Administration of sodium bicarbonate made no significant difference in the sustained return of spontaneous circulation, compared with placebo, in patients who suffered an in-hospital cardiac arrest, according to research published June 11 in JAMA.

The parallel-group, double-blind Bicarbonate For In-Hospital Cardiac Arrest (BIHCA) trial randomized 913 Danish adults – with 779 eligible for primary analysis (median age, 73; 36% women) – with in-hospital cardiac arrest to either up to 100 mmol of intravenous sodium bicarbonate (n=372) or placebo (n=407) following at least one dose of epinephrine.

Results showed that 146 patients (39%) in the treatment arm vs. 150 (37%) in the placebo arm saw sustained return of spontaneous circulation (risk ratio [RR], 1.05; p=0.62). At 30 days post treatment, 45 patients (12%) in the treatment arm vs. 37 (9.1%) in the placebo arm were alive (RR, 1.25), and 30 patients (8.1%) vs. 22 (5.4%) saw a favorable neurologic outcome, defined as a score of 0-3 on the modified Rankin Scale (RR, 1.39). These results were consistent across predefined subgroups.

Alkalosis (35% vs. 20%) and hypernatremia (42% vs. 29%) were more common with sodium bicarbonate than placebo.

"Sodium bicarbonate is commonly used clinically for in-hospital cardiac arrest, with administration in more than half of cardiac arrests in the [U.S.], suggesting that many clinicians consider sodium bicarbonate beneficial in this setting," write trial investigators Asger Granfeldt, MD, PhD, DMSc, et al. "Findings from this trial do not support this practice."

"The results of this trial are strong evidence that the routine use of sodium bicarbonate in this population does not alter important outcomes," writes Clifton W. Callaway, MD, PhD, in an accompanying editorial comment, but adds that it is unlikely to change current, common clinical practice without additional exploration of individual treatment effects.