Risk factors and outcomes associated with isolation of meropenem high-level-resistant Pseudomonas aeruginosa.
OBJECTIVE
To determine risk factors and outcomes for patients with meropenem high-level-resistant Pseudomonas aeruginosa (MRPA) (minimum inhibitory concentration [MIC] > or = 32 microg/mL).


METHODS
Case-control-control.


METHODS
An 867-bed urban, teaching hospital.


METHODS
Fifty-eight MRPA case patients identified from an earlier P. aeruginosa study; 125 randomly selected control patients with meropenem-susceptible P. aeruginosa (MSPA) (MIC < or = 4 microg/mL), and 57 control patients without P. aeruginosa (sampled by case date/location).


METHODS
Patient data, outcomes, and costs were obtained via administrative database. Cases were compared to each control group while controlling for time at risk (days between admission and culture, or entire length of stay [LOS] for patients without P. aeruginosa).


RESULTS
A multivariable model predicted risks for MRPA versus MSPA (odds ratio [95% confidence interval]): more admissions (in the prior 12 months) (1.41 [1.15, 1.74]), congestive heart failure (2.19 [1.03, 4.68]), and Foley catheter (2.53 [1.18, 5.45]) (adj. R(2) = 0.28). For MRPA versus no P. aeruginosa, risks were age (in 5-year increments) (1.17 [1.03, 1.33]), more prior admissions (1.40 [1.08, 1.81]), and more days in the intensive care unit (1.10 [1.03, 1.18]) (adj. R(2) = 0.32). Other invasive devices (including mechanical ventilation) and previous antibiotic use (including carbapenems) were nonsignificant. MRPA mortality (31%) did not differ from that of MSPA (15%) when adjusted for time at risk (P = .15) but did from mortality without P. aeruginosa (9%) (P = .01). Median LOS and costs were greater for MRPA patients versus MSPA patients and patients without P. aeruginosa: 30 days versus 16 and 10 (P<.01) and $88,425 versus $28,620 and $22,605 (P<.01).


CONCLUSIONS
Although antibiotic use has been shown to promote resistance, our data found that prior antibiotic use was not associated with MRPA acquisition. However, admission frequency and Foley catheters were, suggesting that infection control measures are essential to reducing MRPA transmission.
Eagye
Kathryn J
KJ
Center for Anti-Infective Research and Development, Hartford Hospital, CT 06102, USA.
Kuti
Joseph L
JL
Nicolau
David P
DP
D000293:Adolescent; D000367:Age Factors; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016022:Case-Control Studies; D002404:Catheterization / Q000009:adverse effects; D002648:Child; D003428:Cross Infection / Q000517:prevention & control; D024881:Drug Resistance, Bacterial; D005260:Female; D017048:Health Care Costs; D006760:Hospitalization / Q000706:statistics & numerical data; D006784:Hospitals, Teaching / Q000706:statistics & numerical data; D006786:Hospitals, Urban / Q000706:statistics & numerical data; D006801:Humans; D007902:Length of Stay; D008297:Male; D000077731:Meropenem; D008826:Microbial Sensitivity Tests; D015999:Multivariate Analysis; D016017:Odds Ratio; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000191:economics / Q000401:mortality; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification; D012189:Retrospective Studies; D012307:Risk Factors; D013845:Thienamycins / Q000494:pharmacology*; D016896:Treatment Outcome; D055815:Young Adult
D000900:Anti-Bacterial Agents; D013845:Thienamycins; D000077731:Meropenem