While metabolic acidosis is common in critical illness, studies to date have not shown a clear benefit of supplementing sodium bicarbonate (bicarb) in patients with shock requiring vasopressors or in patients during cardiac arrest. Despite the lack of evidence, bicarb is often administered to these patients. Two double-blind randomized trials now investigate whether IV sodium bicarbonate improves outcomes in patients with shock or cardiac arrest.
Key Results
In one study, 500 adult ICU patients with shock requiring vasopressors and with metabolic acidosis (pH <7.3) were assigned to receive up to 5 hours of a bicarb drip or placebo.
- Bicarb did not significantly improve in-hospital mortality, need for renal-replacement therapy, or persistent renal dysfunction at 30 days.
The second study assessed nearly 800 adults with in-hospital cardiac arrest (roughly 90% with nonshockable rhythms) who were assigned to receive either bicarb IV push — 1 ampule (Amp) after the first epinephrine dose and 1 Amp after the second — or placebo.
- Bicarb did not significantly improve sustained return of spontaneous circulation, survival at 30 days, or survival at 30 days with a favorable neurologic outcome.
Comment
These studies should lay to rest the common — and usually unnecessary — practice of administering IV bicarb to some of the most critically ill ICU patients and to patients with in-hospital cardiac arrest. Bicarb did not improve outcomes, and in the case of cardiac arrest, these data support guidelines that recommend against routine bicarb administration; exceptions include when arrest is due to hyperkalemia or acidemia (e.g., ketoacidosis). I will continue to avoid routine use in patients with arrest or shock.