Presentation on theme: "By Lecturer of Forensic Medicine & Clinical Toxicology Definition A thermal injury is a tissue injury resulting from the application of heat in any form."— Presentation transcript:
By Lecturer of Forensic Medicine & Clinical Toxicology Definition 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. Types of thermal injuries Dry or simple burn. Scald or moist burn. Chemical or corrosive burn. Electric burn. Radiation burn. Old classification First degree burn Second degree burn Third degree burn Fourth degree burn Fifth degree burn Sixth degree burn Recent classification Epidermal degree 1 st & 2 nd degree Dermo - epidermal burn 3 rd & 4 th degree Deep burn 5 th & 6 th degree
Dry burn ScaldCorrosive Cause Clothes Charring Flame or heated body Steam or hot liquid Corrosive acid or alkali BurntWet Eaten Present Absent With mineral acid Skin Dry & charred Sodden & bleached Stained & corroded Scar Thick with disfigurement Less disfigurement Much disfigurement Air passage Contains soot No soot Blood Thick, viscid & contains COHb Degree Any degree 1 st, 2 nd & 3 rd 1 st, 3 rd, 4 th Hair SingedWet Eaten Vesicles At circumference of burnt area Over burnt area Rarely found Site & spread From below upward From above downward At & below site of contact
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.
Causes of death from burn II) Rapid death "within 6-48 hours”: I)Immediate causes "within 6 hours“ Neurogenic shock. Associated accidental serious injuries to vital organs. Asphyxia (suffocation). Traumatic asphyxia. S SS Secondary oligaemic shock. S S S Secondary toxaemic shock. A A A Acute oedema of glottis (in the neck). P P P Pulmonary fat embolism (burn in a fatty area.( III) Death within 2-7 days: -Supra-renal haemorrhage. -Bronchopneumonia. -Inflammation of serous membranes. -Septicemia. - Tetanus, gangrene and erysipelas. - Tetanus, gangrene and erysipelas. : IV) Death after one week: - 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.
Burn vitality Line of hyperemia PresentAbsent Antemortem burn Postmortem burn absent poor in albumin and chloride albumin and chloride Albuminous fluid rich in chloride rich in chloride Infl., pus healing Present Absent Nil Vesicles Vital reaction Soot in URT Presence of COHb Cause of death Present Absent Nothing But burn Other causes Age of Burn Erythema 36 hs 48 hs Appearsimmediately Vesicles 1 w 2 ws Appears2-3hs Sepsis 36 hs 2 – 3 days Superficial slough 1 w Deep slough 3 ws Scar 2 m 6 m RedCoppery
Complications of Burn Sepsis Keloid formation Deformities Postmortem Picture of Burn - The body shows evidence of antemortem burns of various degrees. -T-T-T-The body presents a peculiar attitude; attitude of defence, boxing or "Pugilistic attitude". -C-C-C-Crimson red colour of hypostasis. -G-G-G-Generalized visceral congestion and Hge in the internal organs. - Particles of soot are present in the air passage. passage. -Subcutaneous or subserous peticheal hge may be present. 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“.
Points of differentiation () thermal & traumatic fracture Thermal Fracture Traumatic Fracture The brain is shrunken The brain is edematous Extradural haematoma doesn’t fill the space Extradural haematoma fill the space The fracture is not displaced The fracture is displaced Postmortem signs of burn Other postmortem signs of death & associated with contused wound in scalp
Electric burn Factors influencing the effect of electric current PhysicalPhysiological Voltage Nature of current Duration of contact Resistance of body tissue Humidity Pathway of current Anticipation of shock General health
Causes of Death Ventricular fibrillation Respiratory failure Central Peripheral Cerebral anoxia Hyperthermic effect Cardiac arrest Electric burn
P.M. Picture of Electric Burn Rapid onset of rigor mortis Rapid onset of rigor mortis Marked hypostasis Marked hypostasis P PP Presence of current mark Internal signs of asphyxia Internal signs of asphyxia Current Marks N / E appearance Microscopic appearance - Compression of the stratum corni which stains deeply with superficial carbonization. - Separation of the cells in the form of slits (electric channels). (electric channels). - Elongation of both cells and nuclei. - It is of the same size and shape as the conductor. conductor. - Grayish-white painless areas of aseptic necrosis. necrosis. - They vary from superficial circumscribed lesions to severe burns with full thickness lesions to severe burns with full thickness tissue necrosis. tissue necrosis.
Definition It is the discharge of the atmosphere potential () clouds, or () clouds and Earth. -The electric current is DC not AC. -About amperes. -About million volts. - A single flash lasts 1/1000th of a second. Lightning syndrome Characterized by: Loss of consciousness. Loss of consciousness. Skin burn (similar to 1 st degree burn. Skin burn (similar to 1 st degree burn. Conductive deafness. Conductive deafness.