Saline versus 5% dextrose in water as a drug diluent for critically ill patients: a retrospective cohort study

The choice of intravenous infusion products for critically ill patients has been studied extensively because it can affect prognosis. However, there has been little research on drug diluents in this context. The purpose of this study is to evaluate the impact of diluent choice (saline or 5% dextrose in water [D5W]) on electrolyte abnormalities, blood glucose control, incidence of acute kidney injury (AKI), and mortality. This before-after, two-group comparative, retrospective study enrolled adult patients who stayed for more than 48 h in a general intensive care unit from July 2015 to December 2018. We changed the default diluent for intermittent drug sets in our electronic ordering system from D5W to saline at the end of 2016. We included 844 patients: 365 in the D5W period and 479 in the saline period. Drug diluents accounted for 21.4% of the total infusion volume. The incidences of hypernatremia and hyperchloremia were significantly greater in the saline group compared to the D5W group (hypernatremia 27.3% vs. 14.6%, p < 0.001; hyperchloremia 36.9 % vs. 20.4%, p < 0.001). Multivariate analyses confirmed the similar effects (hypernatremia adjusted odds ratio (OR), 2.43; 95% confidence interval (CI), 1.54–3.82; hyperchloremia adjusted OR, 2.09; 95% CI, 1.31–3.34). There was no significant difference in the incidences of hyperglycemia, AKI, and mortality between the two groups. Changing the diluent default from D5W to saline had no effect on blood glucose control and increased the incidences of hypernatremia and hyperchloremia.