Elevated body temperature in ischemic stroke associated with neurological improvement

Body temperature in the acute phase and clinical outcomes after acute ischemic stroke

BACKGROUND

This study aimed to examine whether post-stroke early body temperature is associated with neurological damage in the acute phase and functional outcomes at three months.

METHODS

We included 7,177 patients with acute ischemic stroke within 24 h of onset. Axillary temperature was measured daily in the morning for seven days. Mean body temperature was grouped into five quintiles (Q1: 35.1‒36.5°C, Q2: 36.5‒36.7°C, Q3: 36.7‒36.8°C, Q4: 36.8‒37.1°C, and Q5: 37.1‒39.1°C). Clinical outcomes included neurological improvement during hospitalization and poor functional outcome (modified Rankin scale score, 3-6) at three months. A logistic regression analysis was performed to evaluate the association between body temperature and clinical outcomes.

RESULTS

The patient's mean (SD) age was 70.6 (12.3) years, and 35.7% of patients were women. Mean body temperature was significantly associated with less neurological improvement from Q2 (odds ratios [95% confidence interval], 0.77 [0.65-0.99] vs. Q1) to Q5 (0.33 [0.28-0.40], P for trend <0.001) even after adjusting for potential confounders, including baseline neurological severity, C-reactive protein levels, and post-stroke acute infections. The multivariable-adjusted risk of poor functional outcome linearly increased from Q2 (1.36 [1.03-1.79]) to Q5 (6.44 [5.19-8.96], P for trend <0.001). These associations were maintained even in the analyses excluding patients with acute infectious diseases. Multivariable-adjusted risk of poor functional outcome was higher in patients with early body temperature elevation on days 1-3 and with longer duration with body temperature >37.0°C.

CONCLUSIONS

Post-stroke early high body temperature is independently associated with unfavorable outcomes following acute ischemic stroke.

Temperature management in acute brain injury: A systematic review of clinical evidence

Temperature alterations in neurocritical care settings are common and have a striking effect on brain metabolism leading to or exacerbating neuronal injury. Hyperthermia worsens acute brain injury (ABI) patients outcome. However conclusive evidence linking control of temperature to improved outcome is still lacking. This review article report an update -results from clinical studies published between March 2006 and March 2020- on the relationship between hyperthermia or Target Temperature Management and functional outcome or mortality in ABI patients.

MATERIALS AND METHODS

A systematic search of articles in PubMed and EMBASE database was accomplished. Only complete studies, published in English in peer-reviewed journals were included.

RESULTS

A total of 63 articles into 5 subchapters are presented: acute ischemic stroke (17), subarachnoid hemorrhage (14), brain trauma (14), intracranial hemorrhage (8), and mixed acute brain injury (10). This evidence confirm and extend the negative impact of hyperthermia in ABI patients on worse functional outcome and higher mortality. In particular "early hyperthermia" in AIS patients seems to have a protective role have as promoting factor of clot lysis but no conclusive evidence is available. Normothermic TTM seems to have a positive effect on TBI patients in a reduced mortality rate compared to hypothermic TTM.

CONCLUSIONS

Hyperthermia in ABI patients is associated with worse functional outcome and higher mortality. The use of normothermic TTM has an established indication only in TBI; further studies are needed to define the role and the indications of normothermic TTM in ABI patients.

Temperature-Induced Changes in Reperfused Stroke: Inflammatory and Thrombolytic Biomarkers

Although hyperthermia is associated with poor outcomes in ischaemic stroke (IS), some studies indicate that high body temperature may benefit reperfusion therapies. We assessed the association of temperature with effective reperfusion (defined as a reduction of ≥8 points in the National Institute of Health Stroke Scale (NIHSS) within the first 24 h) and poor outcome (modified Rankin Scale (mRS) > 2) in 875 retrospectively-included IS patients. We also studied the influence of temperature on thrombolytic (cellular fibronectin (cFn); matrix metalloproteinase 9 (MMP-9)) and inflammatory biomarkers (tumour necrosis factor-alpha (TNF-α), interleukin 6 (IL-6)) and their relationship with effective reperfusion. Our results showed that a higher temperature at 24 but not 6 h after stroke was associated with failed reperfusion (OR: 0.373, p = 0.001), poor outcome (OR: 2.190, p = 0.005) and higher IL-6 levels (OR: 0.958, p < 0.0001). Temperature at 6 h was associated with higher MMP-9 levels (R = 0.697; p < 0.0001) and effective reperfusion, although this last association disappeared after adjusting for confounding factors (OR: 1.178, p = 0.166). Our results suggest that body temperature > 37.5 °C at 24 h, but not at 6 h after stroke, is correlated with reperfusion failure, poor clinical outcome, and infarct size. Mild hyperthermia (36.5–37.5 °C) in the first 6 h window might benefit drug reperfusion therapies by promoting clot lysis.

U-shaped relationship between hemoglobin level and severity of ischemic stroke

BACKGROUND AND AIM

We aimed to explore the relation between hemoglobin level and ischemic stroke severity and short-term improvement in patients admitted to hospital within 3 hours of stroke onset.

METHODS

The relation between stroke severity and hemoglobin was explored by locally weighted scatterplot smoothing (lowess smoother) curves. The effect of hemoglobin on short-term outcome was determined by means of linear regression analyses with NIHSS score day 7 as dependent variable after adjusting for confounders including NIHSS score on admission. Analyses were performed to disclose clinical factor associated with hemoglobin level.

RESULTS

This study includes 905 ischemic stroke patients admitted within 3 hours of stroke onset. Lowess smoother curves showed a U-shaped relation between NIHSS score on admission and mRS score day 7 and hemoglobin level. Regression analysis showed low hemoglobin to be independently associated with females, high age, severe stroke, low systolic blood pressure, prior cerebral infarction, not smoking, not atrial fibrillation, and unknown etiology (all P < 0.05). Another regression analysis showed that high NIHSS score day 7 was independently associated with low hemoglobin after adjusting for confounders including NIHSS score on admission.

CONCLUSIONS

We found a U-shaped relationship between hemoglobin level on admission and stroke severity. There was no U-shaped relationship between improvement and hemoglobin level. Poor short-term improvement was associated with low hemoglobin levels.

Anesthesia for stroke rescue

PURPOSE OF REVIEW

To highlight the potential implications of recent advances in the management of large vessel occlusions for intraprocedural anesthetic management.

RECENT FINDINGS

Stroke remains the leading cause of disability in the United States and the second leading cause of death in the world. Several randomized control trials published within the past decade have helped to make endovascular thrombectomy the standard of care for all eligible patients. However, whether intraprocedural anesthesia care practices may significantly improve in-hospital and out-of-hospital morbidity and mortality outcomes are not clear.

SUMMARY

Management strategies that shorten the time to intervention and maintain blood pressure to preserve penumbral tissue may be beneficial. Future well powered studies are necessary to enable inferences on what type of anesthetic management is harmless, neurotoxic, or neural plasticity promoting.