Electrolyte Buffer
Sodium Bicarbonate 8.4%
Brand names: Sodium Bicarbonate 8.4% Injection
Adult dose
Dose: 50–100ml (50–100 mmol) of 8.4%
Route: IV over 5–10 min
Frequency: Guided by ABG — repeat as needed
Hyperkalaemia with ECG changes: 50ml IV (50 mmol). Severe metabolic acidosis (pH <7.1): 1–2 mmol/kg IV. TCA/Na-channel blocker overdose: 1–2 mmol/kg boluses until QRS <120ms. Flush line — incompatible with calcium.
Clinical pearls
- Not recommended routinely in cardiac arrest — produces CO₂, intracellular acidosis, hypernatraemia.
- Clear indications: hyperkalaemia with ECG changes (broad QRS, sine wave), TCA overdose (QRS >120ms), severe hyperchloraemic acidosis, or cardiac arrest with known hyperkalaemia.
- NEVER mix in same line as calcium. Flush with NS between drugs.
- 8.4% = hypertonic (1000 mosmol/L). Use isotonic 1.26% for large-volume or neonatal use.
Contraindications
- Metabolic or respiratory alkalosis
- Hypokalaemia (bicarbonate drives K+ intracellularly)
- Hypocalcaemia (incompatible with calcium — precipitates)
- Respiratory acidosis when ventilation cannot be increased (CO₂ rises)
Side effects
- Hypokalaemia, hypocalcaemia
- Hypernatraemia, fluid overload
- Metabolic alkalosis if overdosed
- Paradoxical intracellular acidosis (from CO₂ production)
Interactions
- Calcium chloride / calcium gluconate: precipitates — never in same IV line
- Digoxin: increased toxicity as pH rises
- Many acidic drugs: chemical incompatibility — flush line between drugs
Reference: UK Renal Association Hyperkalaemia Guidelines 2020; UK Resuscitation Council ALS 2021; NICE BNF 84. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators