A standard adult amp of bicarb (sodium bicarbonate) contains 50 mEq in 50 mL of the 8.4% concentration. A second common formulation, the 7.5% concentration, delivers 44.6 mEq in the same 50 mL volume. These are the two preparations you’ll find on most crash carts and in emergency departments.
The Two Adult Formulations
The 8.4% solution is the more straightforward of the two: each milliliter contains exactly 1 mEq of sodium bicarbonate (84 mg/mL). That makes dose calculations simple. One full 50 mL ampule gives you 50 mEq of sodium and 50 mEq of bicarbonate, totaling 100 mEq of solute in a highly concentrated solution (2,000 mOsm/L).
The 7.5% solution is slightly less concentrated at 0.9 mEq/mL (75 mg/mL). A 50 mL ampule of this formulation contains 44.6 mEq of sodium bicarbonate. Both versions come in prefilled syringes or glass vials, depending on the manufacturer.
The Pediatric Formulation
For infants and children under two years old, a half-strength 4.2% solution is used instead. This comes in a 10 mL prefilled syringe containing 5 mEq total (0.5 mEq/mL, or 42 mg/mL). The lower concentration exists because rapid injection of the more concentrated adult solutions into neonates can cause dangerously high sodium levels, drops in cerebrospinal fluid pressure, and even bleeding in the brain. Dosing in infants is capped at 8 mEq per kilogram of body weight per day.
Quick Reference by Concentration
- 8.4% ampule: 50 mL, 50 mEq, 1 mEq/mL, 84 mg/mL
- 7.5% ampule: 50 mL, 44.6 mEq, 0.9 mEq/mL, 75 mg/mL
- 4.2% syringe (pediatric): 10 mL, 5 mEq, 0.5 mEq/mL, 42 mg/mL
When an Amp of Bicarb Is Used
Sodium bicarbonate works by neutralizing acid in the blood. It’s given intravenously for severe metabolic acidosis, certain drug overdoses (particularly those that widen the QRS complex on an ECG), and dangerously high potassium levels. In cardiac arrest, one to two ampules (44.6 to 100 mEq) may be pushed initially, with additional doses of one ampule every 5 to 10 minutes as needed based on lab values.
That said, the 2025 American Heart Association guidelines note that routine use of sodium bicarbonate during cardiac arrest has not shown a clear benefit. The 2023 AHA focused update found no improvement in outcomes with routine administration. Some newer observational data suggest a possible survival benefit when given before hospital arrival for certain non-shockable rhythms (pulseless electrical activity and asystole), but the evidence isn’t strong enough to change the current recommendation. Bicarb remains indicated for specific causes of arrest, like hyperkalemia, rather than as a default part of the resuscitation algorithm.
Risks of Administration
Because the adult formulations are extremely concentrated, they carry real risks. Pushing bicarb too quickly or giving too much can overcorrect the blood’s pH, swinging it from too acidic to too alkaline. That alkalosis can then drive potassium into cells, causing dangerously low potassium levels in the bloodstream. Excessive sodium loading is another concern: each 50 mEq ampule delivers 50 mEq of sodium, equivalent to roughly 300 mL of normal saline in sodium content alone. In patients with heart failure or kidney disease, this can worsen fluid overload.
Sodium bicarbonate is also incompatible with many IV medications. It can form precipitates when mixed with calcium-containing solutions, and its high pH can inactivate certain drugs if run through the same line without flushing. In practice, the IV line is flushed with normal saline before and after each dose.