Soft-Tissue Injuries: Assessment and Management
I. Introduction to Soft-Tissue Injuries
Soft-tissue injuries are a leading form of injury, and wound care is among the most frequently performed emergency department (ED) procedures. While often dramatic, these injuries are "rarely the most critical concern in serious trauma," and it is "important not to miss higher-priority problems" such as airway threats, impaired ventilation/oxygenation, or inadequate circulation.
Soft tissue is defined as a "group of similar cells that connects, supports, surrounds other structures and organs," including fat, muscles, tendons, ligaments, synovial membranes, blood and lymph vessels, and nerves. Death from soft-tissue injuries is "uncommon" but, when it occurs, is "often related to hemorrhage or infection."
Injuries can result from various mechanisms:
• Blunt injury
• Penetrating injury
• Barotrauma injury
• Burns
II. Structure and Function of the Skin
The skin, or integument, is the "largest organ in the human body" and plays a "crucial role in maintaining homeostasis." Its primary functions include:
• Protection of underlying tissue
• Aid in temperature regulation
• Acting as a watertight seal
• Serving as a sense organ
The skin is composed of three main layers:
• Epidermis: The "outermost layer," serving as the "body’s first line of defence." It consists of five layers, with the outermost stratum corneum being composed of hardened, nonliving cells. Deeper layers contain melanin granules.
• Dermis: A "tough, elastic connective tissue" comprised of collagen fibers, elastic fibers, and mucopolysaccharide gel. It contains fibroblasts (which synthesize collagen and elastin), macrophages, lymphocytes, and mast cells (part of the immune system). The dermis also houses specialized structures such as nerve endings, blood vessels, sweat glands, hair follicles, and sebaceous glands. It includes a papillary layer (provides nutrients, aids thermoregulation) and a reticular layer (provides strength and elasticity).
• Subcutaneous Tissue: Located beneath the dermis.
◦ 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."
Skin Tension Lines: The tautness of skin varies by body region.
• 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."
III. Wound Healing
Wound healing is a natural, multi-stage process, though the "injured area may not be restored" to its original state. The stages are:
1. Hemostasis: The "primary concern" to stop bleeding and prevent impaired elimination of wastes. This involves "constriction of the blood vessels" and "platelets adhere to affected area and form plug."
2. Inflammation: Additional cells, including granulocytes and macrophages (phagocytes), move to the area to initiate repair. Chemotactic factors attract these cells, and granulocytes degranulate.
3. Epithelialization: "New epithelial cells move into injured region" as stratum germinativum cells multiply and redevelop. The "appearance of restructured area seldom returns to preinjury state."
4. Neovascularization: "New blood vessels form," with new capillaries budding to create a "conduit for oxygen and nutrients" and a "pathway for waste removal." Minor injury may cause bleeding due to these new vessels.
5. Collagen Synthesis: "Tough, fibrous protein found in scar tissue, bones, skin, connective tissues" is "synthesized by fibroblasts." Collagen is a "vital structural repair unit" that "provides stability" but "cannot restore damaged tissue to original strength."
Alterations of Wound Healing
Several factors can alter 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."
IV. Types of Wounds
Wounds are broadly categorized as closed or open.
• 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").
Specific types of open wounds include:
• 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: Occurs when "edema and hemorrhage result in increased pressure," compromising circulation. It "commonly develops in the extremities" from both open and closed wounds. Signs are known as the "Six Ps": Pain, Paraesthesia, Paresis, Pressure, Passive stretch pain, and Pulselessness. If it "persists longer than 6 hours," there is "serious risk of death of local tissues," disfiguring wound debridement, and sepsis. In-hospital intervention includes surgical fasciotomy to prevent Volkmann contracture.
V. Assessment of Soft-Tissue Injuries
It is crucial "not to let dramatic soft-tissue injuries distract you from performing thorough initial assessment." The "severity of injury may not be initially apparent."
Scene Safety and Assessment
• Safety: Be aware of hazards like vehicle collisions or reported blasts.
• Mechanism of Injury (MOI): "Evaluate the mechanism of injury." A "high index of suspicion" is needed for significant MOI, considering internal damage from forces involved.
• Number of patients: Determine this for resource allocation.
• Personal Protective Equipment (PPE): "Protect yourself and patient from exposure to body fluids."
Initial Assessment
• "Rapidly determine threats to life."
• Note general impression.
• Assess potential neck or spine injuries.
• Evaluate level of consciousness.
• Assess airway and breathing, then circulatory status (palpate and inspect skin).
• Priority decision: "Significant MOI: rapidly package and transport." "No significant MOI: treat at the scene."
Focused History and Physical Examination
• Physical examination:
◦ Significant MOI/Serious trauma: Perform a rapid trauma assessment (look for DCAP-BTLS: Deformities, Contusions, Abrasions, Punctures/Penetrations, Burns, Tenderness, Lacerations, Swelling). Obtain baseline vital signs and SAMPLE history.
◦ No significant MOI (isolated extremity trauma): Address the chief complaint. Local protocols may allow treatment and release/referral.
• History: Gather information from the patient or bystanders about the injury, including tetanus booster status and medications affecting hemostasis. Use the SAMPLE mnemonic (Signs/Symptoms, Allergies, Medications, Past medical history, Last oral intake, Events leading to injury). Record and relay information.
• Detailed physical examination: Conducted en route to the ED, examining every anatomic region for hidden injuries and clinical signs. "Never delay transport of a patient in critical condition."
• Ongoing assessment: "Frequent reassessments made en route." Stable patients every 15 minutes, serious patients every 5 minutes. Obtain and evaluate vital signs, check interventions, monitor the patient, and document all findings.
VI. Management of Soft-Tissue Injuries
Management varies by injury type and includes attending to the patient's feelings and clinical issues: "Control bleeding," "Irrigate wounds," "Immobilize injury site," and "Thoroughly document care provided."
Treatment of Closed Wounds
For extensive closed injuries, follow the PRICED mnemonic:
• Protect an injured extremity by applying a splint.
• Rest the injured area.
• Apply Ice or cold packs.
• Apply firm Compression.
• Elevate the injured part to a level above the heart.
• Administer analgesic Drugs where locally authorized. An alternative is RICES (Rest, Ice, Compression, Elevation, Splint).
Treatment of Open Wounds
Two general principles:
1. "Control bleeding by whatever method is most effective."
2. "Keep the wound as clean as possible."
• Determine the magnitude of the injury.
• If bleeding is present, determine color, amount lost, and site of origin.
• If bleeding has stopped, ask the patient to describe it.
• Examine healing wounds for proper closure and signs of infection (redness, swelling, pain, systemic signs).
Bandaging and Dressing Wounds
• Uses: "Cover wound, control bleeding, limit motion."
• Dressing: "Directly covers a wound and controls bleeding."
• Bandage: "Keeps the dressing in place."
Types of Dressings:
• Sterile: "Completely free of microorganisms," used with high probability of infection.
• Nonsterile: Used with lower infection risk, applied atop sterile dressings to increase absorption.
• Occlusive: Keeps air from passing through, used for neck and thorax wounds.
• Nonocclusive: Majority of dressings.
• Adherent: Allows exudate to mesh with material, facilitates clotting but painful to remove.
• Nonadherent: Allows wound repair products to pass through, easy removal, doesn't aid clotting, applied after wound closure.
• Dry: Most common in prehospital care.
• Wet: Limited use due to bacterial growth, though moist dressings benefit burn care (commercial water-based gels are better for pain relief).
Types of Bandages:
• Roller and Gauze: Often self-adherent, ideal for wrapping extremity injuries and holding dressings. Absorbent.
• Absorbent Gauze Sponges: Used for heavy bleeding, available in various sizes (sterile or nonsterile).
• Elastic Bandages (Tensor bandages): Apply pressure to protect and facilitate healing, but "be careful to avoid applying excessive pressure (could compromise blood flow)."
• Triangular Bandages (Cravats): Made of cotton, ideal for slings and swaths. Do not stretch much. Can be wrapped into a thin strip for a tourniquet.
• Taping: Secures dressings, use with care on patients with skin conditions.
Complications of Improperly Applied Dressings:
• Wound contamination: Avoid by irrigating with sterile water/saline, applying antibiotic ointment (smaller wounds), then dressing and bandaging. Clean blood around the site.
• Hemodynamic complications: Continued bleeding is possible; "do not remove" dressings once in place (risk disrupting clot). Apply additional dressings if bleeding continues.
• Exsanguination: Possible if pressure dressing fails to stop blood loss.
• Structural elements: Damaged if dressings are "excessively tight" (blood vessels, nerves, tendons, muscles, skin, internal organs).
Control of External Bleeding
External bleeding is visible from a wound.
• Arterial bleeding: "Occurs in spurts," "blood is usually bright red."
• Venous bleeding: "More likely to be slow and steady," "darker coloured blood."
• Capillary bleeding: "Slow, even flow of bright or dark red blood," present in minor injuries.
Methods for Controlling Blood Loss:
• Direct Pressure: "Stops blood from flowing into the damaged vessels." Apply a sterile dressing, then gloved hand pressure. A pressure dressing can be used if continuous manual pressure is not feasible. "Assess distal circulation before and after you apply a bandage or pressure dressing."
• Elevation: For venous bleeding from an extremity, elevating it above heart level can "substantially slowed" bleeding, but "alone will not control bleeding." Useful with another method.
• Immobilization: Any movement "promotes blood flow" and "may disrupt the clotting process." Air splints or padded boards work for extremities. Air splints apply direct pressure but "not sufficient to stop arterial bleeding" as pressure is less than systolic blood pressure. Tourniquets are better for arterial bleeding.
• Hemostatic Dressings: Used in combat, promote coagulation. Useful in areas not amenable to tourniquet use. "Never use on an open cranial wound."
• Tourniquet: "Rarely necessary in civilian setting" due to "potential hazards." "Use only as last resort." Can be lifesaving in military settings for traumatic amputations or gunshot wounds.
Pain Control
• Cold compress: "Reduces pain" and "diminishes blood flow."
• Pharmacological agents: Morphine sulphate (0.05 mg/kg IV every 5 min PRN), acetaminophen, fentanyl, nitrous oxide gas, ketamine. "Avoid: nonsteroidal anti-inflammatory drugs (ketorolac or ibuprofen)." Assess for allergies and document information.
Managing Specific Open Wounds
• Avulsion: "Gently irrigate contaminated wound with normal saline or sterile water." Note and document drainage. "Quickly irrigate dirt or debris." "Gently fold the skin flap back onto the wound." "Hold the flap in place with a dry, sterile compression dressing." "Never remove flap." Apply ice packs for pain/swelling.
• Amputated Parts: "Stabilize patient’s injuries." "Transport patient and part as expeditiously as possible." Notify medical control/ED. Guidelines for preservation: "Rinse with cool, sterile saline," "wrap loosely," "seal inside a plastic bag," "keep it cold, but do not allow it to freeze." "Never warm," "never place in water," "never place directly on ice," "never use dry ice."
• Impaled Objects: "Do not try to remove an impaled object." "Control hemorrhage by direct compression." "Do not try to shorten an impaled object unless it is extremely cumbersome." "Stabilize the object and immobilize the extremity." Limit motion of the object. For thin objects, stack gauze pads cut midway. For larger objects, use rolled towels or splinting materials. For eye objects, use gauze, a cup, and bandage. Removal may be best only if: it interferes with airway control or chest compression, or if impaled on an immovable object.
• Wound Healing and Infection: Basic measures include dressing, bandaging, and pain control.
Dressing Specific Anatomic Sites
Special techniques for: Scalp, face, ear/mastoid, neck, shoulder, trunk, groin/hip, hand/wrist/finger, elbow/knee, ankle/foot.
Management of Soft-Tissue Injuries to Specific Anatomic Sites
These areas have underlying structures "vital to life," leading to additional concerns.
• Head, Face, and Neck: Accurately determine scalp injury extent (hair hides wounds, potential skull damage). May involve airway or large blood vessels. Airway is first priority, ensure adequate oxygen. "Exsanguination can occur." Control bleeding while managing airway.
• Thorax: Injuries "may appear minor" but are "seriously misleading" as gunshot/stab wounds can cause rapid internal damage and death. Assessment includes inspection, palpation, auscultation, percussion. Management often involves "occlusive dressing, taped on three sides."
• Abdomen: Range from abrasions to evisceration. "Visible ecchymosis suggests serious underlying injury with internal bleeding." Cover upper abdominal open wounds with a three-sided occlusive dressing. Maintain a "high index of suspicion" as blunt or penetrating trauma can fracture solid organs or rupture hollow organs.
VII. Special Considerations: Crush and Blast Injuries
Crush Injuries
Result from a "body part crushed between two solid objects." They can range from minor to life-threatening. Forces may be strong enough to rupture internal organs. "The longer the injured area remains compressed, the greater the chance for systemic complications." External appearance may not reflect internal damage. Crushed vessels lose ability to constrict, leading to hemorrhage.
Crush Syndrome
Occurs when a body area is "trapped for longer than 4 hours," compromising arterial blood flow and crushing muscles beyond repair. This "tissue necrosis leads to release of harmful products, a process known as rhabdomyolysis," where destroyed muscle cells release "Potassium, purines, phosphate, lactic acid, myoglobin, thromboplastin, creatine, and creatine kinase." This is known as "smiling death" due to early deaths from hypovolemia and hyperkalemia. Management: "First issue to consider: scene safety." Then, conduct initial assessment as much as possible given entrapment. Leads to renal failure and increased blood potassium. Open injuries can be managed with irrigation, dressings, and bandaging.
Blast Injuries
Result from explosions, caused by terrorist attacks, dust buildup, or transport of explosive products. Injuries occur in 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."
Management of Blast Injuries:
• "Assess the scene for safety hazards."
• "Wear appropriate PPE."
• "Form a general impression."
• "Rapidly perform initial assessment" focusing on "Pulmonary injuries," "Abdominal trauma," "Ears," and "Projectiles."
VIII. Documentation
"Written documentation completed for every patient." Include:
• All relevant scene findings.
• Patient findings.
• Specific injuries.
• Demographic information.
• Interventions provided.