Degree
Involves
Presentation
1st (superficial)
Epidermis only
Similar to sunburn; localized, painful, dry, blanching redness with no blisters
2nd (superficial partial thickness)
All of the epidermis and some dermis
Painful, swollen, warm, mottled areas with blisters
2nd (deep partial thickness)
All of the epidermis and some dermis
Painless, warm, white, mottled areas with blisters that appear to have open weeping surfaces
3rd (full thickness)
All of the skin (epidermis and dermis)
Painless, white, dry, leathery, and do not blanch with pressure
4th
All of the skin and underlying bone, tendon, adipose, or muscle
Similar to third degree; disfiguring
Watch Out
The presence of pain is an easy way to differentiate superficial partial-thickness burns (with pain) from deep partial-thickness burns (without pain).
What Are the Risk Factors for Burn Injuries?
Extremes of age, alcohol or substance abuse, smoking, violence, and low socioeconomic status.
How Does One Determine the Severity of a Burn Injury?
Calculating the total body surface area (TBSA) affected by second- or third-degree burns will allow one to determine the severity of a patient’s burn injuries. This can be approximated using the rule of nines (Fig. 46.1). The body is divided into regions whose surface areas are multiples of nine: head, 9 %; each arm, 9 %; anterior torso, 18 %; posterior torso, 18 %; each leg, 18 %.
Fig. 46.1
Rule of 9s in adults
Watch Out
In areas of patchy involvement, the clinician can use his/her palm to estimate the surface area of the burn. The adult palm represents ~ 1% body surface area.
What Are the Criteria for Transferring the Patient to a Burn Center?
2nd- or 3rd-degree burns > 10 % TBSA in patients <10 or > 50 years of age
2nd- and 3rd-degree burns >20 % TBSA in all patients
2nd- and 3rd-degree burns involving the hands, face, feet, genitalia, perineum, or skin overlying major joints
Electrical and chemical burns
Concomitant inhalational injury
Significant preexisting medical conditions
Suspected child abuse or neglect
What Is the Significance of Carbonaceous Sputum?
Carbonaceous sputum indicates possible inhalational injury. A high degree of suspicion should be held for patients suffering burn injuries within enclosed areas with signs of significant facial burns, change in voice quality, singed nasal hairs, or carbonaceous sputum. There are three components of inhalational injury: upper airway edema, acute respiratory failure (secondary to a chemical pneumonitis from the products of combustion), and carbon monoxide poisoning.
What Is the Significance of Cherry-Red Skin in a Patient Rescued from a House Fire?
This is a classic sign for carbon monoxide (CO) poisoning and typically occurs in patients that were exposed to smoke from house fires or the exhaust from a running car or gas heater. Patients initially present with headaches and other nonspecific constitutional symptoms such as nausea and dizziness. If severe or left untreated, CO poisoning may progress to seizures, coma, and multiorgan failure, and death.
What Is the Significance of a Second-Degree Burn That Progresses to a Third-Degree Burn While in the Hospital?
This is concerning for a burn wound sepsis. Other things to look for include a discolored burn, eschar with green pigment, black necrotic skin, skin separation, and signs of sepsis. Fever is not always reliable since the body’s primary temperature regulator, the skin, is often compromised in burn victims (discussed in Pathophysiology). The diagnosis of burn wound sepsis is based upon the bacterial concentration per gram of tissue in the burn wound or eschar. The finding of >105 bacteria/g of tissue on quantitative analysis is highly suggestive of burn wound sepsis.
What Is the Significance of a Circumferential Burn in the Extremity? How About If on the Chest?
Circumferential full-thickness burns in the extremity significantly increase the risk of developing compartment syndrome. Burn patients with circumferential extremity full-thickness burns with evidence of compromised distal perfusion should undergo escharotomy. Circumferential burns of the chest can compromise a patient’s respiratory efforts due to the inflexible eschar and underlying tissue edema which can prevent chest wall motion and, thus, limit ventilation. These patients should also be considered for escharotomy.
What Population of Patients Has the Highest Morbidity from Burn Injuries?
Children and the elderly
What Other Risk Factors Are Associated With Increased Mortality in Burn Patients?
Greater than 40 % non-superficial TBSA, inhalational injury.
Pathophysiology
What are the Different Causes of Burns?
Cause | Comments |
|---|---|
Thermal | Most common cause of burn injuries is scalding, typically from hot water |
Chemical | Alkali burns are more damaging than acidic burns owing to their ability to penetrate tissues more deeply; acidic burns cause coagulation necrosis whereas alkali burns cause liquefactive necrosis |
Electrical | Immediate life-threatening complication is cardiac arrhythmia; injuries are oftentimes out of proportion to the size of the external burn wound; patients may also develop muscle necrosis, posterior shoulder dislocations, myoglobinuria, and renal failure |
