Critical care: oxyhaemoglobin dissociation curve: 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 · Critical care: oxyhaemoglobin dissociation curve

Sample item

Which condition shifts the oxyhaemoglobin dissociation curve to the right?

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

The answer and the reasoning

D. Acidosis, fever and raised 2,3-DPG

A right shift lowers oxygen affinity and raises the P50 (normally about 26.6 mmHg), favouring unloading in tissues. It is caused by acidosis, hypercapnia, fever and increased 2,3-DPG. Alkalosis, hypothermia, fetal haemoglobin and carbon monoxide shift the curve left.

Option by option

  • A. Alkalosis and hypothermia

    Alkalosis and cold shift the curve left.

  • B. Fetal haemoglobin

    Fetal haemoglobin has higher affinity and shifts the curve left.

  • C. Carbon monoxide

    Carbon monoxide shifts the curve left.

  • D. Acidosis, fever and raised 2,3-DPG (correct)

    Correct. These factors reduce haemoglobin affinity for oxygen.

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 D, Acidosis, fever and raised 2,3-DPG. A right shift lowers oxygen affinity and raises the P50 (normally about 26.

Why is "Alkalosis and hypothermia" not the answer?

Alkalosis and cold shift the curve left.

Why is "Fetal haemoglobin" not the answer?

Fetal haemoglobin has higher affinity and shifts the curve left.

Why is "Carbon monoxide" not the answer?

Carbon monoxide shifts the curve left.

What concept does this question test?

It tests Critical care: oxyhaemoglobin dissociation curve in Anaesthesia. 6 mmHg), favouring unloading in tissues. It is caused by acidosis, hypercapnia, fever and increased 2,3-DPG. Alkalosis, hypothermia, fetal haemoglobin and carbon monoxide shift the curve left.

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 Critical care: oxyhaemoglobin dissociation curve?

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.