Calculation of Table Salt in 3% Hypertonic Saline

Understanding 3% Hypertonic Saline Composition

• 3% hypertonic saline contains 513 mmol/L of sodium (Na+) as shown in the physico-chemical properties table 1, 2
• This concentration is significantly higher than normal saline (0.9%), which contains only 154 mmol/L of sodium 2
• The osmolarity of 3% saline is 1026 mOsmol/L, making it hyperosmolar compared to plasma 2, 3

Calculation Method

• 3% saline means 3 g of NaCl per 100 mL of solution4
• Therefore, 1 L (1000 mL) contains 30 g of NaCl 1, 2
• The molecular weight of sodium chloride (NaCl) is approximately 58.44 g/mol4
• One teaspoon of table salt weighs approximately 5.85 grams 5
• 30 g ÷ 5.85 g/teaspoon = 5.13 teaspoons3

Clinical Relevance of 3% Hypertonic Saline

• 3% hypertonic saline is commonly used for management of increased intracranial pressure 1, 6
• 3% hypertonic saline is used for treatment of severe hyponatremia with neurological symptoms 4
• 3% hypertonic saline is used for volume resuscitation in certain hypotensive states 1
• The primary mechanism of action is through osmotic fluid shifts from intracellular to intravascular space 3

Administration Considerations

• For treatment of hyponatremia, careful monitoring is required to prevent overly rapid correction 4

Safety Considerations

• Target correction rates should not exceed 0.5-1 mmol/L/hr for chronic hyponatremia 4
• Potential complications include hypernatremia and osmotic demyelination syndrome, though these are rare when appropriate protocols are followed 7