Ultrasound of the Week #029

Special thanks to Dr Dom Craver, PEM SpR for this great case and images.

Case:

A 4 year old girl came in having stepped on some broken glass at home from a broken fish tank.  She had some pain in the bottom of her foot and XR showed a possible radio-opaque speck adjacent to one of her metatarsals. 

Ultrasound initially couldn’t locate a FB, but after putting her foot in a ‘waterbath’, the following image was identified.

Question : What does this show?

Answer: this shows an echogenic FB in the sole of her foot at a depth of 0.35cm.

Case progression:

After some LMX gel and lidocaine infiltrated with an insulin needle, the following FB was removed from her foot with a needle and some splinter forceps (seen below).

The shard is seen adjacent to the needle tip

POCUS for Foreign Bodies:

Foreign bodies (FB) are often difficult to locate on X-ray and radiolucent FB’s such as wood, plastic or organic material will not be seen on X-ray.  However, the majority of foreign bodies are echogenic and can be visualised using ultrasound.  The use of a waterbath or stand-off pad (or makeshift one using a water-filled glove or IV fluid bag) makes visualisation of superficial FB’s much easier. In this case a medical vomit bowl filled with water was used, into which the patient’s foot and ultrasound probe could be placed.

Missed FB’s can lead to ongoing pain, local infection and complaints/medicolegal claims and so POCUS for FB’s is an excellent tool for use in the ED.  There is a great review with many examples available at https://www.acep.org/sonoguide2/procedures/foreign-bodies/.

References/Resources:

  1. Bryczkowski, C Foreign Body Localisation, Sonoguide Ultrasound for the Emergency Physician (ACEP)

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