Respiratory medicine: non-invasive ventilation: practice question

A General Medicine 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 Medicine · Respiratory medicine: non-invasive ventilation

Sample item

A 68-year-old man with COPD has had an hour of nebulised bronchodilators, oral prednisolone and controlled oxygen via a 28% Venturi mask. He remains drowsy but obeys commands, with a respiratory rate of 30 per minute. Arterial blood gas shows pH 7.27, PaCO2 75 mmHg and PaO2 62 mmHg. What is the next step?

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

The answer and the reasoning

C. Non-invasive ventilation with bilevel positive airway pressure

Persistent respiratory acidosis (pH below 7.35 with PaCO2 above about 49 mmHg) after an hour of optimal medical therapy in an exacerbation of COPD is the indication for NIV. It lowers the need for intubation, shortens hospital stay and reduces mortality. Intubation is reserved for failure of NIV, a patient who cannot protect the airway or who is severely obtunded.

Option by option

  • A. Immediate endotracheal intubation

    He is still cooperative; intubation is for NIV failure or loss of airway protection.

  • B. Continue the same treatment and reassess in another hour

    Waiting without escalation risks progression to coma and a worse outcome when he already meets criteria.

  • C. Non-invasive ventilation with bilevel positive airway pressure (correct)

    Correct. Bilevel pressure support unloads the tiring respiratory muscles and lowers PaCO2.

  • D. Raise the inspired oxygen with a non-rebreather mask

    Higher FiO2 would worsen hypercapnia without treating ventilatory failure.

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.

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Questions about this General Medicine question

What is the answer to this General Medicine question?

The best answer is C, Non-invasive ventilation with bilevel positive airway pressure. Persistent respiratory acidosis (pH below 7.

Why is "Immediate endotracheal intubation" not the answer?

He is still cooperative; intubation is for NIV failure or loss of airway protection.

Why is "Continue the same treatment and reassess in another hour" not the answer?

Waiting without escalation risks progression to coma and a worse outcome when he already meets criteria.

Why is "Raise the inspired oxygen with a non-rebreather mask" not the answer?

Higher FiO2 would worsen hypercapnia without treating ventilatory failure.

What concept does this question test?

It tests Respiratory medicine: non-invasive ventilation in General Medicine. 35 with PaCO2 above about 49 mmHg) after an hour of optimal medical therapy in an exacerbation of COPD is the indication for NIV. It lowers the need for intubation, shortens hospital stay and reduces mortality. Intubation is reserved for failure of NIV, a patient who cannot protect the airway or who is severely obtunded.

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 Respiratory medicine: non-invasive ventilation?

For each disease know the classic presentation, the best test, and the first-line treatment. Then use the flashcards and the other General Medicine 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.