Sodium Bicarbonate for Critically Ill Adults with Metabolic Acidosis and Shock

BACKGROUND: Metabolic acidosis is common in critically ill patients and is associated with organ dysfunction and death. Sodium bicarbonate is used to correct acidemia, but its benefit in patients with metabolic acidosis who are receiving vasopressors remains uncertain. METHODS: In this pragmatic, adaptive, double-blind, randomized trial, we assigned adults with metabolic acidosis (pH, <7.30; base excess, no more than -4 mmol per liter; and partial pressure of arterial carbon dioxide, ≤45 mm Hg without intubation or ≤50 mm Hg with intubation) who were receiving vasopressors in the intensive care unit (ICU) to receive either sodium bicarbonate or placebo (5% dextrose). Sodium bicarbonate or placebo was infused for up to 5 hours, with the infusion rate adjusted for a target pH of at least 7.30 and base excess of at least 0 mmol per liter. The primary outcome was a major adverse kidney event, defined as death, use of renal-replacement therapy, or persistent renal dysfunction, within 30 days. RESULTS: A total of 500 patients were enrolled in 55 ICUs across seven countries; 245 patients were assigned to receive sodium bicarbonate and 255 to receive placebo. A major adverse kidney event within 30 days occurred in 98 of 244 patients (40.2%) in the sodium bicarbonate group and in 100 of 254 patients (39.4%) in the placebo group (adjusted difference, 1.2 percentage points; 95% confidence interval CI, -7.1 to 9.4; P = 0.78). Renal-replacement therapy was used within 30 days in 16.8% of the patients in the sodium bicarbonate group and in 20.9% of those in the placebo group (adjusted difference, -3.9 percentage points; 95% CI, -10.6 to 2.7). In-hospital mortality by day 30 was 25.4% in the sodium bicarbonate group and 24.0% in the placebo group (adjusted difference, 1.8 percentage points; 95% CI, -5.6 to 9.2). Four patients (1.6%) in the sodium bicarbonate group had an adverse effect, as compared with none in the placebo group (P = 0.06). CONCLUSIONS: The use of sodium bicarbonate in critically ill patients with metabolic acidosis receiving vasopressors did not lead to a lower risk of major adverse kidney events within 30 days than placebo. (Funded by the National Health and Medical Research Council of Australia; SODa-BIC ClinicalTrials.gov number, NCT05697770.).