Thermal Diseases Quiz

Thermal Diseases & Injuries

• Thermal diseases and injuries are caused by a disruption of body temperature control or from external heat
• Normal body temperature is crucial for proper bodily functions
• Examples include heat cramps, heat exhaustion, heatstroke, and hypothermia
• Heat conduction happens via conduction, convection, and radiation
• Different types of burns have unique characteristics and classifications. Classifications include Dupuytren's (1st, 2nd, 3rd, 4th, 5th, 6th) and Wilson's (1st, 2nd, 3rd) classifications.

Introduction

• Medical professionals need basic knowledge to diagnose thermal injuries.
• Knowledge of normal body temperature variations is essential.
• Understanding how air movement affects body heat is crucial.
• Conduction, convection, and radiation are processes through which heat transfer occurs.

Introduction to Thermal Injuries

• Thermal injuries result from a malfunction in the body's temperature control mechanisms or from exposure to external heat.
• Causes include direct burns, corrosive chemicals, electric current, exposure to extreme cold or the use of particular drugs.

Effect of Hypothermia

• Core body temperature drops below 24-32°C
• Recovery becomes unlikely below 26°C
• Skin discoloration (cyanosis) is present in extremities, fingers, toes, nose, and ears.
• Discoloration of large joints and extensor surfaces
• Blistering of the skin
• Myxedema-like facial appearance
• Severe cases may cause acute gastritis, pancreatitis, pulmonary edema, and brain perivascular hemorrhage.
• Low heart rate, low blood pressure, and depressed reflexes are common symptoms.
• Severe hypothermia typically leads to stupor, coma, and possibly death.

Types of Heat Diseases

• Heat Cramps: Muscle spasms due to excessive sodium (Na+) loss in sweat.
• Heat Exhaustion: Gradual peripheral vascular collapse causing symptoms like rapid, weak pulse, low blood pressure, and pale, moist skin.
• Treatment: Move the patient to a cooler environment and address any shock.

Types of Heat Diseases continued

• Heat Stroke: Characterized by dry, hot skin and extremely high body temperature.
• Symptoms may include lack of sweating, rapid breathing, rapid pulse, and altered mental status.

Hyperthermia (Sunstroke/ Heat Stroke)

• Exposure to sun, industries (heat ovens), poorly ventilated environments, and certain drugs can cause malignant hyperthermia
• Heat can damage the heat regulating center in the hypothalamus, disrupting the body's ability to cool itself.
• Extreme elevation in body temperature—above 39°C—without sweating is a critical indicator.
• Other symptoms include rapid breathing, rapid pulse, low blood pressure, watery diarrhea, intense thirst, and chest pain.

Hyperthermia (Heat Stroke) continued

• Severe cases can result in pulmonary edema, haemoptysis (coughing up blood), haematamasis, delirium, stupor, respiratory and cardiac arrest, and death.
• Medico-legal importance is relevant and Post-mortem examination typically doesn't show prolonged cooling.

Classification of Burns

• Dupuytren's classifications (older method) are 1st, 2nd, 3rd, 4th, 5th, and 6th degree.
• Wilson's classifications (newer approach) use 1st, 2nd, and 3rd degree, with more categories further defining the extent of the injury.

Types of Burns (Descriptions)

• 1st degree: Erythema (reddening) of the skin, fully recoverable.
• 2nd degree: Epidermis detaches from the dermis; characteristic blisters, fluid-filled lesions (vesicles).
• 3rd degree: Full-thickness skin damage; nerve endings are destroyed, tissue undergoes massive necrosis, and carbonization might occur.
• 4th degree: Deep burn involving the dermis, subcutaneous tissue, and possibly muscle and bone.
• 5th degree: Burn involving muscles.
• 6th degree: Complete charring and destruction of tissues.

Classification of Burns continued (Wilson's)

• Epidermal: Affecting only the epidermis. 1st & 2nd degree burns (mild to moderate).
• Dermal-epidermal: Affecting the epidermis and dermis, but not including underlying tissues. 3rd & 4th degree burns.
• Deep: Affecting deeper tissues, including skin and underlying tissues. 5th/6th degree burns.

Types of Burns (Examples)

• 2nd degree with blisters: Blistered skin tissue (vesication).
• 3rd degree burn: Severely damaged and charred skin tissue.

Rule of Nines (Wallace)

• Used to estimate the extent of burns, based on percentages of body surface area involved.
• 20% fluid loss is considered significant and serious. 30% to 50% of the body affected is usually fatal.

Types of Burns (Detail)

• Dry burn: Caused by flame or hot objects.
• Wet burn (scald): Caused by hot liquids like steam or boiling water and commonly found in children.
• Chemical burn: Caused by contact with corrosive substances like strong acids or bases (can involve varying degrees of damage, and scarring and disability).
• Electrical burn (electrocution): Caused by high voltage currents.
• Lightning burn: Characterized by electrical pathway damage and potentially fatal.

Electrical Burn (continued)

• High-voltage currents often lead to ventricular fibrillation, or potentially to death.
• An important component is the passage of electrical current, either accidental or suicidal, through bodily tissues.

Post-Mortem Findings for Thermal Injuries

• Pugilistic/boxer attitude: Caused by flexor muscle contractions.
• Skull thermal fractures: Fractures can result from heat exposure.

Thermal Injuries Post-Mortem (continued)

• Heat hematoma: Localized collection of blood in tissues
  • Splits (cuts): Injuries on the flexor surfaces of large joints.
  • Acute tubular necrosis: Damage to the kidney tubules.
  • Soot: Soot presence in trachea & air passages.

Post-Mortem Findings for Thermal Injuries continued

• Cherry-red hypostasis: Possible due to carbon monoxide poisoning.
• Acute ulcers (curling ulcers): Damaged tissues in the digestive tract.
• Heat brain herniation: Damage to the brain tissues.

Differential Diagnosis

• Distinguishing thermal injuries from traumatic injuries to the skull, differentiating in the scalp, skull itself and brain.

Complications of Burns

• Direct complications: Severe tissue damage and death from massive cell necrosis and release of electrolytes (Potassium) leading to cardiac arrest. Severe shock (neurogenic) due to pain and fear. Respiratory death from epiglottis swelling. Injuries to organs like the heart, liver and brain.
• Complications from loss of skin function: Hypovolemic polycythemia (fluid build-up) and potential sepsis (infection).
• Other complications include protein loss, fat emboli (in blood vessels), and gangrene (tissue death).

Medical Tools & Appliances

• Overview of medical equipment used in the examination and treatment of patients with thermal injuries. (Not detailed.)