Oxygen delivery: practice question

A Anaesthesia 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

Anaesthesia · Oxygen delivery

Sample item

Which variable has the greatest effect on arterial oxygen content in most patients?

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

The answer and the reasoning

C. Haemoglobin concentration

Arterial oxygen content is approximately 1.34 times haemoglobin times saturation plus a small dissolved component. Therefore anaemia can markedly reduce oxygen content despite a normal pulse oximetry value.

Option by option

  • A. Serum bicarbonate

    Bicarbonate influences acid-base state, not primary oxygen carriage.

  • B. Dissolved oxygen only

    Dissolved oxygen is usually a small fraction at normal pressures.

  • C. Haemoglobin concentration (correct)

    Correct. Most oxygen is carried bound to haemoglobin.

  • D. Respiratory rate alone

    Respiratory rate affects ventilation but does not determine oxygen content by itself.

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.

More Anaesthesia questions

Questions about this Anaesthesia question

What is the answer to this Anaesthesia question?

The best answer is C, Haemoglobin concentration. Arterial oxygen content is approximately 1.

Why is "Serum bicarbonate" not the answer?

Bicarbonate influences acid-base state, not primary oxygen carriage.

Why is "Dissolved oxygen only" not the answer?

Dissolved oxygen is usually a small fraction at normal pressures.

Why is "Respiratory rate alone" not the answer?

Respiratory rate affects ventilation but does not determine oxygen content by itself.

What concept does this question test?

It tests Oxygen delivery in Anaesthesia. 34 times haemoglobin times saturation plus a small dissolved component. Therefore anaemia can markedly reduce oxygen content despite a normal pulse oximetry value.

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 Oxygen delivery?

Make a table of each agent, its key advantage and its main side effect. Then use the flashcards and the other Anaesthesia 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.