Background: Fever has been associated with worse clinical outcomes in aneurysmal subarachnoid hemorrhage (aSAH). However, the impact of the cause, severity, and duration of fever is not clear. We conducted this study to evaluate the impact of fever and subfebrile load and fever characteristics on functional outcome. Methods: We collected detailed information on fever onset, cause, severity, and duration during the ICU stay in a cohort of 586 consecutive patients with aSAH. Fever was defined as core body temperature ≥ 38.3°C. Subfebrile measurements were those between 37 and 38.2°C. Febrile and subfrebile loads were defined as number of hours with fever or subfebrile measurements. Poor outcome was defined as modified Rankin score (mRS) > 2. Univariate and multivariate logistic regression models were developed to define predictors of outcome using various categorizations of fever cause, severity, and duration. Results: 532/586 patients (90.9%) had fever for a mean of 2.1±3.0 days. Fever started within 24 hours in 69 (11.8%) and within 72 hours in 110 (18.8%). Poor outcome occurred in 175 patients (29.9%). On univariate analysis, days of fever, febrile load, fever onset within 24 hours, and fever onset within 72 hours were associated with poor outcome (all p<0.001), but subfebrile load was not (p=0.58). On multivariate model constructed with all variables associated with outcome on univariate analyses (including age, WFNS grade, modified Fisher grade) days of fever remained independently associated with poor outcome (OR 1.14 of poor outcome per day of fever, 95% CI 1.06-1.22; p=0.0006) displacing all other fever measures from the final model. Conclusions: The great majority of patients with aSAH are febrile during their ICU stay. Early onset of fever, number of hours with fever, and especially days of fever are associated with poor functional outcome. Conversely, the number of hours with elevated but subfebrile temperature does not influence clinical outcome. These data suggest that prolonged fever should be avoided, but subfebrile temperatures do not justify intervention.
Predictors of excellent functional outcome in aneurysmal subarachnoid hemorrhage
OBJECT Case fatality rates after aneurysmal subarachnoid hemorrhage (aSAH) have decreased over time, and many patients treated with modern paradigms return to a normal life. However, there is little information on predictors of excellent functional outcome after aSAH. In this study, the authors investigated predictors of excellent outcome in a modern consecutive series of patients with aSAH. METHODS A retrospective review was conducted of patients with aSAH admitted between 2001 and 2013. The primary outcome measure was excellent functional outcome, defined as modified Rankin Scale (mRS) score of 0 or 1 at last follow-up within 1 year of aSAH. RESULTS Three hundred seventy-three patients were identified with posthospital follow-up. Excellent outcome was noted in 236 patients (63.3%), including an mRS score of 0 in 122 (32.7%) and an mRS score of 1 in 114 (30.6%). On univariate analysis, the following factors were associated with an excellent outcome: indicators of less severe bleeding, such as better World Federation of Neurosurgical Societies grade at any of the times of assessment, better modified Fisher grade, and absence of intracerebral hemorrhage (ICH), intraventricular hemorrhage (IVH), and symptomatic hydrocephalus; aneurysm treatment with coil embolization; absence of symptomatic vasospasm, delayed cerebral ischemia, and radiological infarction; absence of in-hospital seizures; lack of need for CSF diversion; fewer hours with fever; less severe anemia; and absence of transfusion. On multivariable analysis, the 4 variables that were most strongly associated with excellent outcome were presence of good clinical grade after neurological resuscitation, absence of ICH on initial CT scan, blood transfusion during the hospitalization, and radiological infarctions on final brain imaging. CONCLUSIONS Excellent outcomes (mRS score 0–1) can be achieved in the majority of patients with aSAH. The likelihood of excellent outcome is predicted by good clinical condition after resuscitation, absence of ICH on presentation, no evidence of infarction on brain imaging, and absence of blood transfusion during hospitalization.