A missing piece of apple
A 4year old boy presents after choking on a piece of apple. His mum reports that he was eating a slice of apple when he started to cough and struggle to catch his breath. She reports that there was a significant improvement within a minute but that he continues to cough and wheeze since the event. She denies apnoea, colour change or loss of consciousness.
On examination he looks well. He has an intermittent cough and a hoarse voice. He has normal observations, with sats of 99% and a respiratory rate of 32 and normal respiratory effort. Auscultation of his chest reveals good air entry throughout with a focal wheeze to the right lower zone.
Inspiratory and expiratory chest x-rays are performed which are normal. Given the history and focal chest findings, he is referred to ENT and Respiratory who decide to perform a bronchoscopy under general anaesthetic. They find a normal respiratory tract. He is observed overnight, remains well and is discharged the next day.
1) Suspected inhaled foreign body? Order inspiratory and expiratory chest films
Most inhaled foreign bodies are organic in nature and hence not visible on x-ray. If there is obstruction of the bronchus you may however see evidence of this with hyperinflation of the affected side or atelectasis. The ‘classic’ finding of an obstructed inhaled foreign body, is a lung volume that does not change in expiration. In inspiration air may be able to get around the foreign body, but in expiration it acts as a ball valve preventing air from escaping. This means that the affected lung is significantly large in volume in the expiratory film than the unaffected lung.
2) A normal inspiratory/expiratory chest series does not exclude foreign body
It is reported that up to 40% of children with an inhaled foreign body will have a normal inspiratory/expiratory chest x-ray series. If there is a strong clinical suspicion the child should be referred for bronchoscopy regardless of the imaging.
Want to learn more? Here is a great post from radiopedia about airway foreign bodies in children, with examples of abnormal inspiratory and expiratory films.
NB: Subtle changes have been made to this case to protect patient confidentiality
Dr Danielle Scarfe
Dr Danielle Scarfe