Fluid balance in critical illness: choosing our words wisely

• DOI: 10.1007/s44253-025-00061-w
• Publication Date: 2025-02-11T16:35:06Z
• Authors: Chloe G. Braun; David T. Selewski; Adam C. Dziorny; Denise C. Hasson

Abstract It is becoming well accepted that excess fluid buildup, especially in critically ill patients, is both common and portends worse outcomes. With the increasing number of publications over the last 20 years to describe these associations, there have been increasing calls for the harmonization of terminology, with the terms fluid balance, fluid accumulation, and fluid overload predominating. Utilization of the term “fluid overload” to describe all states of positive fluid balance introduces inherent bias, as not all positive fluid balance is associated with deleterious outcomes. The utilization of neutral terminology is important as it allows for the interpretation of fluid status in the context of an individual patient’s pathophysiology, phase of illness, and progression of disease. Fluid nomenclature should be clear and standardized so that fluid balance goals can be set and re-evaluated in a matter understood across disciplines to inform management changes. Together, in a multidisciplinary manner, we must harmonize our nomenclature in order to optimize our clinical assessment of percent cumulative fluid balance and develop an individualized approach to reducing fluid accumulation to improve clinical outcomes. Herein we provide a brief report describing (1) the history and definition of the term fluid overload, (2) the changing paradigm of fluid balance and accumulation, and (3) a proposed framework for the harmonization of terminology.