Fever in critical neurologic illness.

Abstract

Fever is a commonmedical complication formany types of critical neurologic illnesses, including acute ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage, and brain trauma. In prospective observational studies, fever has been found in nearly 75% of patients.1 Fever is a form of secondary injury and independently worsens neurologic outcome and increases themortality in neurologic patients.1 Hence, fever is a therapeutic target that needs tobe identified, understood, and treated. Measuring temperature and determining the presence of fever is straightforward, but thedifferential diagnosis of infectious vs noninfectious (or central) fever is quite challenging and ismore art than science. It is well known that patients with intracranial blood may have noninfectious (or central) fever in the absence of objective signs of clinical infection. The criteria and methodological approach tomaking thedistinction between infectious andnoninfectious feveraresubject toconsiderablevariationamongpractitioners. This variability likely results in someantibiotic overusage,whichcan haveadverseeffects on thepatient inquestionandonmicrobial resistance across a larger cohort of patients. Hence, it is crucial to be able to determine infectious from noninfectious fever. In an article in JAMANeurology by Hocker et al,2 determinants ofnoninfectious feverwere identified froma largesingle-centerneurocritical care cohort of patients with a wide variety of critical neurologic illnesses, ranging fromsubarachnoidhemorrhage, intraventricular hemorrhage, and tumors to status epilepticus. The authors performed a retrospective analysis to design a classification tree schemaofwhich patients are likely to have infectious fever. Noninfectious fever occurring within 72 hours of admission was determined tobepresent in46%ofpatients.Blood transfusionswereanother independent factor associatedwith noninfectious fever. The authors proposed a step-wise selection treemethod for determining the cause of fever. JAMANEUROLOGY