UMEM Educational Pearls

Title: Balanced Multielectrolyte Solution versus Saline in Critically Ill Adults

Keywords: Saline, balanced fluid, critically ill, mortality (PubMed Search)

Posted: 2/8/2022 by Quincy Tran, MD, PhD (Updated: 11/23/2024)
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The debate is still going on: Whether we should give balanced fluids or normal saline.

Settings: PLUS study involving 53 ICUs in Australia and New Zealand. This was a double-blinded Randomized Control trial.

Patients: A total of 5037 adults who were admitted to any ICU.
Intervention: Balanced multielectrolyte solutions (BMES). Once patient is outside the ICU, the type of fluid was decided by the treating physicians.
Comparison: Normal saline
Outcome: 90-day all cause mortality.

Study Results:

Patient characteristics:
- 2515 patients in BMES group vs. 2522 in Saline group. Characteristics were similar in both groups.
- Median fluid amount = 3.9L (BMES group) vs. 3.7L (Saline group).
Primary outcome:
- Mortality = 21.8% (BMES group) vs. 22.0 (Saline), (OR 0.99, 95% CI 0.86-1.14)
Secondary outcomes:
- Requiring Dialysis: OR 0.98 (95% CI 0.83-1.16)
- Requiring vasopressor: OR 0.92 (95% CI 0.78-1.09)
- Maximum creatinine level: similar between groups (155.5 umol/L for BMES vs. 154.5 umol/L for Saline group)

Discussion:

Treatment with saline increased serum chloride, and lower pH than BMES, but kidney function was not affected.

An updated meta-analysis including this trial was also published in January 2022. This updated meta-analysis showed that the risk ratio for 90-day mortality for BMES was 0.96 (95% CI 0.91-1.01). This data suggested that using BMES could reduce risk of death (up to 9%) or increase risk of death (up to 1%).
Appropriate volume resuscitation is still more important than the type of fluid.

Conclusion:

Finfer S, Micallef S, Hammond N, Navarra L, Bellomo R, Billot L, Delaney A, Gallagher M, Gattas D, Li Q, Mackle D, Mysore J, Saxena M, Taylor C, Young P, Myburgh J; PLUS Study Investigators and the Australian and New Zealand Intensive Care Society Clinical Trials Group. Balanced Multielectrolyte Solution versus Saline in Critically Ill Adults. N Engl J Med. 2022 Jan 18. doi: 10.1056/NEJMoa2114464. Epub ahead of print. PMID: 35041780.
Hammond N, Zampieri G, Di Tanna GL, et al. Balanced crystalloids versus sa- line in critically ill adults — a systematic review with meta-analysis. NEJM Evid. D OI: 10.1056/EVIDoa2100010.