Key Practice Points
The most common soft tissue foreign bodies (FBs) are wood, metal, and glass.
Foreign bodies, such as wood, should be removed if they are reactive, as wood and other reactive materials can cause infection or granulomas. Nonreactive objects, such as metal, need not be removed if they are in a noncritical area. If these objects can interfere with weight-bearing areas or joints, they should be removed.
Lead objects can increase blood lead levels, but if they are in anatomically unimportant areas, they need to be removed only if symptoms of toxicity (fatigue, headache, nausea, or other symptoms) are present, and blood lead levels confirm toxicity.
The majority (80%) of foreign bodies, including glass, are visualized directly or indirectly with radiographs. Wood and other organic objects are the least likely to be seen on radiographs. Computerized tomography, MRI, and ultrasound are alternative methods to localize FBs.
Exploration and removal of FBs can be difficult and frustrating. As a rule, if exploration exceeds 20 to 30 minutes, assistance from or referral to a consultant is recommended.
Clean plantar puncture wounds without visible inflammation or foreign material have a low complication rate, and there is no evidence that prophylactic antibiotics have any value.
Plantar puncture wounds with suspected foreign material or contamination should be opened, irrigated and débrided, and treated with antibiotics.
Common nonlaceration problems lend themselves to emergency wound care techniques. These problems include retained foreign bodies and fishhooks, plantar puncture wounds, and abrasions. Although they can appear trivial, each of these problems presents special challenges and occasionally requires sophisticated diagnostic and management procedures. In addition, certain anatomic areas of the body, particularly the structures of the face, hand, and foot, can be fraught with unique difficulties, which are best managed by a thorough understanding of the issues and an application of the proper technique.
Any object becomes a foreign body when it penetrates the skin and lodges in the soft tissue. In a study of 490 cases of foreign-body injuries presenting to an emergency department, the majority of the injuries were caused by wood, metal and glass. Other reported foreign bodies were pencil leads, thorns, nails, and plastic objects. Generally, foreign bodies are classified by material—inert (nonreactive) and organic (reactive). The vast majority of patients presented within 48 hours.
Inert (Nonreactive) Objects
Inert objects include bullets, needles, and other metallic items. Although they do not provoke inflammation, these objects can cause chronic pain and discomfort, especially in weight-bearing areas or near joints. Metals that oxidize (i.e., rust) can cause mild to moderate tissue reaction. The clinical decision to remove an inert object has to be weighed against the potential damage that could be created during a search for the object. Inert objects can be left in place if they are inaccessible and will not cause tissue damage or functional deficit. If left alone, noncritical inert foreign bodies encapsulate within soft tissue and cause no further problem.
A question sometimes arises concerning lead foreign bodies, usually bullets, and the risk of lead absorption and toxicity. When compared with controls, patients with extraarticular retained missiles (lead bullets) show a rise in lead levels over time, but the vast majority (96%) of level increases were shown not to be clinically significant. In a study of patients with retained bullets, lead levels averaged 17 μg/dL compared with 7μg/dL in the control patients ( P < .002). Levels greater than 10 μg/dL are considered toxic. Clinical signs of toxicity are uncommon, however. Symptoms, such as fatigue, headache, and nausea, can be low grade and vague. If toxicity is suspected, patients are referred for lead level testing and evaluation.
Although glass is considered inert, glass foreign bodies are often symptomatic. If the glass is accessible, removal is recommended except for small, insignificant fragments. Pencil “lead” (i.e., graphite) is inert but can cause tattooing. It also can be accompanied by wood fragments during injury. For these reasons, even though it is inert, graphite should be removed from the injury site.
Organic (Reactive) Objects
Objects that are not inert—wood, bone, soil, stones, rubber, and other organic materials such as thorns—must be removed in their entirety. These materials can cause a variety of bacterial and fungal infections. Synovitis from joint penetration, periosteal reactions, foreign-body granulomas, draining fistulas, and pseudotumors of the soft tissue all have been reported with noninert foreign objects. Retained wood objects have been reported to cause chronic inflammation, drainage, and pain for 7 years after penetration. A missed diagnosis or failure to remove all fragments of a noninert object can lead to prolonged disability and patient discomfort.
When a foreign object penetrates the skin, patients cannot reliably report its presence. In glass wounds, reliance on the patient’s history alone would lead to 50% missed fragments. For cases in which no foreign body is reported, certain clinical settings carry a higher risk for one being present. Any injury with glass should raise the suspicion of a retained fragment. For glass injuries, the head and foot are more likely to have retained fragments. For lip or perioral injuries in which there is traumatic loss of dentition, a tooth fragment might be embedded in the soft tissue. Injuries to the feet or hands with needles, nails, or splinters should be suspected of retention if the patient cannot account for the entirety of the injuring object. If the suspicion is strong, the caregiver is obligated to perform a diagnostic evaluation and local exploration to rule in or rule out the possibility of a retained foreign object.
Before anesthetic is administered, gently running a gloved finger over the suspected foreign-body site can elicit in a patient the characteristic sensation. In the anesthetized wound, gently probing and drawing a closed hemostat in and through the wound can alert the operator to the presence of a wood, glass, or metallic foreign body. The hemostat transmits a distinct “grating” sensation. Probing can reveal the presence of an inert object or a wood splinter before it has been softened by the absorption of tissue fluids.
For the most part, radiographs are ordered when there is patient belief or clinical suspicion of a foreign object. Most objects (80%) can be visualized directly or indirectly with the use of radiographs. Radiodense objects, even the size of a pinpoint, are easily seen. Metallic objects, with the exception of aluminum, can be visualized in almost all cases. A common misconception is that glass is not visible by radiograph. In experimental conditions, virtually all types of glass (95%) 2 mm in size can be seen by x-ray. Fragments 0.5mm or larger can be visualized in 50% to 60% of cases. In a clinical study of 98 patients presenting to the emergency department (ED) with foreign-body retention, 24% were radionegative. Other radiodense objects include pencil graphite, some plastics, and gravel.
Nonradiodense objects include wood, thorns, chicken bones, and some plastics. Radiodensity of wood and organic objects depends to some degree on the time in tissue and the absorption of body fluids. Wood has been reported to be visible by radiography in 15% of cases; however, after 48 hours, fluid absorption renders it invisible. Nonradiodense objects (e.g., splinters or plastic fragments) can be revealed as a filling defect or can be outlined by air drawn into the wound during the injury.
Ultrasonography, Computed Tomography, and Magnetic Resonance Imaging
Ultrasonography has become an increasingly important bedside diagnostic aid in emergency departments. Compact portable equipment with versatile transducer probes allows for diagnosis of nonradiodense objects and assisted removal. Ultrasonography can detect nonradiodense foreign bodies 1 × 2 mm or larger. In experimental studies, in which various foreign bodies are introduced to chicken or cadaver flesh, the sensitivity of ultrasound detection varied from 43% to 83%. The specificity ranged from 59% to 86%. In a small clinical study of patients with actual nonradiodense foreign bodies, ultrasound detected 21 of 22 foreign bodies found at operation.
Tendons, deep scar tissue, fresh hematoma, and tissue calcifications can produce false-positive ultrasound readings. Similar to any technical procedure, experience increases the accuracy and effectiveness of the operator.
Computed tomography (CT) scans offer an alternative to ultrasound. Not only can a CT scan identify vegetative objects, such as splinters and thorns, but also it can localize objects in relationship to the surrounding anatomic structures. Magnetic resonance imaging has capabilities similar to CT but should never be used to locate objects that contain metal. CT and magnetic resonance imaging are expensive imaging alternatives and require a high degree of patient cooperation, which often is not possible for a pediatric patient.
For objects that are located below the surface and out of direct sight, careful localization is necessary before proceeding with exploration. Radiodense objects can be localized by a variety of techniques using markers and radiographs. A simple technique recommended by the author is to bend a paper clip to form a flat plane with an extended arm. The extended arm is placed directly over the skin entry wound created by the foreign object, and the paper clip is secured with a small piece of tape ( Fig. 16-1 ). Two radiographs are taken exactly at an angle of 90 degrees to each other (anteroposterior and lateral views) using the plane of the clip as a geometric point of reference ( Figs. 16-2 and 16-3 ). In this manner, the location and the depth of the object relative to the extended arm of the paper clip can be determined. Magnification by this technique occurs, and the distance between the object and the clip on the radiograph is greater than the actual distance. After appropriate cleansing and the administering of an anesthetic, a small incision is made, and exploration is performed until the object can be removed. The radiographs are needed for reference in the care area during the removal.
If ultrasonography is not available to assist in removal, nonradiodense objects are best approached through a more generous incision and thorough exploration by direct visualization. Incisions permit débridement and removal of tissue that is embedded with foreign material. When the foreign body is located in the hand or the foot, the exsanguination tourniquet technique (see Chapter 9 ) is recommended. Even a small amount of bleeding can make visualization impossible.
Techniques for Removal
When attempts to remove foreign bodies are made by an emergency physician, removal was successful in 89% of cases. Consultation by surgical specialist occurred in 47 cases with a success rate of 65.6% of those cases.
The following steps are recommended for buried foreign bodies:
The first step is to decide whether a removal attempt should be made in the ED. Removal is likely to be successful if the object has been under the skin for less than 1 week, the object is visible, the entry wound is fresh, the object can be localized with an imaging procedure, the object is radiodense, or the object can be felt during probing. Success is less likely if the object is deep, if it has been present for several weeks or months (as is often the case with needles), if no entry point is present, if the object is nonradiodense, and if the object cannot be localized.
Ideally, foreign bodies seen in the ED are more easily removed elsewhere in bloodless conditions; however, most FBs are small and superficial enough to be located and removed.
After the decision is made to remove the FB, the area is cleaned with Betadine or chlorhexidine.
In order to prevent excessive swelling, anesthesia should be administered by nerve block if possible. Swelling of local anesthesia can make locating the FB more difficult. If no alternative is available, as little local anesthesia as possible should be used.
A no. 15 scalpel blade is used to make an incision over the entry point, parallel to the axis of the FB if it can be determined.
A small curved clamp can be used to explore the incision site for the FB. The clamp tip is gently “raked” through the site to feel steel against glass, wood, or metal to assist localization.
Once localized, the FB is grasped and removed. See the following text for an explanation of the removal of wood or organic objects.
After removal, the wound is irrigated and a dressing is applied. Incisions, except if they are large and gaping, should not be sutured.
Simple retrieval is not always possible, however. As a rule, if attempts at retrieval exceed 20 to 30 minutes, serious consideration should be given to terminating the procedure and obtaining consultation.
For objects that are partially protruding from the skin, the temptation to “grab and yank” must be resisted. If a wood splinter is pulled out injudiciously through a small, tight entry wound, small fragments can be stripped off the splinter and can be left behind to cause future difficulty. The technique illustrated in Figure 16-4 shows how a small incision is made in the finger parallel to the course and angle of the object. By creating an incision, the splinter can be removed without leaving behind smaller splinters. In addition, the wound can be copiously irrigated to decrease the level of bacterial contamination. These small incisions must not be closed with sutures. They should be left open to drain the site, if necessary, and to prevent the accumulation of purulence that might lead to the formation of an abscess.
Objects under Nail Plates
A common problem is a splinter or other object that is lodged under a nail plate. If the object can be grasped by a hemostat, it can be pulled out carefully from under the nail. Care has to be taken not to strip fragments off a wooden object. For a splinter that cannot be grasped, removal of a small part of the nail plate in a wedge-shaped fashion can be carried out to expose the splinter, as shown in Figure 16-4 (top).
A simple technique for removing small splinters lodged under the nail plate is to bend the tip of a 25-G or 27-G needle so that a small barb equal in size to the diameter of the needle is created. The shaft of the needle is introduced adjacent and parallel to the splinter and is carried back to the most proximal portion of the object. Then the barb is raked along the splinter, and the needle and the foreign object are pulled out from under the nail. Removing objects from under nails is best performed when the patient is anesthetized. The anesthetic usually is delivered via a digital block (see Chapter 6 ).
Thorns and Cactus Spines
Particularly troublesome are small thorns and cactus spines that can become embedded accidentally in the skin in large numbers, usually in children. In a controlled rabbit experiment, Elmer’s Glue-All was applied under a single layer of gauze and was allowed to dry. Gentle peeling successfully removed 95% of all spines. The next most effective method was the manual removal with tweezers, with a 76% rate of spine removal. The combination of tweezer removal of large spines followed by glue application is effective.
When to Consult
Occasionally a foreign body cannot be retrieved successfully by attempts at localization and exploration in an emergency wound care setting. This situation most commonly arises in the case of deep foreign objects in the foot. These foreign bodies are best removed in radiology department suites where ultrasound, image intensifiers, and stereotaxic localization can be applied while a consultant explores the affected area.