Does Administration of Saline Make a Crucial Difference Compared to Balanced Crystalloids in Critically Ill Patients?

Methodology and Study Course

This randomized study was conducted in 5 intensive care units (ICUs) at a university hospital in Nashville. It included 15,802 critically ill adult patients with a median age of 58 years who were administered either saline (0.9% sodium chloride) or balanced crystalloid solutions (Ringer-lactate or Plasma-Lyte A). Randomization occurred at the center level, not at the individual patient level.

The primary monitored parameter was composite and included death from any cause, new need for kidney function replacement, or newly developed renal dysfunction defined as an increase in creatinine levels of ≥ 200% compared to study entry, observed until hospital discharge or during a 30-day hospitalization period (whichever occurred first).

Results

The primary monitored parameter occurred in 14.3% of patients with balanced crystalloids, which was statistically significantly less frequent than in patients with saline (15.4%; conditional odds ratio [OR] 0.90; 95% confidence interval [CI] 0.82–0.99; p = 0.04).

Regarding the included parameters, the overall 30-day mortality during hospitalization was 10.3% in patients with balanced crystalloids compared to 11.1% in patients with saline (p = 0.06). The difference between the groups in terms of the incidence of the need for kidney function replacement or persistent renal dysfunction was not statistically significant (p = 0.08, resp. p = 0.60).

The difference in the incidence of the primary monitored parameter was more pronounced in the subgroup of patients who were administered larger volumes of solutions and in septic patients. The 30-day mortality in the case of sepsis was 25.2% with balanced crystalloids compared to 29.4% in the saline group (adjusted OR 0.80; 95% CI 0.67–0.97; p = 0.02).

Conclusion

In critically ill adults treated in ICUs, the administration of balanced crystalloid solutions was associated with a lower incidence of the composite renal parameter, which included overall mortality and new need for kidney function replacement or new persistent renal dysfunction, compared to the administration of saline for fluid replacement.

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Source: Semler M. W., Self W. H., Wanderer J. P. et al.; SMART Investigators and the Pragmatic Critical Care Research Group. Balanced crystalloids versus saline in critically ill adults. N Engl J Med 2018; 378 (9): 829–839, doi: 10.1056/NEJMoa1711584.