Sodium Bicarbonate
NaHCO3
Alkalinizing buffer / electrolyte
Provides bicarbonate → buffers H⁺ → raises serum + urine pH. Also drives K⁺ intracellularly.
Indications
- •Severe metabolic acidosis (pH <7.1)
- •Hyperkalemia (adjunct)
- •TCA/Na-channel-blocker overdose (wide QRS → serum alkalinization + Na load)
- •LAST (adjunct)
- •Urine alkalinization (salicylate/rhabdo)
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| Code/severe acidosis | 1 mEq/kg IV (50 mEq amp) | — |
| TCA overdose (wide QRS) | 1–2 mEq/kg IV boluses to narrow QRS + pH ~7.45–7.55 | — |
Pharmacokinetics
Onset immediate. Generates CO2 (needs adequate ventilation to clear — otherwise paradoxical intracellular acidosis).
Side effects
- !Hypernatremia, hyperosmolality
- !Hypokalemia, hypocalcemia (ionized ↓)
- !Metabolic alkalosis (overshoot)
- !Tissue necrosis on extravasation
- !CO2 generation → worsens acidosis if hypoventilating
Contraindications
- ×Respiratory acidosis (can't clear CO2)
- ×Hypokalemia/hypocalcemia (worsens)
- ×Metabolic alkalosis
Clinical pearls
- ★Widening QRS from TCA/Na-channel-blocker toxicity → bicarb is the specific treatment (Na load + alkalinization overcome the channel block).
- ★Must ventilate — bicarb generates CO2; if the patient can't blow it off, intracellular acidosis worsens.
- ★Never run in the same line as calcium (precipitates) or catecholamines (inactivated).
Other drugs in Electrolytes
- Calcium Chloride
Replaces ionized calcium → restores cardiac contractility, smooth muscle tone, neuromuscular function. Stabilizes cardiac myocyte membrane in hyperK by raising threshold potential.
- Calcium Gluconate
Provides elemental calcium (1 g calcium gluconate = ~93 mg / 4.65 mEq elemental Ca²⁺). One-third the elemental calcium of an equivalent dose of CaCl2 (1 g = 273 mg / 13.6 mEq). Used to treat hypocalcemia, antagonize cardiac membrane effects of hyperkalemia, magnesium toxicity, calcium-channel-blocker overdose.
- Potassium Chloride
Provides K⁺ for replacement of intracellular and serum stores. Maintains resting membrane potential. 1 mEq KCl = 39 mg potassium.
- Sodium Citrate (Bicitra)
Citrate is metabolized to bicarbonate → neutralizes gastric acid. NON-PARTICULATE → if aspirated, far less lung injury than particulate antacids.
Browse all classes: /reference/drugs
Suggested reading
- •Miller's Anesthesia, 9e
- •FDA package insert
