Executive Summary: Guidelines for Evaluating New Fever in Adult Patients in the ICU

Fever is frequently an early indicator of infection and often requires rigorous diagnostic evaluation. The range of potential etiologies of fever is vast and includes both infectious and noninfectious causes. Noninfectious causes of fever should be considered in the differential diagnosis, but because early treatment initiation may improve patient outcomes of infections, initial evaluation of patients with new-onset fever is usually directed at potential microbial causes, and this is the primary focus of this guideline. It should be noted that not all febrile episodes dictate a need for investigation (i.e., those in which a noninfectious etiology is obvious such as fever occurring immediately in the postoperative state). For those fevers that do require investigation, a good history and physical examination will often reveal potential sources of infection. Diagnostic studies should then be sent with those potential sources in focus rather than reflexively sending cultures for all possible sources. Although much of this document and its recommendations may be applicable to severely immunocompromised patients, such as organ transplant recipients and those with severe neutropenia, these populations are not directly addressed here. The variability and complexities of different types of immunocompromise make this a task that cannot be accomplished in the context of a generally applicable guideline.