What is the infusion rate of 3% (normal saline) NS?

Infusion Rate of 3% Normal Saline

The standard infusion rate for 3% hypertonic saline should be administered at 30-50 mL/hour when given peripherally for most clinical situations requiring continuous infusion. 1

Clinical Indications for 3% Hypertonic Saline

• 3% hypertonic saline is primarily indicated for:
  • Treatment of symptomatic hyponatremia 2
  • Management of increased intracranial pressure 3, 2
  • Exercise-associated hyponatremia 2

Administration Guidelines

• For symptomatic hyponatremia, up to three 100 mL boluses of 3% sodium chloride solution spaced at 10-minute intervals is recommended 2
• For continuous infusion in traumatic brain injury, rates of 30-50 mL/hour are typically used with a target serum sodium concentration of 145-155 mmol/L 4, 1
• In emergency situations requiring rapid administration for neurologic emergencies, 3% hypertonic saline has been safely administered at rates up to 999 mL/hour via peripheral IV 5

Route of Administration Considerations

• While traditionally administered through central venous catheters, peripheral administration of 3% hypertonic saline has been shown to be safe with appropriate monitoring 6, 7
• For peripheral administration:
  • Use 16-20 gauge IV catheters when possible 1
  • Antecubital placement is commonly used (48.6% of cases in one study) 5
  • Maximum recommended continuous infusion rate via peripheral IV is 50 mL/hour 1

Monitoring During Infusion

• Serum sodium should be measured within 6 hours of administration 2
• Re-administration should not occur until serum sodium is <155 mmol/L 2
• Monitor for complications including:
  • Infiltration (reported incidence 3.3%) 7
  • Phlebitis (reported incidence 6.2%) 7
  • Erythema (reported incidence 2.3%) 7
  • Edema (reported incidence 1.8%) 7

Safety Considerations

• Peripheral administration of 3% hypertonic saline carries a low risk of complications when properly monitored 6, 7, 1
• No cases of central pontine myelinolysis or osmotic demyelination syndrome have been reported in pediatric patients receiving 3% saline at recommended doses 4
• The risk of hypernatremia increases with continuous infusion, requiring regular monitoring of serum sodium levels 8
• For patients with underlying cardiac or renal disease, closer monitoring is required during administration 3

Clinical Efficacy

• 3% hypertonic saline is effective in reducing intracranial pressure (Grade A evidence) 3, 4
• However, it has not been shown to improve neurological outcomes (Grade B evidence) or survival (Grade A evidence) in states of raised intracranial pressure 4

Common Pitfalls and Caveats

• Avoid rapid correction of chronic hyponatremia to prevent osmotic demyelination syndrome 2
• Monitor for hypernatremia, especially with prolonged infusions 8
• While central venous administration has traditionally been preferred, the risk of complications from peripheral administration may be overstated compared to the risks of central line placement (infection, pneumothorax, arterial injury) 1