Thermal injuries Presented by Dr Jashwant Guidance by

Thermal injuries Presented by Dr. Jashwant Guidance by Dr. Ganesh Govekar Dr. S. D. Kalele

Classification 1. Due to exposure to extreme cold a)General effects: Hypothermia b)Local effects: Frost bite, Trench foot 2. Due to exposure to extreme heat a)General effects: Heat stroke, heat cramps, heat exhaustion b)Local effects: Burns, scald

Cold Local effects Factors influencing: 1. Body built & physique 2. Age 3. Clothing 4. Medium of exposure Pathology : 1. vasoconstriction: Paleness & blanching of skin 2. vasoparalysis& vasodilatation: Erythema, swelling, oedema

3. Blister formation: May involve skin, subcutaneous tissues, muscles, nerves -Tissues may be frozen, stiff, hard, necrotic Frost bite: -Infarction of peripheral digits& redness, oedema, necrosis beyond line of demarcation -Exposure to dry cold -Temp< 2. 5°C -Also affects nose, ear, face

• Trench foot: Immersion foot -Exposure to wet cold -Temp: 5 to 8°C -Blister formation & dry gangrene General effects: -Hypothermia 1 st stage: cold & shivering 2 nd stage: shivering stops, temp<32°C -Depressed, lethargic, drowsy, sllepy, stupor, coma 3 rd stage: Temp<27°C, Fatal

P. M. findings: External: -Rigor mortis starts late, stay longer -P. M. L. bright red in colour -Generalised oedema Internal : -Organs congested -Ice crystals in blood vessels, heart, interstial tissues -Blood bright red -Necrosis of pancreas

Medico legal importance: -Accidental -Homicidal -Suicidal not common

Heat General effects: 1. Heat cramps: Minor’s cramps, stoker’s cramps, fireman’s cramps 2. Heat prostration: Heat exhaustion, heat syncope, heat collapse 3. Heat hyperpyrexia: Heat stroke, sun stroke P. M. findings: -P. M. caloricity -R. M. appears early, passes off early -Decomposition starts early -organs congested

Burns Definition: An injury caused by application of heat or chemical substances to external or internal surfaces of body, causes destruction of tissues. Injury(sec. 44 IPC): Any harm whatever illegally caused to any person in body, mind, reputation, property. Hurt(sec. 319 IPC): Any bodily pain, disease, infirmity caused to any person Heat: Min. Temp-44°C for 5 -6 hours -Temp. 65°C for 2 seconds

Causes : -Flame -Hot liquids -Chemical, corrosive -X rays -U. V. rays - Electric(Joule) - Flash burn - Explosions - Brush burns, friction burns - Cement (concret) burns

Degree of burns: Dupuytren: 1 st : Reddening 2 nd : Blistering 3 rd : Skin partially destroyed, extremely painful : Scar, no contracture, singeing of hair 4 th : Skin completely destroyed : Scar, not painful 5 th : Subcutaneous tissues, deep fascia : great scaring, deformity 6 th : Muscles, bones.

Blister

Wilson: 1 st degree(1 st&2 nd of Dupuytren): Epidermal 2 nd degree(3 rd&4 th of Dupuytren): Dermo-Epidermal 3 rd degree(5 th&6 th of Dupuytren): Deep Clinical: 1. Superficial 2. Deep

Effects depends on: 1. Intensity of heat 2. Duration of exposure 3. Extent of surface involved: rule of nine 4. Site 5. Age : child & old more susceptible 6. Sex : women more susceptible

Causes of death: 1. Shock: Primary (neurogenic) within few hours Secondary (hypovolemic) within 1 -2 days 2. Toxemia: Toxic substances produced due to burns/ destruction 3. Sepsis : >4 -5 days 4. Biochemical disturbances 5. Acute renal failure 6. G. I. T. disturbances: Curling's ulcer, haemorrhage in intestine 7. Asphyxia : CO& CO 2 poisoning

8. Glottic &/ pulmonary Odema 9. Pyemia, gangrene, tetanus 10. Accidental injury 11. Marjolin’s ulcer 12. Pumonary embolism 13. Inflammation of internal organs Meningitis, peritonitis, pleurasy, bronchitis, bronchopneumonia

Difference Antimortem burns Postmortem burns 1. Line of redness Present Absent 2. Blisters Serous fluid with protiens & cl Air &thin clear fluid 3. Base Red & inflammed yellow 4. Vital reaction Present Absent 5. Repairative process Present Absent 6. Infection Present Absent 7. Enzymes in peripheral Present zone Absent

Post mortem findings: External: -Burnt area -Pugilistic attitude -Kerosene smell -Singeing of hair -Heat rupture: Due to desiccation Over fatty areas Intact vessels & nerves Irregular margins

Internal : 1. Heat heamatoma : -On parietotemporal region -Soft, friable, light chocolate colour, may be pink due to co -Honey comb 2. Skull fracture(thermal fracture): -Rapid increase in I/C pressure leads displacement of fragment outward -Involves outer table only -On parietal bones just above temporo parietal region

3. Brain : -Shrunken, firm, yellow to light brown -Dura leathery 4. Trachea : carbon particles 5. Organs: Congested 6. Liver: Centrilobular necrosis

Difference : Burns Scalds corrosive 1. Cause Flame Hot fluid Acid/ Alkali 2. Splashing Absent Present 3. Skin Dry Shriveled Sodden & black Destroyed 4. Vesicles Circumference Over Burnt area Rare 5. Redline Present Absent 6. Colour Black Bleached Destroyed

Burns Scalds corrosive Charring Present Absent Singeing Present Absent Clothings Burnt Not burnt Destroyed Scar Thickened, Contracted Thin Thick Ulceration

Scald

Medico legal importance: 1. Actual cause of death 2. Accidental, suicidal, or homicidal 3. Postmortem burning 4. Indentification 5. Preternatural combustion

Electrocution Injuries caused depends upon: 1. Kind of current: AC or DC 2. Amount of current: CV/R 3. Path of current 4. Duration of flow Local effects: Joule burns: Specific & Diagnostic of contact with electricity -At point of entry of current - Crater: Round, shallow, pale floor

Entry wound

-When voltage very high & skin offers considerable resistance Sufficient heat produced Burning, Scorching, blackening, charring M/E: -Coagulation of dermis -Separation of epidermis -Flattening of cell

Exit: -Usually on body part in contact with earth(bare sole) -If exit site Hard, thick, dry(sole)→ Rupture of tissues -Generation of heat → burning General features: -Tingling, Numbness -Painless -Stunned -Suspended animation

Exit wound

-Mental confusion -Lack of Response -Retrograde Amnesias -Practical Deafness -Defective vision -Vertigo -If current passes through base of brain Failure of vital centers -If current passes through Heart→ VF

Causes of death: 1. Very low intensity→ VF 2. Paralysis of respiratory centre 3. Paralysis of respiratory muscles 4. Mechanical injury

“Factors Affecting fatality”: 1. Site of contact - Wet body- Wash/Sweat/Bath -Thick epidermis: Sole/Palm - Dermis removed area - High voltage - Charring→↓conductivityof tissue 2. Duration of Contact- Severity High voltage - (m) Conv. → throw victim Low voltage – (m) Spasm contraction – Not allow Separation 3. Heart Disease 4. Earthing

P. M. changes: External: -Examination of scene -Entry &exit wound Internal: -Asphyxial findings -Lungs & brain → Congested & odematous -Petechial haemorrhages along line of passage of current -

Medicolegal importance: -Accidental -Suicidal -Homicidal -Judicial

LIGHTENING Lightening : There is discharge of electricity between the clouds Lightening Stroke : When charge Jumps from clouds to Earth It Chooses the easiest (Not-Shortest) Path and hence it sometimes takes a wandering zigzag path When lightening strikes a person a potential of 1000× 106 Volt cause to pass 20, 000 Amp Current through body → induces lethal electrocution.

- It is of DC type. -Strikes a near by metallic object it may give rise to induced Voltage. Atmospheric gas becomes heated to 20000 C° ↓ Explosive expansion ↓ Blast effect Devastating

• AUTOPSY FINDINGS: (A) Ext – a) Linear Burns: 6 - 25 MP in width - Linear - Moist surface of skin b) Arborescent Burns – Formation of Superficial Thin Tortious Marking over skin Branching pattern of tree ↓ Filigree Burns (Fern like) - in low voltage

c) Surface Burns – Due to Heating up metallic object d) Magnetized object (Sometimes) e) Mechanical Injuries – due to blast effect (expansion/Regressive of area) (B) Other Effects – Clothes may be torn Shoes may burst open Tympanic membrane Burst open

C) Internal – Injuries from may extend to s/c/m/bone - Bone Injuries – Periosteal elevation - Patechial He – Brain spinal cord - Chromatolysis & Fragmentation of Axons - Organs – Congested