Focused Cardiac Ultrasound in Dyspnea of Unclear Etiology in the Emergency Department: Utility of the FLUID Score

We evaluated the utility of focused cardiac ultrasound to predict the length of stay in patients presenting to the emergency department with dyspnea of unclear etiology.

Patients with focused cardiac ultrasound examinations performed in the emergency department for dyspnea over a 34-month period were retrospectively identified. Patients were excluded if they had a prior diagnosis of heart failure, dialysis requirement, or an etiology of dyspnea unrelated to the volume status. Left ventricular function was categorized as normal or reduced, and the inferior vena cava was categorized as normal or increased volume. A fast limited ultrasound to investigate dyspnea (FLUID) score was calculated by adding 1 point for reduced left ventricular function and 1 point for increased volume, producing a score of 0, 1, or 2.

There were 123 patients included. There was a significant correlation between the FLUID score and length of stay, with longer stays for higher scores (FLUID score 0, 7.4 hours median; FLUID score 1, 2.34 days; FLUID score 2, 5.56 days; analysis of variance P < .001). Of the other variables collected, only age, hypertension, diabetes, heart rate, and brain natriuretic peptide were significantly correlated with the length of stay. A multivariate analysis including those variables and the FLUID score showed that the FLUID score was the strongest independent predictor of the length of stay.

Focused cardiac ultrasound and calculation of a FLUID score for patients with undifferentiated dyspnea can be a powerful tool to predict the hospital length of stay.