Sodium Bicarbonate

ADMINISTRATION ROUTES:

IV

ALTERNATIVE NAMES:

Sodium Bicarbonate

ICU INDICATIONS:

1. Correction of normal anion gap acidosis
2. Correction of severe metabolic acidosis contributing to myocardial dysfunction
3. Toxicology indications

Toxicology indications include:

• Cardiotoxicity secondary to fast sodium channel blockers (tricyclics, bupropion, venlafaxin, dextropropoxyphene, propranolol
• Type 1a and 1c antiarrhythmics (flecainide, quinidine, quinine)
• Prevention of redistribution of drug to the CNS (severe salicylate poisoning)
• Immediate correction of profound life-threatening metabolic acidosis (cyanide poisoning, isoniazid poisoning)
• Toxic alcohol poisoning (ethylene glycol, methanol & other toxic alcohols)
• Enhanced urinary drug elimination (salicylate, phenobarbitone)
• Increased urinary solubility (methotrexate toxicity, drug induced rhabdomyolysis)

PRESENTATION AND ADMINISTRATION:

IV:

8.4% (1 mmol/mL) in 10 mL vial and 8.4% 50 & 100 mL glass bottles

Store at room temperature. Do not use solutions which are cloudy or have visible precipitate.

Compatible with the following IV fluids: 0.9% sodium chloride, 5% glucose, glucose and sodium chloride

Administer via a central line if possible. In ICU, it is usual to administer sodium bicarbonate undiluted over an hour. In an emergency situation it can be administered undiluted by direct IV injection.

DOSAGE:

IV:

1 mmol/kg IV

Repeat as required

Alternative dose calculation:

Dose (mmol) = Base Excess x Weight/10

This dose will correct half the base deficit.

In severe cardiotoxicity due to fast sodium channel blockade in drug overdose give 2 mmol/kg. Repeat until cardiovascular stability is achieved.

DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:

Dose in renal impairment

Dose in renal replacement therapy

DOSAGE IN PAEDIATRICS:

Weight < 5 kg:

Dose (mmol) = Base Excess x Weight/4

Weight ≥ 5 kg:

Dose (mmol) = Base Excess x Weight/6

CLINICAL PHARMACOLOGY:

Sodium bicarbonate is a systemic alkalinizing agent which, when given intravenously, will increase plasma bicarbonate, buffer excess hydrogen ion concentration, raise blood pH and reverse the clinical manifestations of acidosis.Sodium bicarbonate dissociates in water to provide sodium and bicarbonate ions (HCO3^-).

The urinary pH will be increased by sodium bicarbonate in patients with normal renal function. Alkalinising the urine can increase the solubility of certain weak acids, and can increase the ionisation and urinary excretion of lipid-soluble organic acids. For this reason it is useful in increasing excretion of phenobarbitone or salicylates in overdose.

CONTRAINDICATIONS:

1. Severe hypernatraemia
2. Alkalosis
3. Hypokalaemia

WARNINGS:

Fluid overload:

Sodium bicarbonate constitutes a significant sodium load and may precipitate fluid overload. Patients with poorly controlled congestive cardiac failure, renal failure and acute pulmonary oedema are at particular risk.

PRECAUTIONS:

General:

Alkalosis may precipitate hypokalaemia

Laboratory Tests:

No tests in addition to routine ICU tests are required.

Drug/Laboratory Test Interactions:

None noted.

IMPORTANT DRUG INTERACTIONS IN ICU:

None

ADVERSE REACTIONS:

Cardiovascular:

Fluid overload, acute pulmonary oedema

Respiratory:

Respiratory depression, hypoxia (secondary to compensatory respiratory acidosis)

Metabolic:

Alkalosis, hypernatraemia, hypokalaemia, hypocalcaemia, hyperosmolarity

Dermatological:

Local tissue inflammation secondary to extravasation