Noninvasive Hemodynamic Profiling of Patients Undergoing Hemodialysis Using a Handheld Ultrasound Device

Abstract

INTRODUCTION: Accurate determination of volume status for patients with end-stage renal disease is essential in determining ultrafiltration rate during hemodialysis (HD). To complement the current dry weight method, inferior vena cava (IVC) collapsibility, made accessible by point of-care ultrasonography, is considered. This study determined the utility of IVC measurement in estimating the volume status of patients during HD in comparison to clinical parameters. METHODS: A single-center cross-sectional design including 53 HD patients was conducted, with IVC measurements done through the Butterfly iQ ultrasound (Butterfly Network, Burlington, Massachusetts). RESULTS: Most patients were hypervolemic before HD based on weight (94.3%) and IVC collapsibility index (IVC-CI; 75.5%), but only 30% had clinical symptoms. Body weight, maximum IVC diameter, minimum IVC diameter, and indexed IVC size significantly decreased after HD, whereas IVC-CI, blood pressure, and heart rate were unchanged. For the subset of patients with symptoms, absolute values of IVC measures were higher, but did not significantly change after HD, unlike in those without symptoms. For volume classification, there are discrepancies in the classifications based on the different measures, with most improvement seen when weight was used, but which was not reflected in IVC-CI. Change in weight and IVC measures were not significantly correlated. DISCUSSION: This pilot study showed that the current dry weight method provides ultrafiltration rate estimation without causing intradialytic events. However, IVC can be a supplemental parameter to set higher targets and increase volume removal enough to cause intravascular change, especially in symptomatic patients. The incongruencies in classifying volume status suggest that there is no single measure to determine hemodynamic status and that using multiple parameters may provide a more reliable estimate. KEYWORDS: inferior vena cava measurement, volume status in hemodialysis, point-of-care ultrasonography