Burn Injuries PDF

## Burn Injuries ### Introduction - 4th most common type of trauma worldwide - Following traffic accidents, falls and interpersonal violence. - Most occur at home, with cooking as the most common activity. - Pediatric burns occur more commonly at home, while unsupervised. - Adults are equally li...

## Burn Injuries ### Introduction - 4th most common type of trauma worldwide - Following traffic accidents, falls and interpersonal violence. - Most occur at home, with cooking as the most common activity. - Pediatric burns occur more commonly at home, while unsupervised. - Adults are equally likely to sustain a burn at home, outdoors or at work. - Elderly are most likely to sustain a burn in the bathroom followed by the kitchen. ### Acute vs Chronic Wound | Type | Characteristics | | ----- | -------- | | Acute | Repair themselves or can be repaired in a timely manner. <br> Due to isolated, non-recurring insult. <br> Expected to heal within a reasonable period. <br> May be small or involved entire body surface. <br> Closure by either epithelialization, wound contraction, skin grafting or combination. | | Chronic | Failed to proceed through an orderly and timely process to produce anatomic and functional integrity. <br> Small due to minor trauma and heals slowly because of other underlying pathology (i.e. DM, CVI etc.). <br> Marked by absence of progressive epithelialization or reduction in wound size over a protracted period of weeks to months. <br> Uniform in Depth | ### Burn Wound Zone - **Zone of Coagulation:** - Inner Zone - Area of cellular death (necrosis) - **Zone of Stasis:** - Area surrounding zone of coagulation - Cellular injury: decreased blood flow & inflammation - Potentially salvable; susceptible to additional injury - **Zone of Hyperemia:** - Peripheral area of burn - Area of least cellular injury & increased blood flow - Complete recovery of this tissue likely. ### Types of Burns #### Chemical Burn - Causes injury due to a wide range of caustic reactions - Radical alteration of pH - Disruption of cellular mechanism - Direct toxic effects on metabolic processes - Determinants of severity of injury - Duration of exposure - Nature of agent - Consider systemic absorption of some chemicals #### Thermal Burn - Determinants of severity of injury - Temperature: protein denaturation occurs at 40deg C - Duration of contact - Thickness of skin - Depth of injury determines healing potential and needs for surgical intervention #### Frostbite - Damages the skin and underlying tissues when ice crystals puncture the cells or when they create a hypertonic tissue environment. - Can interrupt blood flow → hemoconcentration → intravascular thrombosis → tissue hypoxia. - Frostnip or whitening of exposed area does not appear to cause damage but may increase risk of frostbite on future exposure. #### Electrical Burn - Causes damage as electrical energy is transformed into thermal energy as the current passes through poorly conducting body tissues - Also injury to cell membranes disrupts membrane potential and function. - **Cross-sectional area critical** - As the area of exposure decreases, the current density increases, generating greater heat. - **Low tension injuries occur at less than 500 volts; high tension injuries occur above 1000 volts.** - **Cutaneous injury does not reflect extent of injury.** - Iceberg effect - **Injury severity depends on:** - Voltage of source - Amperage of current passing through tissues - Resistance of tissues - Duration of exposure - Pathway of Current - **Current traversing the most resistant tissue produces the greatest heat** - Least conductive tissue is bone → tendon → skin → muscle → blood → nerve ### Burn Depth and Classification - **Burn depth is:** - Significant determinant of mortality - Primary determinant of patient's long-term appearance and functional outcome - **Deeper wounds means destroyed dermal appendages → longer healing and more scarring.** - **Partial (second degree) thickness burns that heals spontaneously without surgery within 2-3 weeks usually resolves without hypertrophic scarring or functional impairment.** - **Wound that takes longer than 3 weeks to heal** - Hypertrophic scarring - Cause functional impairment - Provides only thin layer of epithelial covering that remains fragile for weeks to months. - **Appearance of wounds and apparent burn depth changes within 7-10 days** - Due to thrombosis of dermal blood vessels and death of thermally injured skin cells. - **Superficial burns may convert to deeper wounds due to infection, dessication of wounds or use of vasoactive agents during resuscitation.** #### Burn Depth Classification | Classification | Description | | ----- | -------- | | **Old** | **New** | | First degree/Epidermal | Superficial | | Second degree | First degree | | Third degree | Superficial Partial Thickness | | Fourth degree | 2nd degree | | | Deep Partial Thickness | | | 2nd degree | | | Full Thickness | | | 3rd - 4th degree | #### Burn Depth Clinical Features and Result/Treatment | Depth | Level of Injury | Clinical Features | Result/Treatment | | ----- | -------- | -------- | -------- | | Superficial (first degree) | Epidermis | Dry, red; blanches; painful | Healing time 3-6 days, no scarring | | Superficial partial thickness (superficial second degree) | Papillary dermis | Blisters; moist, red, weeping; blanches; severe pain to touch | Cleaning; topical agent; sterile dressing; healing time 7-21 days; hypertrophic scar rare; return of full function | | Deep partial thickness (deep second degree) | Reticular dermis; most skin appendages destroyed | Blisters; wet or waxy dry; reduced blanching: decreased pain sensation to touch, pain present to deep pressure | Cleaning; topical agent; sterile dressing; possible surgical excision and grafting; scarring common if not surgically excised and grafted; earlier return of function with surgery | | Full thickness (third degree) | Epidermis and dermis; all skin appendages destroyed | Waxy white to leathery dry and inelastic; does not blanch; absent pain sensation; pain present to deep pressure; pain present in surrounding areas of second-degree burn | Treatment as for deep partial-thickness burns plus surgical excision and grafting at earliest possible time; scarring and functional limitation more common if not grafted | | Fourth degree | Involves fascia and muscle and/ or bone | Pain to deep pressure, in the area of burn; increased pain in surrounding areas of second-degree burn | Healing requires surgical intervention | #### Burn Depth and Total Body Surface Area - Average area of skin in adults in 1.82m2; in neonates only 0.25m2. - Only partial and full thickness burns are included in the calculation of TBSA burned. - Surface area determined most accurately by charts that are specific to patient's age (Lund and Browder Chart). - In adults, Rule of Nines can be used. #### Rule of 9's - Diagram illustrating the "Rule of 9's" for assessing burn TBSA in adults and infants. #### Lund and Browder Chart - Diagram illustrating the Lund and Browder Chart for assessing burn TBSA in adults. ### Severity of Injury - **Age** - **Associated injuries (inhalational injury and head injury particularly important)** - **Existing co-morbidities** - **TBSA injured** - **Depth of injury** - **Body part injured** #### Severity of Burns | Burn Type | Criteria | Outcome | | ----- | -------- | -------- | | Minor | <10% TBSA burn in adults <br> <5% TBSA burn in younger or older patients <br> <2% full-thickness burn | Outpatient | | Moderate | 10%-20% TBSA burn in adults <br> 5%-10% TBSA burn in younger or older patients <br> 2%-5% full-thickness burn <br> High-voltage injury <br> Suspected inhalation injury <br> Circumferential burn <br> Medical problem predisposing to infection (e.g., diabetes mellitus, sickle cell disease) | Admit to hospital | | Major | >20% TBSA burn in adults <br> >10% TBSA burn in younger or older patients <br> >5% full-thickness burn <br> High-voltage burn <br> Known inhalation injury <br> Any significant burn to face, eyes, ears, genitalia, or joints <br> Significant associated injuries (fracture or other major trauma) | Refer to burn center | ### Response to Burn Injury #### Local Response to Burn Injury - **Local edema due to:** - Vasodilation - Increased extravascular osmotic activity - Impaired cell membrane function - **Microvascular permeability** - If >30% TBSA is involved, edema is seen in non-burned areas. - **Heterogenous reduction in perfusion creates local ischemia and necrosis.** - **Endothelial cells, platelets and leukocytes migrate injured area; platelets contribute to hemostasis and thrombosis.** #### General Response to Burn Injury - **Hypovolemia is a major problem.** - **Systemic hemodynamic changes include initial depression of cardiac output.** - **Pulmonary function is near normal but inhalational injury is the single most important cause of mortality.** - **Disrupted thermoregulation.** #### Inhalational Injury - **Significant risk factor for morbidity** - **Reduction of available oxygen with toxic smoke components such as carbon monoxide and cyanide increases risk burn injury.** - **Also increase risk for pneumonia, adult respiratory distress syndrome and multi-organ system dysfunction.** ### Phases of Modern Burn Care - **First Phase:** - Initial evaluation and resuscitation - Occurs on the first 3 days after injury - Requires fluid resuscitation and thorough evaluation for other injuries and co-morbid conditons. - **Second Phase:** - Initial wound excision and biologic closure - Series of staged operations - Example: Debridement - **Third Phase:** - Definitive wound closure - Acute reconstruction of small surface but complex areas such as face and hands - Example: Skin grafting - **Fourth Phase:** - Rehabilitation - Reconstruction - Reintegration ### Acute Burn Rehabilitation #### Positioning - **Proper positioning is fundamental to prevent development of contractures and avoid compression neuropathies.** - **Keep tissue elongated.** - **Typically positions of extension and abduction should be chosen, but positioning needs to be individualized according to specific needs.** #### Contracture Prevention Positioning - Diagram illustrating contracture prevention positioning in a patient, such as abduction, external rotation, supination, extension/ hyperextension, straight alignment, no external rotation, no flexion, straight, and dorsiflexion. #### Positioning the Pediatric Patient | Area Involved | Contracture Predisposition | Contracture Preventing Position | | ----- | -------- | -------- | | Anterior Neck | Flexion | Extension, no pillows | | Anterior Axilla | Shoulder adduction | 90 abduction, neutral rotation | | Posterior Axilla | Shoulder extension | Shoulder Flexion | | Elbow/Forearm | Flexion/pronation | Elbows extended, forearm supination | | Wrists | Flexion | 15-20 extension | | Hands <br>MCPs <br>Ips | Hyperextension <br> Flexion | 70-90 flexion <br> Full extension | | Palmar burn | Finger flexion <br> Thumb opposition <br> Lateral/Anterior Flexion | All joints full extension, thumb radially abducted | | Chest | Flexion, adduction, external rotation | Straight, no lateral or anterior flexion | | Hips | Flexion | Extension, 10 abduction, neutral rotation | | Knees | Flexion | Extension | | Ankles | Plantar flexion | 90 dorsiflexion | #### Splinting - **Indications:** - Maintain joint position - Correct or prevent deformities - Control edema - Complement pressure therapy - **Characteristics of a good splint:** - Easy to don and doff - Avoid pressures over bony prominence - Made of moldable materials - Compatible with wound dressings and topical medication #### Exercise - **Initial goal is to maintain normal ROM and strength.** - **Stretching programs are indicated when there is loss of normal ROM** - **Strengthening should begin as soon as tolerated.** - **Precautions with post grafted patients.** ### Post Acute Burn Rehabilitation #### Skin Care - **Healed skin is fragile and easily abraded.** - **Healed burn skin is sensitive to sun and chemicals.** - **Healed burn skin lacks natural lubricant.** - **Advise patient to:** - Use moisturizer and sun blocks - Avoid prolonged water exposure - Avoid drying soap and detergents - Use mild soap - Massage skin often #### Scarring - **Within 1-3 months, hypertrophic scarring occurs creating irregular, raised and red scars.** - **Often regress spontaneously overtime.** - **Differentiate from keloid.** #### Differences Between Keloid and Hypertrophic Scars - **Keloids:** - Grow beyond borders of the original wound. - Size varies between a pea and a football; growth may be widespread, vertical or both. - Itchy and painful. - Appear within several months after initial scar. - Commonly occur on the chest, shoulders, upper back, back of the neck and earlobes, rarely on the palms or soles. - Do not go away on their own. - Larger, thicker and more wavy collagen fibers than normal skin, random collagen fiber orientation, increased ratio of type I to type III collagen. - **Hypertrophic Scars:** - Remain within the boundaries of the original wound. - Rarely more than a centimeter in thickness or width. - Less itchy and painful. - Generally arise within 4 weeks and grow intensely for several months. - No predominant site on the body. - Will spontaneously get smaller often within a year. - Fine collagen fibers running parallel to the epidermis. #### Scarring - **Pressure facilitates parallel orientation of collagen during scar maturation.** - Custom fitted compression garment that provides at least 25mmHg of pressure is worn at least 23h/day. - Custom made acrylic face mask preserves facial contour. - Microstomia can be used to maintain normal aperture of the mouth and stretch scar present. - **Rationale for the use of compression garment:** - Decreases blood flow to the scar. - Reorganization of collagen fibers. - Decreases water content of the scar. - Provides actual pressure to the scar. #### Compression Garment - Image illustrating compression garments such as a face mask, neck support, chest binder, and arm sleeve. ### Neuromuscular Complications in Burn #### Peripheral Neuropathies - **Focal neuropathies:** - Commonly due to faulty positioning, improperly applied splints or bulky dressing. - **Multiple neuropathies:** - Incidence of 2% - M>F (4:1) - Typically asymmetrical. - More likely in UE - Not always on burned areas. - **Generalized peripheral neuropathy** - Incidence as high as 50% - Correlates with amount of TBSA burned. - >20% TBSA in adults. - >30% TBSA in children. - **Theoretical etiologies:** - Neurotoxicity from medications. - Toxicity from circulating neurotoxin from burn injury. #### Heterotopic Ossification - **Abnormal calcifications of soft tissues surrounding a joint.** - **Risk factors:** - >20% TBSA - Open wounds - Immobility - **Most common site is posterior elbow.** - **Second most common is hip in children and shoulder in adults** - **Site does not correlate with burned areas** - **May be single or multiple** - **Signs and symptoms:** - Progressive loss of joint ROM. - Nerve entrapment mononeuropathy. - **May resolves spontaneously.** - **Significantly interferes with function and is unresponsive to non-surgical treatment.** - **Surgery excision only when the bone is matured to prevent risk of recurrence.** #### Burn-Induced Amputation - **Electrical burn is the leading cause of amputation.** - UE more involved than LE. - **Additional issues in burn amputee:** - Skin fragility - Hypertrophic scarring - Burn contractures - Altered skin sensation - **Blistering and open sores can develop more easily than with other patients.** - **Higher rate of successful UE prosthesis use when patients are fitted within 30 days of amputation.** ### Functional Training - **Structured exercise combined with therapeutic and fun activities.** - **May do ADLs appropriate for age and development.** - **Play is considered an ADL and should be encouraged whenever possible.** ### Return to Work - **TBSA injured correlates most strongly with the length of time needed to return to work.** - **Other factors affecting RTW:** - Presence of hand burn - Type of employment - Age - **Overemphasis on ROM without adequate attention to endurance strength and power required in work may delay RTW.** - **In severe injury, 20-50% of patients require change in occupation.** - **Determining level of function after burn should be considered to facilitate work hardening/pre-vocational rehabilitation.**