Management of Hyponatremia Overcorrection
If overcorrection of hyponatremia has occurred (>8 mmol/L in 24 hours), immediately discontinue current fluids, switch to D5W (5% dextrose in water), and administer desmopressin to reverse the rapid sodium rise and prevent osmotic demyelination syndrome. 1, 2
Immediate Interventions for Overcorrection
Stop all sodium-containing fluids immediately and switch to D5W to provide free water and actively lower serum sodium back toward safer correction limits 1, 2
Administer desmopressin (DDAVP) to terminate the unwanted water diuresis and slow or reverse the rapid sodium rise 1, 3, 4, 5
The goal is to bring the total 24-hour correction back to no more than 8 mmol/L from the starting sodium level 1, 2, 5
Defining Overcorrection and Risk Thresholds
Overcorrection is defined as >8 mmol/L increase in 24 hours for high-risk patients (those with advanced liver disease, alcoholism, malnutrition, severe hyponatremia, or prior encephalopathy) 1, 2
For average-risk patients, overcorrection is defined as >10 mmol/L in 24 hours, >18 mmol/L in 48 hours, or >20 mmol/L in 72 hours 4, 5
Even a correction of 10-12 mmol/L in 24 hours carries risk and should be avoided when possible 1, 4
High-Risk Populations Requiring Stricter Limits
Patients with cirrhosis, alcoholism, malnutrition, hypophosphatemia, hypokalemia, hypoglycemia, low cholesterol, or prior encephalopathy are at highest risk for osmotic demyelination syndrome and require maximum correction of 4-6 mmol/L per day, not exceeding 8 mmol/L in 24 hours 1, 2
Liver transplant recipients have a 0.5-1.5% risk of osmotic demyelination syndrome, making cautious correction essential 1, 2
Monitoring Protocol During and After Overcorrection
Check serum sodium every 2 hours during active correction to detect overcorrection early 1, 6
After identifying overcorrection, continue monitoring every 2-4 hours until sodium stabilizes within safe correction limits 1, 2
Monitor for signs of osmotic demyelination syndrome (dysarthria, dysphagia, oculomotor dysfunction, quadriparesis) which typically appear 2-7 days after rapid correction 1, 2
Confirm suspected osmotic demyelination syndrome with brain MRI 2
Desmopressin Dosing and Administration
Desmopressin can be given intravenously, subcutaneously, or intranasally to induce antidiuresis and prevent further sodium rise 3, 4, 5
The FDA label warns that desmopressin itself can cause hyponatremia, so use it specifically to reverse overcorrection, not as primary hyponatremia treatment 3
A reactive strategy (giving desmopressin after detecting overcorrection) is supported by observational data showing 69.3% achieved safe correction with this approach 5
Prevention Strategies to Avoid Overcorrection
Set therapeutic goals of 6-8 mmol/L in 24 hours, 12-14 mmol/L in 48 hours, and 14-16 mmol/L in 72 hours to stay well clear of dangerous correction rates 4
For severe symptomatic hyponatremia requiring hypertonic saline, target only 4-6 mmol/L increase over 6 hours or until symptoms resolve, then stop aggressive correction 1, 7, 8, 6
Frequent monitoring of serum sodium and urine output is mandatory during any hyponatremia treatment, as inadvertent overcorrection can complicate therapy including with vaptans 4, 6
Calculate sodium deficit using: Desired increase in Na (mEq/L) × (0.5 × ideal body weight in kg) to guide replacement 1
Limited Evidence for Treating Established Osmotic Demyelination Syndrome
Once osmotic demyelination syndrome develops, treatment options are limited and largely supportive 2
Case reports suggest potential benefit from plasmapheresis, high-dose corticosteroids, or intravenous immunoglobulin, but evidence is extremely limited 2
Prevention through appropriate correction rates is far superior to attempting treatment after osmotic demyelination occurs 2
Common Pitfalls Leading to Overcorrection
Failing to identify high-risk patients who require stricter correction limits (4-6 mmol/L per day maximum) 1, 2
Inadequate monitoring during active correction, allowing unrecognized water diuresis to drive rapid sodium rise 1, 2, 4
Using hypertonic saline in hypervolemic hyponatremia without life-threatening symptoms 1
Not anticipating spontaneous water diuresis when treating hypovolemic hyponatremia with isotonic saline 4, 6