This week, I’ll be sharing a slew of handy information to keep in mind when dealing with foreign bodies in the Emergency Medicine setting. This post is also an introduction of sorts – Since taking over editor-in-chief duties from Sakib, the founder of this blog, my work thus far has been mostly behind the scenes editing. I’ve also done some back-editing on recent posts that should make scrolling through the Quickhits site while browsing topics much easier. I hope you enjoy! (PS – I apologize for any puns in advance)
Corey Warf, EiC
First, the Quickhit:
- Foreign bodies in tissue generate an inflammatory response which varies in intensity based on the composition of the object: inert materials (glass, plastic, metal) generating less of a response than organic materials such as bone, spines, woody plants, or vegetative material.
- Likewise, risk of infection varies based on foreign body material: inert materials are relatively low risk, while organic materials pose a much higher risk of infection.
- Composition of infections often vary based on material as well: tooth fragments increase the risk of polymicrobial infections while woody materials may increase the risk of fungal infections, e.g.
Presentation and Exam
- Lacerating or penetrating injuries with an object that may break, shatter, or splinter have higher odds of a foreign body being present in the wound.
- Wounds deeper than 5mm or those that cannot be fully explored have a higher risk of foreign body presence.
- An adult who senses a foreign body’s presence in a wound has double the risk of a retained foreign body, compared to an adult who does not sense a foreign body with a similar injury (Note: this only holds true for adults, not pediatric populations, even if verbal).
- Keys to a good exam are adequate lighting, hemostasis, and anesthesia. Try to visualize the entirety of the wound. Puncture wounds can be extended with a scalpel to improve visualization.
- For deeper wounds involving glass or metal, insert a closed hemostat and withdraw – scraping on the way out may indicate a retained foreign body.
- If a foreign body is suspected, order imaging!
- Appropriate imaging studies varies based on situation – no single imaging modality is appropriate for every situation.
- Radiopaque objects such as leaded glass, metal, bone, rocks, and some plastics can be detected with X-ray; however, x-ray often does a poor job with organic materials that are not hard bone.
- CT scan is fairly sensitive for foreign bodies, but has the drawbacks of increased cost and radiation exposure. Also, a weird quirk of CT scan is that wood can sometimes mimic the appearance of air bubbles in soft tissue, which may confuse a foreign body (not-as-bad) with a gas-producing infection (extremely-very-hyper-bad). So keep that in mind.
- Bedside ultrasound has the benefits of being quick, non-irradiating, and performable by the physician at the bedside. As an added bonus, it allows for guided removal of hyperechoic foreign bodies such as glass. However, it can be a difficult skill to master, and false positives may lead to you digging around tissue. Other hyperechoic structures (soft tissue calcifications, bones, tendons) can mask the presence of foreign bodies.
- Again – there is no single best imaging study to order for all situations. Think about the injuring material and its properties. Physics may be boring, but a little bit of knowledge can go a long way.
Treatment and Disposition
- Not all foreign bodies have to be removed! Step One – figure out if it even requires removal.
- Good indications for removal include: toxic material; risk of infection; involvement of nerves, tendons, blood vessels or potential to migrate to those structures.
- Some foreign bodies may require special removal techniques – see relevant discussion below. Foreign bodies that are in very deep tissue or embedded in hands or face may require special surgical consult or specialist follow-up.
- After removal, closure depends on infection risk. Low-risk wounds can be closed with primary intent – all the good evidence shows that these wounds do not require prophylactic antibiotic use.
- Wounds at risk for infection (think heavily contaminated materials, like teeth fragments) may require healing by secondary intent or delayed primary closure. However, in the absence of active infection, prophylactic antibiotic use is currently of unclear benefit at best (I guess if there were active infection, it would no longer be considered “prophylactic antibiotic use” anyway).
- Ensure the wound is cleaned and irrigated post-removal.
- If suspected retained foreign bodies exist after removal, obtain a post-procedure radiograph.
- After discharge, appropriately inform the patient of the risk for a retained foreign body and document, document, document – don’t let them show up 6 months later with a frivolous lawsuit because they had “no idea” a piece of glass would fall out of their arm (even though you told them multiple times).
Continue reading below for further discussion: