Need for a consensus definition of chronic dehydration: A scoping review

Dehydration is common in older adults and impacts their clinical outcomes. Chronic dehydration is especially important as it has been under-recognized. This scoping review aimed to summarize the available definitions of chronic dehydration to identify gaps between each definition and discuss future research needs. Four databases (Pubmed, CINAHL, Cochrane Library, Science Direct) were systematically searched for peer-reviewed articles that clearly described the definition of chronic dehydration published from inception to June 8^th, 2023. Two researchers reviewed the articles independently, and any disagreement was solved upon discussion. We identified five articles with a wide range of subjects from children to older adults. Chronic dehydration was defined as a state of persistently elevated blood urea levels; weight loss ≥ 1% as a result of fluid loss; a ratio of blood urea nitrogen to creatinine > 20; serum osmolarity ≥ 295 mOsm/kg; and a dehydrated state lasting 72 hours or longer. The definition varied among studies, indicating the need to establish an international consensus on the definition of chronic dehydration.