Electrical Safety Flashcards
Electrical Hazards for Patients (3)
Burns
Macroshock
Microshock
What can be felt as tingling on intact skin?
macroshock
What can produce microshock? (2)
vascular access catheters
myocardial lead wires
The threshold of shock perception is ____ mA.
1
The accepted maximal harmless current: ___ mA
5
“Let-go” current. Threshold of tetanic contraction of skeletal muscle. The point person can let go of current conductor is: ______ mA
10-20
Pain, fainting, mechanical injury is ____ mA.
50
Current that induces ventricular fibrillation, respiration remains intact at _____ mA.
100-300
Current resulting in sustained ventricular contraction, has defibrillation effect, and burns if the current is high enough is _____ mA.
6000
1 - 6000 mA current is defined as ______.
macroshock
Recommended safe current limit for directly applied cardiac equipment is ____ microAmp.
10
Maximum fault condition current for cardiac equipment is _____ microAmps.
50
Ventricular fibrillation is induced when current directly applied to myocardium at _____ microAmps.
100
If the current exceeds _____mA, victim cannot let go.
15
Awareness of or a reflex response to the passage of electric current through the body is _____ ____.
electric shock
The threshold of sensation for 99.5% of population is approximately _____ microAmps
300 at a range of 30-100Hz
What makes electrical currents passing through the body so dangerous ? (3)
- Path of the current–worst path is heart or brain
- Current density– higher current densities may come from lower currents passing through a smaller area.
- Frequency–worst is 50- 60 Hz
Current density can cause _____.
burns
If you make current contact over a large area, do you get burned?
No
If you make current contact over a small area, do you get burns?
Yes
Ground wire is _____ and can be filed off if wanted. Not safe though.
green
The part of the electrical plug that is wider is ______.
neutral
What type of outlet is this?
Type “B”
What type of outlet is this?
GFCI
What type of plug is this?
What is the current?
Still Type B, t-shaped
for high current > 20 Amps
What type of plug is this?
How do you unplug it?
Hubbellock device
twist-and-lock
When a faulty piece of equipment without an equipment ground wire is plugged into an outlet, the instrument case will become ____.
“hot”
The principle of earthing of the metal case of apparatus and the use of a fuse indicates Class ___ equipment.
I
What happens to earth ground is cut on faulty equipment?
risk of electrocution of patient in contact with faulty light with faultey earthed equipment
Identify surgical ESU factors: (2)
Isolating capacitor
High frequency current
Anesthetist touching faulty equipment, patient and earthed casing results in:
patient fibrillation
Anesthetist did not perceive
The capacitance that exists in AC powered lines and AC operated equipment results in small “leakage currents” that partially degrade the isolation of the power system is known as _____ ____.
Indicate where this occurs on diagram.
capacitive coupling
Line 2
A broken equipment ______ wire results in a significant hazard to the elecrically susceptible patient. Indicate where this occurs.
ground
When a faulty piece of equipment is plugged into the isolated power system, it will markedly decrease the impedance from line 1 or line 2 to ground. This will be detected by _____ ____ ___ which will sound an alarm.
line isolation monitor
