Thermal Injuries

On this page

Burn Basics - Sparking Knowledge

  • Definition: Tissue injury: thermal, chemical, electrical, radiation.
  • Types:
    • Thermal: Scalds, flame, contact.
    • Chemical: Acids (coagulation necrosis); Alkalis (liquefaction necrosis - severe).
    • Electrical: Entry/exit wounds; cardiac risk.
  • Burn Depth (Degrees):
    • 1st (Superficial): Epidermis. Red, painful.
    • 2nd (Partial Thickness): Dermis.
      • Superficial: Blisters, very painful.
      • Deep: Mottled, ↓ pain, scars.
    • 3rd (Full Thickness): All layers. Leathery, insensate. Grafting.
    • 4th: To muscle/bone.
  • Severity (TBSA %):
    • Rule of Nines (Adults): Head/Neck 9%, Arm 9% (each), Leg 18% (each), Ant. Trunk 18%, Post. Trunk 18%, Perineum 1%.
    • Lund-Browder Chart: For children.
    • Palm Method: Patient's palm ≈ 1% TBSA. Rule of Nines and Lund-Browder Chart

⭐ Inhalation injury (facial burns, sooty sputum) ↑ mortality in burns.

Body's Inferno - Systemic Sizzle

  • Burn Shock:
    • Patho: ↑ Capillary permeability → hypovolemia (fluid loss).
    • Maximal edema: 24-48 hrs.
    • Phases: "Ebb" (↓metabolism, 0-48h), "Flow" (↑hypermetabolism).
  • SIRS & MODS:
    • Cytokines (TNF-α, IL-1, IL-6) → systemic inflammation, MODS.
  • Metabolic Derangements:
    • Hypermetabolism: ↑ Catecholamines, cortisol. RME ↑ up to 100%.
    • ↑ Protein catabolism, hyperglycemia, insulin resistance.
  • Inhalation Injury: Major mortality cause.
    • Upper airway: Thermal edema.
    • Lower airway/Parenchymal: Chemical pneumonitis (smoke) → ARDS.
    • Systemic: CO poisoning (carboxyhemoglobin >10-15% symptomatic, >20% toxic), Cyanide.
    • Signs: Facial burns, singed nasal hairs, soot, hoarseness.
  • Complications:
    • Immunosuppression → Sepsis (Pseudomonas aeruginosa).
    • Renal: ATN (hypoperfusion/myoglobinuria).

    ⭐ Curling's ulcer: Stress ulcer (stomach/duodenum) post-severe burns.

    • Hematologic: Anemia, coagulopathy. Systemic Complications of Severe Burns

Postmortem Puzzles - After the Ashes

  • Antemortem (AM) vs. Postmortem (PM) Burns:
    • Vital Reactions: Redness, blisters (albumin-rich), pus, inflammatory line in AM. Absent in PM.
    • Soot in Airway: In trachea/bronchi indicates AM burning.
    • COHb Levels: ↑ (>10%) suggests AM smoke inhalation.

      ⭐ Cherry-red discoloration of tissues/blood indicates CO poisoning (COHb >20-30%), a vital sign in fire victims.

  • Pugilistic Attitude:
    • Boxer's stance from heat-induced muscle coagulation.
    • Occurs in both AM & PM burns; not a sign of struggle.
  • Heat Ruptures:
    • Irregular skin splits, everted edges, no hemorrhage.
    • Differentiate from AM wounds.
  • Heat Hematoma: Epidural, brick-red, honeycomb appearance; heat-induced, not trauma.
  • Crow's Feet Sign: Spared wrinkles at eye corners; eyes closed during AM burn.

Pugilistic attitude in burn victim with PMCT

Special Cases - Shocking & Scalding

  • Scalds (Hot Liquids/Steam)
    • Patterns: glove & stocking, tide marks, zebra stripes (clothing folds), splash/drip.
    • Immersion: sharp demarcation.
  • Electrical Injuries
    • Joule burn: internal heating ($H = I^2Rt$).
    • AC: more dangerous; tetany ("no-let-go"); Ventricular Fibrillation (VF) at ~25-100 mA.
    • DC: single convulsion; asystole at >300 mA.
    • Entry: small, pale, depressed, charred center.
    • Exit: larger, everted, "exploded". Electrical burn entry and exit wounds on hand
  • Lightning Injuries
    • Lichtenberg figures (ferning): pathognomonic, transient.
    • TM rupture, cataracts, keraunoparalysis.

    ⭐ Lichtenberg figures are pathognomonic for lightning strikes, not true burns, and fade within 24 hours.

High‑Yield Points - ⚡ Biggest Takeaways

  • Rule of Nines estimates adult TBSA; Lund-Browder chart for children.
  • Soot in airways and elevated carboxyhemoglobin (>10%) are vital signs of antemortem burns.
  • Pugilistic attitude is a postmortem heat artifact, not a sign of struggle.
  • Heat hematoma (epidural) is a postmortem artifact, distinct from traumatic hemorrhage.
  • Cherry-red discoloration suggests CO poisoning; >50-60% COHb is often fatal.
  • Scalds show clear demarcation and run-off patterns; flame burns cause singeing of hairs and skin.

Practice Questions: Thermal Injuries

Test your understanding with these related questions

To calculate the initial fluid requirement in a burn patient, the best approach is:

1 of 5

Flashcards: Thermal Injuries

1/4

Post mortem autolysis is carried out by _____

TAP TO REVEAL ANSWER

Post mortem autolysis is carried out by _____

Lysosomes (cellular organelle)

browseSpaceflip

Enjoying this lesson?

Get full access to all lessons, practice questions, and more.

Start Your Free Trial