Soft-Tissue Injuries: Assessment and Management

Soft-tissue injuries

Injuries to tissues that connect, support, and surround organs, including muscles, tendons, and ligaments.

Primary Function of the skin

• Protection of underlying tissue

• Aid in temperature regulation

• Acting as a watertight seal

• Serving as a sense organ

Epidermis

The outermost layer of skin, serving as the body's first line of defense.

Dermis

The layer of skin under the epidermis composed of tough connective tissue, containing blood vessels, nerves, and glands.

Subcutaneous Tissue

The layer of tissue beneath the dermis, primarily composed of fat and connective tissue.

Superficial fascia

Primarily adipose tissue (fat) that "insulates," "provides a cushion," and serves as an "energy reserve."

Deep fascia

A "thick, dense layer of fibrous tissue" with "tough bands" that "supports and protects underlying structures."

Static tension

In areas with limited mobility, "parallel lacerations remain closed," while "perpendicular lacerations remain open." Larger wounds pulled open by normal tension require closure.

Dynamic tension

In areas over muscle, "open injuries interfere with healing," and "abnormal scars may prompt scar revision surgery."

Hemostasis

The process of stopping bleeding, involving constriction of blood vessels and platelet plug formation.

Wound Healing

Hemostasis

Inflammation

Epithelialization

Neovascularization

Collagen Synthesis

Epithelialization

The process where new epithelial cells move into the injured area during wound healing.

Neovascularization

Formation of new blood vessels to supply oxygen and nutrients to healing tissue.

Collagen Synthesis

The production of collagen, a structural protein that is crucial for wound healing.

Anatomic and physiologic factors

Areas of repeated motion, arrangement relative to skin tension lines, medications, and medical conditions.

High-risk wounds

Human and animal bites, embedded foreign bodies or organic matter, injection wounds, devitalized tissue, and crush wounds.

Abnormal scar formation

Excessive collagen can lead to hypertrophic scars or keloid scars.

Pressure injuries

Occur in bedridden, unconscious, or immobilized patients due to localized hypoxia and cell deterioration from tissues being deprived of oxygen.

Wounds requiring closure

Include "highly visible areas," "gaping wounds," "degloving injuries," "ring injuries and skin tears." Closure methods include sutures, staples, wound closure strips, or medical glue. Types of closure are primary closure, closure by secondary intent, and tertiary (delayed primary) closure.

Infection

"Any break in skin can allow invading pathogens to enter." Risk factors include certain wound mechanisms, anatomic locations, and patient populations. Visible clues are "erythema, purulent discharge, warmth, edema, local discomfort." Red streaks indicate lymphangitis. Systemic signs include "fever, rigors, chills, joint pain, hypotension." Infection can delay healing.

Gangrene

"Serious complication involving tissue death, with or without infection," if a wound is not treated. The "skin will become necrotic and infection may lead to bacteremia and sepsis."

Tetanus

Caused by Clostridium tetani, an "anaerobic bacterium produces potent toxin" leading to "painful muscle contractions," often starting in the jaw ("lockjaw"). Mortality rate is "approximately 30%," but it is "rare due to vaccination."

Necrotizing Fasciitis

"Flesh-eating disease; death of tissue from bacterial infection" (most commonly Streptococcus). It is "rare" with a "mortality rate ranges from 70% to 80%." The "clinical hallmark is abnormally severe pain," often with "central wound necrosis with surrounding severe pain or a subcutaneous emphysema on exam." It is a "surgical emergency requiring early and aggressive debridement followed with antibiotic and/or immunoglobulin therapy."

Closed Wounds

"No break in the epidermis." Examples include:

    ◦ Contusion (bruise)

    ◦ Edema (swelling)

    ◦ Ecchymosis (black-and-blue mark)

    ◦ Hematoma (collection of blood beneath skin)Small contusions require no special treatment, but extensive closed injuries require steps to minimize bleeding and swelling (see "Treatment of Closed Wounds").

Open Wounds

Involve a "disruption of the epidermis" and are "more serious than closed wounds" due to vulnerability to infection and potential for significant blood loss ("Patient’s entire blood volume may be lost").

Abrasions

"Superficial wound" from skin rubbing or scraping. They "typically ooze small amounts of blood," "may be painful," and "may be contaminated." Cleaning in the prehospital environment should generally be avoided.

Lacerations

"Cut inflicted by a sharp instrument," which can be a "clean or jagged incision through skin surface and underlying structure." Laceration usually refers to jagged cuts, while incision refers to clean ones. Severity depends on depth and damaged structures. The "first priority: control bleeding" by applying direct manual pressure.

Puncture Wounds

"Stab wound from a pointed object or bullet wound." Most do not cause significant external bleeding but "may produce significant internal bleeding." Potential depth should be considered, and measures to prevent infection are crucial. Special cases include impaled foreign objects and wounds from air-pressurized devices.

Avulsions

"A flap of skin torn loose (partially or completely)." They "may be accompanied by profuse bleeding." The "principal danger is loss of blood supply to the avulsed flap." Treatment involves irrigating with normal saline and placing the flap into anatomic position.

Amputations

"Complete loss of a body part."

◦ From a sharp object: "Less blood loss than expected."

    ◦ From crushing or tearing: "Can result in exsanguination." Wound edges are commonly jagged, and sharp bone edges may protrude. Degloving injuries are a specific type of amputation where skin is peeled off.

Compartment Syndrome

A condition where increased pressure within a muscle compartment compromises circulation and function.

PRICED mnemonic

A first aid protocol used for managing soft-tissue injuries, standing for Protection, Rest, Ice, Compression, Elevation, and Diagnosis.

Arterial bleeding

A type of bleeding that occurs in spurts and the blood is usually bright red.

Venous bleeding

A type of bleeding that is slow and steady, with darker colored blood.

Capillary bleeding

A type of bleeding that flows slowly and evenly, often seen in minor injuries.

Rhabdomyolysis

A serious condition resulting from muscle tissue breakdown, releasing harmful substances into the bloodstream.

Blast Injuries

Injuries resulting from explosions, categorized into five phases.

Primary Phase: Caused by the "pressure wave" from air displacement and heat, damaging "air-filled cavities (ears, lungs)." High risk of injury or death.

Secondary Phase: Caused by "blast wind" (combustible gases), which is "less forceful than the pressure wave, longer lasting." Involves "projectiles" and "blunt and penetrating wounds from flying debris."

Tertiary Phase: From "displacement from high-energy explosions" where victims are "thrown against rigid structures" or structures collapse, leading to "risk for entrapment" and "multiple victims."

Quaternary Phase: "Miscellaneous events that occur during an explosion." Heat causes burns, and falling debris causes crush injuries.

Quinary Phase: Caused by "biologic, chemical, or radioactive contaminants" ("dirty bombs"), an "increased concern due to threats from terrorist organizations."

Crush Injuries

Result from a "body part crushed between two solid objects."

Crush Syndrome

Occurs when a body area is "trapped for longer than 4 hours," compromising arterial blood flow and crushing muscles beyond repair.