Physical Therapy: Burn Injuries

Anatomy and Function of Integumentary System

• Skin is the largest organ and first line of defense, weighing over 4-5 kg in the average person.
• Receives roughly one-third of resting cardiac output.
• Thinnest skin is located on eyelids and eardrums, while thickest skin is on palms and soles of feet.

Incidence of Burn Injuries

• An estimated 6 million people seek medical treatment for burns annually worldwide.
• One-third of burn victims are children, with fire and burn injuries being the second leading cause of death in children between 1-4 years and third leading cause of death in children under 19 years.
• Most burn injuries occur in the home, primarily in kitchens and bathrooms.

Skin Anatomy

• Epidermis: avascular outer layer, 0.06-0.6 mm thick, consisting of 5 stratums with three appendages (hair, glands, and nails) within the dermis.
• Dermis: inner layer, 2-4 mm thick, highly vascular with two layers (papillary and reticular dermis) containing blood vessels, oil glands, sweat glands, hair follicles, fat tissue, nerves, and connective tissue.
• Subcutaneous tissue (Hypodermis): supports skin, consisting of adipose tissue and fascia, storing fat for energy, cushioning, and insulation.

First Aid for Burn Injuries

• Chemical burns: flush with cool running water for 20 minutes, remove contaminated clothes, and call for medical assistance.
• Electrical burns: don't touch the injured person if still in contact with the electrical current, turn off the source if possible, and call for medical assistance.

Outpatient Management

• For 1st and 2nd degree burns less than 10% TBSA: blisters should be left intact and dressed with silver sulfadiazine cream, with daily dressing changes.

Initial Emergency (Hospital) Procedures

• Fluid infusion must be started immediately, with NGT insertion to prevent vomiting and aspiration, and urinary catheter to measure urine output.
• Weight should be taken daily.

Extent of Burn (TBSA or BBSA)

• Rule of Nine: divides the integument into areas roughly equivalent to 9% of TBSA, but consistently overestimates the size of a burn injury.
• Lund & Browder chart: considers variations in body surface area distribution with age, more suitable for children under 16 years old.
• Palmar method: uses the area of the palmar surface of the patient's hand to determine burn size, preferred for small burn areas.

Edema and Limb Circumference

• Edema grading: Grade 0+: no pitting edema, Grade 1+: mild pitting edema, Grade 2+: moderate pitting edema, Grade 3+: moderately severe pitting edema, Grade 4+: severe pitting edema.
• Measurement methods: water displacement method, girth measurement, and ring method.

Age-Related Changes in Skin

• Fat loss from subcutaneous tissue causes prominence of bony protuberances in thorax, scapula, trochanters, and knees.
• Loss of fat padding contributes to development of pressure ulcers.
• Collagen and elastin shrink and degenerate, with collagen content decreasing by 1% per year throughout adult life.
• Skin becomes thin, dry, and inelastic, making it susceptible to skin tears.

Burn Injury

• Coagulation destruction of skin or body parts due to thermal, chemical, electrical, irradiation, or atomic causes.
• Etiology of burn injuries includes:
  • Thermal burns
  • Chemical burns (acidic and alkaline)
  • Electrical burns
  • Irradiation burns
  • Atomic burns

Chemical Burns

• Acidic burns: occur when acidic chemicals come into contact with skin, causing coagulation necrosis and limiting tissue damage.
• Alkaline burns: occur when alkaline chemicals denature skin proteins, causing liquefaction necrosis and deeper tissue damage.
• Alkaline burns tend to be more severe than acidic burns.

Electrical Burns

• Occur when electricity flows through the body, causing resistance and systemic effects.
• Signs and symptoms of hypovolemic shock include:
  • Restlessness and anxiety
  • Pale, cold, and clammy skin
  • Temperature below 37°C
  • Weak and rapid pulse
  • Systolic blood pressure
  • Urinary output < 20 mL/hr
  • Urine specific gravity > 1.025
  • Thirst
  • Hematocrit 35
  • Blood urea nitrogen (BUN)

Burn Management and Evaluation

• Evaluation is a continuing process of collecting and organizing relevant information to plan and implement effective treatment.
• Components of evaluation include:
  • Patient demographic data and history
  • Burn severity index (BSI)
  • Edema and limb circumference
  • Sensory assessment
  • Muscle strength assessment
  • Joint range of motion (ROM) assessment
  • Flexibility assessment
  • Mobility and ambulation assessment
  • Endurance assessment
  • Functional activities assessment
  • Neurological and psychological factors assessment

Burn Severity Index (BSI)

• The Abbreviated Burn Severity Index (ABSI) is a five-variable scale to assess burn severity.
• Variables associated with increased mortality rate in burned patients.

Edema and Limb Circumference

• Edema can be assessed by:
  • Observation and comparison to the unaffected limb
  • Palpation to determine type of edema (pitting or non-pitting)
  • Measurement using water displacement, girth measurement, or ring method
• Edema grading:
  • Grade 0+: No pitting edema
  • Grade 1+: Mild pitting edema
  • Grade 2+: Moderate pitting edema
  • Grade 3+: Moderately severe pitting edema
  • Grade 4+: Severe pitting edema

Volumetric Measurement Method

• Gold standard tool for measuring edema
• Utilizes the principle of water displacement discovered by Archimedes
• Disadvantages include:
  • Time-consuming setup
  • Difficulty in moving the equipment
  • Requires specialized equipment
  • Messy and unsuitable for certain patient populations

Nutrition in Burn Recovery

• Patients require a diet high in calories and protein to counteract hypermetabolic response and support growth of healthy tissue.
• Burn patients require fat in the form of lipids, vitamins, and trace minerals.
• Inadequate nutrition can negatively impact immune response, wound healing, metabolic function, and survival.