Choice of Intravenous Crystalloid Fluid and Mortality in Critically Ill Adult Patients

Abstract

A large trial has suggested the benefit of using balanced crystalloids, as compared to normal saline, for reducing kidney injury in critically ill patients. A review of the literature suggests no clear consensus on the benefit of balanced crystalloids for mortality or other clinically important outcomes in critically ill patients. To this end, the authors performed a systematic review and meta-analysis of the available literature to evaluate the impact of balanced crystalloids compared to normal saline on clinical outcomes in critically ill patients. The authors show that intravenous balanced crystalloid, as compared to normal saline, fluid therapy does not significantly reduce mortality, major adverse kidney events at 30 days, or receipt of new renal replacement therapy in critically ill adult patients. Supplemental digital content is available in the text. Objectives Intravenous balanced crystalloid fluid therapy may improve mortality and other outcomes in critically ill adult patients, but data are conflicting. We conducted a meta-analysis and literature review to evaluate the impact of intravenous balanced crystalloid, as compared with normal saline, fluid therapy on outcomes in critically ill adult patients. Methods We searched PubMed, Scopus, MEDLINE, and the Cochrane Register of Clinical Trials for relevant studies. Randomized controlled trials comparing the effects of balanced intravenous crystalloids with normal saline on intensive care unit (ICU) or hospital mortality were included. Pooled risk ratios (RRs) were calculated using a fixed effects model. Heterogeneity was calculated using the I2 statistic. The risk of bias was assessed using the Cochrane tool. Results Seven randomized controlled trials with 20,171 patients (10,179 participants received balanced crystalloids and 9992 participants received normal saline) were included. For hospital mortality, the pooled RR (95% confidence interval [CI]) was 0.92 (0.85–1.00). For ICU mortality, the pooled RR (95% CI) was 0.91 (0.82–1.00). For major adverse kidney events at 30 days, pooled RR (95% CI) was 0.95 (0.88–1.01). For stage ≥2 acute kidney injury, the pooled RR (95% CI) was 0.94 (0.86–1.02). For receipt of new renal replacement therapy, the pooled RR (95% CI) was 0.91 (0.77–1.07). None of these findings reached statistical significance. Conclusions Intravenous balanced crystalloid use, compared with normal saline, does not result in a statistically significant reduction in hospital or ICU mortality, major adverse kidney events at 30 days, stage ≥2 acute kidney injury, or receipt of new renal replacement therapy in critically ill adult patients.