Pathology of electric burns
Electric current injuries include local injury and general damage, lightning is also an electric burn.
When an electric current is carried into the body, pathological damage is caused by the whole body or on the spot.
It is necessary to distinguish two types of lesions:
Due to electric arc sparks.
Due to the electric current flowing into the body.
Burns caused by sparks: very high temperature from 3200 - 4800 0 C, very short duration of action of 0.2 - 1.5 seconds; 80% of the radiant heat energy of the sparks is the infrared beam that often causes superficial burns, burns to open parts of the body and burns towards the body towards the spark. If the voltage is higher than 1000 volts, it can cause dermal burns and deep burns.
Electric current injuries include local injuries (burns) and systemic damage (respiratory arrest, cardiac arrest, electric shock). Lightning is also an electric burn with a high voltage of millions of volts.
Mechanism of electric burns
The severity of electric burns depends on factors:
Current type: direct current or alternating current.
Current-voltage: high voltage or low voltage.
The resistance of body tissue.
The electric current when passing through the body.
The time the current passes through the body.
Pathway through the body.
High voltage current is from 1000 to 50,000 volts.
The electric current when transmitted through the body will follow the path with least resistance.
The electric current passing through the heart and brain is often dangerous to the life of the burned person.
When the electric current through the body meets the large resistive parts (skin, bone), the electric energy will turn into heat energy according to Joule - Lentz law.
Q calories = 0.24 I2RT
General pathological damage
The greater the electricity, the more strongly stimulates the central nervous system and the centres that regulate the respiratory circulation, the nervous system of plants causing strong inhibition and disturbances of the vital organs of the body. by the following acute pathological disorders:
There are 4 levels:
Mild: muscle spasms, perception intact.
Moderate: the muscles tighten strongly, if, at high altitude, the victim may be jerked off, dropped and lost consciousness.
Severe: loss of consciousness, cardiac dysfunction (ventricular fibrillation), respiratory disorders (respiratory arrest).
Very severe: clinical death. A low voltage flow is often fatal due to cardiac arrest ventricular fibrillation. High-voltage electric current causes death from respiratory arrest.
If the patient is promptly cured and the overall damage is not too severe, the sufferer will get rid of the above condition and enter the episodes of burn disease with the following characteristics:
Burn shock: often with acute renal failure, haemoglobin (haemoglobin) and myoglobin (muscle pigment) urine.
Severe bacterial intoxication. Anaemia due to secondary bleeding. Acute gastrointestinal ulcers. Burns cachexia develops rapidly.
Disorders of sensation, movement, mental illness after-burn.
Injury in place
Electric burns are often deep, local lesions manifest in the entry and exit points of the electric current, the most common locations are hands, feet. In children, the mouth, lips and tongue can burn due to the attachment to the electrodes. The higher the resistance, the greater the intensity of the electric current and the longer the duration of the action, the more extensive the damage in place.
Lesions are necrotic patches of round or oval yellowish or dark gray, charred. Limiting lesions is not easy, in the early days it is difficult to accurately diagnose the depth of the burn.
If burns deeply, the weight layers, muscles, tendons also become necrotic. In areas of the chest wall or abdominal wall, when the necrosis falls, it can expose the pinhole. In the skull region, the frontal bone can see bone necrosis and perforation leading to meningitis. To the limbs often have blood vessel damage-causing secondary bleeding, nerve damage that causes paralysis. Sometimes the entire limb is damaged (necrosis, charring), requiring early amputation.
In electric burns often appear secondary necrosis of tissues arising from blockage of blood vessels, by clots forming in the lumen of the vessels, due to damage to the vessel wall. In the early days, burns can be seen with a certain limit, but during the time the area is anaemic, muscles, tendons become secondary necrosis.
Due to the features on the background of electric burns, complications often occur locally and when they recover, they often leave complications that cause disability.
Comply with the safety regulations on electricity use, well protect the power sources from open circuits and put the power switches up to avoid children from playing with. There are enough fuses properly insurance to cut off the power when the problem occurs. Do not let young children play with power tools.
Need to find ways to cut off the power source and save people from the power source by cutting off the circuit breaker immediately, removing the fuse. For people who are using a dry wooden stick, remove the power cord and pull the victim out of the danger area (hair, clothes). Then must do CPR immediately squeeze the heart outside the chest, suffocate right at the affected place. Avoid wasting time taking patients away without emergency on the spot. If possible, injecting a heart-stimulating drug that stimulates breathing. When self-breathing and heartbeat return, then the problem of burns, pain relief and transfer of patients to the nearest treatment facility. Attention should be paid to treat acute renal failure, monitor urine for the number, colour, pH, density every 2-3 hours and at the same time test for sediment cells, haemoglobin, blockade of liquid 0, 25% on both sides of the kidney, for mannitol osmotic diuretics, alkaline serum, 0.13% serocaine solution,
Anti-infection: bandage clean the wound, block Novocain on the root of the limb, turn wet necrosis into dry necrosis. Injecting antibiotics under necrosis, systemic antibiotics, early removal of necrosis. Use deep lesions. If the whole limb is necrotic, the amputation must be timely. Note good bleeding in surgery. When necrosis in areas with large blood vessels to prevent secondary bleeding, if there is a rupture must promptly stop bleeding and then tie the vessel in the healing area on the damaged area.
When the skull bone is damaged, it is necessary to drill many holes through the dead bone to the healing part to create the seed organization, need to graft in time the necrotic areas or areas with seed organization. Need to monitor, detect and treat complications, meningitis, brain abscess under the necrotic zone.
When electric burns damage the bones, it is necessary to remove the dead bone layers to the area where there is bleeding and wait for the seed tissue to grow, which will graft skin.
The local sequelae of electric burns require plastic surgery to restore body or function after the burn has recovered.