Target Serum Sodium and Osmolality for 3% Saline Post-Stroke
For patients receiving 3% hypertonic saline infusion post-stroke, target a serum sodium concentration of 145-155 mmol/L and maintain osmolality at 310-320 mOsm/kg. 1, 2, 3
Primary Targets
Serum sodium: 145-155 mmol/L - This is the consensus target range recommended by the American College of Surgeons and American Society of Anesthesiologists for continuous 3% saline infusion in stroke patients with elevated intracranial pressure 1, 2
Osmolality: 310-320 mOsm/kg - This target range should be maintained during continuous infusion to optimize ICP control while minimizing complications 3
Critical Safety Thresholds
Do not exceed serum sodium of 155 mmol/L before re-administering additional hypertonic saline boluses 1, 2
Avoid sodium levels >155-160 mmol/L to prevent complications including osmotic demyelination syndrome, as recommended by the American Heart Association 1
**Osmolality should remain <296 mOsm/kg during the initial 7 days** when possible, as elevated osmolality (>296 mOsm/kg) has been associated with increased 3-month mortality in acute stroke patients 4
Monitoring Protocol
Measure serum sodium within 6 hours of any bolus administration to guide further therapy 1, 2
Monitor sodium, osmolality, and chloride levels regularly during continuous infusion to prevent hypernatremia and hyperchloremia 1, 2
Check baseline values before initiating therapy - Most patients should have sodium <150 mmol/L before starting hypertonic saline 5
Administration Context
The evidence strongly supports continuous infusion of 3% saline over bolus therapy for stroke patients. Research demonstrates that early continuous infusion (started within ≤72 hours of symptom onset) targeting sodium 145-155 mmol/L reduces ICP crisis frequency and mortality compared to historical controls 3. The maximum ICP-lowering effect occurs 10-15 minutes after administration and lasts 2-4 hours 1, 2.
Important Caveats
Euvolemia is the goal - The AHA/ASA guidelines emphasize that both hypovolemia and hypervolemia are harmful in acute ischemic stroke, making careful fluid balance essential 4
No proven mortality benefit - Despite effectiveness in reducing ICP (Grade A evidence), hypertonic saline has not been shown to improve neurological outcomes (Grade B) or survival (Grade A) in randomized controlled trials 1, 2
Avoid hypotonic solutions - Do not use 5% dextrose or 0.45% saline, as these distribute into intracellular spaces and may worsen cerebral edema 4