As compared with normal saline, does the use of balanced crystalloids for fluid resuscitation in critically ill patients decrease mortality?

Data from a meta-analysis of 9 studies shows that using balanced crystalloids, such as lactated Ringer's solution, instead of normal saline for fluid resuscitation does not decrease mortality, reduce the incidence of acute kidney injury (AKI), or reduce the need for renal replacement therapy (RRT) in critically ill patients. However, in a subset of patients with sepsis from the SMART trial, the use of balanced crystalloids instead of saline resulted in fewer deaths over the short-term, with a number needed to treat of 20. Further studies are needed to confirm these findings, particularly in patients with sepsis. (LOE = 1a)

Liu C, Lu G, Dong W, et al. Balanced crystalloids versus normal saline for fluid resuscitation in critically ill patients: a systematic review and meta-analysis with trial sequential analysis. Am J Emerg Med 2019;37(11):2072-2078. Brown RM, Wang L, Coston TD, et al. Balanced crystalloids versus saline in sepsis. A secondary analysis of the SMART clinical trial. Am J Respir Crit Care Med 2019;200(12):1489-1495.  [PMID:30852043]

Meta-analysis (randomized controlled trials)

Self-funded or unfunded

Uncertain

Inpatient (ICU only)

These investigators searched MEDLINE, Cochrane Central, and EMBASE, as well as conference proceedings and reference lists of review articles, to find randomized controlled trials that compared the use of balanced crystalloids with normal saline for fluid resuscitation in critically ill adult patients. The primary outcome was mortality and the secondary outcomes were the incidence of AKI and the need for RRT. Two investigators independently selected studies, extracted data, and assessed the methodological quality of individual studies. The quality of the evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology and was assessed as moderate. Nine studies, including <a href="Improved kidney outcomes with intravenous balanced crystalloids instead of saline SMART trial</a> , were included in the meta-analysis. Six of the studies included patients admitted to an intensive care unit, 2 studies included patients with acute pancreatitis, and 1 study included trauma patients. No significant differences were detected between the balanced crystalloids groups and the normal saline groups with regard to mortality, incidence of AKI, or need for RRT. Using trial sequential analysis, the investigators determined that the evidence was not conclusive, and that further large trials are needed to confirm the data. Of note: In a recent secondary analysis of the SMART trial, patients admitted to a medical intensive care unit with sepsis had decreased 30-day in-hospital mortality with the use of balanced crystalloids instead of saline (26.3% vs 31.2%; odds ratio 0.74; 95% CI 0.59 - 0.93; P = .01).