Risk factors for and clinical outcomes of bloodstream infections caused by extended-spectrum beta-lactamase-producing Klebsiella pneumoniae.
OBJECTIVE
To evaluate risk factors and treatment outcomes of bloodstream infections caused by extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP).


METHODS
Retrospective case-control study. Stored blood isolates of K. pneumoniae were tested for ESBL production by NCCLS guidelines, double-disk synergy test, or both.


METHODS
A 1,500-bed, tertiary-care university hospital and referral center.


METHODS
Sixty case-patients with bacteremia due to ESB-KP were compared with 60 matched control-patients with non-ESBL-KP.


RESULTS
There were no significant differences in age, gender, APACHE II score, or underlying diseases between the groups. Independent risk factors for infections caused by ESBL-KP were urinary catheterization, invasive procedure within the previous 72 hours, and an increasing number of antibiotics administered within the previous 30 days. Complete response rate, evaluated 72 hours after initial antimicrobial therapy, was higher among control-patients (13.3% vs 36.7%; P = .003). Treatment failure rate was higher among case-patients (35.0% vs 15%; P = .011). Overall 30-day mortality rate was 30% for case-patients and 28.3% for control-patients (P = .841). Case-patients who received imipenem or ciprofloxacin as a definitive antibiotic had 10.5% mortality. The mortality rate for initially ineffective therapy was no higher than that for initially effective therapy (9.1% vs 11.1%; P = 1.000), but statistical power was low for evaluating mortality in the absence of septic shock.


CONCLUSIONS
For K. pneumoniae bacteremia, patients with ESBL-KP had a higher initial treatment failure rate but did not have higher mortality if antimicrobial therapy was appropriately adjusted in this study with limited statistical power.
Kang
Cheol-In
CI
Department of Internal Medicine, Seoul National University College of Medicine, 28 Yongon-dong Chongno-gu, Seoul 110-744, Republic of Korea.
Kim
Sung-Han
SH
Kim
Dong Min
DM
Park
Wan Beom
WB
Lee
Ki-Deok
KD
Kim
Hong-Bin
HB
Oh
Myoung-Don
MD
Kim
Eui-Chong
EC
Choe
Kang-Won
KW
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000494:pharmacology; D016470:Bacteremia / Q000209:etiology* / Q000401:mortality; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007710:Klebsiella Infections / Q000209:etiology* / Q000401:mortality; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D017211:Treatment Failure; D014546:Urinary Catheterization / Q000009:adverse effects; D001618:beta-Lactamases / Q000096:biosynthesis*
D000900:Anti-Bacterial Agents; D001618:beta-Lactamases