Burns and Wounds

Thermal Burns: Epidemiology

• Risk highest between 18-35 years old

• 75% of all injuries due to fire or scalding

  • 43% of scalding injuries occur in children < 5 y/o

• Elderly individuals have disproportionate higher death rate

Thermal Burns: Pathophysiology

• Depth and severity vary by both age of victim and anatomic locations exposed

• Partial thickness burns disrupt skin barrier → free water loss

  • Becomes significant in moderate to large burns

• Result: spectrum of local and systemic homeostatic disorders contributing to burn shock

• Fluid and electrolyte abnormalities seen in burn shock due to alterations in cell membrane potential

  • Intracellular influx of water and sodium

  • Extracellular migration of potassium due to dysfunction with sodium pump

• Systemic vascular resistance increased due to inflammatory response of the burn

• Significant metabolic acidosis may be present early in large burn injuries

• Massive burns increase blood viscosity in early phases → transition to anemia from erythrocyte extravasation and destruction

• Cellular damage occurs at temperatures > 45 degrees Celsius → denaturation of cellular proteins

• Most important factors

  • Severity of the burn

  • Presence of inhalation injury

  • Associated injuries

  • Patient’s age and comorbid conditions

  • Acute organ system failure

Thermal Burns: Local Effects

• Liberation of vasoactive substances

• Disruption of cellular function

• Formation of edema

Thermal Burns: Systemic Effects

Alters neurohormonal axis and further extends injury

• Histamine release

• Kinin

• Serotonin

• Arachidonic acid metabolites

• Free oxygen radicals

Burn Wounds and their Three Zones

Zones of coagulation

• Tissue is irreversibly destroyed with thrombosis of blood vessels

• No more blood flow and tissue is dead → no coming back and area is gone forever

Zone of stasis

• Stagnation and microcirculation

• Can become progressively more hypoxemic and ischemic if resuscitation is inadequate

• Not a complete destruction

Zone of hyperemia

• Increased blood flow

• Minimal damage to cells and spontaneous recovery is likely

Determining Burn Size

• Rule of nine’s

• The area of the back of the patient’s hand is 1% of their total body surface

• Lund Browder Burn Diagram

  • Allows for age adjusted determination of burn size for a given depth

  • Allows for anatomic differences in children

Rule of Nine’s

WILL BE GIVEN DIAGRAM

Lund Browder Burn Diagram

How to Determine Burn Depth

Historically has been described as degrees

• First

• Second

• Third

• Fourth

Classification based on surgical intervention has become accepted

• Superficial partial thickness

• Deep partial thickness

• Full thickness

Burn Depth

Burn Classification

Superficial Burn

• Only involves epidermal layer of the skin

  • Ex: sunburn

• Burned skin is red, painful, and tender without blister formation

• Usually heals in 7 days without scarring

• Treatment → symptomatic

Superficial Partial Thickness Burn

• Epidermis and superficial dermis (papillary layer) injured

• Deeper layers of dermis, hair follicles, and sweat/sebaceous glands spared

• Often caused by hot water or scalding

• Skin is blistered and exposed dermis is red and moist → painful to tough

• Healing occurs in 14-21 days with minimal scarring

• Have full return of skin function

Deep Partial Thickness Burn

• Extends into the deep dermis (reticular layer)

  • Hair follicles and sweat/sebaceous glands damaged but deeper structures usually spared

• Causes: hot liquids (oil or grease), steam, flame

• Skin may be blistered, exposed dermis is pale white to yellow

  • Burned area does not blanch and has absent capillary refill and absent pain

• Difficult to distinguish from full thickness

• Heals over 3 weeks to 2 months

  • Scarring common

  • Surgical debridement and skin grafting may be required to obtain maximum function

Full Thickness Burn

• Involves entire thickness of skin

  • All epidermal and dermal structures destroyed

• Typically caused by flame, hot oil, steam, contact with hot objects

• Skin is charred, pale, painless, and leathery

• Does not heal spontaneously

  • Surgical repair and skin grafting necessary

  • Significant scarring always present

Fourth Degree Burn

• Extend through skin to subcutaneous fat, muscle, and bone

• Devastating life threatening injury

• Amputation or extensive reconstruction is often required

Burn Center Transfer Guidelines

• Indications based on burn depth

• Patient age < 10 y/o

• Patient age > 50 y/o

• Comorbidities (heart disease, diabetes, COPD)

• Capabilities of receiving institution

• Any burn involving face, hands, feet, genitalia, perineum, or major joints

Burn Treatment Pre-Hospital Care

• Stop the burning process

• Assess and, if needed, secure the airway → special attention to airway since rapid deterioration can occur

• Initiate fluid resuscitation → IV isotonic crystalloid

• Relieve pain → opiate medications

• Protect the burn wound → cover with clean sheet

• Transport patient to appropriate facilitiy

Burn Treatment ED Care

• Obtain directed history from patient and EMS

  • Determine burning agent, involvement of chemicals, duration of exposure, and if injury was sustained in open or enclosed space

• Assess for LOC, risk of blast injury, contact with electricity, or other trauma

• Assess for need of cervical spine precautions

• Quickly assess respiratory and circulation → stabilize as needed

  • Examine for signs of inhalation injuries → respiratory distress, facial burns, carbonaceous sputum, singed nasal hair, soot in mouth

  • If there is evidence of airway compromise with swelling of neck, burns inside of mouth, or wheezing → perform early ET intubation

  • Any airway involvement:

    • 100% humidified oxygen (NRB, BiPAP, NC)

    • Early intubation

    • Bronchodilators

    • Lung protective ventilator settings (low tidal volumes and low airway pressures with high FiO2: concern that parenchyma damaged and at increased risk of pneumothorax)

• Monitor BP, pulse, capillary refill time, mental status, and urinary output (consider urinary catheter placement, especially with perineal burns → can cause strictures and obstruct outflow) → 100-120 bpm considered normal due to catecholamine response

• Perform secondary survey → head to toe assessment including eyes, estimate and record size and depth of burn injuries

• Always gain pertinent PMH → important to get tetanus status (usually give vaccination regardless of status for prevention because of higher risk)

• Consider NG tube for > 20% total body surface area partial thickness burns due to risk of ileus

• Labs based on type and severity of burn

  • CBC (anemia)

  • BMP

  • ABG (inhalation/airway burn)

  • Carboxyhemoglobin

  • Serum creatinine kinase (partial and full thickness: worried about rhabdomyolysis)

  • Urinalysis for myoglobin (monitor end organ injuries and break down of tissues)

• Imaging:

  • CXR (additional if indicated)

  • Fiberoptic bronchoscopy indicated for suspected inhalation injury (consider in intubated patient since it’s both diagnostic and therapeutic)

  • EKG

ED Management of Pregnant Patients

• Significant morbidity to mother and fetus

• Outcome of pregnancy determined by extent of injury to mother

• Spontaneous termination common in large body surface area burns

• Resuscitation requirements may be higher

• Should have fetal monitoring and early OB consultation

• Consider sending to burn center

Fluid Resuscitation

• WILL NEED TO CALCULATE ON EXAM

• Should be guided by monitoring cardiorespiratory status and urine output → trumps any calculated formula

  • Patients with thermal injuries and concomitant multisystem trauma or those with inhalation injuries → more than calculated fluid needs

  • Electrical injuries, incineration burns, associated crush injuries, and severe burns (involvement > 48%) → may produce rhabdomyolysis and myoglobinuria → renal failure (can prevent with dilution: need more volume)

• Most commonly used formula → Parkland formula

  • Total fluid in 24 hours = 4 x weight (kg) x burn percentage

  • Give first half in 8 hours

  • Remainder 16 hours give remaining half

• Fluid of choice → isotonic crystalloid

• Patients with pre-existing cardiac or pulmonary disease need close monitoring to prevent pulmonary edema

• Monitor:

  • Vital signs

  • Cerebral perfusion

  • Skin perfusion

  • Pulmonary status

  • Urine output: should remain between 0.5 and 1.0 mL/kg/hr

Wound Care

• Initially wound should be covered with clean, dry sheet

• Small burns → can be covered with moist saline soaked dressing

  • Best while waiting for admission or transfer

  • Soothing effect of cooling is due to vasoconstrictor in area

  • Stabilizes mast cells and reduces histamine release, kinin formation, and thromboxane B2 production

• Larger burns → sterile drape (saline soaked dressing to large area can cause hypothermia)

Eshcarotomy

• Indicated in circumferential deep burns

  • In the limbs → can cause compromised of distal circulation, especially after initial resuscitation

  • Must monitor distal vascular status

• If vascular compromise evident → eshcarotomy indicated

  • Eschar incised with scalpel at the level of the fat → done on the mid-lateral portion of the limb, avoiding the fascia

  • May extend to hand and fingers

  • Can provoke substantial soft tissue bleeding

• If circumferential burns to chest and neck → may restrict ventilation

  • Incision made along anterior axillary line from level of second rib to level of 12th rib

  • The two incisions should be joined transversely so the chest wall can expand

Pain Control

• Burns are exceedingly painful

  • Superficial burns most painful

  • Cause hyperalgesia → mediated by A fibers

• Local cooling may soothe but do not provide pain control

• Preferred treatment → IV opiates

  • +/- anxiolytics

Care of Minor Burns

• Minor burns typically qualify for ambulatory care

  • Should be:

    • Isolated

    • Not cross joints

    • Be circumferential

  • Should not meet burn center criteria

• Care should be given to:

  • Patient extreme age

  • Patient with significant comorbidities

  • Patients with challenging social situations

  • Patients with inadequate pain control

• Principles

  • Clean burns with mild soap and water

  • Debride ruptured blister and large intact blisters (small blisters can be left intact)

  • Tetanus immunization should be assessed

  • Topical antibiotics are important in reducing bacterial colonization and enhance rate of healing

  • Dressing should be changed twice daily for as long as wound continues to weep and then → daily until healing is complete

• Must discharge patients with:

  • Appropriate wound care instructions

  • Adequate pain control

  • Coordination of outpatient follow up

Inhalation Injuries

• Becoming main cause of mortality in burn patients

• Associated with closed space fire/conditions that decrease mentation (overdose, alcohol intoxication, drug use, head injury)

Inhalation Injury Mechanism

• Thermal injury commonly limited to upper airway

  • Below the level of vocal cords → occurs more in steam inhalation

• Damages endothelial cells, produces mucosal edema of small airways, decreases alveolar surfactant activity

  • Bronchospasm

  • Airflow obstruction

  • Atelectasis

  • Upper airway edema can occur rapidly

  • Lower airway edema may not be clinically evident for 24 hours

  • Over time → tracheal and bronchial epithelial sloughing

• About 50% of intubated burn patients → ARDS

Inhalation Injury Diagnosis

• Diagnosis made from history

• Physical exam

  • Facial burns

  • Singed nasal hair

  • Soot in mouth/nose

  • Hoarseness

  • Carbonaceous sputum

  • Expiratory wheezing

• Labs

  • No single method of labs preferred

  • Arterial carboxyhemoglobin → can document prolonged exposure to products of incomplete combustion

• Imaging

  • CXR: may be normal initially

  • Bronchoscopy: may be useful in evaluating extent of injury

Inhalation Injury Treatment

• Treat suspected inhalation prior to definitive diagnosis

  • Humidified oxygen by face mask

  • Control upper airway with prompt endotracheal intubation

    • Full thickness burns of face or peri-oral region

    • Circumferential neck burns

    • Acute respiratory distress

    • Progressive hoarseness or air hunger

    • Respiratory depression or altered mental status

    • Supraglottic edema and inflammation on bronchoscopy

  • Fluids: careful fluid resuscitation guided by hemodynamically monitoring to prevent pulmonary edema and ARDS

Chemical Burns Epidemiology

• Most exposures occur occupationally

• Morbidity and mortality are high

Chemical Burns Pathophysiology

• Outer stratum corneum layer of skin functions as barrier → some chemicals can penetrate and produce burns, dermatitis, allergic reactions, thermal injuries, and systemic toxicity

• Most chemical burns caused by acids or alkalis

  • Acids tend to cause coagulation necrosis with protein precipitation → tough/leathery eschar → limits deeper penetration of agent

  • Alkalis produce liquefaction necrosis and saponification of lipids → poor barrier to chemical penetration allowing deeper burns and persistent tissue injury

• Multiple factors influence tissue damage and percutaneous absorption of chemicals

  • Duration of contact

  • Concentration of agent

  • Quantity of agent

  • Mechanism of action

  • Extent penetration

• Death early after severe chemical burns is related to hypotension, acute renal failure, and hypovolemic shock (can be from systemic toxicity if agent is absorbed)

• If there is systemic absorption → acidosis, hypotension, hyperkalemia, dysrhythmia, shock

Chemical Burn Treatment

• Initial goal → remove patient from exposure and prevent further exposure

• Aggressive large volume irrigation with water

  • Should be started immediately at scene of accident → chemicals will continue damaging tissue until removed or deactivated and can decrease exothermic reactions

  • Amount of time to initial dilution or removal of chemical is directly related to eventual depth and degree of injury

  • Severe alkali burns require several hours of irrigation → pH indicator should be used to check for continued presence of agent in wound and should continue irrigation until pH is normal

• Dry chemicals should be brushed away before irrigation

• Some chemicals can react with water (sodium metals) → should be covered with mineral oil or excised before irrigation

• Once irrigation is complete:

  • Debride any remaining particles and devitalized tissue

  • Apply topical antimicrobial agent

  • Tetanus immunization as needed

  • Remaining treatment similar to thermal burns

Acid Burns

• Perform complete exam of patients with significant acid burns

  • Can also have respiratory and mucous membrane irritation and skin absorption can result in systemic illness

• Most strong acids (other than hydrofluoric acid) produce coagulation necrosis → denaturation of proteins in superficial tissues

• Most strong corrosives have pH < 2

• Most important chemical burn feature that can be altered by healthcare providers → contact time with skin

Alkali Burns

• Penetrate skin deeper and longer than acids → presents greater danger of toxicity from systemic absorption

• Wound may initially appear superficial → becomes full thickness burn in 2-3 days

• Combines with protein and lipids in tissue → forms soluble protein complexes/soaps → permits passage of hydroxyl ions deep into tissues

• Often have production of soft, gelatinous, friable, brownish eschar

• Strong alkalies have pH > 12

Electrical Burns Epidemiology

• Types

  • High voltage: > 1,000 V

  • Low voltage: < 1,000 V

Electrical Burns Pathophysiology

• Conductors: materials that allow electrical flow easily

• Insulators: materials that do not allow electrical flow

• Tissue/Organ properties

  • Tissue with high fluid and electrolyte content → conduct better than tissue with less

  • Bone: highest resistance

  • Nerves and vascular: low resistance

  • Dry skin: high resistance

  • Wet-sweaty skin: less resistance

• For current to flow through person → complete circuit needs to be created

  • Current flows through person from one contact area to the other in parallel paths

Electrical Burns Physiologic Effects

• Physiologic effects of electric shock related to: amount, duration, and type of current (AC vs DC)

  • AC: standard household electricity

  • DC: electricity in batteries and lightning

  • Both AC and DC can throw patient away from source → blunt injury

• AC can be more dangerous than DC

  • Alternating currents can cause Vfib

  • AC can produce more muscle tetany → cannot let go of electrical source

Mechanism of Electrical Injury

• Risk of serious and fatal electricity injury increases with voltage → associated with severe MSK, visceral, and nervous system injury

  • Especially > 600 V

  • High voltage defined as > 1,000 V

• Mechanisms

  • Direct tissue damage from electrical energy

  • Tissue damage from thermal injury

  • Mechanical injury from trauma due to fall or muscle contractions

  • Burns more common with high voltage

Clinical Features of Electrical Burns

• Immediate cardiac dysrhythmias

• Respiratory arrest

• Seizures

• Cutaneous burns often seen at electrical contact areas

  • Entry and exit wounds in DC

  • Contact wounds in AC

  • Commonly painless, gray-yellow, and depressed

Electrical Burns Treatment

• Same as thermal burns

• Monitor for cardiac dysrhythmias

• Fluid resuscitation guided by Parkland formula

  • Extensive deep tissue damage may be present even if cutaneous injury is limited → fluid requirements often greater than predicted

Wounds: Principles of Initial Evaluation

• Begin with overall patient assessment

• Remove rings or other jewelry to prevent constricting bands in settings of edema

• Control external bleeding with direct pressure

• Replace skin flaps to avoid exacerbating vascular compromise

• Amputated fingers/extremities should be kept moist and sterile → place in waterproof bag and on ice to preserve for possible reattachment

• Provide some form of anesthesia

Wounds: Risk Assessment

• Obtain pertinent patient history

• Predictive factors for infection → mechanism of injury, depth, location, configuration, contamination

• Determine status tetanus immunization

Keloid Scar

• More common in Black and Asian patients

• Result in production of excess collagen beyond wound barriers

• Should be apart of part of history → any experience may predict poor scar formation

Hypertrophic Scar

• Caused by tissue tension during wound healing

• Scars stay within the original wound boundaries

• Tends to undergo partial spontaneous regression within 1-2 years

Wound Closure Timing

• No clearly defined relationship of time to closure of clinical infection

• Time from injury to presentation is only one element to be considered before deciding on primary vs delayed wound closure

  • Should also consider: mechanism, location, degree of contamination, host risk factors, and cosmetic concern

  • Ex: do not like to close bite wounds immediately because have higher risk of infection and therefore abscess formation

Wound Colonization

• Anatomic location of injury helps to predict clinical outcome both in terms of infection and cosmetic result

• Risk of infection is determined by both baseline bacterial colonization and vascular blood supply

  • Density of bacterial population is low on upper arms, legs, torso

  • Moist areas have higher bacterial populations, including anaerobes

• Wounds on highly vascular areas → less likely to be infected

Role of Imaging in Wounds

• Most lacerations do not require imaging

• Wounds with concern for foreign bodies can be imaged

  • Most foreign bodies are much denser → can be seen on X-ray

• CT and MRI → useful for identifying and locating object with similar density to tissue

• U/S may be helpful but limited in small fragments

Wound Preparation

• Wound preparation → aimed at reducing risk of infection, improving cosmetic outcomes, and minimizing pain/discomfort

  • Try to reposition joint to position assumed during injury to better reconstruct mechanism

• Full sterile technique not required

  • Most lacerations can be repaired with clean non-sterile gloves

• Disinfect skin with Chlorhexidine

• Wound anesthesia

  • Most wounds require some form to allow for examination, irrigation, debridement, and repair

  • Specific choice and route determined by: size, location, patient condition

    • Most common local → lidocaine

    • Can consider anxiolysis

    • General anesthesia for severe wounds/sensitive areas

Wound Irrigation

• High pressure irrigation in heavily contaminated

• Should irrigate with at least 50-100 cc of fluid: tap water as effective as normal saline

Wound Debridement

• Devitalized, nonviable tissue increases risk of infection and poor cosmesis

• Remove any non-viable tissue and imbedded foreign bodies → reduces bacterial burden in traumatic wounds

• Can be done using scalpel or fine scissors

Wound Closure

• Can be closed by:

  • Sutures

  • Staples → better for head wounds

  • Adhesive tapes

  • Tissue adhesives

  • Hair apposition

Sutures

• In the ED: the choice between adsorbable and non-adsorbable material for percutaneous sutures is clinically irrelevant

• Larger diameter material produces more damage to tissue and leaves larger holes → should use thinner material when possible

  • Lower number → higher diameter → bigger hole

Sutures: Non-adsorbable

• Retain tensile strength for at least 60 days

• Most often used to close outermost layer of skin or repair tendons

• Avoid deep vascularized tissue → have to go back in to remove, which can cause more damage

• Origin and structure

  • Monofilament: preferred for non-adsorbable

  • Polybutester: can elongate which can be useful if wound edema is anticipated

  • Nylon and polypropylene: cannot expand and may lacerate wound edges if tissues swell

Sutures: Adsorbable

• Lose their tensile strength in < 60 days

• Better for deep structures and high tension wounds

• Have many different types (do not need to know the different types)

Timing of How Long Sutures Stay In

Should know that there are recommendations but do not need to know specific recommendations

Wound Dressing

• Sutured or stapled lacerations can be covered with protective non-adherent dressing for 24-48 hours

• Maintain moist environment to increase rate of re-epitheliazation (occluded wounds heal faster than those exposed to air)

• Topical antibiotic creams can be used to maintain moist environments → should not be used if tissue adhesives used because it can prematurely break adhesive

Prophylactic Antibiotics

• Not recommended except for select circumstances

  • Human bites

  • Cat bites

  • Deep dog bites

  • Bite wounds to hand

  • Open fractures

  • Wounds that expose joints/tendons

• Compulsive wound cleaning is far more important to reduce post repair infection

• Bite wounds → Augmentin

• Uncomplicated → cefalexin

Tetanus Recommendations

Mammalian Bites

• Most bites in ED from domestic dog or cat

• Complications

  • Mechanical injury from bite itself

  • Local bacterial infection

  • Systemic infection or illness

• In most animal bite wounds, there is isolated soft tissue injury → wound management and prevention of infection are key issues

• Some bites can undergo primary repair → increased risk of post repair wound infection

  • Should give prophylaxis with Augmentin

• Non-closure or delayed primary closure is applicable for management of contaminated bite injuries, especially areas other than face

Wounds with Highest Risk of Infection

Cat and Dog Bites

• Most dog bite wounds are relatively superficial → may not need antibiotics

• Up to 50% of cat bites will become infected if not treated due to sharper teeth and deeper wounds

• Should use prophylactic antibiotics on higher risk uninfected wounds

  • All cat bites

  • Immunocompromised patients

  • Dog bite puncture wounds

  • Hand wounds

  • Wounds undergoing surgical repair

Human Bites

• More serious than domestic animals

  • HSV can cause herpetic whitlow after human bite with infected saliva

• Usually polymicrobial → most commonly staph and strep

  • Adequate initial agent → cephalexin or can also use Augmentin

• Prophylaxis should be considered after all but trivial human bites