OR Safety Flashcards
flow of electrical charges
current
the path that current flows through
circuit
current moves easily
conductor
current moves through poorly
insulator
amount of current flow per second
amps
pressure pushing electrons
voltage
measure of resistance
ohms
number of cycles per second
hertz
amount of current and area it flows over
current density
what are the 3 circuits
hot: supplies current
neutral: supplies return
ground: catches any strays or leakage
true or false
flow/electrons always goes to the least resistance
TRUE
what can current flow through
unbroken, closed circuit
(it can escape the designated circuit and travel an alternate path-leakage)
true or false:
1 Hz is 1 cycle per second*
true
true or false:
the higher the frequency, the LESS dangerous*
true
what is minimum current for fibrillation
50 to 60 Hz
what can interfere with depolarization and repolarization in myocardium and cause arrhythmias
0 Hz to 1 kHz
what can long power cords do
lead to higher resistance
1 million ohms (resistance)
dry/healthy intact skin
12,000 ohms
Perspiring, intact skin
1000 ohms
Conductive jelly applied
< 100 ohms (less resistance)
Catheter, pacer wires
as current flows through skin, resistance will ___________
decrease
Threshold of perception
1 mA
Maximum harmless current intensity
5 mA
“Let go” prevent release of object; contraction of muscle but it wont let go
10 to 20 mA
Pain, mechanical injury (tissue injury)
50 to 100 mA
vent fibrillation
100 to 2500 mA
Sustained myocardial contraction, resp. paralysis, burns if current density is high
> 6000 mA
what is a current applied directly to body surface
macroshock
what determines the effects of macroshock
surface area, amount of current flow (amps), duration of exposure, frequency of the current, path
______shock produces muscle contraction, pain, burns, open wounds, pacer disruption, arrhythmias
requires a large amount of current to overcome skins resistance
macroshock
what is a current directly applied to heart
microshock
Small amounts of voltage or current applied directly to the myocardium bypassing the skin via a IV catheters, pacer wires, etc.
microshock
1000 microamps (uA) =
1 milliamp (mA)
1000 milliamps (mA) =
1 amp
current that escapes the circuit due to stray capacitance and poor insulators
leakage current
knows exactly how much current is flowing, measures current flow, tries to measure how much is going in and out, alarms if high
line isolation monitor
Electrical current used to cauterize vessels and cut tissue.
electrosurgical units (ESU) / bovie
applied as close as possible to surgical site, large surface area to minimize current density; not required for bipolar
disperal pad (bovie pad/grounding pad)
two pronged cutting electrode instrument. Current travels only between the two prongs
bipolar
current applied using a single electrode that returns to the ESU by way of the dispersal pad.
unipolar
what is high frequency
300 kHz – 2 MHz
what are 4 surgeries where the bipolar pad would be used
brain, ovarian, or fallopian tube
ALSO WITH PACEMAKERS
true or false:
large surface area is the best for the dispersal pad
TRUE (reduces the chance of a high density burn)
what is most important thing to remember about the ESU/bovie and pacemakers*
ESU (bovie) current traveling through pacer can alter functioning
USE BIPOLAR
what should be done for AICD
turn it off/call the representative
when using unipolar (not recommended) for pacemaker, what should you also have with you
magnet
know whether the patient is pacemaker dependent
what can be irritated by antiseptics and disinfectants
eyes
