Chapter 31: Ready for Review The skin is a complex organ that fulfills several crucial roles, including maintaining homeostasis, protecting tissue from injury, and regulating temperature. The main layers of the skin are the epidermis and the dermis. The epidermis, the outer layer, serves as the principal barrier. The dermis, the inner layer, includes collagen, elastin, and ground substance, which contribute to the skin’s strength. It also contains nerve endings, blood vessels, sweat glands, hair follicles, and sebaceous glands. The subcutaneous layer lies beneath the dermis and contains adipose tissue. Below the subcutaneous layer is the deep fascia, which offers support and protection to underlying structures such as muscle and bone. The skin is arranged in patterns of tautness known as tension lines. Wounds that occur parallel to skin tension lines may remain closed. Wounds that run perpendicular to tension lines may remain open. Soft-tissue injuries may be dramatic looking but are seldom the most serious injuries. Do not let them distract you from performing a thorough primary assessment! In a closed wound, the skin is not broken but soft tissues beneath the skin are damaged. An example is a bruise. A hematoma (collection of blood beneath the skin) can also form. In an open wound, the skin is broken. Such an injury can become infected and can result in serious blood loss. Open wounds include abrasions, lacerations, puncture wounds, avulsions, bites, and amputations. In a crush injury, a body part is crushed between two solid objects, resulting in damage to soft tissues and bone. The patient’s external appearance may not adequately represent the level of internal damage. The first stage of wound healing is cessation of bleeding. The body uses several mechanisms to control bleeding, such as constricting the size of vessels and releasing platelets to form a blood clot. The second stage of healing is inflammation, in which additional cells enter the damaged area in an effort to repair it. Epithelialization (creation of a new layer of epithelial cells) occurs, followed by neovascularization (formation of new vessels). Wound healing is affected by factors such as the amount of movement the part is subjected to, medications, and medical conditions. A wound is more likely to become infected if it is caused by a human or an animal bite or if a foreign body has been impaled. Pressure injuries can develop when a patient is bedridden or remains on a backboard for too long. Signs of infection include redness, pus, warmth, edema, and local discomfort. Gangrene, tetanus, and necrotizing fasciitis are serious infection-related conditions that must be recognized early. Observe scene safety before assessing patients with soft-tissue injuries; hazards that caused the injury may still be present. Regardless of how dramatic a soft-tissue injury looks, assess the ABCs first. When you are obtaining a patient history, ask about the event that caused the injury, such as whether a weapon was used or whether the patient lost consciousness. Find out when the patient last had a tetanus booster. Pay attention to whether the patient is taking any medications that may affect hemostasis. Depending on the mechanism of injury, complete your physical exam en route or at the scene, respectively. Direct your attention to the chief complaint and area of injury, and perform frequent reassessments. Document scene findings, including vehicle damage or the caliber of weapon used; patient presentation and position; size, location, depth, and complications of injuries; assessment findings; and interventions. Be empathetic to patients with soft-tissue injuries. Managing soft-tissue injuries includes controlling bleeding. With closed injuries, follow the ICES mnemonic: Ice, Compression, Elevation, and Splinting. When you are managing open wounds, control bleeding and keep the wound as clean as possible by irrigating and using sterile dressings. Try to determine the color and type of bleeding and the amount of blood the patient has lost. Dressings and bandages are used to cover the wound, control bleeding, and limit motion. Types of dressings include sterile and nonsterile, occlusive and nonocclusive, adherent and nonadherent, and wet and dry. Types of bandages include roller and gauze, absorbent gauze sponges, elastic, and triangular bandages. Medical tape may be used to secure a bandage in place, except for patients with thin skin such as older individuals because it can cause damage on removal. Do not apply dressings too tightly. Methods of bleeding control include direct pressure, elevation, immobilization, and tourniquets. Cold compresses may help reduce pain. IV medications may be administered if basic measures do not relieve pain. Dressing and bandaging techniques vary for different parts of the body. For example, the shape of the skull and the presence of hair make dressing the scalp challenging. Management of an avulsion includes irrigation, gently folding the flap back onto the wound, and applying a dry, sterile compression dressing. If the wound is an amputation, preserve the amputated part and transport it with the patient to the ED. Do not remove impaled objects in the field. Instead, stabilize the object in place with a bulky dressing. Control bleeding with direct compression, but do not apply pressure on the object or on the immediately adjacent tissues. Animal and human bites can lead to serious infection and must be treated by a physician. Dogs and cats can carry rabies, a fatal viral infection present in their saliva. By law, all animal bites must be reported to the appropriate authority. Crush syndrome may develop after a body part has been trapped for more than 4 hours. Necrosis occurs in crushed muscles, and harmful products are released in a process called rhabdomyolysis. Freeing the trapped body part can cause these harmful products to be released into the circulation, which can prove fatal. Kidney damage, cardiac arrest, and dysrhythmias can also result. Patients who have been trapped for a prolonged period of time must be managed before being freed from the crushing object because this approach improves their chances of survival after experiencing crush syndrome. Aggressive fluid resuscitation can help prevent kidney failure. Normal saline should be infused. Administration of sodium bicarbonate may help prevent an efflux of potassium. Contact online medical control before treatment and rapidly transport the patient once freed. Compartment syndrome results when pressure increases inside a closed soft-tissue compartment. Tissue necrosis and sepsis may then develop. Patients present with all or some of the six Ps: Pain, Paresthesia, Paresis, Pressure, Passive stretch pain, and Pulselessness. Blasts (explosions) can result in soft-tissue injuries. Blast injuries can include pulmonary damage such as tension pneumothorax and pulmonary contusion, abdominal trauma such as ruptured organs and internal hemorrhage, damage to the ears, and penetrating wounds. Use the DCAP-BTLS guideline to assess the patient rapidly. High-pressure injection injuries involve the injection of foreign material into soft tissue. High-pressure injection may cause acute or chronic inflammation, even leading to systemic complications or amputation. Gathering and relaying appropriate information to the receiving facility can potentially reduce mortality. Soft-tissue injuries of the face, neck, thorax, and abdomen deserve special attention because these areas contain vital structures. Do not underestimate the seriousness of these injuries, and maintain a high index of suspicion.