Antimicrobial de-escalation as part of antimicrobial stewardship in intensive care: no simple answers to simple questions-a viewpoint of experts

Antimicrobial de-escalation (ADE) is defined as the discontinuation of one or more components of combination empirical therapy, and/or the change from a broad-spectrum to a narrower spectrum antimicrobial. It is most commonly recommended in the intensive care unit (ICU) patient who is treated with broad-spectrum antibiotics as a strategy to reduce antimicrobial pressure of empirical broad-spectrum therapy and prevent antimicrobial resistance, yet this has not been convincingly demonstrated in a clinical setting. Even if it appears beneficial, ADE may have some unwanted side effects: it has been associated with prolongation of antimicrobial therapy and could inappropriately be used as a justification for unrestricted broadness of empirical therapy. Also, exposing a patient to multiple, sequential antimicrobials could have unwanted effects on the microbiome. For these reasons, ADE has important shortcomings to be promoted as a quality indicator for appropriate antimicrobial use in the ICU. Despite this, ADE clearly has a role in the management of infections in the ICU. The most appropriate use of ADE is in patients with microbiologically confirmed infections requiring longer antimicrobial therapy. ADE should be used as an integral part of an ICU antimicrobial stewardship approach in which it is guided by optimal specimen quality and relevance. Rapid diagnostics may further assist in avoiding unnecessary initiation of broad-spectrum therapy, which in turn will decrease the need for subsequent ADE.