Discuss strategies to limit antimicrobial resistance (AMR) in the ICU.

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College answer

Factors driving antimicrobial resistance (AMR) include inappropriate use of antibiotics, inadequate monitoring and surveillance, poor infection control practices and failing antibiotic pipeline. 
 
Strategies to limit AMR include: 
1. Antimicrobial Stewardship 
Appropriate antimicrobial prescribing (right indication, right drug(s), right dose, right dosing regime, right duration) 
Liaison with microbiology / infectious diseases team 
Knowledge of local antibiograms 
Streamlining to narrow spectrum drugs / oral agents when appropriate Education of staff 
Computer-assisted prescribing 
Prescribing protocols 
Cycling of antibiotics (uncertain benefit) 
Antimicrobial prescribing committee 
 
2. Infection control 
Hand hygiene 
Barrier precautions 
Environmental cleaning 
Isolation / cohorting of patients 
Surveillance / screening / monitoring 
Appropriate staff:patient ratios 
Limit indwelling devices / appropriate asepsis for insertion etc 
Care bundles to reduce VAP, reduce time on ventilator, early enteral feeding etc 
 
3. Other 
Vaccination programs 
Adequate source control e.g. surgical drainage of abscesses Future directions include: 
More rapid and accurate diagnosis of sepsis 
Advances in genomics 
Immunomodulating agents  
Use of bacteriophages 
Use of antibiotics in agriculture and animal husbandry 
New drug development 
Synergistic combinations of antibiotics and drugs with no antimicrobial effect (eg minocycline and loperamide enhances action against staph aureus) 
 

Discussion

Prevention of resistance development

  • Use of some antibiotics should be restricted/reserved
    • Use in agriculture and animal husbandry needs to be limited
  • Broad spectrum antibiotics must be deployed intelligently
    • Rapid diagnostic methods to guide rapid de-escalation
  • Antibiotics must be reviewed daily, and narrowed or discontinued when appropriate
  • Infectious diseases physicians should have greater input into prescribing practices
  • Perioperative prophylaxis needs to be rationalised
  • Antibiotic cycling may be helpful in preventing the emergeance of resistant strains
  • Combination therapy may be relevant to some species (eg. rifampicin plus fusidic acid, rather than either one as a sole agent).
  • Selective digestive tract decontamination could potentially be useful
  • Scrupulous attention to source control (i.e. do not use antibotics as a substitute for source control)

Prevention of MRO transmission:

  • Routine barrier and infection control process needs complicance monitoring and regular review.
  • Surveillance for MROs must be proactive.
  • Patient isolation should be practiced
  • Decolonisation may be used in certain circumstances

Prevention of clinically relevant MRO infections in colonised patients

  • Careful monitoring of indwelling devices
  • Vaccinations

Management of MRO infections

  • Multi-drug cocktails might be helpful
  • Use of a higher concentration of a drug may defeat resistance 
  • MIC monitoring may guide dosing
  • New drugs may need to be developed
  • Novel drug combinations which exploit a synergy between antibiotics and non-antibiotic drugs - the college mention minocycline with loperamide but there are numerous others (Worthington, 2013)
  • Non-drug (eg. bacteriophage, immunoglobulin, hyperbaric oxygen) therapy may become necessary

References

References

Elliott, T. S. J., and P. A. Lambert. "Antibacterial resistance in the intensive care unit: mechanisms and management." British medical bulletin 55.1 (1999): 259-276.

Brusselaers, Nele, Dirk Vogelaers, and Stijn Blot. "The rising problem of antimicrobial resistance in the intensive care unit." Annals of intensive care 1.1 (2011): 1-7.

Niederman, Michael S. "Impact of antibiotic resistance on clinical outcomes and the cost of care." Critical care medicine 29.4 (2001): N114-N120.

Kollef, Marin H., and Victoria J. Fraser. "Antibiotic resistance in the intensive care unit." Annals of internal medicine 134.4 (2001): 298-314.

Spellberg, Brad, John G. Bartlett, and David N. Gilbert. "The future of antibiotics and resistance." New England Journal of Medicine 368.4 (2013): 299-302.

Di Bella, Stefano, and Nicola Petrosillo. "Management of antibiotic resistance in the intensive care unit setting from an international perspective."Microbiology Australia 35.1 (2014): 63-65.

Worthington, Roberta J., and Christian Melander. "Combination approaches to combat multidrug-resistant bacteria." Trends in biotechnology 31.3 (2013): 177-184.