Burn Injuries

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Burn Classification & Extent - Sizzling Start

  • Depth:
    • 1st: Epidermis; red, pain.
    • 2nd (Partial): Dermis; blisters (superficial), mottled/less pain (deep).
    • 3rd (Full): All layers; leathery, insensate.
    • 4th: Muscle/bone.
  • Extent (TBSA):
    • Rule of Nines (Adults): 📌 Multiples of 9! Head 9%, Arm 9%, Leg 18%, Trunk (Ant/Post) 18% each, Perineum 1%.
    • Lund-Browder: Accurate for children.
    • Palm Method: Palm ≈ 1% TBSA. Rule of Nines for Adult Burn Assessment

⭐ In children, head TBSA is larger (e.g., infant 18% vs adult 9%); Lund-Browder is key.

Burn Etiology & Patterns - Fiery Foes

  • Thermal Burns:
    • Dry Heat (Flame): Deep, charring, soot, singed hairs.
    • Moist Heat (Scalds): Sharply demarcated, "tide mark", "zebra stripes"; often superficial.
    • Contact: Mirror image of hot object.
  • Chemical Burns:
    • Acids: Coagulative necrosis (e.g., $H_2SO_4$ - black, $HNO_3$ - yellow).
    • Alkalis: Liquefactive necrosis, deeper penetration, soapy feel.
  • Electrical Burns:
    • Entry (dry, grey-white, depressed) & Exit (everted, may be larger).
    • "Joule burn" (internal heating).
  • Radiation Burns: UV, X-rays, nuclear. Delayed onset.
  • Lightning: Characteristic "Arborescent" or "Filigree" (Lichtenberg) figures.

Alkali burns are generally more severe than acid burns due to deeper tissue penetration via liquefactive necrosis.

Pathophysiology & Complications - Systemic Storm

Systemic effects of severe burns diagram

  • Initial Cascade: Burn → massive release of inflammatory mediators (cytokines, histamine).
    • Causes ↑ capillary permeability → significant plasma loss, third spacing, and edema.
  • Burn Shock: Primarily hypovolemic; develops rapidly.
    • Leads to ↓ cardiac output, ↓ organ perfusion. Max edema by 24-48 hrs.
  • Systemic Effects:
    • SIRS (Systemic Inflammatory Response Syndrome) is common.
    • Intense hypermetabolic state: ↑BMR, catabolism, high O₂ demand.
    • Profound immunosuppression: ↑ susceptibility to infections.

⭐ Sepsis is the leading cause of death in burn patients after the initial 24-48 hours resuscitation period.

Forensic Autopsy in Burns - Charred Clues

  • Key Objectives: Determine if burns antemortem/postmortem, cause of death, identity.
  • Antemortem Burn Indicators (Vital Signs):
    • Soot in Airways: Trachea, bronchi; indicates breathing during fire.
    • Carboxyhemoglobin (COHb): Levels > 20-50% for significant exposure; cherry-red discoloration of tissues/blood.
    • Vital Reaction: Blisters with albuminous fluid, red line of demarcation.
  • Postmortem Burn Features:
    • Absence of soot in deep airways.
    • No significant COHb elevation.
    • Blisters without inflammation, easily rubbed off.
  • Other Significant Findings:
    • Pugilistic Attitude: Flexion of limbs due to heat-induced muscle coagulation (not a sign of struggle).
    • Heat Hematoma: Epidural, brick-red/chocolate-colored, honeycomb appearance (vs. traumatic hematoma).
    • Heat ruptures/splits in skin.

⭐ Modern forensic practice emphasizes multidisciplinary approach including advanced imaging (PMCT), toxicological analysis, and genetic analysis alongside soot deposition in deep airways to differentiate antemortem from postmortem burns.

  • Internal Examination: Assess for visceral injuries, pre-existing diseases, toxic substances (e.g., cyanide).

High‑Yield Points - ⚡ Biggest Takeaways

  • Rule of Nines (adults) & Lund-Browder chart (children) for TBSA estimation.
  • Pugilistic attitude: Post-mortem heat artifact, not a sign of struggle.
  • Cherry-red tissues: Indicate CO poisoning in fire victims.
  • Soot in airways: Vital sign, proves victim was alive during fire.
  • Heat hematoma: Post-mortem epidural artifact, not true antemortem hemorrhage.
  • Scalds show clear margins, trickling; flame burns have singed hair, soot.
  • Burn degrees impact prognosis; shock & sepsis are key complications.

Practice Questions: Burn Injuries

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Burns present as all the following EXCEPT

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Flashcards: Burn Injuries

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No vital reaction is seen in a(n) _____-mortem wound

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No vital reaction is seen in a(n) _____-mortem wound

Post (Ante/Post)

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