A patient in ICU after major hepatic resection has serum Na 118 mEq/L and is asymptomatic. The rate of correction of hyponatraemia must not exceed which limit to prevent osmotic demyelination syndrome (ODS)?
- A 24 mEq/L in the first 24 hours
- B 6 mEq/L in 24 hours
- C 10–12 mEq/L in any 24-hour period and <18 mEq/L in 48 hours ✓
- D 2 mEq/L per hour irrespective of daily total
Correct answer: C. 10–12 mEq/L in any 24-hour period and <18 mEq/L in 48 hours
Explanation
Osmotic demyelination syndrome (central pontine myelinolysis) occurs with overcorrection of chronic hyponatraemia. Current guidelines cap correction at 10–12 mEq/L per 24 hours (with some advocating ≤8 mEq/L in high-risk groups such as alcoholism, malnutrition, liver disease) and no more than 18 mEq/L in any 48-hour period. Correction at 2 mEq/hr is acceptable as a rate but must respect the 24-hour ceiling. An asymptomatic chronic hyponatraemia warrants slow, cautious correction.
Reference: Morgan & Mikhail's Clinical Anesthesiology, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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