Optimizing Empirical Antimicrobial Therapy for Infection due to Gram-Negative Pathogens in the Intensive Care Unit: Utility of a Combination Antibiogram

Christoff, Jennifer; Tolentino, Jocelyn; Mawdsley, Emily Landon; Matushek, Scott; Pitrak, David; Weber, Stephen G.

doi:10.1086/650446

Cited by 32 publications

(31 citation statements)

References 32 publications

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“…The addition of ciprofloxacin did not significantly improve the in vitro efficacy of piperacillin/tazobactam (87% versus 91%) or cefepime (89% versus 93%). A retrospective study by Christoff et al (2010) looked at over 5000 isolates of gram-negative organisms, including P. aeruginosa, in the ICU. They reported combination antimicrobial therapy significantly increased the likelihood that the gram-negative organism was adequately covered in the ICU using piperacillintazobactam, ceftazidime, or imipenem/cilastatin plus an additional agent.…”

Section: Discussionmentioning

confidence: 99%

“…To assist clinicians in selecting the most effective twodrug antibiotic regimen, combination antibiograms have been employed (Apisarnthanarak and Mundy, 2008;Christoff et al, 2010;Fox et al, 2008;Mizuta et al, 2006;Pogue et al, 2011). These antibiograms can be displayed in matrix form showing the percentage of isolates susceptible to various single agents and combinations of antibiotics.…”

Section: Ajidmentioning

confidence: 99%

See 1 more Smart Citation

UTILITY OF A COMBINATION ANTIBIOGRAM FOR TREATING <i>PSEUDOMONAS AERUGINOSA</i>

Thurman¹

2014

American Journal of Infectious Diseases

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Empiric combination antibiotic therapy is often used to treat severe P. aeruginosa infections. Combination antibiograms have been employed to assist clinicians in selecting the most effective two-drug antibiotic regimens. The objectives of this study were to develop a combination antibiogram in order to compare betalactam monotherapy versus dual-therapy with a fluoroquinolone or aminoglycoside, identify optimal combination regimens, describe the differences between combination therapies with an aminoglycoside versus a fluoroquinolone and to evaluate susceptibility rates based on the source of infection and Intensive Care Unit (ICU) or non-ICU location. A retrospective observational study at a Veterans Affairs (VA) hospital in the Southwestern region of the U.S. was conducted. P. aeruginosa isolates were collected between January 2008 and February 2012 in hospitalized veterans. A total of 374 isolates were included, of which 61 (16%) were obtained from the ICU. Susceptibility rates for monotherapy with a beta-lactam ranged from 83.7 to 90.6%. Collectively, all P. aeruginosa isolates benefited in coverage with the addition of a fluoroquinolone or an aminoglycoside to one of the beta-lactams considered for monotherapy (p<0.01 for each comparison). Monotherapy with a beta-lactam could be considered for mild to moderate wound infections which had beta-lactam susceptibility rates greater than 90% and the addition of a fluoroquinolone did not significantly extend the spectrum. Combination susceptibility rates ranged from 89.0 to 99.2%. Dual therapy of a beta-lactam with amikacin or tobramycin resulted in significantly better coverage than with a fluoroquinolone (p<0.03 for all combinations). For severe infections dual therapy with tobramycin or amikacin may be preferred over fluoroquinolones, but the risks versus benefits of aminoglycoside therapy must be weighed for each patient. In conclusion, combination antibiograms are useful for evaluating the treatment of P. aeruginosa. Choosing the ideal antibiotic regimen ultimately deals with many factors and results of this combination antibiogram are only specific to this institution.

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Section: Discussionmentioning

confidence: 99%

Section: Ajidmentioning

confidence: 99%

UTILITY OF A COMBINATION ANTIBIOGRAM FOR TREATING <i>PSEUDOMONAS AERUGINOSA</i>

Thurman¹

2014

American Journal of Infectious Diseases

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“…An institutional antibiogram that tabulates laboratory susceptibilities of common pathogens to antibacterial drugs can be a useful tool in selecting empirical therapy (3,7,8). The specificity of antibiogram results for a given patient case can be increased by reporting on subsets of organisms from various body sites or from patients in various care locations.…”

mentioning

confidence: 99%

Optimizing Empiric Antibiotic Therapy in Patients with Severe β-Lactam Allergy

Koliscak

Johnson

Beardsley

et al. 2013

Antimicrob Agents Chemother

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Antibiotic selection is challenging in patients with severe ␤-lactam allergy due to declining reliability of alternate antibiotics. Organisms isolated from these patients may exhibit unique resistance phenotypes. The objective of this study was to determine which alternate antibiotics or combinations provide adequate empirical therapy for patients with ␤-lactam allergy who develop Gram-negative infections at our institution. We further sought to determine the effects of risk factors for drug resistance on empirical adequacy. A retrospective analysis was conducted for adult patients hospitalized from September 2009 to May 2010 who had a severe ␤-lactam allergy and a urine, blood, or respiratory culture positive for a Gram-negative organism and who met predefined criteria for infection. Patient characteristics, culture and susceptibility data, and predefined risk factors for antibiotic resistance were collected. Adequacies of ␤-lactam and alternate antibiotics were compared for all infections and selected subsets. The primary outcome was adequacy of each alternate antibiotic or combination for all infections. One hundred sixteen infections (40 pneumonias, 67 urinary tract infections, and 9 bacteremias) were identified. Single alternate agents were adequate less frequently than ␤-lactams and combination regimens. Only in cases without risk factors for resistance did single-agent regimens demonstrate acceptable adequacy rates; each factor conferred a doubling of risk for resistance. Resistance risk factors should be considered in selecting empirical antibiotics for Gram-negative pathogens in patients unable to take ␤-lactams due to severe allergy.

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“…Another important phenomenon common to critically ill patients is that of enhanced renal elimination of drugs, a phenomenon known as augmented renal clearance (ARC) [10,54]. Enhanced renal elimination of solutes will also increase clearance of renally cleared antibiotics, reducing their concentration and jeopardising their therapeutic effect [32].…”

Section: Changes In Renal Functionmentioning

confidence: 99%