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

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.

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.

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.

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.