Fluids: correction of hyponatraemia: practice question

A General Surgery question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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General Surgery · Fluids: correction of hyponatraemia

Sample item

A patient with chronic symptomatic hyponatraemia of 112 mmol/L is given hypertonic saline. What is the maximum safe rate of correction in 24 hours?

AAbout 20 mmol/LBFull correction to 140 mmol/L within hoursCAbout 30 mmol/LDAbout 8 to 10 mmol/L

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

D. About 8 to 10 mmol/L

Rapid correction of chronic hyponatraemia can cause osmotic demyelination syndrome, resulting in dysarthria, quadriparesis and locked-in state. Correction should not exceed 8 to 10 mmol/L in 24 hours, and a bolus of hypertonic saline is used for severe symptoms such as seizures. Frequent sodium monitoring is essential.

Option by option

A. About 20 mmol/L
Faster rates risk osmotic demyelination.
B. Full correction to 140 mmol/L within hours
Full correction in hours is unsafe.
C. About 30 mmol/L
Such a rapid correction is dangerous.
D. About 8 to 10 mmol/L (correct)
Correct. A slow correction limit protects against demyelination.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this General Surgery question

What is the answer to this General Surgery question?

The best answer is D, About 8 to 10 mmol/L. Rapid correction of chronic hyponatraemia can cause osmotic demyelination syndrome, resulting in dysarthria, quadriparesis and locked-in state.

Why is "About 20 mmol/L" not the answer?

Faster rates risk osmotic demyelination.

Why is "Full correction to 140 mmol/L within hours" not the answer?

Full correction in hours is unsafe.

Why is "About 30 mmol/L" not the answer?

Such a rapid correction is dangerous.

What concept does this question test?

It tests Fluids: correction of hyponatraemia in General Surgery. Correction should not exceed 8 to 10 mmol/L in 24 hours, and a bolus of hypertonic saline is used for severe symptoms such as seizures. Frequent sodium monitoring is essential.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Fluids: correction of hyponatraemia?

Learn classic signs and eponyms alongside what they diagnose. Then use the flashcards and the other General Surgery questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.