Cardiac Arrest — ORE Part 1 MCQ

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EasyPharmacology & TherapeuticsCardiac ArrestORE Part 1

A patient collapses in the dental chair. They are unresponsive, not breathing normally, and have no pulse. What is the correct compression to ventilation ratio for adult CPR?

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Correct answer: E — 30:2

Explanation lettering: C = shown as A · E = shown as B · B = shown as C · A = shown as E

The correct compression-to-ventilation ratio for adult CPR is 30:2. This means delivering 30 chest compressions followed by 2 rescue breaths. In 2005, international resuscitation guidelines changed from the previous standard of 15:2 to 30:2 to optimise uninterrupted chest compression time while maintaining adequate ventilation. This ratio balances effective perfusion pressure with minimal interruption to compressions and reduced rescuer fatigue. Option B (15:2) was the earlier standard but is now superseded. Options C, D, and E are not recognised adult CPR ratios. This is the current standard taught by Resuscitation Council (UK) and NHS guidance.

Reference: NHS (2024). First aid - CPR. https://www.nhs.uk/tests-and-treatments/first-aid/cpr/ and Resuscitation Council (UK) (2021). Adult Basic Life Support Guidelines.