Results: Overall, there was poor agreement among the different FRes assessments evaluated. The only measures that showed fair agreement were LVOTVTI and carotid Vmax (κ = 0.34) as well as carotid Vmax and femoral Vmax (κ = 0.26). IVC respiratory variation showed poor agreement with all other measures studied (κ = 0 to -0.01). Clinician judgment showed poor agreement with all ultrasound measures studied (κ = -0.15 to 0.18). Clinicians rated their judgment as “highly certain” 45 percent of the time, “somewhat certain” 35 percent of the time, and “not at all certain” 20 percent of the time.

Projected Impact: This research will hopefully contribute to our understanding of how ultrasound may be used by emergency physicians to support clinical judgment when making complex decisions regarding fluid management in septic and critically ill patients. Even when performed by expert sonographers, the variety of ultrasound measurements currently in use to assess FRes show only poor to fair agreement with one another. Despite experienced clinicians expressing a high or moderate degree of certainty in their clinical assessment of FRes 80 percent of the time, there was poor agreement of these assessments with all ultrasound measures of FRes. Given the increasing recognition of the importance of accurate assessment of FRes in critically ill patients, future studies will need to clarify which measures should be used by emergency physicians when assessing FRes as these data suggest that the same patient could be deemed fluid responsive or nonresponsive depending on the method of assessment used.

Dr. Crager is a critical care fellow in the Department of Anesthesia at Stanford Hospital in Stanford, California.