W7 Antimicrobial Stewardship

Question 1

What are the causes of abx resistance? (6)

Answer 1

• Over prescribing of antibiotics: prescribing antibiotics for viral or self-limiting infections. Using broad-spectrum agents when narrower spectrum would have been sufficient. Antibiotics taken as self-care. Inappropriate dosing.
• Patient non-compliance: Patients not completing the course or unable to afford the full course. Not taking as prescribed
• Poor quality of antibiotics: expired or falsified/substandard medicine.
• Use of antibiotics in domestic animals: increase pressure on antimicrobial resistance and opportunity for resistant microbes to spread through food and water systems (livestock and fishing)
• Poor hygiene and sanitation: Poorly filtered waste water can lead to the spread of resistant microbes. Poor hand hygiene and infection control measures in health care settings increase spread of resistant genes between organisms.
• Lack of new antibiotics being developed: prescribing pressures on antibiotics that we have access to, increasing use and exposure.

Question 2

Development of AMR for info:

Answer 2

1. Antimicrobial products are used to kill or significantly slow the growth of disease-causing microbes
2. Under certain conditions, selective pressure drives the evolution of mechanisms that allow some microbes to resist antimicrobial activity
3. Resistant microbes can survive antimicrobial treatment and continue to replicate
4. AMR microbes pass resistance genes to other microbes via vertical and/or horizontal transfer, increasing both the quality and type of resistant pathogen.

Question 3

What are the most efficient ways to prevent the spread of antibiotic resistance? (8)

Answer 3

1. Infection prevention and control practices such as hand hygiene to avoid infection spread in healthcare settings
2. Awareness about the issue among general public, prescribers, media
3. Diagnostic tools for rapid and reliable detection of resistance
4. Vaccines for some important infections
5. New antibiotics to treat infections caused by multi-drug resistant bacteria
6. Surveillance programs to track the number and type of abx resistant infections in a given area, city, country etc
7. Waste management and water sanitation
8. Coordinated response among all countries

Question 4

What are the consequences of Antimicrobial Resistance at a patient level? (3)

Answer 4

Patients colonised by resistant bacteria more likely to develop an infection with these resistant bacteria than with susceptible variants of the same bacteria.
* Delay in appropriate antibiotic therapy: Worse patient outcomes and death
* Increased hospital length of stay
* Alternative antibiotics need to be used: Increased likelihood of adverse effects, cost implications and oral antibiotics may not be available

Question 5

What is Antimicrobial Stewardship (AMS)

Answer 5

An organisational or healthcare-system-wide approach to promoting and monitoring judicious use of antimicrobials to preserve their future effectiveness

“Prudent prescribing is not to prescribe as few antibiotics as possible but to identify that small group of patients who really need
antibiotic treatment and then explain, reassure and educate the large group of patients who don’t.

Includes:
* Educating staff
* Enhancing infection prevention and control
* Prescribing antibiotics when they are truly needed
* Prescribing appropriate antibiotic(s)
* Using the shortest duration of antibiotics based on evidence
* Reassessing treatment when culture results are available
* Supporting surveillance of AMR and HAis and monitoring of antibiotic consumption
* Educating staff
* Supporting an interdisciplinary approach
* Enhancing infection prevention and control

Question 6

What is meant by Start Smart then Focus?

Answer 6

Start Smart:
Do not start antibiotics in the absence of clinical evidence of bacterial infection:
1. Take through drug allergy hx
2. Initiate prompt effective abx treatment within one hour of diagnosis (or asap) in patients with severe sepsis or life-threatening infections
3. Comply with local antimicrobial prescribing guidance
4. Document clinical indication and disease severity if appropriate, dose and route on drug chart and in clinical notes
5. Include review/stop date or duration
6. Obtain cultures prior to commencing therapy where possible (but do not delay therapy)

Then focus:
Clinical review & Decision at 48-72 hours
Clinical review, check microbiology and make a clear plan. Document this decision.

1. STOP
2. IV to oral switch
3. Change antibiotic
4. Continue
5. OPAT* (outpatient parenteral abx therapy)

Document, Decision & Next Review Date or Stop Date for all the above decisions

Question 7

Establishing presence of bacterial infection

Answer 7

• Often difficult to differentiate between infective (bacteria vs virus vs fungal) and non-infective causes of symptoms.
• Severity assessment tools to determine the likelihood of bacterial infection in some conditions such as FEVERPAIN/CENTOR for Strep throat infections.
• Evidence-based point-of-care testing (POCT) is available in some clinical
  scenarios such as:
  -Urine dipsticks (not reliable in elderly patients or patients with catheters)
  -CRP for acute cough/IECOPD
  -Sore throat test and treat services with antigen testing

Question 8

What is an alternative prescribing strategy?
What are the 6 R’s?

Answer 8

• Back-up (delayed) prescribing (which
  can be post-dated) given to a patient or
  carer, with the assumption that it will not be dispensed immediately, but in a few days if symptoms worsen.

Remember the 6 R’s:
1. Reassurance
2. Reasons not to use abx (side effects/allergy/AMR)
3. Relief: Support paracetamol
4. Realistic natural history
5. Reinforce key message- only use if getting worse or not even starting to settle in the expected average time
6. Rescue (safety netting)

Question 9

Empirical Antibiotics:
When is empirical treatment indicated?

What two main factors determine how effective empirical treatment will be?

How should empirical therapy evolve when following best practice?

Answer 9

• When pathogen and/or antibiotic sensitivities are uncertain (best guess)
• Local pathogen epidemiology data
• Local antibiotic sensitivity data
• Streamline to narrow-spectrum antibiotic when sensitivities are available
  (Don’t use a sledgehammer to crack a nut)

Question 10

Broad Spectrum Vs Narrow Spectrum Antibiotic:

Answer 10

Narrow-spectrum antibiotics are more
specific and are only active against certain groups or strains of bacteria.

Broad-spectrum antibiotics instead, inhibit a wider range of bacteria and are more likely to drive resistance and have increased likelihood of causing C.difficile infection

Question 11

What is the WHO AWaRe Classification?
(for info)

Answer 11

• The AWaRe Classification of antibiotics was developed in 2017 by the WHO as a tool to support antibiotic stewardship efforts at local, national and global levels.
• Antibiotics are classified into three groups, Access, Watch and Reserve, taking into account the impact of different antibiotics and antibiotic classes on antimicrobial resistance, to emphasize the importance of their appropriate use. The tool classifies 258.
• Useful tool for monitoring antibiotic consumption, defining targets and
  monitoring the effects of stewardship policies that aim to optimize antibiotic use and curb antimicrobial resistance

Question 12

WHO AWaRe classification:
What do the letters stand for?

Answer 12

Access: First or second-choice antibiotics offer the best therapeutic value, while
minimizing the potential for resistance
e.g. Amoxicillin, doxycycline, metronidazole

Watch: first or second-choice antibiotics only
indicated for a specific, limited number of
infective syndromes
More prone to be a target of antibiotic
resistance and therefore prioritised as targets of stewardship programs and monitoring
e.g. cefuroxime, ciprofloxacin, meropenem

Reserve: “last resort”
Highly selected patients (life-threatening
infections due to multi-drug-resistant bacteria)
Closely monitored and prioritised as targets of stewardship programs to ensure their
continued effectiveness
e.g. colistin, ceftazidime/avibactam, linezolid

Question 13

Antimicrobial Guidelines should include what following advice?

Answer 13

• Clinical diagnosis - to include: case definition, evidence of infection, severity assessment and relevant microbiology investigations
• Recommendations for non-antimicrobial treatment (eg fluid resuscitation, surgery, self-
  care)
• Empirical or targeted antimicrobial treatment recommendations (specify the choice of drug(s), route of administration and dose)
• When to contact microbiology/infectious diseases consultant
• Oral switch guidance
• Duration of therapy (IV and oral agents)
• Monitoring and contingency advice for treatment failure

Question 14

Penicillin allergies:
What issues arise?

Answer 14

• Penicillin allergy most frequently reported allergy. About 10% of the UK population report penicillin allergy, but less than 1% will truly be allergic.
• Allergy vs adverse drug reaction – Important to take an accurate allergy history. Penicillin De-labelling programmes actively trying to remove these false labels

Question 15

What are the consequences of incorrect allergy coding? (4)

Answer 15

• Unnecessary avoidance of penicillin and other beta-lactam antibacterials
• Increased use of broad-spectrum antibiotics
• Higher rates of C. difficile and resistant infections
• Increased hospital stays and treatment costs with poorer clinical outcomes

Question 16

Definitions:
Infection?
Colonisation?
Carriage?

Answer 16

Infection
* Invasion of the body or a body part by a pathogenic organism, which multiplies and
produces harmful effects on the body’s tissues.

Colonisation
* the presence and multiplication of microorganisms without tissue invasion or damage

Carriage
* the condition of harbouring a pathogen within the body e.g. nasal carriage of MRSA

Question 17

Interpreting Culture & Sensitivity
results:

Answer 17

• Timing
  -In relation to symptoms/signs of infection
  -Before antibiotic started?
• Consider natural flora – consider if this will have been affected due to environment i.e. long stay in hospital/heath-care facility

Patient
*Are they unwell?
*Treat the patient, not the result
-Exceptions:
-Positive culture results from sites that are usually sterile
-Skin flora usually contaminants unless the sample has been taken aseptically

Question 18

Microbiology reporting to support AMS? (3)

Answer 18

• Support earlier use of narrow spectrum agents and IV to oral step-down
• Selective reporting of antimicrobial susceptibility testing results: tailoring susceptibility reports to show antibiotics that are consistent with hospital treatment guidelines or recommended by the
  stewardship program
• Comments in microbiology reports: for example, to help providers know which pathogens might represent colonisation or contamination

Question 19

IV antibiotics are favoured at the start of treatment for serious or deep-seated
infections in seriously ill patients due to what? (2)

Answer 19

• Short time taken to reach maximum serum concentrations
• 100% bioavailability – NB Lots of oral antibiotics have excellent bioavailability

The ideal route of administration of any medication is the one that achieves serum concentrations sufficient to produce the desired effect without producing any untoward effects.

Question 20

IV to Oral Switch:
When is it done?

Answer 20

Many patients who require IV
therapy initially can be switched to
oral after 24-48 hours provided that
they are improving clinically and are able to tolerate an oral formulation.

Not all infections are suitable for IV
to oral switch
Not all patients are suitable for IV to
oral switch

Question 21

What is the IV to Oral Checklist? (3)

Answer 21

1. Patient has an infection that can be effectively treated with oral abx
2. There are NO concerns about oral absorption
3. Patient is showing signs of clinical improvement

Question 22

What are the benefits of the IV to PO switch? (7)

Answer 22

• Remove lines quicker – reduce risk of line related infections and phlebitis /
  thrombophlebitis
• Reduced nursing work load
• increased patient satisfaction and comfort
• Facilitate earlier discharge
• Decreased costs
• Most sustainable – less plastic needed
• Narrow spectrum agents – reduce AMR and other consequence of broad
  spectrum agents such as C.difficile

Question 23

Why is there so much inappropriate prescribing of antibiotics? (6)

Answer 23

• Lack of awareness of guidelines or current evidence-based for non-antimicrobial
  treatment strategies. ‘This is how we’ve always done it’
• Time constraints. Interviews with prescribers reveal that they may quickly prescribe antibiotics because they want to avoid lengthy explanations of why the drugs are not needed and because a shorter appointment allows them to see more patients. In at least one study of general practitioners, busier physicians who see more patients prescribed antibiotics at a higher rate than did their less busy colleagues.
• Decision fatigue. The process of repeatedly diagnosing and treating large numbers of patients may affect a prescriber’s ability to make consistent prescribing decisions. For example, a recent study showed that as their workdays wore on, physicians became significantly more likely to prescribe antibiotics to patients with acute respiratory infections
• Uncertain diagnoses. Patients with viral and bacterial infections often have similar
  symptoms—congestion, cough, sore throat—making it difficult for prescribers to
  differentiate between the two in the absence of a diagnostic test. In these cases,
  prescribers may go ahead and prescribe antibiotics because they perceive the risk of not
  prescribing them as greater than that from unnecessary antibiotic use.
• Assuming that other prescribers are the problem. In some cases, even when prescribers agree that antibiotic overuse is a major problem or know that the drugs are not appropriate for a specific condition, they may not think their individual practices, or
  those of peers in the same medical specialty, contribute significantly to the problem.
  Rather, studies show that physicians attribute inappropriate prescribing to other
  clinicians or blame other areas of medicine
• Patient satisfaction and pressure Patients or their families may expect to
  get a prescription at an appointment, whether or not an antibiotic is necessary. Even when there is no expectation of antibiotics from patients or their families, doctors may think there is. Studies show that physicians can be affected by this pressure—real or perceived—and as a result are more likely to prescribe antibiotics