What can be expected from antimicrobial de-escalation in the critically ill?

Excerpt

Antimicrobial de-escalation is a clinical approach to empirical antibiotic treatment of serious infections that attempts to balance the need for appropriate initial therapy with the need to limit unnecessary antimicrobial exposure in order to curtail the emergence of resistance [1]. When risk factors for antibiotic resistance are identified in patients with a serious infection, broad-spectrum antimicrobials should be prescribed. A de-escalation approach usually requires initial combination antimicrobial treatment targeting resistant non-fermenting gram-negative bacilli (NFGNB) (Pseudomonas aeruginosa, Acintobacter species) and methicillin-resistant Staphylococcus aureus [2]. However, depending on clinical presentation, patient risk factors, and local epidemiology, other pathogens such as Candida species and Clostridium difficile, especially when diarrhea is present, may also need to be covered. Once the microbiologic results are available and the patient’s clinical response is observed, the antibiotic regimen can be narrowed on the basis of the susceptibilities of the identified pathogens. …