The BIHCA randomized trial found routine sodium bicarbonate did not improve ROSC, 30-day survival, or neurological outcomes in adult in-hospital cardiac arrest.
Written by: Mayuresh Salvi, PharmD
Reviewed by: Pharmacally Editorial Team
Routine administration of sodium bicarbonate during adult in-hospital cardiac arrest did not significantly improve sustained return of spontaneous circulation (ROSC), 30-day survival, or neurological outcomes compared with placebo, according to results from the landmark BIHCA randomized clinical trial published in JAMA. The findings provide high-quality randomized evidence against the routine use of bicarbonate during resuscitation and reinforce current guideline recommendations that reserve its use for specific clinical indications.
Sodium bicarbonate has long been administered during cardiopulmonary resuscitation (CPR) to counter severe metabolic acidosis that develops during prolonged cardiac arrest. Despite decades of clinical use, robust randomized evidence supporting this practice has been limited, and international resuscitation guidelines have recommended restricting bicarbonate therapy to selected situations such as severe hyperkalemia, tricyclic antidepressant overdose, or documented metabolic acidosis. The BIHCA trial provides important evidence evaluating whether routine bicarbonate administration improves clinically meaningful outcomes during adult in-hospital cardiac arrest.
Study Design
The Bicarbonate for In-Hospital Cardiac Arrest (BIHCA) study (NCT05564130) was a multicenter, randomized, double-blind, placebo-controlled, parallel-group clinical trial conducted across 21 hospitals in Denmark.
Adults experiencing in-hospital cardiac arrest who had received at least one dose of epinephrine during advanced life support were eligible for enrollment. Between February 6, 2023, and February 11, 2026, investigators screened 2,913 patients, randomly assigning 913 participants to receive either intravenous sodium bicarbonate or placebo. After applying predefined eligibility criteria, 779 patients were included in the primary analysis, comprising 372 patients in the sodium bicarbonate group and 407 patients in the placebo group.
The median age of participants was 73 years (interquartile range, 64–79 years), and 502 patients (64%) were male.
Participants received up to 100 mmol of intravenous sodium bicarbonate or a matching placebo under blinded conditions.
The primary endpoint was sustained return of spontaneous circulation (ROSC). Key secondary endpoints included 30-day survival and 30-day survival with a favorable neurological outcome, defined as a modified Rankin Scale (mRS) score of 0–3.
Enrollment concluded in February 2026, with the final 90-day follow-up completed on May 4, 2026, and the final statistical analysis conducted on May 5, 2026.
Key Findings
Routine sodium bicarbonate administration did not significantly improve the primary outcome of sustained return of spontaneous circulation (ROSC). Sustained ROSC was achieved in 39% of patients receiving sodium bicarbonate compared with 37% of those receiving placebo, corresponding to a risk ratio (RR) of 1.05 (95% CI, 0.88–1.24; P = 0.62), indicating no statistically significant difference between the treatment groups.
Secondary outcomes also showed no statistically significant benefit. At 30 days, 12% of patients in the sodium bicarbonate group were alive compared with 9.1% of those in the placebo group (RR, 1.25; 95% CI, 0.84–1.88). A favorable neurological outcome, defined as a modified Rankin Scale (mRS) score of 0–3, occurred in 8.1% of patients receiving sodium bicarbonate versus 5.4% of patients receiving placebo (RR, 1.39; 95% CI, 0.82–2.34). Although both secondary outcomes numerically favored sodium bicarbonate, neither difference reached statistical significance.
Safety Profile
The investigators observed a higher incidence of alkalosis and hypernatremia among patients receiving sodium bicarbonate. However, these biochemical changes did not translate into improvements in sustained ROSC, survival, or neurological recovery.
Clinical Perspective
The BIHCA trial provides important, randomized evidence evaluating routine sodium bicarbonate use during adult in-hospital cardiac arrest. While severe metabolic acidosis commonly develops during prolonged resuscitation, the study found that routine correction with sodium bicarbonate did not improve sustained ROSC or longer-term clinical outcomes.
The investigators concluded that routine sodium bicarbonate administration during adult in-hospital cardiac arrest does not improve sustained ROSC and that the findings do not support routine administration of sodium bicarbonate in these patients.
Evidence-based resuscitation measures, including high-quality CPR, prompt defibrillation for shockable rhythms, appropriate epinephrine administration, and rapid identification and treatment of reversible causes of cardiac arrest, remain the cornerstone of advanced cardiac life support.
What These Results Means
The BIHCA trial is among the largest randomized studies evaluating sodium bicarbonate during adult in-hospital cardiac arrest and provides robust evidence supporting current Advanced Cardiac Life Support (ACLS) recommendations against its routine use.
Although modest numerical improvements were observed in survival and neurological recovery, these differences were not statistically significant, indicating that routine bicarbonate administration does not improve clinically meaningful outcomes in this patient population.
From a clinical perspective, future research may explore whether carefully selected patient subgroups, such as those with profound metabolic acidosis, severe hyperkalemia, or toxin-induced cardiac arrest, could benefit from targeted bicarbonate therapy. However, the current trial does not address these subgroup-specific questions.
For clinicians, the study reinforces an important message: optimizing established, evidence-based resuscitation interventions remains more impactful than the routine use of adjunctive pharmacologic therapies that have not demonstrated clinical benefit.
Reference
About the Writer
Mayuresh Sunil Salvi (Linkedin) is a PharmD professional and healthcare writer with a strong interest in pharmacovigilance, drug safety, and emerging medical research. He is passionate about exploring new drug discoveries, clinical research, and advances in evidence-based medicine. His interests also include ward rounds, prescription audits, and treatment analysis to support rational pharmacotherapy and improved patient care.