Electrical Safety

Question 1

Electrical Hazards for Patients (3)

Answer 1

Burns

Macroshock

Microshock

Question 2

What can be felt as tingling on intact skin?

Answer 2

macroshock

Question 3

What can produce microshock? (2)

Answer 3

vascular access catheters

myocardial lead wires

Question 4

The threshold of shock perception is ____ mA.

Answer 4

1

Question 5

The accepted maximal harmless current: ___ mA

Answer 5

5

Question 6

“Let-go” current. Threshold of tetanic contraction of skeletal muscle. The point person can let go of current conductor is: ______ mA

Answer 6

10-20

Question 7

Pain, fainting, mechanical injury is ____ mA.

Answer 7

50

Question 8

Current that induces ventricular fibrillation, respiration remains intact at _____ mA.

Answer 8

100-300

Question 9

Current resulting in sustained ventricular contraction, has defibrillation effect, and burns if the current is high enough is _____ mA.

Answer 9

6000

Question 10

1 - 6000 mA current is defined as ______.

Answer 10

macroshock

Question 11

Recommended safe current limit for directly applied cardiac equipment is ____ microAmp.

Answer 11

10

Question 12

Maximum fault condition current for cardiac equipment is _____ microAmps.

Answer 12

50

Question 13

Ventricular fibrillation is induced when current directly applied to myocardium at _____ microAmps.

Answer 13

100

Question 14

If the current exceeds _____mA, victim cannot let go.

Answer 14

15

Question 15

Awareness of or a reflex response to the passage of electric current through the body is _____ ____.

Answer 15

electric shock

Question 16

The threshold of sensation for 99.5% of population is approximately _____ microAmps

Answer 16

300 at a range of 30-100Hz

Question 17

What makes electrical currents passing through the body so dangerous ? (3)

Answer 17

• 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

Question 18

Current density can cause _____.

Answer 18

burns

Question 19

If you make current contact over a large area, do you get burned?

Answer 19

No

Question 20

If you make current contact over a small area, do you get burns?

Answer 20

Yes

Question 21

An electrosurgical unit uses ____ current density onto a ______ plate.

Answer 21

high

return

Question 22

If the return plate is not properly applied, the plate can burn the patient. True or false?

Answer 22

true

Question 23

Temperature of ___ºC and above may cause skin injury which is very dependent on blood flow.

Lack of blood flow where pressure applied on the patient may cause temperature to increase where the patient is on the return pad.

Answer 23

45

Question 24

Return current pad can cause _____ if you touch it.

Answer 24

macroshock

Question 25

Do not ever touch the hot while which is ____ because you can complete a circuit.

Answer 25

black

Question 26

Ground wire is _____ and can be filed off if wanted. Not safe though.

Answer 26

green

Question 27

Neutral wire is _____ and is connected at the source of electricity to earth ground.

Answer 27

white

Question 28

The part of the electrical plug that is wider is \_\_\_\_\_\_.

Answer 28

neutral

Question 29

What type of outlet is this?

Answer 29

Type "B"

Question 30

What type of outlet is this?

Answer 30

GFCI

Question 31

What type of plug is this? What is the current?

Answer 31

Still Type B, t-shaped for high current \> 20 Amps

Question 32

What type of plug is this? How do you unplug it?

Answer 32

Hubbellock device twist-and-lock

Question 33

When a faulty piece of equipment without an equipment ground wire is plugged into an outlet, the instrument case will become \_\_\_\_.

Answer 33

"hot"

Question 34

If an individual touches a "hot" unit, he/she will receive a shock because he /she is \_\_\_\_\_\_.

Answer 34

standing on the ground completing the circuit

Question 35

Current =

Answer 35

Potential / Impedance Impedance is skin

Question 36

Class I equipment is \_\_\_\_\_\_.

Answer 36

grounded

Question 37

Class II equipment is:

Answer 37

double insulated Most OR equipment, power tools

Question 38

Class III equipment is: \_\_\_\_\_\_\_\_

Answer 38

equipped with internal power source like transport monitors

Question 39

The principle of earthing of the metal case of apparatus and the use of a fuse indicates Class ___ equipment.

Answer 39

I

Question 40

What happens to earth ground is cut on faulty equipment?

Answer 40

risk of electrocution of patient in contact with faulty light with faultey earthed equipment

Question 41

A Bovie is also known as what?

Answer 41

Electrosurgical system, or ESU

Question 42

Bovies use ___ \_\_\_ _____ to avoid shocking the patient.

Answer 42

high frequency current (signal)

Question 43

Identify surgical ESU factors: (2)

Answer 43

Isolating capacitor ## Footnote High frequency current

Question 44

The return-pad of the ESU is a grounding pad. True or false?

Answer 44

False NOT

Question 45

The right leg lead on ECT is a ground. True or false?

Answer 45

false

Question 46

Microshock susceptible patient are those with: (2)

Answer 46

* Pulmonary Artery Catheter * Port cross-sectional area very small * Contact with ventricular wall will not require much current to cause fibrillation * Central line * Atrial Fibrillation – depending upon catheter location

Question 47

Anesthetist touching faulty equipment, patient and earthed casing results in:

Answer 47

patient fibrillation Anesthetist did not perceive

Question 48

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.

Answer 48

capacitive coupling Line 2

Question 49

A broken equipment ______ wire results in a significant hazard to the elecrically susceptible patient. Indicate where this occurs.

Answer 49

ground

Question 50

Name types of safety power systems: (3)

Answer 50

isolation transformers line isolation monitors ground fault circuit interrupters

Question 51

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.

Answer 51

line isolation monitor