Thermal Deaths

Question 1

Define “Thermal Deaths”

Answer 1

• Deaths which are due to effects of systemic / localised exposure to XS Heat + Cold

Question 2

Define “Hypothermia”

Answer 2

• When Oral / Axillary temperature is less than 35 °C

Question 3

What are the Local & General Effects of Cold?

Answer 3

LOCAL

• Blanching / paleness of skin = due to Vascular Spasm
• Erythema, Oedema, Swelling = due to Vascular Dilation + Paralysis
• Blister Formation

GENERAL

• Stage 1 = Feeling cold + shivering
• Stage 2 = Shivering stops BELOW 32°C; Feeling depressed, lethargic + sleepy into comatose
• Stage 3 = BELOW 27°C - FATAL if for 24h or longer - resulting in Death, by ANOXIA

Question 4

What are the External & Internal Signs of Cold Death?

Answer 4

EXTERNAL

• Pale Skin w/ irregular patches of redness
• Gangrene of cheeks, lips + exposed parts

INTERNAL

• BRIGHT RED Blood = Due to 02 Retention by Hb at LOW temp
• WISCHNEVSKY’S Gastric Lesion = Cystic Dilation of the Capillaries - due to collapsed microcirculation in gastric mucosa

Question 5

Define “Heat”

Answer 5

• Form of energy which when it’s transferred to the body, it produces thermal injury via burns / scalds

Question 6

What are the Causes of Death by Burns?

Answer 6

WITHIN 24h

• Neurogenic Shock - due to pain
• Hypovolemia
• Toxaemia - due to absorption of toxic material from burn site

AFTER 72 - 96h

• Infection
• Renal Damage
• Hemorrhage from Erosions
• Curling’s Ulcers of GI Tract

Question 7

What are the 3 Types of Burns?

Answer 7

1) Epidermal Burns

2) Dermo-epidermal Burns

3) Deep Burns

Question 8

What are Epidermal Burns?

Answer 8

• Where lesion’s confined to Epidermis
• Blistering
• Capillary Dilatation
• Transudation of Fluid into the tissues - causing Swelling

Question 9

What are Dermo-epidermal Burns?

Answer 9

• Destruction of FULL Thickness
• Coagulated / Charred Epidermis
• Central Zone of Necrotic Tissue - surrounded by 1st Degree Burns / Hyperaemia

Question 10

What are Deep Burns?

• Explain the RULE of 9

Answer 10

Destruction of DEEPER tissues BELOW skin surface

RULE of 9

• Head + Neck = 9%
• Upper Extremity = 9%
• Lower Extremity = 18%
• Front Trunk = 18%
• Back Trunk = 18%
• Genitals= 1%

Question 11

What are the 3 SIGNS of Burns?

Answer 11

1) Heat Hematoma = Occurs in Epidural Space

• Resembling ** Traumatic Epidural Hematoma** - originating from Venous Sinuses
• Charring of the Skull

2) Heat Ruptures = Skin contracts + splits

3) Heat Rigor = Mainly in Muscles - in cases of Extensive Burn Injury

• Due to Coagulation + Protein Denaturation

Question 12

What are the External & Internal Signs of Burn Death?

Answer 12

EXTERNAL

• Tongue Protrusion - due to Cough Reflex
• Reddened / Blistered
• Singeing

INTERNAL

• CHERRY RED Blood - due to carboxy-hb
• Epidural Hematoma
• Congestion of Brain + Lungs
• Soot Particles in Respiratory Tract - due to Smoke Inhalation
• CURLING’S ULCERS of Stomach + Duodenum

Question 13

What are the 3 Types of Burns from Lighting Death?

Answer 13

1) Linear = They’re 3 - 30mm; Occur on moist surfaces of skin

2) Arborescent = Formation of superficial, thin, tortuous marking resembling branching tree

3) Surface = Due to worn metallic objects being heated

Question 14

What are the Internal Signs of Lighting Death?

Answer 14

• Rupture of Tympanic Membrane
• Periosteal Elevation (Of Bone)
• Petechial Hemorrhages in Brain + Spinal Cord i.e. Axonal Fragmentation
• Organ Congestion i.e. Pulmonary Oedema
• SAME *Signs of Asphyxia**

Question 15

Explain Electrocution

Answer 15

• Where AC Current of 70 - 80 mA becomes in contact with muscles
• Producing tetanic stimulation, thereby inducing spasm

Question 16

What is the Point of Entry / Exit in Electrocution?

Answer 16

JOULE BURN = this is the point of Entry (when current enters)

• It’s round / oval
• Surrounded by ridge of skin that’s 2-4mm HIGH
• With floor that’s pale, flat with surrounding hyperaemic zone
• Burns maybe seen in BOTH Entry + Exit

Question 17

What are the Causes of Death in Electrocution?

Answer 17

• Ventricular Fibrillation
• Respiratory Failure - due to *spasm of resp muscles**
• Cerebral ANOXIA