Paediatric anaesthesia: oxygen consumption in neonates: 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.

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Anaesthesia · Paediatric anaesthesia: oxygen consumption in neonates

Sample item

Why do neonates desaturate faster than adults during apnoea?

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

The answer and the reasoning

D. Higher oxygen consumption per kilogram with a low functional residual capacity

Neonatal oxygen consumption is roughly 6 to 8 mL/kg/min compared with 3 to 4 mL/kg/min in adults, while functional residual capacity per kilogram is similar or smaller because of compliant chest walls and early airway closure. This leaves little oxygen reserve. Preoxygenation gives a short safe apnoea time, so intubation attempts must be brief.

Option by option

  • A. Lower oxygen consumption

    Consumption is higher, not lower, in neonates.

  • B. Higher haemoglobin affinity for oxygen that releases it quickly

    Fetal haemoglobin has higher affinity and releases oxygen less readily, which does not explain rapid desaturation.

  • C. A larger functional residual capacity

    The functional residual capacity is not larger in relation to oxygen demand.

  • D. Higher oxygen consumption per kilogram with a low functional residual capacity (correct)

    Correct. High consumption with little reserve leads to rapid desaturation.

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 Anaesthesia question

What is the answer to this Anaesthesia question?

The best answer is D, Higher oxygen consumption per kilogram with a low functional residual capacity. Neonatal oxygen consumption is roughly 6 to 8 mL/kg/min compared with 3 to 4 mL/kg/min in adults, while functional residual capacity per kilogram is similar or smaller because of compliant chest walls and early airway closure.

Why is "Lower oxygen consumption" not the answer?

Consumption is higher, not lower, in neonates.

Why is "Higher haemoglobin affinity for oxygen that releases it quickly" not the answer?

Fetal haemoglobin has higher affinity and releases oxygen less readily, which does not explain rapid desaturation.

Why is "A larger functional residual capacity" not the answer?

The functional residual capacity is not larger in relation to oxygen demand.

What concept does this question test?

It tests Paediatric anaesthesia: oxygen consumption in neonates in Anaesthesia. This leaves little oxygen reserve. Preoxygenation gives a short safe apnoea time, so intubation attempts must be brief.

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 Paediatric anaesthesia: oxygen consumption in neonates?

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.