K-3498. Outcomes of P. aeruginosa Bacteremia (PSAB) Treated with Piperacillin/Tazobactam (PT)
Session: Poster Session: Pseudomonas and Other Gram Negatives
Monday, October 27, 2008: 12:00 AM
Room: Hall C
Background: Recent studies suggest standard dosing of PT is suboptimal for many PSAB with MICs at the high end of the susceptibility range. Our objective was to characterize outcomes of PSAB treated with PT at a 900-bed urban tertiary care center. Methods: Study population: consecutive cases of PSAB (non-hemodialysis) treated with PT from (2004-2007). Pts categorized as adequate (PT regimen provided >80% probability of achieving 50% T>MIC) or inadequate (PT regimen provided < 80% probability of achieving 50% T>MIC). PT MICs were reported via VITEK II or E-test. Demographics, comorbid conditions, microbiologic data, antimicrobial data, and clinical outcome were compared. Results: 44 patients included; 33 (75%) received combination therapy for at least 1 day. PT MIC distribution: 25 MIC<=4 mg/L, 6 with MIC=8, 2 MIC=16, 1 MIC=32, 10 MIC=64. Study groups: 24 adequate, 20 inadequate. No differences in baseline characteristics and disease severity were noted between groups. See table for additional characteristics and outcomes. Conclusion: PSAB is associated with significant morbidity/mortality, and typical dosing regimens are not adequate for isolates with elevated MICs.
Characteristics
*p<.05
Adequate; n=24
n (%)
Inadequate; n=20
n (%)
Comorbid conditions
prior hospitalization
prior antibiotics
prior surgery*
decubitus ulcer
diabetes
16 (67)
15 (63)
10 (42)
3 (13)
8 (33)
10 (50)
14 (74)
3 (15)
7 (35)
7 (35)
Acquisition
community acquired
community with healthcare contact
nosocomial (>48h in hospital)
2 (8)
14 (58)
8 (33)
5 (26)
6 (32)
8 (42)
Outcomes
duration of pip/tazo (median)
duration of all antibiotics
total length of stay*
clinical success at end of PT
30-day mortality
8 days
14 d
14 d
18 (75)
4 (17)
9 days
14 d
29 d
11 (55)
8 (40)
Ryan Attwood, Henry Ford Hospital, Detroit, MI, Susan L Davis, PharmD, Wayne State University College of Pharmacy, Detroit, MI, Thomas Lodise, PharmD, Albany College of Pharmacy, Albany, NY and  R. J. Attwood, None.