Hypernatremia in Hospitalised Adult Patients—A Scoping Review

Background Hypernatremia is a common condition associated with poor outcomes. We aimed to provide an overview of hypernatremia in hospitalised patients, focusing on its occurrence, treatment strategies, treatment‐associated serious adverse events and reported outcomes in studies investigating hypernatremia. Method The review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses extension for Scoping Reviews and a pre‐published protocol. We searched Medline, PubMed, Embase and Cochrane Library from inception without restrictions to language, publication date or study design. Any study reporting on hypernatremia in hospitalised adults was eligible. Results We included 200 studies: 198 observational studies and two randomised clinical trials, comprising 111 (55.5%) intensive care unit (ICU) studies, 89 (44.5%) non‐ICU studies, with data from over 431,000 patients with hypernatremia. The median proportion of patients with hypernatremia was 3.5% (IQR: 2.0%, 9.4%) in non‐ICU studies and 21.8% (IQR: 7.9%, 37.5%) in ICU studies. The variations were partly due to differing definitions. The reported treatments of hypernatremia included hypotonic fluids (three studies), thiazide diuretics (three studies) and renal replacement therapy (four studies). Serious adverse events were rarely reported. Patient‐important outcomes were frequently reported, including mortality in 186 studies (93.0%), ICU or hospital length of stay in 109 studies (54.5%) and use of mechanical ventilation in 47 studies (23.5%). Conclusion In this scoping review, hypernatremia was present in 3.5% of the patients in non‐ICU studies and in 21.8% in ICU studies. Most studies reported on mortality and length of stay. Treatment with hypotonic fluids, thiazides and renal replacement was investigated in nine studies and serious adverse events were rarely reported. Current evidence precludes firm conclusions regarding the safety and efficacy of specific therapies. Editorial Comment This scoping review presents an overview of published assessments of hypernatremia and treatments in hospitalized cases and is mostly composed of non‐interventional cohort studies with follow‐up. To date, there is not enough published evidence to confidently identify efficacy and safety for different treatment approaches.