ELECTRIC SHOCK

The possibility of life-threatening electrical injury exists wherever there is electric power or lightning. The amount and type of current, the duration and area of exposure, and the pathway of the current through the body determine the degree of damage. If the current passes through the heart or brain stem, death may occur immediately owing to ventricular fibrillation or apnea. Current passing through skeletal muscle can cause muscle necrosis and contractions severe enough to result in bone fracture. Current traversing peripheral nerves can cause acute or delayed neuropathy. Delayed effects can include damage to the spinal cord, peripheral nerves, bone, kidneys, and gastrointestinal tract as well as cataracts.

Direct current is less dangerous than alternating current. With alternating currents of 25 - 300 Hz, low voltages tend to produce ventricular fibrillation; high voltages, respiratory failure; intermediate voltages, both. More than 100 mA of domestic house current of 110 volts at 60 Hz is, accordingly, dangerous to the heart, since it can cause ventricular fibrillation. DC current contact is more likely to cause asystole.

Lightning injuries differ from high-voltage electric shock injuries in that lightning usually involves higher voltage, briefer duration of contact, asystole rather than ventricular fibrillation, nervous system injury, and multisystem pathologic involvement.

Electrical burns are of three distinct types: flash burns, flame burns, and the direct heating effect of tissues by the electric current. The latter lesions are usually sharply demarcated, round or oval, painless yellow-brown areas with inflammatory reaction. Significant subcutaneous damage can be accompanied by little skin injury, particularly with larger skin surface area electrical contact.

Electric shock may produce loss of consciousness. With recovery there may be muscular pain, fatigue, headache, and nervous irritability. The physical signs vary according to the action of the current. Ventricular fibrillation or respiratory failure can occur; the patient may be unconscious, pulseless, hypotensive, cold and cyanotic, and without respirations.

Electric shock may be a hazard in equipment that is usually considered to be harmless. Proper installation, utilization, and maintenance of equipment by qualified personnel should minimize this hazard.

Treatment

A. Emergency Measures :

The victim must be freed from the electric current prior to initiation of CPR or other treatment; the rescuer must be protected. Turn off the power, sever the wire with a dry wooden - handled axe, make a proper ground to divert the current, or drag the victim carefully away by means of dry clothing or a leather belt.

Lightning injury. Victims of lightning injury, in whom coma may last for a few minutes to several days, should receive prompt and sustained artificial resuscitation. This should be continued as long as there is no clinical evidence of brain death.

B. Hospital Measures :

Lightning or unstable electric shock victims should hospitalized when revived and observed for shock, arrhythmia, thrombosis, infarction, sudden cardiac dilation, hemorrhage, and myoglobinuria. A urinalysis, serum Ck and CK-MB, and an electrocardiogram should be obtained immediately. Victims should also be evaluated for blunt trauma, dehydration, skin burns, hypertension, posttraumatic stress, acid-base disturbances, and neurologic damage. Indications for hospitalization include significant arrhythmia or electrocardiographic changes, large burn, loss of consciousness, pulmonary or cardiac symptoms, or evidence of significant deep tissue or organ damage. Extra caution is indicated when the electroshock current has followed a transthoracic route (hand to hand or hand to foot) and in patients with a cardiac history.

To counteract fluid losses and myoglobinuria due to electric shock (not lighting ) burns, aggressive hydration with Ringer's lactate should seek to achieve a urine output of 50-100 mL/h.

Prognosis

Complication may occur in almost any part of the body but most commonly include sepsis, gangrene requiring limb amputation, or neurologic, cardiac, cognitive, or psychiatric dysfunction.