Should I stop the half-normal saline infusion in a patient with hypernatremia?

Management of Hypernatremia with Sodium Level of 145 mmol/L

You should stop the half-normal saline infusion when the serum sodium reaches 145 mmol/L to prevent further increases in sodium levels and potential complications. 1

Assessment of Hypernatremia

• Hypernatremia (serum sodium >145 mmol/L) indicates an imbalance in water balance, often resulting from increased free water loss compared to sodium excretion 2
• Clinical presentation may include central nervous system dysfunction (confusion, coma) and pronounced thirst in awake patients 2
• Rapid changes in serum sodium concentration can lead to serious neurological complications 2

Management Approach

Immediate Actions

• Discontinue half-normal saline infusion immediately when sodium reaches 145 mmol/L 1
• Switch to hypotonic fluids (such as D5W) if continued fluid administration is necessary 2
• Assess for symptoms of hypernatremia including mental status changes, confusion, or neurological deficits 3

Monitoring and Follow-up

• Monitor serum sodium levels frequently (every 4-6 hours initially) to ensure appropriate correction 1
• Calculate free water deficit to guide replacement therapy if needed 1
• Monitor for signs of cerebral edema if rapid correction occurs 4

Special Considerations

Rate of Correction

• For chronic hypernatremia (>48 hours), sodium should not be reduced by more than 8-10 mmol/L/day to prevent osmotic demyelination syndrome 2
• For acute hypernatremia (<24 hours), more rapid correction may be appropriate but still requires close monitoring 2

Clinical Context Considerations

• In patients with cerebral edema or raised intracranial pressure, targeted hypernatremia (145-155 mmol/L) may sometimes be deliberately maintained as a therapeutic strategy 4
• In patients with liver disease, hypernatremia is particularly concerning as it may indicate worsening hemodynamic status 1

Common Pitfalls to Avoid

• Continuing saline infusions despite rising sodium levels 1
• Overly rapid correction of chronic hypernatremia, which can lead to cerebral edema 2
• Inadequate monitoring during active correction of sodium abnormalities 1
• Failing to recognize and address the underlying cause of hypernatremia 1

Fluid Selection Guidelines

• Balanced crystalloids should be used in preference to 0.9% normal saline for maintenance fluids and volume resuscitation 4
• High chloride content in normal saline can lead to hyperchloremic metabolic acidosis, electrolyte derangements, and negative impacts on renal function 4

Remember that preventing complications from sodium imbalances requires careful monitoring and appropriate fluid management based on the patient's clinical condition and laboratory values.