LAUSR

INTRODUCTION Ischemic stroke is the one of the most severe and debilitating diseases, and despite animal models, there is much to learn about the neuropathology in humans in a way that could inform the development of therapies. We have developed a protocol to collect and evaluate arterial blood immediately distal and proximal from the removed intracranial thrombus during mechanical thrombectomy. These samples provide a unique resource in evaluating acute changes in acid/base and electrolyte concentrations at the time of ischemic stroke. The purpose of this study was to compare acid/base and electrolytes obtained proximal and distal to the occluded intracranial thrombi between male and female acute ischemic stroke subjects at the time of thrombectomy; and to determine whether arterial blood gas values predict outcomes in male and female subjects. METHODS We analyzed the first 49 subjects (age = 67 ± 15.0, 21 males) in the BACTRAC registry. We compared arterial blood gas of blood distal versus proximal to the thrombus during thrombectomy which provided acid/base levels (pH, pCO2, pO2, BD, HCO3-) and electrolyte values (iCa2+, K+, and Na+). Comparisons were evaluated by one-way repeated measures ANOVA (p < .05). Moderated multiple regression with an interaction term of sex determined predictors of infarct volume, edema volume, and infarct time. RESULTS In general, distal intracranial luminal blood sample showed a compensated metabolic acidosis with an elevated oxygen concentration in both blood samples. Analysis indicated several significant differences in the proximal blood samples between sexes (pH, pCO2, and K+). Bicarbonate and base deficit were predictors of infarct time specifically in female subjects. DISCUSSION AND CONCLUSION Acid/base and electrolyte response to ischemic conditions differ between men and women, and these early changes could be used to predict local acid/base changes and how they develop differently in men and women during ischemia. These findings provide a novel insight into the pathology of large vessel stroke in humans, particularly potential variations based on sex.