Risk Factors and Outcomes Associated with Isolation of Meropenem High-Level-Resistant Pseudomonas aeruginosa.

Infect Control Hosp Epidemiol. 2009 Jul 7; Eagye KJ, Kuti JL, Nicolau DPObjective. To determine risk factors and outcomes for patients with meropenem high-level-resistant Pseudomonas aeruginosa (MRPA) (minimum inhibitory concentration [Formula: see text] mug/mL). Design. Case-control-control. Setting. An 867-bed urban, teaching hospital. Patients. Fifty-eight MRPA case patients identified from an earlier P. aeruginosa study; 125 randomly selected control patients with meropenem-susceptible P. aeruginosa (MSPA) ([Formula: see text] mug/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. [Formula: see text]). 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. [Formula: see text]). 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 ([Formula: see text]) but did from mortality without P. aeruginosa (9%) ([Formula: see text]). Median LOS and costs were greater for MRPA patients versus MSPA patients and patients without P. aeruginosa: 30 days versus 16 and 10 ([Formula: see text]) and $88,425 versus $28,620 and $22,605 ([Formula: see text]). 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.