Multicentre pragmatic embedded stepped wedge cluster randomised trial comparing glucose 5% with sodium chloride 0.9% as the default drug diluent in the ICU: the sweet-water trial protocol.

Introduction: Hypernatraemia, defined as a plasma sodium concentration >145 mmol/L, is a frequent complication in critically ill patients treated in the intensive care unit (ICU) (= ICU-acquired hypernatraemia), with reported prevalence ranging from 4% to 26%. Hypernatraemia adversely affects various physiological functions and is associated with delirium, prolonged length of stay and increased ICU and post-discharge mortality. The sodium load from intravenous drug diluents significantly contributes to ICU-acquired hypernatraemia, with drug infusions comprising about 30% of the daily fluid volume of an average ICU patient. This study aims to investigate if using glucose 5% solution as the default drug diluent, instead of sodium chloride 0.9%, can reduce the prevalence of ICU-acquired hypernatraemia and improve patient outcomes.

Methods And Analysis: To test the effectiveness of glucose 5% solution as the default drug diluent, we will conduct a multicentre, pragmatic, embedded, open-label, stepped-wedge, cluster-randomised trial. The study will include twelve clusters (ICUs and one intermediate care unit) across six hospitals in Germany, with a projected total sample size of 4485 patients. In line with the stepped-wedge cluster-randomised design, one ICU will transition every 4 weeks, in a randomised sequence, from using sodium chloride 0.9% as the default drug diluent to glucose 5%.The primary endpoint is the prevalence of hypernatraemia >150 mmol/L through day 28. The number of days alive and free of the ICU through day 28 will be tested hierarchically as a key secondary endpoint. Other exploratory endpoints include ICU mortality, ICU-free days, hospital-free days and other clinical outcomes. The primary endpoint will be analysed using a logistic mixed-effects model.

Ethics And Dissemination: The trial was approved by the Charité-Universitätsmedizin Berlin Ethics Board and by the ethics board of each enrolled hospital. The results will be submitted for publication in a peer-reviewed journal and presented at one or more scientific conferences.

Trial Registration Number: The trial protocol was registered with the German Clinical Trials Register on 21 June 2024 prior to initiation of patient enrolment (DRKS00033397).