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# Bicarbonate in shock fixed the blood gas, not the outcome: the blinded SODa-BIC trial and what comes next
- URL: https://nephspace.com/soda-bic-bicarbonate-icu-acidosis/
- Published: 2026-10-12T09:58:00.000Z
- Updated: 2026-10-12T09:57:59.000Z
- Description: In 500 ICU patients on vasopressors with metabolic acidosis, sodium bicarbonate did not significantly lower the risk of death, dialysis or lasting kidney damage at 30 days. An NEJM editorial and two ASN Kidney News viewpoints take it to the bedside.
- Author: Dr Wael Hussein
- Tags: AKI and critical care, #story, #has-audio, #research, #full-story, #electrolytes-acid-base, Stories

**🎧 Listen:** [Weekly · Oct 12](https://nephspace.com/weekly-oct-12/), from 07:02.

### The background

It's two in the morning, the patient is on a vasopressor, and the blood gas shows a pH of 7.22 and a bicarbonate of 15\. Should you give bicarbonate? (The scenario is adapted from Dr. Sette's viewpoint, below.) The argument for it: severe acidemia may weaken the heart and blunt the response to catecholamines. The argument against: bicarbonate brings a sodium and fluid load, produces carbon dioxide the lungs must clear, and can lower potassium and ionized calcium. Two earlier French trials, BICAR-ICU and BICARICU-2, tested it in patients with a pH of 7.20 or lower, but neither was blinded.

### What the trial did

SODa-BIC is a pragmatic, adaptive, double-blind randomized trial in 55 ICUs across seven countries (April 2023 to December 2025). It enrolled 500 adults who had been on a vasopressor for up to 48 hours and had metabolic acidosis defined from the whole blood gas, not the bicarbonate alone: a pH below 7.30, a base excess of −4 or lower, and a PaCO2 of 45 mm Hg or less (50 or less if intubated), so the acidosis was mainly metabolic. Patients with diabetic ketoacidosis, major bicarbonate losses, an eGFR below 30 from chronic kidney disease, current or planned kidney replacement therapy, or a high risk of cerebral edema were excluded.

Patients received either sodium bicarbonate in 5% dextrose or 5% dextrose alone as a placebo, in identical bags, for up to 5 hours, adjusted toward a pH of at least 7.30\. Patients and treating teams didn't know which. The primary outcome was a major adverse kidney event within 30 days: death, kidney replacement therapy, or persistent kidney dysfunction (creatinine at least double the baseline).

### What they found

- The median pH at enrollment was 7.26, less severe than in the earlier trials.
- Primary outcome: 40.2% with bicarbonate vs 39.4% with placebo (adjusted difference 1.2 percentage points; 95% CI, −7.1 to 9.4).
- In-hospital death by day 30: 25.4% vs 24.0%. Kidney replacement therapy: 16.8% vs 20.9% (not significant). Still on kidney replacement therapy at day 30: 5.7% vs 9.1% (not significant). Days free of vasopressors were similar.
- The chemistry worked: metabolic acidosis came back in 32.0% of the bicarbonate group and 55.7% of the placebo group.
- Adverse effects were uncommon: 1.6% with bicarbonate (mostly low potassium needing correction) vs none with placebo.

### What the editorial and the viewpoints add

In an NEJM editorial, Dr. Marlies Ostermann and Dr. Deborah Cook call SODa-BIC a rigorous, blinded trial and a new chapter. They point out that it was powered to detect a 14-percentage-point absolute difference, larger than most treatment effects seen with this composite outcome, and that the start of kidney replacement therapy was not protocolized, unlike in the French trials, which makes the dialysis component hard to interpret. They also summarize a pooled analysis of the two French trials (1,016 adults): no lower 90-day mortality overall, less kidney replacement therapy with bicarbonate, and an apparent mortality benefit only in the subgroup with a pH of 7.10 or lower. Their conclusion: the full story is not yet written. The editorial points to MOSAICC, a larger UK trial now recruiting; Teixeira and colleagues also list ESCALATE in Germany.

Two short viewpoints in ASN Kidney News take the trial to the bedside. Dr. Luis Sette, a nephrology fellow at Mass General Brigham, titles his piece "A Better Blood Gas but Not a Better Outcome." He argues that bicarbonate isn't "never": with a pH of 7.20 or lower and moderate to severe AKI, earlier trials suggest it may reduce or delay dialysis, while SODa-BIC shows no benefit of routine use in less severe acidemia. Dr. J. Pedro Teixeira, Dr. Lenar Yessayan and Dr. Ashita Tolwani ask whether we are "improving outcomes or just fixing numbers." They note the 2026 Surviving Sepsis Campaign's conditional suggestion for bicarbonate in septic shock with a pH below 7.2 and stage 2 to 3 AKI (very low-certainty evidence), that there is little evidence either way at a pH of 7.10 or lower, and that SODa-BIC excluded higher-risk patients, so its safety findings shouldn't be stretched to them.

### Why it matters

Our take: before answering the 2 a.m. call, read the whole gas, the pH and the PaCO2, not just the bicarbonate; that's how the trial picked its patients. For a patient like the one above, with a pH in the low 7.20s, routine bicarbonate fixed the gas and not the outcome. For a pH of 7.10 or lower, especially with serious kidney injury, it remains a judgment call while larger trials report.

### Caveats

The trial could have missed a smaller benefit. Dialysis start was left to each team, and knowing the blood gas had improved could have delayed it. The infusion lasted at most 5 hours, open-label bicarbonate was allowed afterward at the team's discretion, and patients in whom bicarbonate was considered unsafe were excluded.

Funding and ties: SODa-BIC was funded by the National Health and Medical Research Council of Australia. The editorial authors' disclosure forms are available at NEJM.org. Dr. Sette reports no conflicts. As printed with their viewpoint, Dr. Teixeira reports consulting fees from Mallinckrodt, Outset Medical, Talphera and Vantive and stock in Eli Lilly, Novo Nordisk and Pfizer; Dr. Yessayan reports consulting fees from Vantive and a seat on a Fresenius Medical Care medical advisory board; Dr. Tolwani reports speaking and consulting for Baxter/Vantive, a patent on a citrate solution for kidney replacement therapy anticoagulation licensed to Baxter, and a scientific advisory board role at SeaStar Medical. Dr. Hussein also serves on a Fresenius Medical Care advisory board (see our disclosures).

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**The source:** The SODa-BIC Investigators and the Australian and New Zealand Intensive Care Society Clinical Trials Group. Sodium Bicarbonate for Critically Ill Adults with Metabolic Acidosis and Shock. N Engl J Med 2026;395:1062-1074\. doi:10.1056/NEJMoa2600526 [Read the original](https://doi.org/10.1056/NEJMoa2600526?ref=nephspace.com)

**Also discussed:**

- Ostermann M, Cook DJ. Sodium Bicarbonate in Critical Illness — A New Chapter for the Book. N Engl J Med 2026;395 (editorial). doi:10.1056/NEJMe2610218 [Link](https://doi.org/10.1056/NEJMe2610218?ref=nephspace.com)
- Sette L. A Better Blood Gas but Not a Better Outcome: Rethinking Bicarbonate in the ICU. Kidney News 2026;18(10/11):59\. doi:10.62716/kn.004282026 [Link](https://doi.org/10.62716/kn.004282026?ref=nephspace.com)
- Teixeira JP, Yessayan L, Tolwani A. Intravenous Bicarbonate for Metabolic Acidosis in the ICU: Improving Outcomes or Just Fixing Numbers? Kidney News 2026;18(10/11):60-61\. doi:10.62716/kn.004552026 [Link](https://doi.org/10.62716/kn.004552026?ref=nephspace.com)

**🎧 Listen:** [Weekly · Oct 12](https://nephspace.com/weekly-oct-12/), from 07:02.

*Physician-led, AI-assisted. Dr. Wael Hussein chooses every item NephSpace covers and reviews and edits every story before it is published. The first draft was written in our own words with AI (Claude, by Anthropic) from the full text of the paper and checked against our reading notes; Dr. Hussein then reviewed and edited it. For education and information only, not medical advice. Please talk to your own physician or care team about your health. Clinicians: read the original before changing practice. See our* [*disclaimer*](https://nephspace.com/disclaimer/) *and* [*disclosures*](https://nephspace.com/disclosures/)*. Spotted an error?* [*Tell us*](mailto:hello@nephspace.com?subject=Correction)*.*