics and processes of care were evaluated to identify factors contributing to in-hospital mortality. Multiple logistic regression was performed based on univariate comparisons to determine independent risk factors for in-hospital mortality. Among the 124 cases of bacteremia, the crude in-hospital mortality rate was 21% (26 cases). Univariate analysis revealed that survivors were more likely to receive an aminoglycoside as part of their empiric antimicrobial regimen (40% [39/98]) compared with nonsurvivors (19% [5/26], p=0.05). Other factors related to antimicrobial therapy including choice and number of agents used did not differ between survivors and nonsurvivors (p>0.05). Vasopressor use (31% [30/98] vs 62% [16/26]), care in an intensive care unit (19% [19/98] vs 54% [14/26]), and acute renal failure (13% [13/98] vs 31% [8/26]) occurred more frequently in nonsurvivors (p<0.05). Multiple logistic regression identified resistance to second- or third-generation cephalosporins (adjusted odds ratio [OR] 5.16, 95% confidence interval [CI] 2.66-10.0, p=0.013), trimethoprim-sulfamethoxazole resistance (adjusted OR 5.44, 95% CI 2.53-11.7, p=0.027), and mechanical ventilation (adjusted OR 12.2, 95% CI 5.99-24.5, p<0.001) as independent determinants of mortality.


CONCLUSIONS
Among patients with Enterobacter sp or C. freundii bloodstream infections, those with trimethoprim-sulfamethoxazole-resistant or second or third-generation cephalosporin-resistant strains or those who required mechanical ventilation had an increased risk of mortality.
Deal
Eli N
EN
Department of Pharmacy, Barnes-Jewish Hospital, St. Louis, Missouri 63110, USA.
Micek
Scott T
ST
Ritchie
David J
DJ
Reichley
Richard M
RM
Dunne
W Michael
WM
Kollef
Marin H
MH
D000368:Aged; D016470:Bacteremia / Q000401:mortality; D002511:Cephalosporins / Q000627:therapeutic use; D016971:Citrobacter freundii; D015331:Cohort Studies; D004351:Drug Resistance; D004754:Enterobacter; D004756:Enterobacteriaceae Infections / Q000188:drug therapy / Q000401:mortality*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012121:Respiration, Artificial; D012189:Retrospective Studies; D013223:Statistics as Topic; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000627:therapeutic use
D002511:Cephalosporins; D015662:Trimethoprim, Sulfamethoxazole Drug Combination