Foreign Body Ball Valve Mechanism — RACP Paediatrics MCQ

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ModerateRespiratoryForeign Body Ball Valve MechanismRACP Paediatrics

An 8-year-old chokes on a grape. Unilateral hyperinflation on CXR. Mechanism?

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Correct answer: A — Ball-valve obstruction trapping air during expiration

FB acts as ball valve: air enters on inspiration but is trapped on expiration.

Reference: RCH Melbourne – 2024 – Foreign Body Aspiration