To test the feasibility and acceptability of a non-invasive cardiac output monitor (NICOM) for the measurement of hydration status in a group of hospitalized patients with acute ischemic stroke, and to test its relationship with a common indirect laboratory-based measure of hydration status.

Individuals who are dehydrated, volume contracted or both at the time of hospitalization following ischemic stroke have worse clinical outcomes than do individuals with optimal volume status. Currently, there is no gold standard method for measuring hydration status, except indirect markers of a volume contracted state (VCS) including elevated blood urea nitrogen (BUN)/creatinine ratio.

We performed a prospective feasibility study of acute ischemic stroke patients admitted to a comprehensive stroke center. Patients were included if hospitalized within 24 hours of acute ischemic stroke onset. We collected hemodynamic data from the NICOM device and recorded blood urea nitrogen (BUN)/creatinine ratio, measured in serum within 12 hours from NICOM use. Successful acquisition of relevant hemodynamic data, including the (cardiac) stroke volume index (SVI), was the primary objective of this study. Laboratory-based criteria for a volume contracted state were met if BUN/creatinine ratio > 15. Cohen’s kappa statistic was used to evaluate level of agreement between these two potential markers of hydration status.

Thirty patients were enrolled. Of those, 29 out of 30 tolerated NICOM assessment and hemodynamic data were collected in all 30 patients. Data capture took an average of 10 min (SD 112 seconds). Agreement between NICOM and BUN/creatinine ratio was 70%; (expected agreement 51%; kappa 0.38).

NICOM assessment was feasible in hospitalized stroke patients with hemodynamic disturbance and comorbid conditions. There was moderate agreement between VCS as measured by NICOM and BUN/creatinine ratio. The identification of an objective, real-time measure of hydration status would be clinically useful, and could allow delivery of individualized and goal-directed care.