The evaluation of fever in the intensive care unit.

F ever is a common complaint of patients seeking medical care. Depending on the cause ofthe fever, treatment can be as simple as reassurance or it can necessitate immediate admission to the intensive care unit (ICU). Hospitalized patients often develop fever. Two large studies reported fever occurring in 29 percent’ and 36 percents f medical inpatients. Mortality in those patients who developed fever was 13 percent as compared with 3 percent of those patients who remained afebrile.2 Within the hospital, the ICU is a likely place to observe fever. Patients with the most serious infections are usually admitted to the ICU, and the ICU likely represents the most common source of nosocomial infections.3 Infections in the ICU can lead to sepsis and multisystem organ failure-one of the most common causes of death in ICU patients.4 Given these facts, it is surprising fever occurrence in the ICU is not well documented in the medical literature. Although prospective studies ofthe frequency and cause of fevers in ICU patients are lacking, there exist abundant reports depicting individual accounts of infectious and noninfectious causes of fever in the ICU. An understanding of the diverse causes of fever in the ICU should aid clinicians when confronted with patients in whom fever of unclear cause develops.