Approach to the febrile patient in the ICU.

Fever is a normal adaptive brain response to infectious and noninfectious causes involving a cytokine-mediated response, the generation of acute phase reactants, and the activation of numerous physiologic, endocrinologic and immunologic systems. Ninety percent of patients with severe sepsis in the intensive care unit (ICU) will experience fever during their hospitalization, while the half of the new detected febrile episodes are of noninfectious origin. In the ICU, fever should be treated in cardiorespiratory and neurosurgical patients and in those in whom temperature exceeds 40 degrees C (104 degrees F). Antipyretic therapy must be justified regardless of the metabolic cost (if fever exceeds its physiologic benefit), the result (if the symptomatic relief adversely affects the course of the febrile illness) and the side effects.