Chapter 32: Soft-Tissue Injury and Wound Repair

• In assessing a child with a minor wound, exclude more serious, sometimes occult, injuries that take precedence in management.

• Assess the length and depth of the injury, circulatory status, motor and sensory function, and the presence of foreign bodies and contaminants.

• Topical anesthetics provide effective anesthesia and are a necessary adjuvant for pediatric lacerations.

• Many lacerations are suitable for closure using noninvasive methods of closure.

• Splint a wound overlying a joint in the position of function for 7 to 10 days.

• Antibiotics are indicated for patients who have significant immune-compromising disease, who present with a wound infection, who present for care late (12–24 hours), and in certain specific instances (intraoral lacerations, wounds of the hand, and cat bites).

• Patient and parents should be given thorough after-care instructions about care of the wound and what to expect.

Lacerations and soft-tissue injuries are among the most common reasons for children to present to the ED.¹ These encounters, if handled incorrectly, can be difficult for the child, parent, and physician.² To maximize cosmetic and functional results, ensure meticulous wound care and repair. Many techniques exist to maximize the satisfaction and clinical results. A solid understanding of the basic tenets of wound care is necessary to do so.

The appearance and function of a healed wound is somewhat predicted by the magnitude of the tension on the surrounding skin, but there is great intra- and interindividual variability. The most cosmetically pleasing scar results when the long axis of the wound is in the direction of maximal static skin tension, along “Langer's lines” (Fig. 32-1). Examination of the wound in the ED is a reliable method to predict the appearance of the healed wound in the absence of confounding variables, such as the development of an infection or keloid. Dynamic skin tension (caused by joint movement and muscle contraction) also has an impact on the degree of scar formation and post repair function. A wound intersecting the transverse axis of a joint may result in a significant contracture, as scars do not have the elasticity of uninjured tissue.

Unfortunately, soft-tissue wounds are unplanned events and often have axes that are perpendicular to the direction of static skin tension or parallel to the dynamic skin tension. Therefore, it is always essential to warn the child and parent of possible adverse cosmetic outcomes.

Lacerations

Lacerations are the most common soft-tissue injury seen in the ED. The face, scalp, and hands are the most common sites of injury in children. As lacerations generally require more complicated treatment than other minor wounds, much of this chapter deals with the assessment and treatment of lacerations. All lacerations can be associated with occult injuries and require thorough exploration to detect deeper injuries. The three main classes of lacerations are shear, tension, and compression.

Shear injuries are caused by sharp objects and generally cause little damage to adjacent tissues but can cause nerve, tendon, and vascular damage. Shear injuries usually heal fastest and have the lowest incidence of wound infection.

Tension lacerations occur when stresses cause the skin to tear. There is often associated damage to the surrounding tissues, and these lacerations are irregularly shaped.

Compression lacerations occur during a crush injury and have irregular, often stellate, wound edges. They are often associated with a significant amount of injury to the adjacent skin, contusion to the underlying structures, and they have a higher incidence of wound infection than other types of lacerations.³

Abrasions

Abrasions are injuries in which layers of the skin are scraped or sheared away. In superficial abrasions, only the cornified epidermis is removed, there is minimal or no bleeding. Healing is rapid. Deeper abrasions involving the dermis are prone to bleeding and are more susceptible to infection, pigment change, and prolonged healing.

Contusions and Hematomas

Contusions are the result of direct blows to the tissues and often injure underlying structures. Localized bleeding and edema can cause swelling and pain to the injured area, and on rare occasion, may result in secondary ischemic injuries. Management of all contusions involves elevation of the injured area, application of ice packs intermittently for the first 24 to 48 hours, and careful monitoring of circulation and neurologic function.

Hematomas are localized collections of extravasated blood that are relatively or completely confined within a space or potential space. Hematomas must be observed closely for signs of infection and, in some instances, may benefit from drainage.

Prehospital care of minor wounds includes control of bleeding and attention to the damage to underlying structures. Control of blood loss is accomplished by direct manual pressure or use of a pressure dressing. If bleeding is not controlled with these methods, inflation of a sphygmomanometer or application of a tourniquet proximal to the bleeding site on an injured extremity can be safely employed even for prolonged (at least 2 hours) transport times.^4,5 Assess neurovascular status. Apply moist dressings. Document what patients, parents, and providers have done in the prehospital setting.

In assessing a child with a minor wound, first exclude more serious injuries that will take precedence in management. Then the management of soft-tissue injuries can be compartmentalized by addressing host factors, wound factors, and after-care.

The history should include the time and mechanism of the injury, the full extent of the injured areas, and whether there could be possible contaminants or foreign bodies in the wound. Obtain a detailed history of the patient's host factors with particular attention to the child's immunization status, medical problems or allergies, any medications that the child takes, and what prehospital wound care was performed prior to arrival in the ED. Always consider nonaccidental trauma, especially when the history and the injury pattern are inconsistent.

Addressing the wound factors involves a physical examination that must assess the length and depth of the injury, circulatory status, motor and sensory function, the presence of foreign bodies and contaminants, and the involvement of underlying structures (nerves, tendons, muscles, ligaments, vessels, bones, joints, and ducts). The sensory examination must precede the administration of anesthesia, but the remainder of the examination should be performed with adequate anesthesia. To avoid fear in the child, anxiety in the parents, and frustration for everybody else, use a calm, unhurried, reassuring, and honest approach throughout the evaluation and management.

Test sensation by measuring two-point discrimination distal to an injury. For children younger than 3 years, use an appropriate stimulus to provide a sensory and a partial motor assessment. As normal autonomic tone produces a degree of normal sweating, denervated fingers do not sweat, which may provide a clue to injury if this is not seen under magnification. Evaluate peripheral pulses, skin temperature, skin color, and rapidity of capillary refill. Test tendons, muscles, and ligaments distal to an injury. With cooperative older children, one can test these structures' functions individually. However, with younger, less cooperative children, one must rely on observation of symmetry, function, and exploration of the wound. Use a toy or penlight that requires manipulation by the child to help in evaluating motor function. Involve child life providers and observe the child at play to evaluate wounds that might involve underlying motor structures.⁶

Instruments, Sutures, Staples, Tape, and Tissue Adhesives

The technical approach for wound closure depends on the host and wound factors of the laceration. Sutures, staples, surgical tape, closure devices, and tissue adhesives each have intrinsic pros and cons for their use (Table 32-1). Most wound repairs can be accomplished with basic instruments and supplies (Fig. 32-2) as well as gloves,^7,8 personal protective equipment, anesthetic agent(s), and irrigation equipment.

A number of needle types are available for use, and manufacturers generally place a life-size and cross-sectional diagram of the needle on each suture package. Typical ED wound repair can be accomplished with reverse precision point cutting needles that are manufactured in various sizes, curvatures, and paired with differing thread types.

Suture choice is one of the most fundamental options in wound and laceration repair. Each suture type has inherent characteristics that are suited for specific uses. The most basic choice is absorbable versus nonabsorbable suture material. Historically, absorbable suture was relegated to use as a deep (nonepidermal) closure, whereas nonabsorbable sutures were used externally (epidermal). Recently, strong consideration has been given toward the use of absorbable suture externally to eliminate the need for return visit for suture removal.⁹ Because of the inflammatory response that absorbable sutures generate during the degradation process, the cosmetic outcome must be considered. Using absorbable sutures on noncosmetically important areas (extremities, trunk) has been studied and accepted¹⁰; the use of absorbable sutures on cosmetically critical regions (the face) has been studied with good outcomes compared with other standard methods.¹¹ Each wound requires a certain tensile strength for a certain amount of time and the characteristics of each suture type should be understood (Table 32-2).

Surgical staples are a useful alternative to suturing for selected wounds. Sharp lacerations of the scalp, trunk, and extremities are rapidly and effectively closed using staples. Staples induce a minimal inflammatory reaction and produce similar cosmetic results compared with suturing. Staples are often not well suited for use in stellate or angulated wounds, hand wounds, or wounds which sit in recessed contours of the body. Recall that staples are hard and relatively nonmalleable when compared with sutures (Fig. 32-3). When stapling the scalp, ask the sleep position preference for patients or consider the position in which they will lay while hospitalized. Metallic staples are also radiopaque and give off a significant artifact when CT scan imaging is obtained. Magnetic resonance imaging (MRI) of metallic staples is safe as long as consideration is given to the heat that may be generated during the MRI. Absorbable intradermal staples offer the advantage of rapid closure without the side effects of CT scan artifact or MRI heat development.

Steri-strips are an effective alternative for the closure of small linear lacerations that are under minimal tension (Fig. 32-4). Taped wounds offer an advantage over sutured wounds in that they do not require return to the ED for removal. If applied with an adhesive, such as tincture of benzoin, tape should remain in place for several days. Tape can also be used for skin closure of partial-thickness wounds and of wounds that are closed in a layered fashion with well-approximated wound edges. Tape closure is a reasonable alternative technique for the repair of multiple tangential skin flaps.

Tissue adhesives have been used for many years and remain another option for rapid repair of pediatric lacerations. Adhesives have less tensile strength across wound edges and are therefore suited for use in low-tension wounds.^12,13 The failure of adhesives is typically because of the poor choice of wound type for adhesive use. Adhesives should not be used in wounds with high mobility (fingers, across joints). If you have concern that adhesives would not provide the strength, consider using deep absorbable sutures to provide that necessary strength, or avoid adhesives altogether. If tissue adhesives are to be used near the eye, use a ribbon of petroleum as a barrier to protect against inadvertent instillation of the adhesive into the eye. If the eye is accidentally glued shut, careful use of nail polish remover will free the eyelashes—do not cut the lashes. Although tissues adhesives provide their own waterproof and antimicrobial barrier, wound preparation remains very important for wounds repaired with tissue adhesives as it does with any other wound closure method. Take care to ensure that adequate anesthesia, wound irrigation, and wound exploration occur regardless of the method of closure. With the right choice of wound, noninvasive repair can be faster, less painful, require no suture removal follow-up, and results in patient and parental satisfaction.¹⁴

Analgesia, Local Anesthesia, Nerve Blocks, and Sedation

Most wounds are adequately anesthetized using local infiltration of lidocaine, 1% to 2% with or without epinephrine. Lidocaine has a rapid onset of action and duration of action of approximately 1 to 2 hours. Commercial preparations/dilutions of epinephrine containing anesthetics are safer than older literature suggests and their use in regions supplied by end-arteries has been shown to be safe.¹⁵ Consider the use of a longer-acting agent, such as bupivacaine, to spare patient repeated injections if wound repair may be interrupted. Bupivacaine's onset of action is moderate, and duration of action is approximately 2 to 6 hours.¹⁶ Take care not to use more than the recommended dose per kilogram of the local anesthetic agent. For plain lidocaine and lidocaine with epinephrine, 4.5 and 7 mg/kg are the recommended maximum doses, respectively.¹⁷ Buffering lidocaine with bicarbonate, in a 10:1 dilution, and warming the anesthetic agent may also reduce the pain of injection.^18,19

Anesthetic infiltration should be performed prior to irrigation; however, for grossly contaminated wounds, it is occasionally necessary to irrigate away gross contaminates first. Infiltration is achieved by means of a 25- to 27-gauge needle, injected slowly into the wound margins.²⁰

Strongly consider the use of topical anesthetics on any wound prior to injectable anesthetics as an adjuvant to care.²¹ Topical lidocaine–adrenaline–tetracaine (LAT), as well as tetracaine–adrenaline–cocaine (TAC), provides effective anesthesia for pediatric facial and scalp lacerations.^22,23 Use of LAT has compared favorably with TAC without the risks and administrative complications of cocaine.²⁴ The mixture can be applied to the wound by using saturated sponges, gauze pads, or cotton swabs held in place by a parent or caregiver wearing gloves. Transient anesthesia can also be obtained by applying a solution of 4% lidocaine to a wound prior to infiltration anesthesia or to an abrasion that requires mechanical scrubbing.

Use regional nerve blocks for large lacerations and for lacerations in areas where the anatomy will be distorted if local infiltration is performed. They are especially useful for anesthetizing digits, for facial lacerations, and wounds of the foot.

Moderate sedation is usually not required for the management of wounds in older children. However, for the child who is too uncooperative to permit adequate wound management, consider sedation with agents such as midazolam, nitrous oxide, or ketamine. Perform appropriate cardiac and respiratory monitoring during sedation. There should be constant attendance of the patient, and have available airway management equipment at the bedside, as well as having readily available reversal agents (naloxone and flumazenil). The patient should be discharged after the agents have worn off and the child has returned to an appropriate level of consciousness.

Some form of physical restraint during wound assessment and management may be necessary for children younger than 2 years and sometimes is required for children up to 5 or 6 years. A child may be immobilized using a folded sheet or a commercially available papoose board. Neither method provides adequate immobilization of the head. The perceived time benefit obtained through the use of physical restraints should be carefully balanced against the potential psychologic stressors that physical restraints might put on a child and/or the parents. Careful selection of a case for either chemical and/or physical restraint requires a thorough discussion of risk/benefit of each modality with the parents.

Hemostasis

Hemostasis is necessary during all stages of wound management and usually is achieved by applying direct pressure for 10 to 20 minutes. For control of more brisk bleeding, include elevation of the wound, infiltration of lidocaine with epinephrine, packing with absorbable gel foam, temporary instillation of hemostatic topical agents into the wound, or direct visualization and cautery or ligation of the offending vessel. Short-term (<30 minutes) tourniquet use may be helpful for control of persistent, profound, or multiple sites of distal blood loss. Do not suture or clamp vessels blindly because of the risk of injuring adjacent structures.

Antisepsis and Scrubbing

Clean the skin surrounding the wound prior to wound irrigation and repair. Various antiseptic skin cleansers can be used, including povidone-iodine and chlorhexidine gluconate. Avoid mechanical scrubbing of the wound unless there is gross contamination. Although scrubbing can remove debris from the wound, it increases wound inflammation. If it is decided to perform scrubbing, use a fine-pore sponge to minimize tissue abrasion and a nonionic surfactant to minimize tissue toxicity and inflammation.

Hair Removal

As infection rates are significantly greater in wounds that are shaved, remove hair by clipping if it interferes with the procedure. In almost all wounds, even those to the scalp, hair removal is not necessary. Moistening the hair in the area of the laceration with lubricating jelly usually keeps it out of the way. Never shave or clip the eyebrows. They serve as valuable landmarks for alignment during wound repair and, if removed, can take a long time to grow back.

Irrigation

Irrigation with between 5 and 8 psi of normal saline is the method of choice for removing bacteria and debris from most wounds.²⁵ Low-pressure irrigation with a bulb syringe does not adequately remove bacteria and debris from a wound. The pressure delivered by a simple assembly consisting of an 18- to 20-gauge plastic catheter or needle attached to a 30-mL syringe is 6 to 8 psi. Commercial systems to facilitate irrigation are available, including spring-loaded syringes with one-way valves connected to a standard intravenous (normal saline) setup, prepackaged irrigation fluids with irrigation nozzles, and cap devices that attach to standard fluid containers. Regardless of the system used, maintain the tip of the irrigation device between the wound and 5 cm above the intact skin. Use between 50 and 100 mL per centimeter of length or per square centimeter of wound, with more irrigation for increasing wound complexity or contamination.

Normal saline remains the default irrigation fluid, and is relatively inexpensive, decreases bacterial loads, and reduces wound infection rates. However, it is not bactericidal. Commercial strength povidone-iodine solution is tissue toxic and has no beneficial clinical effect on wound infection rates. When it is diluted to a 1% solution, however, it does not damage tissue and still retains its bactericidal properties but has no proven clinical benefit.²⁶ Tap water is cheaper than normal saline and is without tissue toxicity. Various methods of tap water irrigation have been evaluated, and as long as irrigation pressures remain in the 5 to 8 psi range, tap water is equivalent to normal saline.^27–29

A consequence of irrigation is splatter, which can be minimized using one of many techniques.³⁰ Commercially available plastic shields that attach directly to the irrigation syringe provide good protection against splatter while permitting visualization of the wound. An inexpensive version of these plastic shields is formed by puncturing the base of a plastic medication cup with the irrigation needle.

Foreign-Body Evaluation

After anesthesia, perform wound exploration on all injuries to determine the extent of damage and to remove foreign material. The failure to diagnose foreign bodies in wounds is a frequent cause of litigation against emergency physicians.³¹ Remove large debris from the wound with forceps. Inert foreign bodies such as glass or metal should be removed if possible (Fig. 32-5). Radiographs are occasionally required for precise localization of a foreign body, which can be aided by taping a radiopaque marker such as a paper clip to the skin overlying the suspected location. Other studies that can aid in the localization of foreign bodies include ultrasonography, CT scan, and MRI. If an inert foreign body is small and cannot easily be removed, it may be left in place and the patient or parent informed of its presence. Organic foreign bodies require urgent removal to prevent inflammatory reactions and potential infection. Consultation or urgent follow-up for surgical removal is warranted in cases where this type of material cannot be removed in the ED. Regardless of the findings on examination, or your ability to remove foreign bodies from the wound, parents and patients should be warned of potential residual contaminants in dirty wounds.

Debridement

Debridement is necessary in the management of contaminated wounds or wounds with nonviable tissue. Through removal of contaminants and devitalized tissue from wounds, debridement increases a wound's ability to resist infection, shortens the period of inflammation, and creates a sharp, trimmed wound edge that is easier to repair and more cosmetically acceptable. If the devitalized edge of an irregular wound is debrided, the subcutaneous tissue of the wound can be undermined to avoid excess tension on the wound.

Primary Wound Closure

Perform primary closure, using sutures, staples, tape, or tissue adhesive on lacerations that were recently sustained (<24 hours on the face and <12 hours on other areas of the body), are relatively clean, and have minimal tissue devitalization. Before beginning closure, identify all the injured layers, such as fascia, subcutaneous tissue, muscle, tendon, and skin. During repair, always match each layer edge to its counterpart and ensure that when the sutures are placed, they enter and exit the appropriate layer at the same level so there is no overlapping of layers. A laceration that has been appropriately closed in layers usually does not need large or tight skin sutures to complete the closure. However, in hands and feet, placement of deep sutures increases the risk of infection, and they should be avoided in these areas.

The size of suture to be used for wound closure depends on the tensile strength of the tissue in the wound. Use 3-0 suture for tissues with strong tension, such as fascia in an extremity, and 6-0 suture for tissues with light tension, such as the subcutaneous tissue of the face.

Buried Stitch

Deep (buried) sutures serve four key functions and are required for many lacerations to ensure the best cosmetic result. They provide 2 to 3 weeks of additional support to the wound after skin sutures or tape is removed. They help preserve normal function of the underlying or involved muscles if the muscular fascia is sutured. They reduce the likelihood of development of a hematoma or abscess by minimizing the potential space. They avoid pitting in the injured region caused by inadequate healing of the deep tissues.

Unfortunately, deep sutures can result in damage to nerves, arteries, and tendons and can increase the risk of infection. As suture material is a foreign body, even in clean or minimally contaminated wounds, use as few deep sutures as necessary. The most common deep suture for laceration repair is the buried knot stitch, where one begins and ends at the base of the wound so as to bury the knot (Fig. 32-6).

The buried horizontal mattress stitch results in passage of suture material at the dermal–epidermal junction, with the knot placed subcuticularly below the dermis. The subcuticular stitch is a running buried suture at the dermal–epidermal junction that is actually used for skin closure (Fig. 32-7). Enter the skin initially, approximately 3 mm to 2 cm from one end of the laceration, and allow the needle to emerge at the subcuticular plane at the wound apex. Pass the suture through the subcuticular tissue on alternate sides of the laceration. The point of entry of each stitch should be directly across from or slightly behind the exit point of the previous stitch. At the other end of the laceration, burrow the needle again into the dermis to exit the skin 3 mm to 2 cm from the end. Ensure that there is no skin puckering, and then tape the free suture at both ends of the laceration in place. This stitch can be left in place if absorbable suture is used, or can be removed in 2 to 3 weeks if nonabsorbable suture is used.

Skin Closure

If you choose to repair the epidermis and superficial layer of the dermis with sutures, place sutures such that the same depth and width is entered on both sides of the incision. A key to cosmetically acceptable closure is edge eversion, which is obtained by entering the skin at a 90-degree angle, and, in some cases, by using a skin hook. For wounds whose edges tend to invert despite proper technique, vertical mattress stitches can be used (Fig. 32-8). The number of sutures used to repair a laceration will vary with each case. For facial lacerations, sutures are generally placed 2 to 4 mm apart and 2 to 3 mm from the wound edge.

Simple Interrupted Stitch

The simple interrupted stitch is used most frequently for skin closure (Fig. 32-9). It involves placing separate loops of suture using proper eversion technique, followed by tying and cutting each stitch. Although it is time-consuming, if one stitch in the closure fails, the remaining stitches will hold the wound together. This technique is useful for stellate lacerations, wounds with multiple components, and lacerations that change direction. It is also helpful for approximation of landmarks on the skin, to achieve the best cosmetic result.

Running Stitch

The running or continuous stitch is well suited for pediatric laceration repair for numerous reasons (Fig. 32-10): first, it is rapid; second, removal is easier; third, it provides more effective hemostasis; and finally, it distributes tension evenly along its length. The technique cannot be used over joints because if one point were to break, the entire stitch would unravel.

To begin a simple running stitch, place an interrupted stitch at one end of the wound and cut only the free end of the suture. Continue suturing in a coil pattern, ensuring that the needle passes perpendicularly across the laceration with each pass. After each pass, tighten the loop slightly so that tension is equally distributed. To complete the stitch, place the final loop just beyond the end of the laceration and tie the suture with the last loop used as the tail. An interlocking continuous stitch can be used to reduce slippage of loops and for more irregular lacerations (Fig. 32-11). It is performed by pulling the needle through the previous loop each time it exits the skin. However, if the loops are tied too tightly, the resultant imprinting of the skin can increase tissue scarring.

Mattress Stitches

The horizontal mattress stitch can be used for single-layer closure of lacerations under tension (Fig. 32-12). It approximates skin edges closely while providing some eversion, and decreases the time needed to suture because half the number of knots are tied. A running horizontal mattress suture can be used in areas of the body where loose skin could overlap or invert easily, such as the upper eyelids (Fig. 32-13).

The half-buried horizontal mattress stitch (corner stitch) is the suture of choice for closure of complex wounds with angulated (V-shaped) flaps (Fig. 32-14). Enter and exit the skin directly across from the flap and course the suture loop within the subcuticular tissue of the flap to maximize blood supply to the tip of the flap.

The vertical mattress stitch is helpful to evert skin edges (Fig. 32-8). It is useful in areas of the body with little subcutaneous tissue. The stitch begins in the same way as a simple interrupted stitch, but after the loop is made, re-enter and re-exit the skin approximately 1 to 2 mm from the wound edge and tie. A common technique is to alternate vertical mattress stitches with simple interrupted stitches to close a wound.

Correction of Dog-Ears

When wound edges are not precisely aligned, an excess of skin on one or both ends (dog-ears) result. A dog-ear can be corrected using the following technique (Fig. 32-15). First, elevate the excess skin with a skin hook and make an oblique incision from the apex of the wound toward the side of the dog-ear. Then undermine the flap and lay it flat, excise the excess triangle of skin, and complete the closure.

Secondary Closure

Secondary closure is a technique that allows wounds to heal by granulation and re-epithelialization. It is used to manage ulcerations, drained abscess cavities, deep puncture wounds, older or infected lacerations, and many animal bites. Daily packing may be performed with saline-soaked gauze until granulation tissue closes the potential space.

Delayed Primary (Tertiary) Closure

Delayed primary closure with sutures is performed on wounds 3 to 5 days after they have been initially cleansed, debrided, and dressed appropriately.³² Wounds amenable to this form of closure are those too contaminated for primary closure but not associated with significant tissue loss or devitalization. The utility of antibiotics during this “watch and wait” approach has not been closely studied.

Wound Dressing, Drains, and Immobilization

Sutured and stapled lacerations heal best in a moist environment. Thus, after laceration repair with sutures or staples, cleanse the skin of residual blood and povidone-iodine, and apply a light coat of antibiotic ointment. ³³ If the antibiotic ointment is to be used only for maintaining a moist environment, apply a nonadherent dressing to the laceration instead. Use a second layer of sterile gauze, or adhesive bandage. Alternatively, use an occlusive or semiocclusive dressing. If there is potential for the formation of a hematoma, apply a pressure dressing, taking care to avoid compression of arterial, venous, and lymphatic circulations.

Drains should rarely be used in sutured wounds. They act as foreign bodies and may promote rather than prevent infection. If a wound is considered a high risk for infection, attempt delayed primary closure rather than suturing and placing a drain in the wound. Drains should also not be used for hemostasis, which is better achieved by proper laceration repair, electrocauterization, and pressure dressings.

Splint a wound overlying a joint in the position of function for 7 to 10 days. For children, a bulky dressing may act as a splint and minimize motion at the wound, as well as prevent the child from tampering with the wound repair; it is especially helpful for hand and foot wounds.

Antibiotic use and Tetanus Prophylaxis

More than 95% of wounds treated in the ED heal without complications if given appropriate wound care. Antibiotics should be considered in a few instances.³⁴ Antibiotics should be given to patients who present with a wound infection. Other indications are for wounds heavily contaminated with feces or saliva, which may best be treated initially with secondary or delayed primary closure. Intraoral lacerations may benefit from a short course (5 days) of penicillin.³⁵ Consider antibiotic use for any high-risk wounds in which there is involvement of cartilage, joint spaces, tendon, or bone; and despite literature that refutes the necessity, wounds of the hand are often treated with antibiotics.^34,36,37 Finally, consider antibiotics for high-risk wounds (contaminated or devitalized), especially in compromised hosts, such as children with sickle cell disease, diabetes, steroid use, or lymphoma.

When antibiotics are indicated, their effectiveness depends on early administration. Give the first dose in the ED (preferably within 3 hours of the injury), regardless of the route of administration. The choice of antibiotics depends on the type of wound, although most infections are caused by sensitive staphylococci and streptococci that will respond to penicillin, first-generation cephalosporins or erythromycin for penicillin-allergic patients. Consideration of methicillin-resistant Staphylococcus aureus infection as a pathogen should be given, particularly to those patients who worsen or do not improve with standard therapy. Wounds contaminated with feces require coverage against facultative organisms, coliforms, and obligate anaerobes. Reasonable choices would include second- and third-generation cephalosporins, or the combination of clindamycin and an aminoglycoside.

Mammalian bite wounds are a complex subject. The cumulative research suggests that dog bites in normal hosts with low-risk wounds will do well with meticulous wound care, closure, splinting, elevation, and close follow-up without antibiotics.³⁸ All noncanine bites merit a short course of antibiotics. Generally, 3 to 5 days of oral antibiotics are prescribed for these bite injuries, but no definitive studies have examined appropriate duration of therapy.

Tetanus prophylaxis begins with appropriate wound care. If the wound is tetanus prone, determine the child's immunization status (Fig. 32-16). If the child was not immunized or only partially immunized, or if their immunization status is unknown, treat the child as if they have no protection. Give human tetanus immune globulin (HTIG) 250 U IM and complete or initiate primary immunization. If a child has completed primary immunization and has received appropriate boosters, then HTIG is not required.³⁹

Successful outcome of wounds is partly dependent on wound care after discharge from the ED. Therefore, give the patient and parents thorough instructions about care of the wound and what to expect. Inform the patients and families that all wounds of significance heal with scars, regardless of the quality of care. The final appearance of the scar cannot be predicted before 6 to 12 months after the repair. Inform them about the possibility of infection and that there is always the possibility, despite appropriate management, of a residual foreign body in the wound.

Because lacerations are bridged by epithelial cells within 48 hours, the wound is less susceptible to the entry of bacteria after 2 days. Give instructions to keep the dressing in place and the wound clean for 24 to 48 hours. Change the dressing if it becomes soiled or soaked by exudates from the wound. Remove the dressing to check for signs of infection, such as erythema, pain, warmth, purulent discharge, excessive edema, or red streaks suggestive of lymphangitis, all of which mandate a reevaluation. If parental reliability is questionable, the patient should have the wound reexamined in the ED in 2 to 3 days. If there are no signs of infection, instruct the patient or parents to gently wash the wound daily with soap and water to remove dried blood and exudates. Generally, the wound should be protected with a dressing during the first week, with daily dressing changes. Once the dressing is removed, patients and parents should be instructed that sunscreen should be applied to the scar for at least 6 months to prevent hyperpigmentation of the scar.

Suture removal should be done at an appropriate time so as to prevent dehiscence of the wound seen with premature removal and to prevent suture track marks and stitch abscesses resulting from late removal (Table 32-3). Children both heal and form suture track marks faster than adults and thus need earlier suture removal. After suture removal, skin tape should be applied, because wound contraction and scar widening will continue to occur for several weeks after an injury. Patients will often ask what can be done to prevent scar formation, and the literature suggests that the mechanical action of rubbing may be the common thread by which all the various commercially available topical products have positive effects.^40,41

Abrasions

Clean the abrasions and dress them with a nonadherent dressing or antibiotic ointment that is changed daily after cleaning. Treat deeper abrasions similar to skin graft donor sites with cleansing and a fine-mesh gauze dressing. Remove any foreign bodies (e.g., gravel, dirt, or tar) to avoid infection or tattooing (road rash) of the wound. Anesthesia for the cleansing of abrasions can be difficult, and large abrasions may require general anesthesia or procedural sedation to permit adequate debridement. For smaller areas, topical anesthesia with 2% lidocaine or LAT solution, infiltration of local anesthetic, or nerve blocks can be used. Children with large or deep abrasions should have their wounds reexamined in 2 to 3 days to monitor healing.

Scalp Lacerations

There are five anatomic layers in the scalp: skin, superficial fascia, galea aponeurotica, subaponeurotic areolar connective tissue, and periosteum. The presence of a rich vascular supply and vessels that tend to remain patent when cut are responsible for the profuse bleeding associated with scalp injuries. Usually, the bleeding is halted by direct pressure, epinephrine infiltration, and rapid closure.

The subgaleal layer of connective tissue contains “emissary veins” that drain through vessels of the skull into the venous sinuses within the cranial vault. In scalp wounds that penetrate the galea, bacteria can be carried by these vessels, and although exceedingly rare, a wound infection can result in osteomyelitis, meningitis, or an intracranial abscess. Approximation of galeal lacerations will not only help to control bleeding, but may theoretically safeguard against the spread of infection.

Although most lacerations that involve multiple layers of tissue should be closed in layers, scalp wounds are best closed with a single layer of sutures that incorporates the skin, the subcutaneous fascia, and the galea. Some advocate separate closure of the galea with absorbable suture material, which allows its more careful approximation but introduces a foreign body into the wound, thus increasing chances of infection. In order to find the ends of the tied sutures, these should be left longer than usual, and the use of blue nylon may also facilitate removal. Superficial scalp lacerations are also amenable to staple closure as discussed earlier.

Forehead Lacerations

Lacerations that are limited to the area above the supraorbital rim can be anesthetized with supraorbital and supratrochlear nerve blocks, thus avoiding tissue distortion associated with local infiltration. Explore the lacerations for skull fractures and foreign bodies. Close the forehead in layers, beginning with the approximation of the frontalis fascia. Continue the layered closure, taking care to align landmarks such as forehead furrows.

Eyelid Lacerations

The thin, flexible skin of the eyelid is quite simple to suture (Fig. 32-17). However, it is essential that the emergency physician be aware of injuries that require consultation with an ophthalmologist. A thorough eye examination needs to be performed whenever there is a laceration of the eyelid or periorbital region. Also, ensure that the levator palpebrae muscle and its tendinous attachment to the tarsal plate are intact, or ptosis may result. A laceration to the medial aspect of the lower lid often involves the lacrimal duct, which requires specialized repair by an ophthalmologist. If consultation is not required, close lid lacerations in a single layer with 6-0 suture, taking care to avoid skin inversion.

Ear Lacerations

Injuries to the ears require expedient cleansing, debridement of devitalized tissue, and coverage of exposed cartilage to avoid chondritis. Anesthesia of the external ear is simply accomplished with a field block of the auriculotemporal, greater auricular and occipital nerves, performed by infiltration at the base of the auricle. Once cleansing and debridement of devitalized tissue is performed, approximate cartilage with 5-0 absorbable suture material placed through the posterior and anterior perichondrium. Keep tension to a minimum to prevent tearing of the cartilage. Finally, approximate the visible surface of the ear using 5-0 or 6-0 suture, ensuring approximation of landmarks such as folds. No cartilage should be left exposed. After repair, dress the ear with a compression dressing, including coverage of the anterior and posterior aspects of the auricle. This prevents accumulation of a perichondral hematoma, which can lead to necrosis of cartilage and subsequent deformity (cauliflower ear).

LIP Lacerations

Lip lacerations are common in the pediatric age group and require careful attention to ensure a good cosmetic result (Fig. 32-18). Prior to beginning repair, inspect the oral mucosa and teeth for lacerations and trauma. As local infiltration of anesthetic obscures the lip's landmarks, consider performing a mental nerve block for the repair of lower lip lacerations or an infraorbital nerve block for upper lip lacerations.

After anesthesia, cleanse and irrigate the wound in the usual manner, and then place the first stitch at the vermilion border. If deep sutures are required, leave the initial stitch untied and proceed with deep closure. Through-and-through lip lacerations require three-layer closure. Approximate the orbicularis oris muscle with 4-0 or 5-0 absorbable suture. Close the mucosa with 5-0 absorbable suture to obtain a tight seal. Finally, after irrigation of the outside surface, close the skin with 6-0 suture material (Fig. 32-19). Four-layer closure, including the subcutaneous layer, can be used to facilitate skin closure. Through-and-through lip lacerations are prone to infection, and prophylaxis with penicillin or erythromycin for 5 days may diminish infection rates.³⁵

Fingertip Injuries

Young children often injure fingers in doors and windows. Distal fingertip injuries, even complete amputations, heal remarkably well in children. Therapy of distal fingertip amputations consists first of a digital block or local infiltration, followed by appropriate cleansing and dressing of the wound with antibiotic ointment or nonadherent gauze, and a splint or bulky dressing for protection while radiographs are obtained.

Prognosis of distal amputations depends on how much of the tip is lost. If the fingernail and nail bed are not involved, prognosis is excellent. If the bone is spared but there is involvement of the nail or nail bed, there may be shortening of the digit. Injuries involving the distal phalanx, especially those at the base of the nail, heal most poorly. More proximal amputations uniformly require consultation with a hand surgeon.

A subungual hematoma is a collection of blood under a fingernail or toenail, usually sustained after a direct blow. If the nail is intact, pressure from the hematoma can cause substantial pain. If the hematoma involves less than 25% to 50% of the nail bed, trephinate the nail using one of a number of techniques. The use of electrocautery has most recently been advocated as the simplest, safest, and least painful method to drain a subungual hematoma. Prior to trephination, cleanse the nail and once blood escapes through the nail, remove the cautery to avoid nail bed damage. For subungual hematomas involving >50% of the nail bed, there is controversy as to what treatment is best. Nail removal used to be advocated, because of the perceived need to repair the underlying nail bed laceration. However, this practice has been questioned as long as the nail and surrounding nail fold are intact. Nail bed lacerations associated with disruption of the nail itself may be closed with 6-0 absorbable sutures (Fig. 32-20). Debridement should be kept to a minimum, and the paronychium and eponychium must be prevented from forming adhesions with the nail bed by packing the space with nonadherent gauze or using the nail itself as a stent after repair of the nail bed. If there is an underlying fracture of the distal phalanx, splint the finger and prescribe antibiotics appropriate for an open fracture.

A paronychium is a cutaneous abscess at the lateral aspect of fingernails or toenails. As the fingers and toes are vulnerable to trauma during childhood, including nail biting and finger sucking, an acutely painful, swollen, erythematous, and tender paronychia is not an uncommon ED complaint. For fingers, an extensive procedure is rarely required for treatment of a paronychia. Most often, the cuticle (junction between the nail and the skin) can be elevated or incised with a No. 11 blade, and the abscess can be drained and irrigated. Systemic antibiotics are needed only when there is an accompanying cellulitis or lymphangitis. Paronychias of the toes are often caused by ingrown toenails. Thus, removal of the ingrown portion of the nail is required to avoid a recurrence. As this is a more extensive and painful procedure, consider a digital nerve block in conjunction with moderate sedation.

Puncture Wounds to the Foot

Puncture wounds, most often to the foot, have a low potential to result in significant morbidity.⁴² Although rare, cellulitis, plantar space infections, abscesses, retained foreign bodies, and osteomyelitis can result from a benign-appearing wound (Fig. 32-21). A reasonable approach to puncture wounds of the foot is to obtain a radiograph to ascertain bony involvement, air in the joint spaces, and radiopaque foreign bodies. Anesthetize the wound and then explore the puncture site, cleanse the wound, and remove any foreign bodies. The use of prophylactic antibiotics is controversial, and likely not warranted on a patient's initial accession to care. However, in the setting of infection at the time of presentation, debridement should be performed and broad-spectrum antibiotics should be given. For puncture wounds sustained through the sole of a tennis or rubber soled shoe, coverage was typically aimed at Pseudomonas aeruginosa as that pathogen has been associated with post-puncture osteomyelitis.⁴³ Patients who present quickly after puncture wounds, have normal host factors, and no evidence for retained foreign body may be discharged without antibiotics and reevaluated after 48 hours of elevation, nonweight bearing, and meticulous wound care.⁴⁴

Specialty consultation should be considered for the following:

• Complex or extensive wounds which exceed your resources or skill set.

• Wounds with large tissue defects not amenable to repair in the ED.

• Wounds in which there is tendon, nerve, joint, or critical vessel involvement.

• Lacerations involving the parotid or lacrimal ducts.

• Lacerations of the eyelid tarsal plates.

• Lacerations over fractures.

• Facial lacerations in which cosmetic results are a concern.

• Wounds about which there is physician uncertainty.