Antimicrobial stewardship: an essential approach to the looming crisis of antibiotic resistance
Antimicrobial stewardship is a systematic approach to optimising the use of antimicrobials in healthcare institutions. An antibiotic stewardship program is a new requirement for hospital accreditation, stimulated by the Australian Commission on Safety and Quality in Health Care publication Antimicrobial Stewardship in Australian Hospitals (2011).
The goals fo the antibiotics stewardship program
To promote best evidence based practice in prescribing antimicrobials in order to:
- optimise the treatment of infections and improve patient outcomes
- minimise inappropriate antibiotic use and the development of resistance
- minimise antibiotic related adverse events
- ensure cost effective prescribing.
The functions of the antibiotic stewardship program
- To put in place antimicrobial prescribing guidelines.
- To put in place an antimicrobial formulary and approval system.
- To conduct antimicrobial prescribing audit with feedback to prescribers.
- To liaise with microbiology to:
- monitor resistance trends
- ensure susceptibility reporting is consistent with prescribing guidelines and the formulary
- produce cumulative antibiograms that can inform potential changes to prescribing guidelines.
- To monitor antimicrobial dispensing data and the use of non-formulary antimicrobials.
- Provide education relating to antimicrobial prescribing.
Why has antimicrobial stewardship become necessary?
Modern medicine is not possible without effective antimicrobials: consider that neonatal intensive care, prosthetic joint surgery, cancer chemotherapy, organ transplantation and many other parts of modern medicine depend upon the existence effective antimicrobial therapy for either prophylaxis or treatment of complications.
Infections with antibiotic-resistant organisms are increasingly common in the community as well as in healthcare and are associated with increased morbidity and mortality. Some examples are:
- MRSA: Community strains of MRSA are currently the most common isolate from boils swabbed in EDs in Metro south. About 25% of Staph aureus bacteraemias from the community are now MRSA. In 2001, it was less than 1%.
- ESBL (Extended Spectrum Beta-Lactamase producing) E. coli is an increasingly common cause of community-associated UTI and urosepsis, and may require IV antibiotics as there are no effective oral options. ESBL E. coli is strongly selected for by the use of ceftriaxone.
- VRE (Vancomycin-resistant E. Faecium) has become endemic in Queensland Health hospitals in the last few years and is associated with infections in cancer chemotherapy and liver transplant patients. VRE is strongly selected for by the use of ceftriaxone and vancomycin.
- NDM-1 is an antibiotic resistance gene found in gram-negative bacteria such as E. coli. It confers resistance to carbapenems (e.g. meropenem), which are usually reserved as last-line agents in serious or antibiotic-resistant infections. It was first described in 2008. It has since spread globally, including two cases indentified in Queensland.
- C. difficile. In North America and Europe in recent years there have been epidemics of a hypervirulent strain of C. difficile, infection which is associated with very high mortality rates. This strain is selected for by the newer broad-spectrum quinolones. A small number of cases have been identified in Australia, but not yet in Queensland.
There are few new antibiotics in the development pipeline and none in new classes effective against gram-negative bacteria.
Changes in institutional prescribing practices can influence local resistance rates and it has been proven that by minimising the unnecessary prescription of antibiotics, the progression towards more resistance can be slowed, hopefully until either new antimicrobials or other new approaches such as vaccines can be developed.
Therefore only judicious, evidence-based use can be justified. Antibiotics that are less likely to select for multi-resistant organisms should be preferentially used when the safety of the patient isn’t compromised by doing so.