What are the principles of effective antimicrobial (antibiotic) stewardship?

Antimicrobial Stewardship: Core Principles and Implementation

Antimicrobial stewardship programs optimize patient outcomes by ensuring the right diagnosis, drug, dose, duration, and de-escalation while minimizing antimicrobial resistance, adverse events, and healthcare costs. 1

Fundamental Goals

The primary objective is to improve patient outcomes while simultaneously minimizing unintended consequences including adverse events, selection of pathogenic organisms, and emergence of resistance. 1 This requires moving beyond simply comparing relative effectiveness of therapies to reliably achieving high cure rates—the infectious disease approach that has proven superior to trial-and-error methods. 2

The "5 Ds" Framework

Effective antimicrobial prescribing follows five critical principles: 1

• Right Diagnosis: Obtain appropriate cultures and diagnostic tests before initiating therapy to identify the causative organism and its susceptibility patterns 2
• Right Drug: Select antimicrobials based on local susceptibility patterns and the WHO AWaRe classification, prioritizing "Access" group antibiotics (lower resistance potential) over "Watch" group agents when appropriate 2
• Right Dose: Optimize dosing based on patient characteristics, pathogen, infection site, and pharmacokinetic/pharmacodynamic properties 3, 4
• Right Duration: Shorten therapy duration according to current guidelines to reduce selective pressure for resistant bacteria 3, 4
• Right De-escalation: Narrow or discontinue therapy based on culture results and clinical response 1

Essential Program Components

Leadership Structure

Antimicrobial stewardship requires dedicated leadership by infectious disease physicians partnered with clinical pharmacists who have infectious disease expertise. 1 This core team must collaborate with clinicians, microbiologists, and primary care providers across all clinical areas. 3 Emergency departments require dedicated representation given their unique challenges of rapid patient turnover and high provider variability. 3, 4

Primary Intervention Strategies

Two proactive approaches form the foundation of effective programs: 1

• Formulary restriction and preauthorization: Control antimicrobial use at the point of ordering 1, 5
• Prospective audit and feedback: Review prescribed antimicrobials with real-time intervention to optimize therapy 1, 3

Both strategies have proven effective, though prospective audit may offer advantages by maintaining prescriber autonomy while still achieving stewardship goals. 5, 6

Supplemental Strategies

Active educational programs including seminars and roundtable discussions promote clinician engagement, but education alone without complementary strategies is insufficient for sustained practice change. 3, 2 Additional effective approaches include: 3, 4

• Biomarker testing and rapid pathogen identification to distinguish viral from bacterial infections 3, 4
• Watchful waiting or delayed prescribing for select patients with less severe infections 4
• Structured culture follow-up programs for discharged patients with pending cultures 4
• Clinical decision support systems that deliver information at the point of care 2
• Intravenous-to-oral switch protocols when clinically appropriate 5, 6

Surveillance and Susceptibility Testing

Local antimicrobial surveillance programs with routine susceptibility testing are fundamental to antimicrobial stewardship, yet H. pylori and many other pathogens remain excluded from these programs despite recognition as a serious national problem. 2 When local susceptibility patterns are stable, effective optimized susceptibility-based therapies can be used empirically, but this requires: 2

• Continuous monitoring of local and regional antimicrobial susceptibility 2
• Tracking treatment outcomes and test-of-cure data 2
• Communication of resistance patterns to clinicians with recommendations for therapy modification 2
• Integration of prescription practices into local stewardship programs 2

Development of Clinical Guidelines

Facility-specific clinical practice guidelines must be based on local resistance patterns and adapted to individual settings rather than relying solely on national recommendations. 3, 2 Guidelines should explicitly define appropriate and inappropriate antimicrobial use, including guidance on when NOT to treat with antibiotics—particularly relevant for non-antibiotic responsive upper respiratory tract infections. 2 The multidisciplinary development process should incorporate local susceptibilities, facilitate implementation through provider education, and include systematic evaluation. 2

Monitoring and Measurement

Track these key metrics to evaluate program effectiveness: 1, 3

• Antimicrobial utilization patterns and resistance trends 1, 3
• Appropriateness of antibiotic therapy choice 1, 3
• Rehospitalization rates and time to culture review 1, 3
• Clostridium difficile infection rates 5, 7
• Drug-related adverse events 2, 5
• Healthcare costs and length of stay 2, 5

Critical Implementation Pitfalls to Avoid

Failing to adapt guidelines to local resistance patterns and patient populations significantly reduces program effectiveness. 3 Other common failures include: 3

• Implementing restrictive policies without adequate educational support, leading to clinician resistance 3
• Neglecting to include frontline clinicians in program development 3
• Overlooking diagnostic stewardship alongside antimicrobial stewardship 3
• Failing to address barriers including provider concerns about medical liability, patient satisfaction pressures, and resource constraints 3, 4

Special Considerations for Emergency Departments

Emergency departments sit at the critical interface between community and hospital settings, making initial antibiotic choices particularly impactful for both admitted and discharged patients. 2 The tension between appropriate broad-spectrum antibiotic use for life-threatening infections and stewardship goals requires acknowledgment and specific protocols. 3, 4 Blood cultures should be obtained selectively rather than routinely, particularly when signs of sepsis are absent. 4 Post-prescription review with patient follow-up ensures appropriate transitions to outpatient care. 4