BUN/Cr-based Hydration Therapy to Improve Outcomes for Dehydrated Patients With Acute Ischemic Stroke.

The investigators have recently reported a novel finding that the blood urea nitrogen (BUN)/creatinine (Cr) ratio, a marker of hydration status, was an independent predictor of SIE among patients who had suffered acute ischemic stroke. The investigators found that patients who had a BUN/Cr ratio ≥ 15 were 3.4-fold more likely to experience SIE than patients who had a BUN/Cr ratio < 15. The ratio of SIE was 13.9% in all patients, with 20% in patients who had a BUN/Cr ratio ≥ 15 and 8.3% in patients who had a BUN/Cr ratio < 15. Among the patients presenting with acute ischemic stroke, 37% of them had a BUN/Cr ratio ≥ 15.

The investigators' recent pilot study was designed to determine if providing hydration therapy, specifically intravenous saline infusion, to patients with a blood urea nitrogen/creatinine ratio (BUN/Cr) ≥15 reduces the occurrence of SIE after acute ischemic stroke. Patients in the hydration group received a significantly larger (all P < 0.001) median volume of infused saline than patients in the control group. And this allowed 82% of the patients to maintain their BUN/Cr ratio <15 in first 8 hours. The proportion of patients who experienced SIE was significantly lower in the hydration group compared with the control group.

Dehydration, as indicated by an increased BUN/Cr ratio, is known to be relatively common among patients who have experienced stroke. According to the result of our pilot study, a hydration strategy with intravenous 20 cc per kilogram of body weight normal saline in first 8 hours was safe and effective to prevent dehydration related early neurological deterioration.

In this study, the investigators conduct a randomized double-blind control trial to test the hypothesis that whether BUN/Cr ratio based hydration therapy has clinical activity.

Inclusion criteria

• Acute ischemic stroke diagnosed by the clinical presentations and brain imaging is confirmed by a stroke care specialist.
• has a measurable neurologic deficit according to the National Institutes of Health Stroke Scale (NIHSS)
• the time between the onset of neurological symptoms and starting therapy are less than 12 hours
• admission BUN/Cr≧15

Exclusion criteria

• no informed consent obtained
• initial NIHSS >15
• prepared for or received fibrinolytic therapy
• prepared for or received surgical intervention with 14 days
• congestive heart failure according to past history or Framingham criteria
• history of liver cirrhosis or severe liver dysfunction (alanine aminotransferase or aspartate aminotransferase > x 3 upper normal limit)
• admission blood Cr >2 mg/dl
• initial systolic blood pressure <90 mmHg
• fever with core temperature >=38°C
• indication of diuretics for fluid overload
• any conditions needed more aggressive hydration or blood transfusion
• cancer under treatment
• life expectancy or any reasons for follow-up < 3 months