General
· Transient inflammation is an integral part of normal wound healing.
· Foreign debris in a wound provokes an inflammatory response in an effort to eliminate or contain the invader.
· Large quantities of devitalized tissue, foreign debris, bacteria, or other irritants present within a wound intensify this protective response.
· Prolonged or intense inflammatory responses delay wound healing and destroys surrounding tissue and bone.
· If the body can’t dissolve or dispose of foreign material, it gets encapsulated within a fibrous capsule.
· Type of foreign body can make a difference in the inflammatory reaction
o Inert Material (glass, metal, plastic) may have no abnormal tissue response. Some metals may have oxidizing properties that can cause minor inflammation.
o Vegetative Material (wood, thorns, spines) trigger SEVERE inflammatory reactions.
o Marine material (sea urchin spines) can cause chronic inflammation with granuloma formation.
· Infections are the most common complication of retained objects.
o Typically, they can be resistant to therapies such as antibiotics, anti-inflammatory drugs, and steroids.
o Some infections will resolve spontaneously once the foreign body is removed.
o Vegetative foreign bodies may also cause fungal infections, particularly in immunosuppressed patients.
o Chronic, delayed, and recurrent infections are associated with retained foreign bodies
Physical Exam
· Make effort to visually inspect all recesses of a wound.
· Wounds deeper than 5 mm and wounds whose depth cannot be visualized have a higher association with foreign bodies.
· If punctures and other narrow wounds make direct visualization difficult and there is concern about a foreign body below the surface, the wound margins should be extended with a scalpel.
· Blind probing with a hemostat is a less effective but sometimes is an acceptable alternative to wound exploration when the wound is narrow and deep and extending the wound is not desirable.
· A closed hemostat should be introduced into the wound and either used as a probe or spread open and then withdrawn.
· If an instrument strikes a metallic or glass foreign body, it will produce a grating sensation.
Imaging
· Beneficial to obtain post removal imaging of multiple foreign bodies to ensure all pieces were found
Localizing Techniques
· It’s easier to detect the presence of a foreign body than to locate its exact position.
· If radiopaque, can estimate location and depth by taping radiopaque skin markers such as paper clips on skin at wound entrance or directly above the object.
· Another method is using hypodermic needles, two or three needles inserted into skin near the object after anesthetizing the area at 90 degrees to each other to create a frame of reference.
· Almost all glass is visible on radiographs if it is 2 mm or larger, and glass does not have to contain lead to be visible on plain films
· Ultrasound can identify a wide variety of soft tissue foreign bodies such as wood, fish bones, sea urchin spines, other organic material, fiber, and plastic, with >90% sensitivity for foreign bodies >4 to 5 mm
o Foreign bodies appear as hyperechoic foci, usually with acoustic shadowing extending distally.
o A hyperechoic rim, or halo sign, indicates an abscess or granuloma around the object.
o Sonography can estimate the depth of a foreign body below the skin surface and guide object removal in real time.
Treatment
· Not all foreign bodies must be removed, and not all that require removal must be extracted in the ED
· Thorns, spines, wood splinters, and other vegetative materials should be promptly removed because they cause intense and excessive inflammation.
· Heavily contaminated objects such as teeth and soil covered objects should be removed ASAP.
· Antibiotics treatment CANNOT replace foreign body removal.
· Glass, metal, and plastic are relatively inert, and removal can be postponed, if necessary.
o Glass foreign bodies in hands or feet can cause persistent pain with gripping or walking, and they can sever nerves or tendons years after the initial injury.
o Deep, sharp foreign bodies in these locations should be referred to appropriate specialists for eventual removal.
· Use adequate anesthetics to achieve pain control, good lighting, and tourniquets if needed.
· Although most foreign bodies in hands should be removed because the hand is mobile and sensitive, deep exploration of the hand by the emergency physician is not recommended because knowledge and experience are needed to avoid injury to numerous closely spaced vital structures.
Post Removal Treatment
· After removal irrigate wound thoroughly
· In general, if concern for contaminated puncture wound, then enlarge entrance wound to allow for more effective cleaning.
· Post procedure x-ray if multiple objects removed
· Update tetanus
· Wounds in which all foreign contaminants can be removed and those in locations with good blood supply can be closed primarily. Otherwise, delayed primary closure is preferred.
· NO PROVEN BENEFIT FOR PROPHYLACTIC ANTIBIOTICS FOR UNINFECTED WOUNDS CONTAINING FOREIGN BODIES
· Antibiotics are justified for infected wounds, particularly when removal must be postponed
· Delayed removal – refer to surgeon or interventional radiologist for delayed removal of foreign bodies.
o If a foreign body is near a joint or highly mobile region, the affected area should be splinted before removal to prevent further injury or migration of the object.
References
Tintinallis Emergency Medicine A Comprehensive Study Guide
https://www.aafp.org/afp/2007/0901/p683.html
http://www.emdocs.net/soft-tissue-foreign-bodies-ed-presentation-evaluation-and-management/