Approximately 12 million wounds are treated in EDs in the United States each year.¹ Data on the true incidence of wounds are limited because many are thought to be treated away from the ED or urgent care setting. Of individuals with wounds seen in the ED, the majority are men.² Wounds can clearly occur anywhere on the body, but lacerations on the upper extremities, head, and neck constitute the majority of cases encountered in EDs.

Pathophysiology

Skin, the largest organ in the body, has numerous functions, most prominently heat exchange, prevention of infection, and provision of a tactile interface with the environment. The layers of skin—epidermis, dermis, and connective tissue—all play different roles in wounds and healing. The thickest and most important layer, the dermis, serves as structural integument, supports conveyance of nutritional and waste products, and contains cutaneous nerves (Fig. 186.1).

Fig. 186.1 Skin anatomy.

The layers of skin—epidermis, dermis, and connective tissue—all play important roles in wound healing. The dermis is the most important and thickest, but it thins with age or steroid use. Note the tearing appearance of the skin of this elderly patient, who fell on an escalator.

Disruption of the skin may be caused by an infinite number of means, from simple cutlery accidents to industrial mishaps or intentional violence. Wounds that disrupt the full depth of skin are fundamentally different from those that affect only the superficial layers. Wounds that affect merely the epidermis may typically be cleansed and dressed appropriately with less concern for complications. However, it is imperative to assess seemingly superficial wounds in a diligent manner to ensure that more significant injuries are absent.

After injury, a continuum of coagulation, hemostasis, inflammation, tissue formation, and tissue remodeling quickly ensue. Each of these steps is influenced by the patient’s condition and the clinician’s wound repair skills. Clearly achieving hemostasis is a primary concern for wound repair, both to prevent exsanguination and to allow adequate visualization of the wound, as well as closure of it. Any delay in wound closure allows the later three steps of inflammation, tissue formation, and remodeling to proceed naturally, which will probably result in skin that is functional but scarred.

The aesthetic qualities of a scar are influenced by its thickness, color, and height or degree of depression. Thickness is most dependent on the width of the healing wound and on whether additional granulation tissue is necessary to fill gaps (as in secondary intention). The height of a scar is altered by the alignment and apposition of the healing skin edges, as well as by tensile and shear forces across the wound and the amount of inflammation preceding the formation of scar tissue. The increased height of a hypertrophic scar is the result of redundant tissue. If it extends beyond the original margins of the wound, it is called a keloid. Depressed scars create shadowing (consider the visibility of age-associated wrinkles), which makes them appear darker than the neighboring reflective surfaces. The color of a scar results from its vascularity and pigmentation with respect to surrounding healthy tissue. Melanocytes do not produce pigment at the same rate in injured and healing tissue or in scars as they do in normal tissue.

All these factors in scar formation vary among individuals. Some patients heal very well, whereas hypertrophic keloids invariably develop in others. However, steps to improve outcomes generally remain the same in emergency management.

Presenting Signs and Symptoms

Wound repair may be sought intentionally or be required following evaluation of other complaints, such as a syncopal event. It is not uncommon for patients to be entirely unaware of their wounds (as in trauma) or to be unimpressed with the severity of their lesion because of more painful conditions, such as a fracture. For all these reasons, a thorough physical examination plus evaluation of all wounds is required. Through this evaluation and assessment of the patient’s unique situation, an appropriate approach may be undertaken to address a wound. The overall risk for infection and the likelihood of complications can be predicted by considering wound and host factors. A major pitfall of wound management is fixation on the wound without sufficient attention to the host. For example, a 4-cm linear laceration on the arm of a healthy 18-year-old patient has a different prognosis than the same wound on the shin of a 73-year-old diabetic patient with peripheral vascular disease (Box 186.1).

Differential Diagnosis and Medical Decision Making

Patient Evaluation

With an infinite variety of medical conditions and circumstances requiring ED management, each patient has a unique environment for wound healing. Hosts also change over time: thinning of the dermis, varying degrees of vascular compromise, increased likelihood of fractures, and medication use. Assessment of patient status before the injury, as well as prediction of the patient’s capacity for healing, is important before initiating wound repair.

A wound is the physical manifestation of an injurious force exerted on the body. Accordingly, careful evaluation of the patient as a whole is critical. A common pitfall is focusing on the most visible injury and not recognizing other lesions that were caused by one event, such as trauma. Understanding the injurious mechanism also enables better prediction of the wound’s severity. As an example, blunt force injuries have significantly greater potential for diffuse tissue nonviability and are consequently more prone to infection.³ Once all injuries have been catalogued, each may be addressed. Important considerations include knowing how the patient was injured (shear, abrasion, compression), whether the location of the wound is in a cosmetically or functionally vital area, and whether potentially confounding influences on the potential for healing are present.

Injury to Underlying Structures

When sufficiently breached, skin fails in its protective role and may allow underlying structures to be injured (Fig. 186.2). Diligent assessment of the functionality of surrounding anatomic structures is of utmost importance.

Fig. 186.2 Injury to underlying structures.

Missing an associated nerve, tendon, vascular, or bony injury is a significant pitfall in wound care. This patient had partial facial nerve palsy from her injury that was slightly exacerbated by anesthesia, but it resolved almost completely over time.

Tendon function should be assessed throughout its range of motion. It may help to ask the patient to estimate the position of a body part at the time of the injury, especially with hand injuries. Tendons may be partially lacerated but their range of motion may remain intact, thereby misleading the practitioner. Patients’ complaints of pain or subjectively decreased range of motion, despite objectively normal findings on examination, should raise suspicion for partial disruption.

Nerves can be injured by the wounding mechanism itself or by iatrogenic maneuvers, especially indiscriminate ones. Clamping, blind probing, and injudicious débridement may all disrupt adjacent nerves. The hands and face are at greatest risk because nerves run in close proximity to the vasculature; zealous attempts to control bleeding vessels can result in damage to adjacent nerves. Injected anesthetics may also injure nerves as a result of pressure necrosis in finite spaces. Examples include injections into the olecranon grooves or foramina in the hard palate of the mouth.

Muscles are highly vascular tissue and are often disrupted with deep wounds. Because muscles are dynamic units, subsequent hematomas, scars, or infection can result in dysfunction. Unnecessary débridement should be avoided and bleeding controlled with direct pressure. Muscle can usually be repaired by securing the surrounding structures, thereby placing the cut surfaces of the muscle in direct apposition. Muscle tissue should be repaired directly only when the foregoing maneuver is insufficient.

Occasionally, a wound is the first sign of an underlying fracture, either because the skin was injured with the force carried onto the bone or because the broken bone edges penetrated the skin from inside.

Foreign Bodies

Foreign bodies can be driven into wounds through innumerable routes of entry. Common situations include shattered glass in motor vehicle accidents, vegetative material in wounds during outdoor pursuits, and puncture wounds through footwear. Foreign bodies increase the risk for infection and may prevent healing. The following section on puncture wounds specifically addresses foreign bodies in these situations. For additional discussion of foreign body evaluation and management, see Chapter 187.

Treatment

The emergency physician (EP) can close most wounds; some situations requiring specialist consultation are listed in Box 186.2.

Wound Preparation

To meet the goals of reducing risk for infection, minimizing damage to underlying structures, and forming a functional and cosmetically acceptable scar, preparation of the wound can be tantamount to or may surpass closure in importance. An appropriately prepared wound has been anesthetized, has been decontaminated of large particles or foreign bodies, has minimized bacterial counts, and has edges amenable to optimal repair.

Tips and Tricks

Wound Preparation

Always place the patient in a comfortable position, preferably supine.

Remove as much gross contamination as possible before pressure irrigation.

Lidocaine with epinephrine may be used in most areas of the body.

Water is an acceptable initial irrigating fluid for many wounds.

Hair does not need to be removed.

The composition of irrigating fluid has been debated and studied inconclusively, but no significant inferiority has been demonstrated for normal saline. Antiseptics such as povidone-iodine kill bacteria in wounds, but they can also kill fibroblasts and harm normal tissue in the process, particularly if the antiseptics are not diluted to less than the typical 10% preparations. Anecdotally, some clinicians reserve diluted povidone-iodine irrigation for grossly contaminated or high-risk wounds and use saline solution for other wounds, but no conclusive evidence supports this approach.⁷ At the other end of the spectrum, some studies demonstrate favorable results when irrigation with tap water is used rather than sterile water or saline solution.⁸ The benefits of using water for irrigation include ease of use and drainage and some modest cost savings. Tap water may be used for irrigation of wounds on body parts well suited to it (e.g., the hand), either alone or as an adjunct to subsequent pressure irrigation, depending on the risks associated with the individual wound and host. In summary, the composition of the fluid is much less important than its mechanical action in decontaminating a wound.

Wound Edge Preparation

Hair does not generally need to be removed. Shaving has been shown to increase the rate of infection. Hair that directly and substantially interferes with proper suture placement can be clipped near the wound edges with scissors.

In general, one should not débride any more than is absolutely necessary to remove clearly devitalized tissue. An irregular, undulating wound may be superior to a straight, linearly excised wound because the longer surface area results in better tensile strength across the healing wound and it maintains the natural contours and marks of the original skin. If débridement is necessary, high-quality forceps and a No. 15 scalpel blade should be used.

Planning the Repair

The first decision to be made is whether to close a wound primarily. The time elapsed since the injury, the degree of contamination, host factors, and wound factors all play a role in deciding the best option. Primary closure refers to mechanical apposition of the wound edges with subsequent wound healing. Delayed primary closure is the same technique carried out 4 to 5 days after the injury.⁹ At this point the host’s defenses against infection have been mustered locally, and the risk for subsequent infection with primary closure declines significantly. In secondary closure (secondary intention), gaps between the wound edges become filled with granulation tissue by the body and reepithelialization subsequently occurs.

No well-accepted studies have established firm guidelines for the timing of closure on different portions of the body. Nonetheless, many clinicians agree that certain wounds on the face and head, especially in pediatric patients, have such a low risk for infection that they may be closed after protracted times from injury, including up to 1 to 2 days later. However, wounds of the same size on the hand or forearm of adults probably do have a higher risk for infection after passage of a similar amount of time from injury.¹⁰

If the decision is made to close a wound primarily, various options are available. As with almost all decisions in wound management, more than one alternative may be correct, but one option is often best. Methods available for closure include sutures, staples, tissue adhesives, and wound tape or strips.

Wound Closure Techniques

Suture Repair

Sutures offer the most detailed and meticulous closure option, arguably the greatest tensile strength across the wound, and the best choice for certain considerations such as the amount of time that they must remain in the body. However, sutures can be time-consuming to place, require the discomfort of anesthesia, and typically require removal later. Additionally, a suture is a foreign body with attendant risk for infection and inflammation. In particular, EPs should avoid placing deep sutures in a high-risk wound. Monofilament, braided, absorbable, and nonabsorbable sutures also have varying risk for infection, as well as raise other concerns.

Selection of sutures for a wound should be based on size, absorbability, tissue reactivity, risk for infection, and ease of use. In general, nonabsorbable and monofilament sutures are the easiest to use and have the least tissue reactivity and risk for infection. They are best for percutaneous closure. Traditionally, absorbable suture is used for subcutaneous closure. However, some cutaneous closures can be done with absorbable suture, thus obviating the need for removal.^11,¹²

Tips and Tricks

Suture Placement

Use longitudinal traction to assess how the wound edges correspond and affix the wound (even temporarily) to maintain appropriate alignment.

If you place a suture that seems poor, use the spot to place another knot and remove the original one.

Muscle can typically be repaired by aligning adjacent tissue.

Do not place sutures in high-risk wounds.

The goal of suturing is to have a trapezoidal stitch to disperse tensile force.

Sutures should be removed at the earliest appropriate time.

At a minimum, four basic suture patterns should be at the command of EPs: the simple interrupted suture, the corner stitch, and two mattress suture techniques. One should master the simple interrupted pattern first and then move to the others and subsequently to more advanced subcuticular and plastic techniques as required (Fig. 186.3, A and B).

Fig. 186.3 A and B, Simple interrupted suture. This is easy to do, harder to master. Enter the skin pointing away from the wound edge and exit the skin pointing toward it to achieve a trapezoidal cross section and slightly everted skin edges.

Simple Interrupted Suture

Though simple in name, proper placement of an interrupted suture requires fastidious practice. Effecting proper wound apposition with regard to the height of each plane of skin and eversion of the closed product will result in more exact healing and a flatter scar. The angle of entry is often suggested to be 90 degrees; however, because the goal is to achieve a trapezoidal cross-sectional stitch with a wider base than top, the angle of entry can exceed 90 degrees. Simply stated, the needle should enter the skin pointing away from the wound edge and should exit the skin on the opposite side of the wound pointing toward the wound edge.

Running Suture

The tenets of eversion and alignment of skin planes are the same if the suture is continued in running fashion. After starting at one end with a simple interrupted pattern, the needle end of the suture is run along the length of the wound. Tying the needle end of the suture to the last-placed loop finishes the suture.

Running Subcuticular Sutures

Subcuticular sutures are more difficult to master. They are useful in that the entire suture remains under the surface of the skin and typically does not need to be removed because absorbable sutures are used. However, many wounds that were previously closed with subcuticular running suture and were of low tension and of some cosmetic importance are now amenable to closure with tissue adhesive.

Deep Sutures

Subcutaneous or deep sutures are useful to eradicate a large dead space that could accumulate hematoma and to give structural support to the wound and skin. By drawing the skin edges closer together, these sutures also reduce the tension needed to close the wound percutaneously or may allow closure of the skin with tissue adhesive (Fig. 186.4, A and B).

Fig. 186.4 A and B, Deep suture. Use deep sutures with a buried knot to bring wounds closer together and to decrease tension on the edges of the skin.

Corner Stitch

A corner suture should be considered when a Y- or V-shaped incision is encountered. The shape of the wound should be assessed for the most advantageous flap to secure into an apex. A corner suture encompasses both percutaneous and subcutaneous portions, but as a single first stitch it can achieve excellent overall wound alignment and thus facilitate placement of subsequent interrupted sutures to finish closing the wound (Fig. 186.5, A and B).

Fig. 186.5 A and B, Corner suture. Use this stitch to secure a triangular flap into an apex for rapid reapproximation of the wound architecture.

Mattress Sutures

Both horizontal and vertical mattress sutures provide, as a single benefit, better eversion of the wound edges than other sutures do. The horizontal mattress pattern has the additional benefit of some added speed by covering more linear wound length with each knot tie. However, it does result in more pressure on the epidermis by the suture material, which can have cosmetic effects. Horizontal mattress sutures may be useful to evert a problematic section of wound that has a tendency to roll inward. It may then either be replaced with interrupted sutures to hold it in place or be left as is with timely suture removal. Similarly, an isolated vertical mattress suture may be useful to effect better skin eversion (Fig. 186.6).

Fig. 186.6 Mattress sutures.

When wound sections are difficult to properly evert, consider a mattress suture. A single horizontal mattress suture (arrow) corrected a depressed area of the laceration.

Red Flags

Wound Repair

Insufficient preparation will also create issues with wound treatment and resolution.

Tendons may be partially torn or lacerated while range of motion remains intact. Thorough evaluation of any suspected lesion is thus warranted.

Excessively tight sutures—or those without appropriate angles—place an undue amount of pressure on the epidermis that increases the risk for tissue dehiscence and decreases the probability of a good cosmetic outcome.

Negligence in providing appropriate aftercare and home care instructions increases the likelihood that the patient will return to the emergency department and decreases the prospects for good recovery from the injury.

Staples

Staples can be used in many places where sutures would also be appropriate. Staples also have the benefits of speed and ease of placement and removal. However, staples may offer somewhat less meticulous closure and have a tendency to leave punctate marks alongside the linear scar. For this reason they should not be used for facial lacerations, on fine skin, or in other areas where cosmesis is of particular importance. Although staples are frequently used to close scalp wounds, it is wise to ask patients about their preferred sleeping position and whether they wear headgear in sports or work because staples can be uncomfortable if direct pressure is applied against them during wound healing. Staples are most often used to close wounds on the proximal ends of extremities.

Tissue Adhesives

Tissue adhesives have been approved for use in the United States since 1998. The majority of products today consist of 2-octylcyanoacrylates. These compounds are similar to cyanoacrylate, commonly known as superglue. Additional modifications to the chemical composition have been made in an effort to reduce tissue reactivity, increase pliability of the finished bond, and make the substance more suitable for use on human skin. Studies have demonstrated antibacterial properties of these products as well.¹³

These substances were originally thought to replace suture closure in 25% to 32% of wounds, but it is unclear how often they are actually used in lieu of traditional repair. The most common use of tissue adhesives is for low-tension, nongaping wounds on the face, particularly in pediatric patients. Wounds that would otherwise be closed with 5-0 or 6-0 suture may be considered for adhesive repair. Adhesives are also useful for small avulsion injuries with flaps and occlusion over abrasion injuries as a protective barrier. The material is not suitable for use within the wound itself. Tissue adhesives should not be used in areas of high tension (e.g., across joint surfaces) or to close significantly gaping wounds. Aftercare is similar to that for other repair mechanisms, but the tissue adhesive will gradually slough off without assistance.

Tips and Tricks

Placement of Adhesive

Place the patient so that any excess adhesive runs away from important structures such as the eyes.

Have both hands free to place the adhesive; an aide may be useful.

Because each brand of adhesive is different, ensure that the number of coats recommended for the product is applied.

Maintain the wound in the desired position for a sufficient amount of time.

Wound Tape and Strips

Wound tapes or strips may be an option for wounds in which placement of a foreign body (i.e., suture) may be disadvantageous, in initial management of wounds that may undergo delayed primary closure, or in wounds with a protracted time until treatment. Many wounds that were previously closed with wound tapes or strips are now amenable to closure with tissue adhesive. Examples of wounds and their preferred and alternative closure methods are presented in Table 186.1.

Table 186.1 Special Wound Locations

Puncture Wounds

By their nature, puncture wounds are different from other lacerations in mechanism, risk, and prognosis. No definitive studies exist to guide evaluation, acute management, or risk stratification of puncture wounds. Despite years of publications, the data available are largely retrospective and observational. What is clear is that plantar puncture wounds, in particular, are commonplace and that many patients do not go to the ED for evaluation. One self-reported survey indicated that 44% of persons had experienced a plantar puncture wound at some time during their life. However, perhaps only half of those wounded underwent medical evaluation.¹⁴ It has been assumed that puncture wounds may have a higher complication or infection rate than other wounds, but the true incidence is unknown. Wounds on the plantar surface of the foot that become infected may have very serious complications, including osteomyelitis, osteochondritis, and septic arthritis. The bones of the foot are in close proximity to the skin, and the mechanism of injury typically includes significant force of the weight of the body on the penetrating object.

Evaluation of plantar wounds includes the same delineation of host and wound factors as mentioned previously. Additional considerations with puncture wounds include possible penetration of a sock and shoe by a nail or by objects with various degrees of contamination.

Many authors believe that the timing of arrival at the ED also guides initial evaluation and treatment. Patients seen within 24 hours of injury tend to have lower rates of cellulitis at the time of evaluation, but they may also have a greater possibility of useful manipulative intervention. Patients seen after 24 hours may have concerns about infection and may be more likely to require invasive exploration for foreign material in the wound.¹⁵ One study indicated that 3% of plantar puncture wounds had a foreign body after initial cleansing without exploration.¹⁶

Reasonable recommendations for the management of plantar puncture wounds include consideration of enlargement of the wound and tissue exploration or excision when the puncture wound mechanism is significant. Concerning mechanisms include puncture of protective footwear while wearing socks, wounds in immunocompromised patients, and wounds caused by organic or contaminated objects. In the last instance, thorns, sharp pieces of wood, and other vegetative matter may be more difficult to identify, and these materials carry a higher risk for bacterial infection. It is also reasonable to consider excision of tissue if particulate foreign material is found in the wound. In the instance of thin needles, either hypodermic or sewing, radiography may be useful for identification, but exploration is not typically needed in these patients if no foreign body is identified.

Anesthesia of the sole of the foot is mandatory to allow a good degree of wound care and possible exploration or excision. Ankle blocks are relatively easy to perform, they can provide adequate anesthesia for the plantar surface, and they obviate the need for painful injections into the thick connective tissue of the sole (see Chapter 188).

Patients with overt signs of infection should be assumed to have a foreign body in the wound. A thorough radiographic, ultrasonographic, and local search for foreign bodies should be conducted. In the presence of infection or when the clinician decides to use prophylactic antibiotics, a fluoroquinolone may be the best choice because of improved Pseudomonas coverage.¹⁷

Follow-Up, Next Steps in Care, and Patient Education

Too often, aftercare equals afterthought with underemphasis, lack of instruction and documentation, and inadequate knowledge of evidence-based principles. As in other aspects of laceration and wound care, the aims of aftercare are to optimize the chance of a wound healing without infection and with a functional, aesthetically pleasing scar. Generally accepted principles that promote wound healing include maintenance of a clean environment, immobilization, and elevation to reduce edema.

Application of an antibiotic ointment is commonly recommended. Whether the petroleum vehicle promotes a moist environment for reepithelialization or the antibiotics have an actual effect is unclear, but at least one study supports the use of these ointments.¹⁸ Immobilization should be considered at least until epithelialization occurs (usually 2 days) or considerably longer in wounds subjected to high tension (e.g., laceration over the kneecap or shin). Optimal times for removal of sutures (for a wound that is not under tension) from various body parts are listed in Table 186.2.

Table 186.2 Optimal Time for Removal of Sutures

LOCATION	OPTIMAL TIME FOR REMOVAL
Hands or fingers	7-9 days
Forearms	10-12 days
Feet	10-12 days
Lower extremity	10-12 days
Torso (chest or back)	10-12 days
Scalp	5-7 days
Face	3-5 days

The patient’s scar represents a permanent reminder of the wound, but the medical record is also an enduring account of the events. As a simple guideline with regard to wound documentation, “if you did it or said it, write it” (see the “Documentation” box). Critical elements of record keeping include a description of the mechanism, the patient’s history, and previous home care of the wound; documentation of the function of surrounding structures before and after any medical maneuvers; and description of the steps taken to reduce infection, search for foreign bodies, and close the wound. Furthermore, the instructions given to patients need to include precautions for return, signs of infection, and step-by-step short- and longer-term instructions for aftercare of the wound. Pitfalls in documentation are inadequately addressing the search for a foreign body, irrigation, and assessment of surrounding function, as well as failure to describe the wound’s length and complexity.¹⁹

Documentation