Antimicrobial Stewardship in Australian Hospitals

Antimicrobial resistance poses a major threat to public health and human life, with infections from antibiotic resistant organisms threatening patient lives and compromising the safety and quality of healthcare. With up to 40% of hospital inpatients receiving antibiotics at any time, and with the resistance of bacteria to antimicrobials linked to the duration of antibiotic therapy; there is a pressing need to stop increasing resistance and produce new antibiotics with very different modes of action.

The most effective approach to improving antimicrobial use in hospitals is an organised antimicrobial management program, called Antimicrobial Stewardship (AMS). AMS involves a clear approach to optimising the use of antimicrobials in order to: reduce inappropriate use of antibiotics, improve patient outcomes, and reduce adverse consequences of antimicrobials (including antimicrobial resistance, toxicity and unnecessary costs).

The National Safety and Quality Health Service (NSQHS) Standards include antimicrobial stewardship as a mandatory requirement for accreditation. This means that antimicrobial stewardship must be addressed within the hospital environment to show an effective model for appropriate use and infection control. Special attention should be paid to ‘Standard 1: governance for safety and quality in health service organisations’, ‘Standard 3: Preventing and controlling healthcare associated infections’ and ‘Standard 4: Medication Safety’.

Strategies to treat infection in cases of resistance may require different types of antibiotics, specific dosing schedules (such as higher doses and extended infusion times), novel delivery methods (such as nebulisation), or combinations of partially active or individually inactive antibiotics may be utilised in difficult cases of multi-resistance. Of particular concern within hospitals is the control of infection by methicillin resistant Staphylococcus aureus (MRSA) and vancomycin resistant Enterococcus (VRE).

Which antibiotics are most commonly involved in multi-resistance?

• Aminoglycosides
• Ampicillin/Amoxycillin
• Antipseudomonal penicillins (Piperacillin, Ticarcillin)
• Carbapenems
• Cephalosporins
• Colistin
• Tetracycline

Few new antibiotics have been produced since the 1960s and resistance is occurring at an alarming rate.

Figure 1. The development of new antibacterial drug classes.* (Click image to enlarge)

Bacteria develop resistance at varying rates. Penicillin resistant bacteria were identified within twelve months of mass production of penicillin being initiated in 1943.

Some new antibiotics have been produced, mainly targeting bacterial cell wall integrity.

• Ceftaroline fosamil – increases the permeability of cell membranes to allow entry to cell
• Daptomycin – disrupts cell membrane function
• Fosfomycin – interferes with the cell wall synthesis
• Fidaxomicin – inhibition of RNA synthesis
• Colistin – disruption of cell membrane and leakage of cellular contents

Effective AMS programs have been shown to decrease antibiotic use by between 22% and 36%, improve patient care, improve appropriateness of antimicrobial use and reduce hospital resistance rates, as well as reduce morbidity and mortality. Reduced demand for medicines also reduces healthcare costs.

There are seven strategies that are considered important for an AMS program:

• Implementation of clinical guidelines that are consistent with the latest version of Therapeutic Guidelines: Antibiotic, Version 15, 2014. These updated guidelines, released in November 2014, can take into account local microbiological and antimicrobial susceptibility patterns. Therapeutic Guidelines should be available at the point of prescribing (in nurses’ stations or drug rooms). The online version should be used to ensure that the information is the most up to date.
• Establishing antimicrobial formulary restrictions and approval systems that include restricting broad-spectrum and later generation antimicrobials to patients in whom their use is clinically justified.
• Reviewing antibiotic prescribing with intervention and direct feedback to the prescriber. This should include intensive care patients.
• Monitoring of antimicrobial prescribing by collecting unit or ward specific usage data. Antimicrobial use should be audited and assessed using quality use of medicines indicators. Involvement in the annual National Antimicrobial Prescribing Survey (NAPS) audit and reporting antibiotic usage to the National Antimicrobial Utilisation Surveillance Program (NAUSP) will provide comparative data with other hospitals. Intensive care units should be included.
• Surgical antibiotic prophylaxis should be used for as short a time as possible, in accordance with the Therapeutic Guidelines.
• Encouraging switching intravenous (IV) to oral as soon as clinically appropriate. In general, IV antimicrobials should only be prescribed for two to four days, after which the prescription should be reviewed and the patient should be switched to an oral form, if appropriate. Oral therapy is preferred as it has a lower treatment cost, reduced length of stay in hospital, reduced morbidity and greater patient satisfaction. IV to oral switch should be considered for pneumonia, skin and soft tissue infections, urinary tract infections, uncomplicated Gram negative bacteraemia and intra-abdominal infection which do not have deep-seated infections.
• AMS should be used in association with a hand hygiene and infection surveillance program.

Almost all infections have standard durations of treatment; however these may need to be tailored to individual responses to therapy, particularly in immunocompromised patients. Antimicrobials should generally be prescribed for seven days, or a shorter period if clinically appropriate. Prolonged parenteral therapy is required for many serious infections. In these cases the appropriate course of treatment should be completed. It is important that the hospital culture includes daily review, prescribing with a maximum duration set, and an automatic stop that is followed unless there is a clear indication in the medical record of a change to the plan.

What can you do?

• Participate in Antibiotic Awareness Week by putting up posters or organising a speaker for your area about appropriate antibiotic use. Go online to the National Prescribing Service (NPS) and answer the questions to receive a free antibiotic resistance fighter T-shirt to wear during Antibiotic Awareness Week.
• Encourage staff to complete the NPS e-learning modules related to antibiotics and infection.
• Encourage your facility to participate in the NAPS survey during Antibiotic Awareness Week and the NAUSP antibiotic survey. This will provide some evidence of the use and misuse of antibiotics in your hospital.
• Ensure current references are available at the point of care.
• Number the days of antibiotic therapy administered, and query the need for prolonged courses.
• Ask the question about switching from IV to oral antibiotics.
• Consider a “traffic light” antimicrobial restriction list in your facility:
  • Green: for no restriction
  • Amber: for limited conditions/microbiological results
  • Red: for requiring Infectious Disease consultant approval for use past one dose.