Burns

Types of Burn Injury

• Thermal Burns• Chemical Burns• Smoke Inhalation Injury• Electrical Burns• Cold Thermal Injury

Types of Burn InjuryThermal Burns

• Caused by flame, flash, scald, or contact with hot objects

• Most common type of burn

Full-Thickness Thermal Burn

Fig. 24-1, A

Partial-Thickness Burn to the Hand

Fig. 24-1, B

Partial-Thickness Burns Due to Immersion in Hot Water

Fig. 24-1, C

Types of Burn InjuryChemical Burns

• Result from tissue injury and destruction from necrotizing substances • Most commonly caused by acids• Respiratory & systemic problems• Eye injuries• Tissue destruction may continue for up to 72 hrs after

injury

Types of Burn InjurySmoke Inhalation Injuries

• Result from inhalation of hot air or noxious chemicals • Cause damage to respiratory tract• Important determinant of mortality in fire victims CO poisoning Inhalation injury

Types of Burn Injury Smoke Inhalation Injuries

Carbon monoxide (CO) poisoning• CO is produced by the incomplete combustion of burning materials• Inhaled CO displaces oxygen

Types of Burn InjuryElectrical Burns

• Result from coagulation necrosis caused by intense heat generated from an electrical current• May result from direct damage to nerves and vessels causing tissue anoxia and death

Electrical Burn- Hand

Fig. 24-2, A

Electrical Burn- Back

Fig. 24-2, B

Types of Burn Injury Electrical Burns

• Severity of injury depends on the amount of voltage, tissue resistance, current pathways, surface area, and on the length of time of the flow

Types of Burn Injury Electrical Burns

• Electrical sparks may ignite the patient’s clothing, causing a combination of thermal and electrical injury

Types of Burn Injury Cold Thermal Injury

• Frostbite

Classification of Burn Injury

• Severity of injury is determined by- Depth of burn- Extent of burn - Location of burn- Patient risk factors

Classification of Burn InjuryBurn Injury

- In the past, burns were defined by degrees:

• First-degree, second-degree, and third- degree burns

Cross Section of Skin

Fig. 24-3

Classification of Burn InjuryDepth of Burn

- Burns now classified according to depth of skin destruction: • Partial-thickness burn • Full-thickness burn

Classification of Burn InjuryDepth of Burn

- Superficial partial thickness • Involves the epidermis- Deep partial thickness • Involves the dermis- Full thickness • Involves fat, muscle, bone

Partial Thickness (Superficial)

• Redness• Pain• Moderate to severe tenderness• Minimal oedema• Blanching with pressure

Superficial Burns

Partial Thickness Burns

Partial-Thickness (Deep)

• Moist blebs, blisters• Mottled white, pink to cherry red• Hypersensitive to touch or air• Moderate to severe pain• Blanching with pressure

Partial Thickness Burns

Full-Thickness

• Dry, leathery eschar• White, waxy, dark brown or charred

appearance• Strong burn odour• Impaired sensation when touched• Absence of pain with severe pain in

surrounding tissues• Lack of blanching with pressure

Full Thickness Burns

Full Thickness Burns

Full Thickness Burns

Partial & Full Thickness Burns

Classification of Burn InjuryExtent of Burn

- Two commonly used guides for determining the total body surface area:

• Lund-Browder chart • Rule of nines

Lund-Browder Chart

Fig. 24-4, A

Rule of Nines Chart

Fig. 24-4, B

Classification of Burn InjuryLocation of Burn

Location of the burn is related to the severity of the injury:– Face, neck, chest → respiratory

obstruction

– Hands, feet, joints, and eyes → self-care

– Ears, nose → infection

Classification of Burn InjuryLocation of Burn

- Circumferential burns of the extremities can cause circulatory compromise

- Patients may also develop compartment syndrome

Circumferential Burns

Classification of Burn Injury Patient Risk Factors

• Older adults heal more slowly than young adults• Preexisting cardiovascular, respiratory, renal disease• Diabetes mellitus• Alcoholism• Drug abuse• Malnutrition• Concurrent fractures, head injuries, or other trauma

Emergent Phase

• Emergent phase is the period of time required to resolve the immediate problems resulting from burn injury• From burn onset to 5 or more days• Usually lasts 24 to 48 hours • The phase begins with fluid loss and edema formation and continues until fluid mobilization

and diuresis begin

Emergent PhasePathophysiology

• Fluid and Electrolyte Shifts- Greatest threat is hypovolaemic shock,

caused by a massive shift of fluids out of blood vessels as a result of increased capillary permeability

Conditions Leading to Burn Shock

Fig. 24-5

Emergent PhasePathophysiology

• Fluid and Electrolyte Shifts- The net result of the fluid shift is

intravascular volume depletion • Oedema

• ↓ Blood pressure

• ↑ Pulse

Emergent PhasePathophysiology

• Fluid and Electrolyte Shifts- Normal insensible loss: 30 to 50 ml per

hour- Severely burned patient: 200 to 400 ml per

hour

Emergent PhasePathophysiology

• Fluid and Electrolyte Shifts- RBCs are haemolyzed by a circulating

factor released at the time of the burn- Thrombosis- Elevated haematocrit

Emergent PhasePathophysiology

• Fluid and Electrolyte Shifts- Na+ shifts to the interstitial spaces and

remains until oedema formation ceases- K+ shift develops because injured cells and haemolyzed RBCs release K+ into

extracellular spaces

Effects of Burn Shock

Fig. 24-6

Emergent PhaseClinical Manifestations

• Shock from pain and hypovolaemia• Blisters• Adynamic ileus• Shivering• Altered mental status

Debriding Full-Thickness Burn

Fig. 24-9

Acute Phase

• The acute phase begins with the mobilizationof extracellular fluid and subsequent diuresis

• The acute phase is concluded when the burnedarea is completely covered by skin grafts orwhen the wounds are healed

Acute PhasePathophysiology

• Diuresis from fluid mobilization occurs, andthe patient is no longer grossly edematous

• Bowel sounds return• Healing begins when WBCs have surrounded

the burn wound and phagocytosis occurs

Surgeon Harvesting Skin

Fig. 24-11, A

Donor Site After Harvesting

Fig. 24-11, B

Healed Donor Sites

Fig. 24-11, C

Healed Split-Thickness Skin Graft

Fig. 24-11, D

Application of Cultured Epithelial Autograft

Fig. 24-12, A

Healed Cultured Epithelial Autograft

Fig. 24-12, B

Escharotomy of the Lower Extremity

Fig. 24-7

Acute PhaseComplications

• Infection- Localized inflammation, induration, and suppuration- Partial-thickness burns can become full- thickness wounds in the presence of

infection

Contracture of the Axilla

Fig. 24-13

Contractures

Rehabilitation Phase

• The rehabilitation phase is defined asbeginning when the patient’s burn wounds arecovered with skin or healed and the patient isable to resume a level of self-care activity