The Importance of an Antimicrobial Stewardship Program
An antimicrobial stewardship program (ASP) is designed to provide guidance for the safe andcost-effective use of antimicrobial agents. This evidence-based approach addresses the correct selection of antimicrobial agents, dosages, routes of administration, and duration of therapy. In other words, the ASP necessitates the right drug, the right time, the right amount, and the right duration.1 The ASP reduces the development of multidrug-resistant organisms (MDROs), adverse drug events (such as antibiotic-associated diarrhea and renal toxicity), hospital length of stay, collateral damage (development of Clostridium difficile colitis), and health care costs. Review of the literature has shown the ASP reduces hospital stays among patients with acute bacterial-skin and skin-structure infections along with other costly infections.2
The ASP is not a new concept, but it is a hot topic. A successful ASP cannot be achieved without the support of the hospital leadership to determine and provide the needed resources. Its success stems from being a joint collaborative effort between pharmacy, medicine, infection control (IC), microbiology, and information technology. The purpose of the ASP is to ensure proper use of antimicrobials within the health care system through the development of a formal, interdisciplinary team. The primary goal of the ASP is to optimize clinical outcomes while minimizing unintended consequences related to antimicrobial usage, such as toxicities or the emergence of resistance.
In today’s world, health care clinicians are dealing with a global challenge of MDROs such as Enterococcus faecium, Staphylococcus aureus (S aureus), Klebsiella pneumonia, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacter species (ESKAPE), better known as “bugs without borders.”3 According to the CDC, antibiotic-resistant infections affect at least 2 million people in the U.S. annually and result in > 23,000 deaths.2 According to Thomas Frieden, director of the CDC, the pipeline of new antibiotics is nearly empty for the short term, and new drugs could be a decade away from discovery and approval by the FDA.2
Literature Review
Pasquale and colleagues conducted a retrospective, observational chart review on 62 patients who were admitted for bacterial-skin and skin-structure infections (S aureus, MRSA, MSSA, and Pseudomonas aeruginosa).4 The data examined patient demographic characteristics, comorbidities, specific type of skin infection (the most common being cellulitis, major or deep abscesses, and surgical site infections), microbiology, surgical interventions, and recommendations obtained from the ASP committee.
The ASP recommendations were divided into 5 categories, including dosage changes, de-escalation, antibiotic regimen changes, infectious disease (ID) consults, and other (not described). The ASP offered 85 recommendations, and acceptance of the ASP recommendations by physicians was 95%. The intervention group had a significantly lower length of stay (4.4 days vs 6.2 days, P < .001); and the 30-day all-cause readmission rate was also significantly lower (6.5% vs 16.71%, P = .05). However, the skin and skin-related structures readmission rate did not differ significantly (3.33% vs 6.27%). It was impossible for the investigators to determine exact differences in the amount of antimicrobials used in the intervention group vs the historical controls, because the historical data were based on ICD-9 codes, which may explain the nonsignificant finding.4
D’Agata reviewed the antimicrobial usage and ASP programs in dialysis centers.5 Chronic hemodialysis patients with central lines were noted to have the greatest rate of infections and antibiotic usage (6.4 per 100 patient months). The next highest group was dialysis patients with grafts (2.4 per 100 patient months), followed by patients with fistulas (1.8 per 100 patient months). Vancomycin was most commonly chosen for all antibiotic starts (73%). Interestingly, vancomycin was followed by cefazolin and third- and/or fourth-generation cephalosporin, which are risk factors for the emergence of multidrug-resistant, Gram-negative bacteria that are highly linked to increased morbidity and mortality rates. The U.S. Renal Data System stated in its 2009 report that the use of antibiotic therapy has increased from 31% in 1994 to 41% in 2007.5
In reviewing inappropriate choices of antimicrobial prescribing, D’Agata compared prescriptions given to the Healthcare Infection Control Practices Advisory Committee to determine whether the correct antibiotic was chosen. In 164 vancomycin prescriptions, 20% were categorized as inappropriate.5 In another study done by Zvonar and colleagues, 163 prescriptions of vancomycin were reviewed, and 12% were considered inappropriate.6
Snyder and colleagues examined 278 patients on hemodialysis, and over a 1-year period, 32% of these patients received ≥ 1 antimicrobial with 29.8% of the doses classified as inappropriate.7 The most common category for inappropriate prescribing of antimicrobials was not meeting the criteria for diagnosing infections (52.9% of cases). The second leading cause of inappropriate prescription for infections was not meeting criteria for diagnosing specific skin and skin-structure infections (51.6% of cases). Another common category was failure to choose a narrower spectrum antimicrobial prescription (26.8%).7 Attention to the indications and duration of antimicrobial treatment accounted for 20.3% of all inappropriate doses. Correction of these problems with use of an ASP could reduce the patient’s exposure to unneeded or inappropriate antibiotics by 22% to 36% and decrease hospital costs between $200,000 to $900,000.5
