Abstract 4013: The Hydration Influence on the Risk of Ischemic Stroke Outcome (THIRST-O) Study

Abstract

Background: Alterations in electrolyte balance and other basic elements such as serum osmolarity have been claimed to play a role in the pathophysiology of ischemic cerebrovascular disease. However, the relationship between the serum osmolarity pattern, clinical severity and outcome after an acute ischemic stroke is not fully understood. Acute ischemic stroke may be due to heperviscosity that is commonly secondary to dehydration. Also, there is a decreased sensation of thirst and ability to swallow fluids in post stroke patients. It is unclear whether these changes contribute to cerebral ischemic events. This study may add to our understanding of previously published findings of THIRST study. Objective: The aim of the present study was to test whether the calculated serum osmolarity on admission and discharge have correlation with severity, as measured by National Institute of Health Stroke Scale(NIHSS); and outcome of ischemic stroke patients, as measured by Discharge Modified Rankin Scale (DCmRS). Methods: Consecutive patients presenting to a university affiliated community hospital within 24 hour of symptom onset, and a discharge diagnosis of acute ischemic stroke were identified. Their serum BUN level and calculated plasma Osmolality at the time of presentation and before discharge was compared. Correlation coefficient (Spearsman’s rho) and Mann Whitney test were performed. SPSS version 11 was utilized for data analysis. Results: A total of 540 patients met the study criteria. We divided the patients into two groups, Osmolarity more than 295 (group A= 217 patients) and less than 295 (group B=323 patients). The initial NIHSS (p=0.036) and DCmRS (p=0.19) were statistically different in both groups. We found a similar trend between day of discharge serum osmolarity and DCmRS. Conclusion: Our study suggests that high initial and discharge serum osmolarity has a negative impact on stroke severity and outcome especially in elderly patients. A future prospective randomized study is warranted.