Patients with wounds at risk for tetanus who have not had a booster within 5 years, are not sure of immunizations, or cannot provide a history of immunization status, require a tetanus booster. Non-tetanus-prone wounds reduce the cutoff to 10 years since last booster. If a patient with a high-risk wound has never been immunized or has not completed the three-dose tetanus immunization, tetanus immune globulin should be administered.

The administration of systemic antibiotics in acute trauma patients is controversial. With the rapid proliferation of antibiotic-resistant organisms, prophylactic antibiotics are not indicated except for selected cases, including open fractures, open joints, exposed cartilage, heavy contamination, bite wounds, delayed wound management, and patients with impaired wound healing (immunosuppressed, diabetic, and severe atherosclerosis). Topical antibiotics, including antibiotic ointments, silver impregnated dressings, or saline dressings, are more often appropriate.

In wounds amenable to management in the priority setting, the principles are wound preparation, local anesthesia, decontamination, and closure. The area surrounding the wound should be prepared with topical bactericidals such as iodine or chlorhexidine products. These products are cellular toxins in the concentrations used to prepare the skin surrounding the wound and as such are detrimental to wound healing.² They are not recommended for open wound application. Shaving the surrounding area is not necessary and has actually been shown to increase wound infections in some cases.^{3 4}

Before wound manipulation, adequate anesthesia must be obtained. This can be accomplished in smaller wounds with local injection or nerve blocks because topical anesthetics are of limited benefit in traumatic wounds. Dosages, durations, and adverse reactions of local anesthetics vary depending on the anesthetic and the physician must be aware of these (see Table 1). Local anesthetic central nervous system (CNS) toxicity begins with tinnitus, tremors, metallic taste in the mouth, numbness, and can progress to seizures. Cardiovascular toxicity is the result of myocardial depression, leading to hypotension, altered heart rate, and ultimately arrhythmias.

Larger areas can be anesthetized with minimal anesthetic with knowledge of the anatomy of sensory nerves. The most common regional blocks performed include digital blocks (radial and ulnar digital nerves), wrist blocks (median nerve, ulnar nerve, and radial sensory nerve), and facial blocks (supraorbital, infraorbital, or mental nerve) (see Fig. 1). Ears, nose, and genitalia are frequently anesthetized with field blocks of anesthetic without epinephrine to avoid vascular compromise.

Finally, the largest wounds will require general anesthetics and must be explored in the operative suite to allow adequate exposure, to control hemorrhage, and to have access to needed operative tools to do the procedure in an optimal manner. Indeed, the test of whether one must
treat the wound in the operative suite must be judged by whether the operative surgeon can do the procedure just as well in the setting of the emergency department (see Fig. 2).

After obtaining adequate anesthesia, the open wound requires exploration for additional injuries, removal of contamination and foreign bodies, irrigation, and debridement of nonviable or heavily contaminated tissue. As stated, topical antiseptics impair wound healing unless used in a very dilute solution. Surgical debridement and copious irrigation are necessary and sufficient to decontaminate the open wound. The decision regarding how much to debride requires multifactorial analysis. Obviously, nonviable tissue should be debrided as it impairs
healing and increases the risk of infection. Marginal tissue may best be managed by preservation with plans for repeat debridement and delayed closure unless it is of minimal functional benefit. Once the wound has been irrigated and debrided, the physician must determine whether the wound is amenable to closure based on size, available tissue, and level of contamination.

The decision to dose a wound or to manage it as an open wound requires a determination of the likelihood of success of primary closure. The risk of failure of primary closure can lead to more damage and a worse outcome than open wound care with delayed healing. An important factor to consider in this decision is the length of time since injury. Six to eight hours is considered the “golden period” during which primary closure is possible. After this period of time, bacterial counts are significantly higher. Longer periods of time (typically 24 hours) are acceptable for injuries above the neck as these wounds are cosmetically more apparent and relatively resistant to infection due to better blood supply.

The degree of contamination either based on mechanism, history, or examination is another important variable to weigh. Relative contraindications to primary closure include human bites, nonhuman bites (except for the face), and embedded foreign material.

Systemic factors must also be considered in the decision for wound closure. Associated conditions to consider
include patient age, diabetes, immune function, vascular status, immunization history, coagulation status, and associated injuries. For example, a patient with intra-abdominal hemorrhage may be too unstable to undergo wound closure on the face until fluid resuscitation is complete.

Questions of the viability of adjacent tissues should preclude primary closure. This is an important variable in thermal burns, electrical injury, crush injury, and “missile” injury. In each of these situations there is frequently found a zone of nonviable tissue and an area of tissue of questionable viability. This is similar to the zones established in burns, which Jackson referred to as the zone of coagulation, the zone of stasis, and the zone of hyperemia.⁵ The zone of coagulation in burns is quite similar to the zone of necrotic tissue found in a crush or avulsion type injury. This tissue is dead at the time of first observation and must be removed from the wound to avoid progressive sepsis or myoglobinuria. Adjacent to this is an area of edema and tissue of questionable viability, which is the zone of stasis. In this tissue, the blood flow is sluggish and depending upon the events of the next few days may go on to survive or die. As a result, in many complicated injuries such as open tibial fractures, serial debridements are necessary before closure. In some cases, this may take several surgeries over a period of 2 weeks or more. It is the authors’ experience that in these situations, the temptation is to dose the wound sooner than is biologically safe leading to infection, dehiscence, and increased morbidity and hospital stay. As a result, the “rule-of-thumb” is to debride the wound “N + 1” times. That is, it is recommended that in order to minimize the risk of failure of closure that the wound be debrided one more time after the wound appears that it “might” be able be closed safely.

An additional surgical debridement is usually beneficial before closure and rarely harmful

In healing by primary intention (primary closure), the wound can be reapproximated in one or multiple layers. Deeper wounds require closure of structures of strength. Fascial layers that have been violated should be dosed in order to reduce tension on the skin. If necessary, the skin edges can be undermined or fascias can be incised and released remotely from the wound to allow closure of the wound.

The cutaneous edges can be closed in many ways. The strongest closure is closure of the deep dermis with
an absorbable suture (i.e., polyglycolic acid) followed by closure of the epidermis with subcuticular or intercuticular suture. This is called a layered closure. The least amount of observable scar is created with a running, nonabsorbable, subcuticular suture with the least inflammatory response (i.e., polypropylene). However, this suture does require removal (see Table 2). An absorbable subcuticular suture (i.e., poliglecaprone 25) can be used but has a prolonged inflammatory phase during suture degradation. Small, clean, simple lacerations with minimal retraction can be managed with noninvasive techniques, including suture strips and cutaneous adhesive (i.e., Dermabond, Ethicon: Cornelia, GA). If external sutures are used in an interrupted, mattress, or running fashion, they should be removed as early as possible to minimize scarring from the suture. Staples can also be used and are preferred in the scalp to expedite closure and reduce pain of application and removal without compromising cosmesis.⁷ Vertical mattress sutures are used for extra strength and eversion of wound edges. Horizontal mattress sutures provide additional hemostasis (see Figs. 3 and 4).

The most complex form of primary closure occurs when an appendage is amputated in such a way that it can be replanted. This is frequently performed for thumbs, fingers, hands, penises, and scalps. It has also been used for ears, nose, hands, feet, and entire extremities. Replantation requires repair of support structures (bones/tendons/fascia) followed by microvascular arterial and venous anastamoses and nerve repair. The skin is closed last. To be suitable for replantation, the amputated part must meet certain general criteria. Specific criteria are beyond the scope of this chapter. The amputated part must be present, preserved appropriately, recently amputated, minimally contaminated, and presumed to be viable. The patient must be medically stable and informed of the prognosis and need for prolonged postoperative care and therapy. Maximum ischemia time is frequently quoted to be 6 hours based on muscle damage at room temperature beyond 6 hours, but when preserved appropriately, cold ischemia can be extended even beyond 24 hours in amputated parts with minimal muscle (i.e., hands/digits). Preservation should include wrapping the part in sterile gauze moistened with lactated Ringers, sealing the part in a plastic bag, and placing the plastic bag in a container of water and ice at 4°C. Viability is compromised by crush injuries, avulsion injuries, and injuries at multiple levels.⁸,⁹

Healing by secondary intention is necessary when wounds are too large and/or too contaminated to close by other means. The wound is debrided and left open to heal secondarily. Healing is by a combination of contraction, proliferation of granulation tissue, and epithelialization. Epithelialization occurs from wound edges and skin appendages if still present. Secondary healing can be dramatically augmented by subatmospheric pressure therapy (see subsequent text).

Healing by third intention is also known as delayed primary closure and is typically performed in smaller wounds that are contaminated. The patient undergoes initial debridement followed by open wound care for typically 3 to 5 days, at
which point the local phagocytic activity is maximized. The wound is then closed. These wounds are typically drained. This technique reduces infection rates in high-risk wounds. Wounds treated initially with wound care followed by skin grafting or flap closure as discussed in the next section could be considered a variation of tertiary intention healing.