Sodium Bicarbonate

Sodium Bicarbonate in Pediatric Emergency Medicine

Sodium bicarbonate is an alkalinizing agent used to treat severe metabolic acidosis in pediatric emergencies. It works by increasing the plasma bicarbonate concentration, thereby raising the pH of the blood.

Key Points:

Used in specific situations of severe metabolic acidosis
Available as 4.2% (0.5 mEq/mL) and 8.4% (1 mEq/mL) solutions
Controversial use in pediatric cardiac arrest due to potential adverse effects
Requires careful consideration of risks and benefits before administration
Can cause significant electrolyte imbalances if used inappropriately

Indications for Sodium Bicarbonate Use in Pediatrics

Severe metabolic acidosis (pH < 7.1) unresponsive to other interventions
Hyperkalemia with ECG changes
Tricyclic antidepressant overdose
Sodium channel blocker toxicity
Certain cases of rhabdomyolysis
Uric acid and methotrexate nephropathy (urinary alkalinization)

Note: Use in pediatric cardiac arrest is controversial and generally not recommended unless there is known severe metabolic acidosis, hyperkalemia, or specific toxicological indications.

Dosage and Administration

Severe Metabolic Acidosis:

Initial dose: 1-2 mEq/kg IV slow push over 10-20 minutes
Can be repeated based on serial blood gas measurements

Hyperkalemia:

1-2 mEq/kg IV over 5-10 minutes

Tricyclic Antidepressant Overdose:

1-2 mEq/kg IV bolus, followed by infusion to maintain blood pH 7.45-7.55

Urinary Alkalinization:

1-3 mEq/kg/day in divided doses or as a continuous infusion

Preparation: For neonates and infants <2 years old, use 4.2% solution (0.5 mEq/mL). For older children, 8.4% solution (1 mEq/mL) can be used.

Precautions and Side Effects

Precautions:

Use with extreme caution in neonates and young infants
Avoid rapid administration, especially in neonates (risk of intracranial hemorrhage)
Use cautiously in patients with renal impairment or congestive heart failure
Be aware of potential drug interactions (e.g., decreased efficacy of vasopressors)
Consider the underlying cause of acidosis and treat it simultaneously

Side Effects:

Metabolic alkalosis
Hypernatremia
Hyperosmolality
Hypokalemia
Hypocalcemia
Increased intracellular acidosis
Fluid overload
Decreased cardiac output
Paradoxical cerebrospinal fluid acidosis
Tissue necrosis if extravasation occurs

Monitoring

Continuous cardiac monitoring
Frequent blood pressure measurements
Serial arterial or venous blood gas analysis
Serum electrolytes, especially sodium, potassium, and calcium
ECG for changes related to electrolyte imbalances
Fluid balance and urine output
Neurological status, especially in neonates
Injection site for signs of extravasation

Important Considerations:

1. Overcorrection can lead to metabolic alkalosis, which can be as dangerous as acidosis.

2. In cardiac arrest, prioritize high-quality CPR, defibrillation when indicated, and addressing reversible causes over sodium bicarbonate administration.

3. Always reassess the patient's clinical status and repeat blood gas analysis after administration to guide further management.