Introduction: An estimated 44-70% of stroke patients present to the hospital in a dehydrated state. Prior studies suggest that volume contraction contributes to worsened neglect syndromes and reduced chance of early recovery. Thus we hypothesized that patients who were clinically dehydrated at the time of stroke carried a higher probability of worse functional outcome at three months.
Methods: We enrolled a consecutive series of ischemic stroke patients who presented to the hospital within 12 hours from stroke symptom onset. Patients were excluded if they had baseline kidney disease, presented with signs of active infection, or were unable to complete MRI. Clinical function was measured via daily NIHSS and 3 month modified Rankin scale (mRS). A priori, we defined a volume contracted state as BUN/creatinine ratio > 15 or urine specific gravity (SG) > 1.010.
Results: One hundred and four patients were eligible for inclusion after 1 year of recruitment, of whom 83 (80%) had urinalysis measured and were thus included in this analysis. 62/83 patients (75%) had elevated urine SG consistent with a clinically dehydrated state. Independent of age, sex, and baseline NIHSS score, patients with elevated urine SG > 1.010 had a 3.6 increased odds (95% CI; 1.31-9.93) of being in a higher (worse) modified mRS category (Figure). A combined model defining volume contraction using both elevated BUN/creatinine ratio and urine SG did not demonstrate a statistically meaningful difference in outcomes.
Conclusions: Elevated urine specific gravity at the time of ischemic stroke is associated with worse 3 month outcome. This objective marker may represent a readily available, standardized way to measure clinical dehydration syndromes as we attempt to define structured rehydration strategies for this population of patients.