Pathophysiology of Burns and Smoke Inhalation

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Questions and Answers

What is a key component of nutritional support for burn patients?

Lower calorie intake

Higher protein requirements (correct)

Reduced carbohydrate intake

Increased fluid intake

Which phase of burn care focuses on wound healing and rehabilitation?

Rehabilitation phase (correct)

Resuscitation phase

Curative phase

Acute phase

What is the primary purpose of the Lund and Browder chart in burn assessment?

To assess burn depth

To identify critical burns

To classify burn causes

To calculate burn extent (correct)

What physiological change is commonly associated with smoke inhalation?

Airway edema Signup and view all the answers

Which factor does NOT classify a burn as critical?

Burns from thermal sources Signup and view all the answers

What is the primary function of burn centers?

To manage the care of patients with serious burns Signup and view all the answers

Which phase of burn care focuses on stabilization and prevention of complications?

Resuscitative phase Signup and view all the answers

What is the primary dietary consideration for patients recovering from burns?

Increased caloric intake to support healing Signup and view all the answers

How is the extent of burns typically assessed in adults?

Using the Rule of Nines Signup and view all the answers

Which of the following is a common pathophysiological response to smoke inhalation burns?

Activation of pulmonary alveolar macrophages Signup and view all the answers

What complication is associated with sympathetic nervous system activation in burn patients?

Increase in catabolism Signup and view all the answers

According to the Lund and Browder chart, what percentage of the total body surface area is assigned to the 'Right leg'?

15% Signup and view all the answers

What is a potential consequence of metabolic acidosis in burn patients?

Decreased cellular function Signup and view all the answers

Which factor is NOT considered when assessing the severity of burns?

Type of burn Signup and view all the answers

What distinguishes a third-degree burn from a second-degree burn?

It destroys all skin appendages. Signup and view all the answers

What physiological change is associated with burn injury?

Capillary permeability increase Signup and view all the answers

Which nutritional support is critical for burn patients?

High-caloric intake Signup and view all the answers

What is the main component of burn shock in major burns greater than 30% TBSA?

Myocardial depressant factor Signup and view all the answers

Which condition can result from the pathophysiology of smoke inhalation?

Hyperkalemia Signup and view all the answers

What does the zone of stasis in burn injuries represent?

Tissue with reversible damage Signup and view all the answers

Which type of burn is characterized by blisters and severe pain?

Second-degree superficial burn Signup and view all the answers

Study Notes

Sympathetic Nervous System Activation

Release of adrenal corticoid hormones and catecholamines increases blood pressure
Peripheral vasoconstriction occurs
Tachycardia is present
Hyperglycemia develops
Increased catabolism increases the risk of Curling's ulcer
Afterload increases
Cardiac output increases
Risk of acute renal failure and ileus increases
Metabolism increases after burn shock resolves

Tissue Perfusion

Reduced renal and Gl blood flow occurs
Anaerobic metabolism leads to metabolic acidosis
Tissue damage and potential necrosis can occur
Cellular dysfunction leads to cell swelling

Pathophysiology of Smoke Inhalation Burns

Activated pulmonary alveolar macrophages release chemotactic factors
Chemotactic factors cause neutrophil aggregation and activation
Neutrophils release oxygen radicals and proteases
Thromboxane released from the lungs increases pulmonary artery pressure
Tracheobronchial epithelial injury results in exudate case formation and small airway obstruction
Atelectasis and air trapping can occur
Increased pulmonary endothelial permeability causes pulmonary edema
Pneumonia and pulmonary fibrosis can develop

Burn Extent

The Rule of Nines is used to estimate burn size in adults
Palm size can be used to estimate small, scattered burns
The Rule of Five is used to estimate burn size in pediatric patients
The Lund and Browder Rule is a more accurate method for estimating burn size, especially in children

The Rules of Nines

Head: 9%
Neck: 9%
Anterior Trunk:18%
Posterior Trunk: 18%
Right Arm: 9%
Left Arm: 9%
Buttocks: 1%
Genitalia: 1%
Right Leg: 18%
Left Leg: 18%

Lund and Browder Chart

REGION	PT %	FT %
Head	4.5%	4.5%
Neck	9%	9%
Ant.trunk	13	13
Post.trunk	13	13
Right arm	9	9
Left arm	9	9
Buttocks	1.5%	1.5%
Genitalia	1	1
Right leg	15	15
Left leg	15	15

Burn Centers

Burn centers are specialized facilities with highly trained healthcare professionals dedicated to managing severe burn injuries

Burn Severity

Burns can be classified as minor, moderate, or severe
Severity depends on the temperature and duration of exposure, location, extent, and the patient's age and medical condition

Burn Depth

Burns are also classified by depth of tissue damage
Superficial (first degree): involves only the epidermis
Partial thickness (second degree): involves the epidermis and dermis
Full thickness (third degree): involves the epidermis, dermis, and subcutaneous layers

Burn Depth Classification

Depth	Histology	Appearance	Sensation	Healing
First-degree:	Epidermis only	Erythema; blanches with pressure	Intact; mild to moderate pain	3-6 days without scarring
Second degree: - Superficial	Epidermis and superficial dermis; skin appendages intact	Erythema, blisters, moist, elastic; blanches with pressure	Intact, severe pain	1-3 weeks; scaring unusual
- Deep	Epidermis and most dermis; most skin appendages destroyed	White appearing with erythematous areas, dry, waxy, less elastic; reduced blanching to pressure	Decreased; may be less painful	>3 weeks; often with scarring and contractures
Third-degree:	Epidermis and all of dermis; destruction of all skin appendages	White, charred, tan, thrombosed vessels; dry and leathery, does not blanch	Anesthetic, not painful (although surrounding areas of second-degree burns are painful)	Does not heal; severe scarring and contractures

The Body's Response To a Burn

Burn injuries trigger both local and systemic responses

Clinical Image of Burn Zones

Burn wounds have three zones:
Central necrosis: area of irreversible damage
Zone of stasis: area of potential damage
Zone of hyperemia: area of inflammation and potential recovery

Physiology/Pathophysiology of Burns

Cell lysis and hemolysis release hemoglobin and myoglobin into the urine, leading to hyperkalemia
Increased red blood cell concentration and blood viscosity
Increased capillary permeability causes a shift of sodium, water, and protein from the intravascular to interstitial spaces, leading to a decrease in circulating blood volume (up to 50%)
Hyponatremia and thermo-regulation problems can occur
Inflammation and impaired immune response

Major Burns (>30% TBSA)

Burn shock can develop due to the release of a myocardial depressant factor
Massive stress response is triggered

Inhalation Injury: Smoke Inhalation Suspected In:

Hypoxemia
Unconsciousness in enclosed spaces
Exposure to toxic chemicals
Tracheobronchitis and epithelial fibrin casts
Airway obstruction

Classifications of Burns

Causes of burns can be classified as:
Thermal/scald: caused by hot liquids, solids, or flames
Chemical: caused by contact with corrosive substances
Electrical: caused by electric current
Ionizing radiation: caused by exposure to radiation
Inhalation injury: caused by breathing in smoke or hot gases

Critical Burns

Potential life-threatening, disfiguring and disabling burns require qualified medical and nursing care
Burns from chemicals, electrical sources, or inhalation injury
Full-thickness burns in patients younger than 5 or older than 50
Difficulty breathing, burns around the mouth, head, neck, hands, feet, or genitals
Burns associated with other trauma or diseases

Burn Injury, Plastic & Reconstructive Surgery Management

Burns are a special type of soft tissue injury
They cause physical and psychological damage
Account for about 25% of all soft tissue injuries

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Description

This quiz explores the complex pathophysiological changes that occur due to sympathetic nervous system activation following burns and smoke inhalation. It covers the release of hormones, blood flow alterations, and the impact on various organs and tissues. Understanding these mechanisms is crucial for managing burn injuries effectively.