Abstract 18863: Clinical Assessment of Volume Status in Heart Failure is Inaccurate at Detecting Hypervolemia and Anemia as Quantified by Blood Volume Measurement

Abstract

Introduction: Blood volume status is a crucial input for care decisions, especially the use of diuretics for decongestion, in acute decompensated heart failure (ADHF). In the absence of direct measurements, total blood volume (TBV) status is typically measured via clinical assessment of external fluid overload (edema, jugular venous distension, etc.), and red blood cell volume (RBCV) is assessed via hematocrit. A recent retrospective analysis showed that direct blood volume assessment (BVA) leads to better outcomes in ADHF. Hypothesis: We hypothesize that BVA-guided ADHF care can be protocolized and integrated into clinical workflow of ADHF management. Methods: The objective of this study is to prospectively compare the efficacy of standard care treatment decisions to those in a BVA-guided fluid management protocol. ADHF patients admitted to a Veterans Affairs Medical Center were randomized to either a control (n=8) or BVA-guided (n=8) arm. TBV, plasma volume (PV) and RBCV were measured at admission and prior to discharge by BVA utilizing an I-131 labeled albumin indicator-dilution technique (Daxor BVA-100). Clinician assessments of volume status were collected for all patients prior to BVA measurement. TBV status was defined relative to patient norms as: Hypovolemic (< -10%), Euvolemic (-10% to +10%), Hypervolemic (> +10%). RBCV status was defined as Anemic (< -10%) Not Anemic (> -10%). Results: Measured volume status at admission was quite heterogeneous, with 62.5% Anemic, and with 37.5% Hypovolemic, 31.25% Euvolemic, and 31.25% Hypervolemic. Clinical assessment at admission was notably inaccurate, with only 56% accuracy (sensitivity 40%, specificity 83%) on the presence of anemia, and only 31% accuracy on the presence of hypervolemia, with 94% of patients assessed by clinicians as hypervolemic. Non-hypervolemic patients in the BVA-Guided group received less diuretic treatment than non-hypervolemic controls. Conclusions: We successfully embedded a BVA guided treatment protocol into the clinical workflow of ADHF management at a large medical center. Clinical assessment of volume status was less accurate that direct BVA. Future studies will address whether BVA guided treatment leads to better outcomes in ADHF.