Relationship between body temperature and neurological outcome in patients with acute brain injury: systematic review of clinical evidence (06AP03-11)

Background and Goal of Study: Temperature alterations in neurocritical care setting are common and have striking effect on brain metabolism leading or exacerbating neuronal injury. Fever (T >38,3°C) also negatively impact on acute brain injury (ABI) patients outcome. Conclusive evidence linking temperature control to improved outcome is still lacking. Aim of this review article is to evaluate the relationship between changes in body temperature in ABI and outcome. Materials and Methods: A literature search of 2 medical database was accomplished: PubMed Medline. Only complete studies (no abstracts), published in English in peer-reviewed journals were included. Two authors (M.P and P.S) independently screened and assessed titles, abstracts, and the full-text papers, using inclusion and exclusion criteria. A total of 32401 papers were screened and 32354 were excluded. We present 47 articles into 5 subchapters: mixed acute brain injury (7), brain trauma (6), intracranial hemorrhage (5), subarachnoid hemorrhage (12); ischemic stroke (17). Results and Discussion: ABI: fever correlates with increased inhospital mortality and functional outcome increasing brain metabolism and reducing blood flow. Brain trauma: fever in the first 48 hours after trauma did not predict mortality. Both the degree and duration of early post-trauma hyperthermia were strongly related with outcome.Intracranial hemorrhage: fever determines prognosis. Also subacute fever in large volume hematoma is a driver of neurological deterioration. Subarachnoid hemorrhage: the impact of fever on poor outcome is related to cerebral inflammatory response initiated at the time of aneurysm rupture, increased rate of vasospasm and delayed ischemic neurological deficits (DIND), increased ICP related to metabolic distress. Ischemic stroke: delayed hyperthermia is adverse associated with long-term outcomes and mortality compared with early period after an ischemic stroke. In patients treated with recanalization the role of hyperthermia on outcome is still controversial. Conclusion(s): Fever, infectious or central, is strongly correlated with poor neurological and functional outcome. Optimal patient temperature management and optimal method to recognise and treat infections in absence of fever remain still to define. References: Greer DM, Funk SE, Reaven NL, Ouzunelli M, Uman GC, Impact of Fever on Outcome in Patients With Stroke and Neurologic Injury A Comprehensive Meta-Analysis, Stroke. 2008;39: 3029-3035