M.L. aspects of thermal injuries Degree of burn Definition Types of thermal injuries MEDICOLEGAL ASPECTS OF THERMAL INJURIES Old classification Recent classification A thermal injury is a tissue injury resulting from the application of heat in any form to the external or internal surface of the body. First degree burn Epidermal degree 1st & 2nd degree • Dry or simple burn. • Scald or moist burn. • Chemical or corrosive burn. • Electric burn. • Radiation burn. Second degree burn By Third degree burn Dermo - epidermal burn 3rd & 4th degree Fourth degree burn Dr. Doaa Abdel Wahab Lecturer of Forensic Medicine & Clinical Toxicology Fifth degree burn Deep burn 5th & 6th degree Sixth degree burn
M.L. aspects of thermal injuries Dry burn Scald Corrosive Degree Any degree 1st, 3rd, 4th 1st, 2nd & 3rd Air passage Contains soot No soot No soot Eaten Hair Singed Wet Thick, viscid & contains COHb Blood Sodden & bleached Skin Dry & charred Stained & corroded Flame or heated body Cause Steam or hot liquid Corrosive acid or alkali Much disfigurement Less disfigurement Thick with disfigurement Scar Eaten Burnt Wet Clothes From above downward From below upward At & below site of contact Site & spread With mineral acid Present Charring Absent At circumference of burnt area Over burnt area Rarely found Vesicles
M.L. aspects of thermal injuries Factors affecting degree of burn A) Extent of burnt area: is determined by rule of nine of Wallace. B) Depth of burn: The 3rd degree burn is the most serious one. C) Site of burn. Neck, abdominal wall or genitalia are more dangerous than those of the extremities. D) Age E) Sex F) General health.
Immediate causes "within 6 hours“ Neurogenic shock. Associated accidental serious injuries to vital organs. Asphyxia (suffocation). Traumatic asphyxia. M.L. aspects of thermal injuries II) Rapid death "within 6-48 hours”: Causes of death from burn IV) Death after one week: III) Death within 2-7 days: • Secondary oligaemic shock. • Secondary toxaemic shock. • Acute oedema of glottis (in the neck). • Pulmonary fat embolism (burn in a fatty area.( • Supra-renal haemorrhage. • Bronchopneumonia. • Inflammation of serous membranes. • Septicemia. - Tetanus, gangrene and erysipelas.: - Rupture of an acute duodenal ulcer (at 12th day)(curling's ulcer) (stress ulcer): may be due to hypovolaemia causing devitalization of mucous membrane in addition to the absorbed burn toxins which are excreted by the liver into the duodenum. -Liver, kidney or heart damage: cell degeneration and necrosis of these organs due to the effect of burn toxins metabolism.
M.L. aspects of thermal injuries Burn vitality Age of Burn Antemortem burn Postmortem burn Appears immediately Erythema 36 hs 48 hs Line of hyperemia Present Absent Appears 2-3hs Vesicles 1 w 2 ws Presence of COHb Present Vesicles Albuminous fluid rich in chloride Absent absent poor in albumin and chloride Sepsis 2 – 3 days 36 hs Vital reaction Infl., pus healing Nil Superficial slough 1 w Nothing But burn Other causes Cause of death Deep slough 3 ws Sootin URT Present Absent Red Coppery 6 m Scar 2 m
M.L. aspects of thermal injuries Postmortem Picture of Burn Complications of Burn • -Particles of soot are present in the air • passage. • Subcutaneous or subserous peticheal hge • may be present. • Haemoconcentration of blood due to loss • of plasma and cherry red colour of the skin. • - Skull may show thermal fracture "fissure • fracture“. • -The body shows evidence ofantemortem • burnsof various degrees. • The body presents a peculiar attitude; • attitude of defence,boxing or "Pugilistic • attitude". • Crimson red colour of hypostasis. • Generalized visceral congestion and Hge • in the internal organs. Sepsis Deformities Keloidformation
M.L. aspects of thermal injuries • Points of differentiation () thermal & traumatic fracture Traumatic Fracture ThermalFracture The fracture is displaced Postmortem signs of burn The fracture is not displaced The brain is edematous Other postmortem signs of death & associated with contused wound in scalp The brain is shrunken Extradural haematoma fill the space Extradural haematoma doesn’tfill the space
M.L. aspects of thermal injuries Electric burn Factors influencing the effect of electric current Physical Physiological Resistance of body tissue Voltage Humidity Nature of current Pathway of current Anticipation of shock Duration of contact General health
M.L. aspects of thermal injuries Causes of Death Ventricular fibrillation Central Respiratory failure Peripheral Cardiac arrest Cerebral anoxia Electric burn Hyperthermic effect
M.L. aspects of thermal injuries Current Marks P.M. Picture of Electric Burn N / E appearance Microscopic appearance • Rapid onset of rigor mortis • Compression of the stratum corni which • stains deeply with superficial carbonization. • Separation of the cells in the form of slits • (electric channels). • - Elongation of both cells and nuclei. • It is of the same size and shape as the • conductor. • Grayish-white painless areas of aseptic • necrosis. • -They vary from superficial circumscribed • lesions to severe burns with full thickness • tissue necrosis. • Marked hypostasis • Presence of current mark • Internal signs of asphyxia
M.L. aspects of thermal injuries Lightining Lightning syndrome Definition • The electric current is DC not AC. • About 20.000 amperes. • About 100 - 1000 million volts. • - A single flash lasts 1/1000th of a second. Characterized by: Loss of consciousness. Skin burn (similar to 1st degree burn. Conductive deafness. It is the discharge of the atmosphere potential ()clouds,or ()clouds and Earth.