Balanced crystalloids versus saline in critically ill adults with low plasma bicarbonate: A secondary analysis of a clinical trial.

Abstract

We aimed to determine if balanced crystalloids compared with saline improve outcomes in critically ill adults admitted with low plasma bicarbonate. We performed a secondary analysis of the Isotonic Solutions and Major Adverse Renal Events Trial (SMART). We included patients who presented to the Emergency Department with a first measured plasma bicarbonate less than 20mmol/L. Among these patients, we compared the effect of balanced crystalloid versus saline on the primary outcome of major adverse kidney events within 30days (MAKE30), defined as a composite of death, new renal-replacement therapy, or persistent renal dysfunction (final inpatient creatinine ≥200% baseline). Secondary outcomes included 30day in-hospital mortality, receipt of new RRT, persistent renal dysfunction, incident AKI, and vasopressor-free days. Among the 2029 patients with an initial plasma bicarbonate concentration<20mmol/L, there was no difference in the incidence of MAKE30 between those assigned to balanced crystalloid versus saline (21.8% vs 21.3%; P=0.93). Secondary outcomes were similar between the balanced crystalloid and saline groups. Among critically ill adults presenting to the Emergency Department, initial plasma bicarbonate concentration does not appear to be a useful marker to guide the selection of balanced crystalloid versus saline.