Effect of electric current on human body

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Effect of electric current on human body
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What is electric current?
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(No Transcript)
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What is making particles to move?
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Where can we meet with electric current?
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What are AC and DC?
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Electric current in human body

• heart
• muscles
• brain
• threshold of perception
• let-go current
• ventricular fibrillation (pacemaker with
  defibrillaror)

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Why AC is more danger than DC?
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How can we calculate the value of the current
flowing through any circuit?
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I U/R
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Body resistance

• in ohms/cm2
• resistance of dry, well-keratinized, intact skin
  averages 20,000 to 30,000 ohms/cm2
• for a thickly calloused palm or sole, it may be 2
  to 3 million ohms/cm2
• resistance of moist, thin skin is about 500
  ohms/cm2
• if the skin is punctured (e.g., from a cut or
  abrasion or by a needle) or if current is applied
  to moist mucous membranes (e.g., mouth, rectum,
  vagina), resistance may be as low as 200 to 300

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What about the heat effects of electric current?
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heat amperage2 resistance time

• Q I2 . R. t

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Symptoms and signs

• depend on the pathway of electric current
• from arm to arm
• from arm to foot
• conduction between legs or leg and the ground
• electrical injuries to the head
• in Czech republic in half of electric injuries
  at home children under 5 y are insulted
• high voltage vs. low voltage injuries (special
  category ? bathtub accidents)

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Ligthning injury

• Neuropsychologic damage, pain syndromes, and
  sympathetic nervous system damage are the most
  common long-term sequelae.
• Cardiopulmonary arrest is the most common cause
  of death.

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Hypotension, fluid and electrolyte disturbances,
and severe myoglobinuria may cause acute renal
failure. Dislocations, vertebral or other
fractures, blunt injuries, and loss of
consciousness may result from powerful muscle
contractions or falls secondary to the electric
shock (eg, electricity can startle a person,
causing a fall).
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Treatment

• separating the patient from the current source
• rapid cardiopulmonary resuscitation (ABC)
• care in hospital

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Baseline assessment for all electric injuries

• ECG
• cardiac enzymes
• urinalysis, especially for myoglobin
• cardiac monitoring for 12 h
• CT or MRI scan to rule out intracranial
  hemorrhage.

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If myoglobinuria is present, fluid replacement
and alkalinization therapy is essential to reduce
the risk of renal tubular myoglobin
precipitation.Mannitol or furosemide may be
indicated to increase renal flow
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Victims of lightning injuries

• Fluid restriction is the rule because of
  potential brain edema.

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Prevention

• respect in dealing with electricity
• proper design, installation and maintenance of
  all electric devices
• education and care about children