Electrical Safety in Intensive Care Units (ICU’s)
Introduction:
1) Electricity presents a serious hazard in hospitals.
2) It is not possible to determine the incidence of fatal and non-fatal hospital electrical accidents.
3) Estimates vary from 1200-1500 per year.
4) Accidents generally unreported.
5) ICU’s presents serious hazard due to:
- Number of electrically powered machines.
- The number of conductors in, on, and around patients.
- Times when unsafe conditions are present: fluid or blood on the floor, bed, or on other equipment
6) We must have knowledge of electrical safety to protect the patient, others, and yourself.
7) Electric current consists of a flow of electrons through a conducting pathway or circuit. The circuit must be closed with a difference in potential existing between two points. Current must be continuous flow in one direction (DC) or reverse its direction frequently (AC).
8) The amount of current flowing between two points of different electrical potential vides inversed with the intervening resistance. Resistance is the impedance to flow. When resistance is low, large amounts of current flow and inversely when resistance is high.
9) Electricity is carried into the hospital via a hot line and is carried back to the power source via a neutral line. This is a 2-wire system.
10) When a 3-wire system is used a ground is used. A ground works to transfer all excess leakage of current to the ground.
11) As electrical current leaks. The amount of current is re-circulated and is harmless if the equipment is normal grounded.
12) Electric shock refers to the effects and reaction produced by passage of an electric current through the body. The effect varies with the amount of current delivered, its duration, pathway through the body, area of exposure, and the tissues lying in the pathway of the current.
Electric Shocks Can Be Lethal When the Heart is a Component of the Circuit
1. Most shocks are due to improperly grounded equipment.
2. Skin provides a high-resistance barrier to the transit of current through the body of externally applied current. The resistance to flow is greatest when the body surface is dry. Skin of the planar surface offers the highest resistance. Sweat or saline, application of BCO jelly, or cleansing with soap reduces this resistance.
3. Very Small Currents can Be Lethal When Current Finds a low impedance Pathway Directly to the Heart
4. The chief danger to a patient in contact with electrical equipment is the initiation of ventricular fibrillation by electric shock.
5. Shocks from large counts of electricity, perhaps full line of current of 110 volts externally applied are referred to a Macroshock.
6. Microshock is dangerous only if applied directly, myocardium or internally through an intracardir catheter, probe, pacing wire, or needle. Micro shocks are imperceptible.
7. Applied to mucous membranes or to a break in the skin, both, which offer less resistance, the game amperage crates a more intense sensation.
8. Heart muscle is particularly sensitive to electrical stimulation; the cause of death from electrocution is most often ventricular fibrillation.
Precautions!
1. Perception of shock is a warning to the operator and patient alike of a possible electrical malfunction. Do Not Ignore!
2. All equipment should be grounded. Never use a two-wire system.
3. Never adapt a 3-wire to a 2-wire outlet.
4. Never use a frayed or broken cord.
5. Do no use equipment the patient has brought from home, unless Instrumentation engineer has approved it. Use battery-powered equipment when possible.
6. All new equipment is to be checked by Instrumentation engineer.
7. Rubber gloves should be placed over the pacer terminal.
8. Wear rubber gloves when working with the pacer generator or wire.
9. Keep the patient and patient area dry in case electrical equipment (defibrillator) needs to be used.
10. An electrical equipment must be checked at lest every 6 months. Remember that equipment still operates with defective ground connection.
11. Turn equipment off before unplugging to prevent arching.
12. If the Hazard Alarm sounds, investigate by unplugging equipment to identify source. Notify biomedical department.
13. When checking defibrillator, do not hold the paddles together a do not hold them facing each other but not touching.
14. When defibrillating, do not touch the paddle to the electrode.
15. Never plug, unplug equipment, turn on etc. while your hand or other part of your body is in contact with water, steam pipes, radiators, or plumbing fixtures.
16. Do not intentionally ground the patient by letting him come in contact with or touch any metal object, switch, or device, which may provide an alternate path of low resistance.
17. Clean electrodes after used to prevent corrosion. Carefully store, to prevent breakage.
Prof. Prashant B. Patel, PICT, Pune-43
