AMS in the ICU/Critical Care

The following article on the importance of AMS in the ICU and how to successfully implement strategies was written by Nesrine Rizk MD and Nisrine Haddad PharmD.

Patients in the ICU are particularly at risk of acquiring antimicrobial-resistant (AMR) infections due to immune deficiencies, invasive devices, increased risk of transmission, and exposure to antibiotics.

There is a considerable rise in the prevalence of infections in the ICUs, with 51% of ICU patients having an infection, and 71% of ICU patients receiving antibiotics.

Contributors to the Spread of AMR in the ICU

• Older age

• Lack of functional independence and/or decreased cognition

• Presence of underlying comorbid conditions

• Higher severity of acute illness indices

• Long duration of hospitalisation prior to the ICU admission (e.g. nursing homes)

• Frequent encounters with health care environments (hemodialysis units, IV infusion centres)

• Frequent contact with health care personnel concurrently caring for multiple patients

• Shared equipment and contaminated environments such as reservoirs and/or vectors that contribute to the acquisition of infections

• Presence of indwelling devices such as CVCs, urinary catheters, ETTs, all of which bypass natural host defence mechanisms and serve as portals of entry for pathogens

• Recent surgery or other invasive procedures

• Receipt of antimicrobial therapy prior to the ICU admission, leading to selective pressure promoting the emergence of multidrug-resistant bacteria

Consequences of AMR and Antibiotic Misuse

Infections caused by gram-negative multidrug-resistant organisms (MDRO) are associated with high morbidity and mortality, significant direct and indirect costs, and prolonged hospitalisations due to antibiotic treatment failures.

Antibiotic misuse in the ICU leads to an increasing prevalence of AMR to β-lactam antibiotics, the fact that limits treatment options. It also contributes to the increasing incidence of C. difficile.

Barriers to Successful Antimicrobial Stewardship (AMS) in the ICU

1) Fear of not adequately covering the causative pathogen/broad-spectrum (e.g. Using broad-spectrum combination gram-negative coverage for patients with septic shock from CAP, with no risk factors for MDRO)

2) Suspected vs definite diagnosis

• bacterial vs. viral pneumonia
• BAL or direct sampling in intubated patients is recommended by the European hospital-acquired pneumonia (HAP)/VAP guidelines, the Infectious Diseases Society of America/American Thoracic Society (IDSA/ATS) guidelines

3) Urinary tract infections

4) Colonisation vs. real infection

• Underappreciation of the toxicity of antibiotics

Check an example of AMS major activities in the ICU.

Key Elements of AMS in the ICU

1) Leadership: The role of hospital leadership is primordial but there is an even greater benefit from integrating AMS with ICU leadership, building collaborative practice, and sharing antibiotic utilisation data between the AMS and ICU leadership

2) Bundles

3) Prospective audits: These are mainly performed through handshake stewardship, which is a new, preferred method of performing AMS. It involves a prospective review of hospital-wide antimicrobial ordering and includes a compressed “second look” of relevant clinical and historical patient data. In-person recommendations are then provided directly to the medical team.

Defining and reporting process measures is essential to identify the gaps and assess the effectiveness of an antimicrobial stewardship program in the ICU or in any other setting. Examples of defining and reporting process measures can be found here.