Noninvasive cardiac output monitor to quantify hydration status in ischemic stroke patients: A feasibility study

Background: Individuals who are dehydrated, volume contracted or both at the time of hospitalization for acute 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 sought 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 ischemic stroke patients, and explore the relationship with a common indirect laboratory -based measure of VCS.Methods: We performed a prospective observational feasibility study of hospitalized acute ischemic stroke pa-tients. We collected hemodynamic parameters using the NICOM device before and after fluid auto-bolus via passive leg raise and BUN/creatinine ratio. Successful acquisition of relevant hemodynamic data was the primary objective of this study. We explored agreement between the NICOM results and BUN/creatinine ratio using Cohen's kappa statistic.Results: Thirty patients hospitalized with acute ischemic stroke were enrolled. We found that 29/30 patients tolerated assessment with NICOM. Hemodynamic data were collected in all 30 patients. Data capture took an average of 10 min(SD +/- 112 s). Agreement between NICOM and BUN/creatinine ratio was 70%; (expected agreement 51%; kappa 0.38). Agreement was stronger in the cohort without history of diabetes (81% agreement, kappa 0.61).Conclusions: NICOM assessment was feasible in hospitalized stroke patients. The identification of an objective, real-time measure of hydration status would be clinically useful, and could allow precise, goal-directed care.