Electrocution occurs when electric current passes through the body, damaging tissues. The current typically enters through one point and exits through another, following the path of least resistance. Factors like voltage, amperage, resistance, duration of contact, and direction of current flow determine the severity of injury. Death from electrocution is usually due to ventricular fibrillation or respiratory arrest. External injuries include contact burns, spark burns, and flash burns. Internally, pulmonary edema or cerebral edema may be present.

1. Electrocution
Submitted By: FAISAL SHAHAZAD SOMROO(sec-B)
Reg.No. 14-ARID-2022 (Evening)
PMAS

2. Electrocution
• Electric Injuries (Electrocution)
• Damage to the tissues due to the passage of electric current is called electrical injury. The injury is
also commonly called as ‘electrocution’.
• General Features
• The current enters at one point and leaves the body at an exit point.
• For electrocution to occure, there must be a pathway for electricity (or electrons) through the
tissues.
• The pathway tends to take the shortest route between the entry and best exit
• Most dangerous pathway is entry through right hand and exit through left foot, because current
passes obliquely along the heart axis.

3. Factors Affecting Electric Injury
• 1. Voltage
• Death is uncommon below 100V, domestic voltage is 220V, residential area mains are 11000V,
power house mains have up to 100,000V.
• Low tension voltage = <500V
• High tension voltage = >1000 V
• 2. Amperage
• 30mA can be tolerated. 50-80mA across heart is fatal in a few seconds.
• 3. Resistance
• The major barrier to electric current is skin resistance. Skin resistance is decreased if wet. Due to
high electric resistance of skin, heating up causes skin burns.

4. Cont…
• 4. Duration of Contact
• Low ampere current if passed through the body for a longer time is fatal.
• 5. Direction of Pathway of Current
• Current follows the routes of least resistance which include blood filled vessels, and may thus
reach the heart even though it does not lie in a straight line between the entrance and exit.
• 6. Anticipation of shock
• There are more chances of death, when the animal is not prepared for the shock
encountered

5. Cont….
• Causes of Death in Electrocution
• 1. Ventricular fibrillation is the most common mode of death in electric injury
2. Respiratory arrest due to spasm of muscles of respiration
3. Rarely brain stem arrest also occurs
• 4. Injuries:
• Due to fall from height
• Extensive burns
• Fractures due to muscle spasms

6. Cont…
• 5. Hold on effect
• If someone catches a live wire, spasm of flexor muscles occurs and cannot get rid of the wire, due to
extensive flexor spasm
• Types of Electrical Injuries
• Contact burns
• Spark burns
• Flash burns
• Grounding or exit injuries
• Vasospasm
• Convulsions

7. Cont..
• Spark Burns
• There is no actual contact but electricity sparks to the skin through a narrow zone of air.
• Temperature is very high which causes the keratin to melt over a small area, which gets the shape
of a hard brownish nodule, usually raised above the surrounding skin surface. This is called spark
lesion.
• The surrounding area is blanced or pale.
• Flash Burns
• These occur due to jumping of current from high tension wires. All types of burns may occur.
• Typical lesion is ‘crocodile skin’ lesion

8. Cont…
• Grounding or Exit Injuries
• These are not commonly seen. Exit injury may have a split appearance.
• Vasospasm
• Gangrene of the affected limb occurs.
• Convulsions (Muscle Spasms)
• Respiratory paralysis
• Fractures
• Associated injuries
• ‘Hold on’ effect

9. Cont…
• Post mortem Appearance
• External Contact Marks/Burns
• Characteristic electric burns
• Pattern of the electrode
• Metallic burns
• Light green imprint with copper/brass
• Vaporized metal in skin may be visible to naked eye or detected on scanning electron microscopy.
• Chemical metal elusion tests
• Rigor mortis develops early

10. Cont…
• Internal Appearance
• Usually no significant findings
• Pulmonary edema or general signs of asphyxia may be present
• Cerebral edema may be present
• Perivascular hemorrhages may be found
• Injury to the bones may have occurred