Airway: heliox in upper airway obstruction: practice question

A ENT 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.

Try it

ENT · Airway: heliox in upper airway obstruction

Sample item

A patient with severe upper airway obstruction from a tracheal tumour is waiting for definitive treatment. How can a helium and oxygen mixture help temporarily?

AIt relaxes bronchial smooth muscleBIt dissolves the tumourCIt has a low density, so it reduces turbulent flow and the work of breathingDIt raises the oxygen content above 100 percent

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

The answer and the reasoning

C. It has a low density, so it reduces turbulent flow and the work of breathing

Helium is less dense than nitrogen, so the gas mixture flows more laminarly through a narrowed airway, which cuts resistance and effort. Heliox is a bridge only, as the oxygen fraction is limited and the cause must be treated.

Option by option

A. It relaxes bronchial smooth muscle
Bronchodilation is not its mechanism.
B. It dissolves the tumour
It has no effect on tumour tissue.
C. It has a low density, so it reduces turbulent flow and the work of breathing (correct)
Correct. Reduced gas density lowers resistance in turbulent flow.
D. It raises the oxygen content above 100 percent
The oxygen concentration is limited in heliox mixtures.

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 ENT question

What is the answer to this ENT question?

The best answer is C, It has a low density, so it reduces turbulent flow and the work of breathing. Helium is less dense than nitrogen, so the gas mixture flows more laminarly through a narrowed airway, which cuts resistance and effort.

Why is "It relaxes bronchial smooth muscle" not the answer?

Bronchodilation is not its mechanism.

Why is "It dissolves the tumour" not the answer?

It has no effect on tumour tissue.

Why is "It raises the oxygen content above 100 percent" not the answer?

The oxygen concentration is limited in heliox mixtures.

What concept does this question test?

It tests Airway: heliox in upper airway obstruction in ENT. Heliox is a bridge only, as the oxygen fraction is limited and the cause must be treated.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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 Airway: heliox in upper airway obstruction?

Learn tuning fork results and audiogram patterns by sketching them. Then use the flashcards and the other ENT 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.