Effect of electric current on Effect of electric current on human bodyhuman body

What is electric current?What is electric current?

What is making particles to What is making particles to move?move?

Where can we meet with Where can we meet with electric current?electric current?

What are AC and DC?What are AC and DC?

EElectric current in human bodylectric current in human body

heartheart musclesmuscles brainbrain threshold of perceptionthreshold of perception let-go currentlet-go current ventricular fibrillationventricular fibrillation (pacemaker (pacemaker

with defibrillaror)with defibrillaror)

Why AC is more danger than DC?Why AC is more danger than DC?

How can we calculate the value How can we calculate the value of the current flowing through of the current flowing through

any circuit?any circuit?

I = U/RI = U/R

Body resistanceBody resistance in ohms/cm2in ohms/cm2 resistance of dry, well-keratinized, intact skin resistance of dry, well-keratinized, intact skin

averages 20,000 to 30,000 ohms/cm2averages 20,000 to 30,000 ohms/cm2 for a thickly calloused palm or sole, it may be 2 to for a thickly calloused palm or sole, it may be 2 to

3 million ohms/cm23 million ohms/cm2 resistance of moist, thin skin is about 500 resistance of moist, thin skin is about 500

ohms/cm2ohms/cm2 iif the skin is punctured (e.g., from a cut or f the skin is punctured (e.g., from a cut or

abrasion or by a needle) or if current is applied to abrasion or by a needle) or if current is applied to moist mucous membranes (e.g., mouth, rectum, moist mucous membranes (e.g., mouth, rectum, vagina), resistance may be as low as 200 to 300vagina), resistance may be as low as 200 to 300

What about the heat effects of What about the heat effects of electric current?electric current?

heat = amperageheat = amperage22 × resistance × resistance ×× time time

Q = IQ = I22 . R. t . R. t

Symptoms and signsSymptoms and signs ddepend on the pathway of electric currentepend on the pathway of electric current from arm to armfrom arm to arm from from arm to footarm to foot conduction conduction between legs or leg and the between legs or leg and the

groundground eelectrical lectrical injuries to the headinjuries to the head iin Czech republic in half of electric injuries n Czech republic in half of electric injuries

at home children under 5 y are insultedat home children under 5 y are insulted hhigh voltage vs. low voltage injuries igh voltage vs. low voltage injuries

(special category (special category bathtub accidents) bathtub accidents)

Ligthning injuryLigthning injury

Neuropsychologic damage, pain syndromes, and Neuropsychologic damage, pain syndromes, and sympathetic nervous system damage are the sympathetic nervous system damage are the most common long-term sequelae. most common long-term sequelae.

Cardiopulmonary arrest is the most common Cardiopulmonary arrest is the most common cause of death.cause of death.

Hypotension, fluid and electrolyte Hypotension, fluid and electrolyte disturbances, and severe disturbances, and severe

myoglobinuria may cause acute myoglobinuria may cause acute renal failure. Dislocations, vertebral renal failure. Dislocations, vertebral or other fractures, blunt injuries, and or other fractures, blunt injuries, and

loss of consciousness may result loss of consciousness may result from powerful muscle contractions from powerful muscle contractions or falls secondary to the electric or falls secondary to the electric

shock (eg, electricity can startle a shock (eg, electricity can startle a person, causing a fall).person, causing a fall).

TreatmentTreatment

sseparating the patient from the eparating the patient from the current sourcecurrent source

rapid cardiopulmonary rapid cardiopulmonary resuscitation (ABC)resuscitation (ABC)

care in hospitalcare in hospital

Baseline assessment for all electric Baseline assessment for all electric injuriesinjuries

ECGECG cardiac enzymes cardiac enzymes urinalysis, especially for myoglobinurinalysis, especially for myoglobin cardiac monitoring for 12 h cardiac monitoring for 12 h CT or MRI scan to rule out CT or MRI scan to rule out

intracranial hemorrhage.intracranial hemorrhage.

If myoglobinuria is present, fluid If myoglobinuria is present, fluid replacement and alkalinization replacement and alkalinization

therapy is essential to reduce the risk therapy is essential to reduce the risk of renal tubular myoglobin of renal tubular myoglobin

precipitation.Mannitol or furosemide precipitation.Mannitol or furosemide may be indicated to increase renal may be indicated to increase renal

flowflow

Victims of lightning injuriesVictims of lightning injuries

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

Prevention Prevention

respect in dealing with electricityrespect in dealing with electricity proper design, installation and proper design, installation and

maintenance of all electric devicesmaintenance of all electric devices education and care about childreneducation and care about children