Balanced crystalloids versus isotonic saline in critically ill patients: systematic review and meta-analysis

Objectives: Intravenous fluids are one of the most used medical therapy for patients, especially critically ill patients. We conducted a meta-analysis comparing between balanced crystalloids and normal saline in critically ill patients and its effect on various clinical outcomes. Design: Meta-analysis and systematic review of randomized clinical trials (RCTs). Methods and data source: Electronic search was performed using PubMed, Cochrane library, and clinical trials. gov from inception through March 1, 2018, with inclusion of prospective studies that investigated one of the primary outcomes which were acute kidney injury (AKI) and in-hospital mortality while secondary outcomes were intensive care unit (ICU) mortality and new renal replacement therapy (RRT). Results: Six RCTs were included. Total of 19,332 patients were included in the final analysis. There was no significant difference in in-hospital mortality (11.5% vs 12.2%; OR 0.92; 95% CI 0.85-1.01; P = 0.09; I-2 = 0%), incidence of AKI (12% vs 12.7%, OR 0.92; 95% CI 0.84-1.01; P = 0.1; I-2 = 0), overall ICU mortality (OR 0.9, 95% CI 0.81-1.01, P = 0.08, I-2 = 0%), or need for new RRT (OR 0.92, 95% CI 0.67-1.28, P = 0.65, I-2 = 38%) between balanced crystalloids and isotonic saline in critically ill patients. Conclusion: Balanced crystalloids and isotonic saline have no difference on various clinical outcomes including in-hospital mortality, AKI, overall ICU mortality, and new RRT. Further powerful clinical trials are required to determine the relationship between crystalloid fluid type and clinical outcomes.