Do buffered solutions lower mortality better than regular saline in critical illness?
Buffered solutions (like lactated Ringer's) are sometimes thought to be better than regular saline because they may cause less metabolic acidosis and fewer electrolyte problems. However, a comprehensive meta-analysis of 34 randomized trials found no significant difference in mortality between buffered solutions and 0.9% saline for critically ill adults and children 6. This means that, based on current evidence, choosing one over the other does not appear to affect survival.
What the research says
A 2023 meta-analysis (updated in 2025) pooled data from 34 randomized controlled trials comparing buffered solutions to 0.9% saline in critical care settings 6. The analysis included patients needing fluid resuscitation or maintenance therapy. The primary outcome was mortality, and the results showed no statistically significant difference between the two fluid types 6. This finding was consistent across various subgroups, including trauma, burns, and emergency surgery patients 6.
While buffered solutions may reduce the risk of metabolic acidosis and hyperchloremia (high chloride levels), these laboratory improvements did not translate into a survival benefit in the meta-analysis 6. The review authors noted that the overall certainty of the evidence was moderate, meaning future research could still change the conclusion, but the current best evidence does not support using buffered solutions to lower mortality 6.
Other studies in critical care have examined different interventions to reduce mortality, such as continuous glucose monitoring 2 or enteral nutrition strategies 4, but these are separate questions. For fluid choice specifically, the meta-analysis remains the most comprehensive and direct source of evidence 6.
What to ask your doctor
- What type of intravenous fluid do you typically use for patients in the ICU, and why?
- Are there specific situations where a buffered solution might be preferred over saline for my condition?
- How do you monitor for electrolyte imbalances or acidosis when giving IV fluids?
- Should I be concerned about the type of fluid I receive if I am critically ill?
This question is drawn from common patient questions about Pulmonology & Critical Care and answered using cited medical research. We do not provide individualized advice.