Hypertonic Saline Dosing for Elevated Intracranial Pressure and Severe Hyponatremia
For elevated intracranial pressure, 3% hypertonic saline should be administered at an initial dose of 2-3 ml/kg as an IV bolus over 15-20 minutes, with continuous monitoring of ICP, blood pressure, serum sodium, and osmolality. 1
Dosing for Elevated Intracranial Pressure
3% Hypertonic Saline (First-line)
- Initial dose: 2-3 ml/kg IV bolus over 15-20 minutes 1
- Alternatively: 1.4 ml/kg has been shown effective in reducing ICP below 15 mmHg within approximately 16 minutes 2
- Administration rate: Can be safely administered peripherally at rates up to 999 ml/hr in emergent situations 3
- Target serum sodium: 145-155 mEq/L 1
- Target serum osmolality: 310-320 mOsm/L 1
23.4% Hypertonic Saline (For severe cases/herniation)
- Can be administered as a rapid IV push over 2-5 minutes in emergency situations 4
- Typical dose: 0.7 ml/kg 5
- Can be given through central or peripheral line with low risk of adverse events 4
Monitoring During Administration
- Measure serum sodium within 6 hours of bolus administration 6
- Do not re-administer until serum sodium is <155 mmol/L 6
- Monitor:
- Intracranial pressure
- Blood pressure (maintain MAP >80 mmHg)
- Serum sodium and osmolality
- Neurological status
- Fluid balance and renal function 1
Dosing for Severe Hyponatremia
Acute Symptomatic Hyponatremia (<48 hours)
- 3% hypertonic saline is the treatment of choice for symptomatic patients 7
- Correction rate: Can be initially rapid but should not exceed 15 mEq/L in 24 hours 7
- In patients with risk factors for osmotic demyelination (hypokalemia, liver disease, poor nutrition, burns), limit correction to <10 mEq/L in 24 hours 7
Efficacy Comparison
3% hypertonic saline has been shown to be more effective than mannitol in:
- Maximum reduction of ICP (60% vs 55%) 2
- Faster time to reduce ICP below 15 mmHg (16 minutes vs 23 minutes) 2
- More sustained ICP reduction (significant reduction maintained at 120 minutes) 5
Potential Adverse Effects and Precautions
- No clear evidence of adverse effects with bolus doses of hypertonic saline 6
- Rapid peripheral administration of 3% hypertonic saline is safe with no reported extravasation or phlebitis 3
- Central pontine myelinolysis risk is minimal with proper monitoring and adherence to correction rate limits 7
- Continuous infusions of 3% saline appear well-tolerated, though studies are limited in power to detect all adverse effects 6
Important Considerations
- Despite effective ICP reduction, hypertonic saline has not been shown to improve neurological outcomes or survival compared to other treatments 6, 1
- The timing of administration appears critical, with ultra-early administration potentially providing greater benefit in traumatic brain injury 6
- Comprehensive recommendations on ideal concentration and formulation are difficult to construct due to heterogeneous clinical studies 6
Hypertonic saline should be used within a well-defined protocol with appropriate monitoring to maximize efficacy while minimizing potential adverse effects.