mini study guide (OR Safety) Flashcards
give the equation for electricity that follows Ohm’s Law?
voltage= current x impedance
voltage is known as the?
driving pressure
current is also known as?
flow
impedance is also known as?
resistance
the electrocautery delivers a high frequency current that is ____ to ____ hertz
500,000 to 1 million hertz
the electrocautery is used to?
cut, coagulate, dissect, or destroy tissue
the higher the frequency on the electrocautery, they will have a _____ tissue penetration and does not affect _____ cells. thus what is not a risk?
low
excitable
Vfib
monopolar electrocautery requires a?
grounding pad
a grounding pad is placed on a patient to allow?
for the exit point of a return current
a grounding pad is also called a?
functional return electrode
A functional return electrode serves as the exit point by providing?
a large, low impedance surface area for the electrical current to exit the body and return to the power generator
if a return electrode fails, what does this place the patient at risk for?
burns
if the return electrode malfunctions the electrical current will?
find another pathway to exit the patient, such as the EKG electrodes, temperature probe, or metal components of the surgical table.
the smaller the area that the electricity exits the body other than the functional return electrode, the greater the?
intensity of the burn
To prevent burns at the return pad site, the entire surface of the return electrode should be?
in direct contact with the patient’s skin
the functional return electrode should never be placed where?
over bony prominences ro metal implants
what happens if the gel on the functional return electrode dries out?
the electrical current won’t have a direct path to the return electrode and will find another way to exit the body
the electrocautery can emit ____ and cause a fire
sparks
the bipolar electrocautery has two electrodes known as?
active and return electrode
the bipolar electrocautery does not have a ?
return pad
what is a critical aspect of using an electrocautery on a patient with a pacemaker or an ICD?
the current must not pass across the pacemaker.
to recieve a shock, a person must become a part of and complete an?
electrical circuit
for current to flow, there has to be a voltage difference across an ______.
impedance.
therefore, if a closed circuit exists, then exposure to a live electricity source provides an electromotive force (voltage) that pushes the current through an impedance. The impedance can be?
you or the patient
an electrical current that enters the body will exit the body along the path?
of least resistance
name three consequences of electrical injury?
cardiac arrhythmias
nerve injury
thermal injury
with electrical injury resulting in nerve injury you could have _____ paralysis and muscle contractions
diaphragmatic
with thermal injury from an electrical injury the damage to the ______ may be more extensive than the damage you observe on the skin
internal organs
define macroshock?
a comparatively larger amount of current that is applied to the external surface of the body.
why must larger amounts of current be applied to the external surface of the body?
because the impedance of the skin offers a high resistance
1 mA of macroshock results in?
threshold for touch perception of electrical shock
5 mA of macroshock results in?
maximum current for a harmless electrical shock
10-20 mA of macroshock results in?
“let go” current occurs before sustained contraction
50 mA of macroshock results in?
loss of consciousness
100 mA of macroshock results in?
ventricular fibrillation
define microshock?
a comparatively smaller amount of current that is applied directly to the myocardium
with microshock, the high resistance of the skin is bypassed, so it takes a significantly ____ amount of current to induce ventricular fibrillation.
smaller
10 uA of microshock results in?
maximum allowable current leak in the OR
100 uA of microshock results in?
ventricular fibrillation
what unit are used in microshock?
uA
what unit of measurement are used in macroshock?
mA
What type of devices provide a direct conductive pathway to the heart, so it should make sense that they increase the patient’s susceptibility to microshock.
central line
PA catheter
pacing wires
How does the electrical system in the OR reduce the risk of electrical shock in what two ways?
OR power supply is NOT grounded
the equipment is grounded
for an electrical shock to occur in the OR there must be ___ faults in the system, which are?
2 faults
first, the OR power supply becomes grounded
second, the equipment is not grounded.
the line isolation monitor serves what purpose?
to assess the integrity of the undergrounded power system in the OR
the line isolation monitor, tells you when the OR becomes grounded and how much?
current could potentially flow through you or a patient if a second fault occurs
if the line isolation monitor alarm sounds what should you do?
the last piece of equipment that was plugged in should be unplugged
the line isolation monitor will alarm when?
when 2-5 mA of leak current is detected
all electrical devices leak a small amount of?
current
if the sum of the leak of currents from devices in the OR exceeds 2-5 mA, the LIM alarm will sound, however, there is no risk of electrical shock in this situation, and what corrective action is required?
none
does the LIM by itself protect you or the patient from macro or micro shock?
no
what is the primary purpose of the LIM?
to alert the OR staff of the first fault, meaning the OR has become grounded
CRNAs are at greater risk for exposure to ____ radiation
ionizing
where are potential areas for ionizing radiation exposure for the CRNA?
CT, CCL, EP lab, IR, NM, RAD therapy, anywhere fluoroscopy is used
ionizing radiation can remove electrons from atoms, this causes ______.
free radicals
free radicals can be damaging on the ____ level
which includes risk of tissue injury, chromosomal damage or malignancy
cellular
most exposure of ionizing radiation is the result of ___ ____ , not direct exposure
scattering x-rays
how do we quantify exposure to ionizing radiation?
roentgen (R)
the roentgen equivalent in man (REM) is a unit dose equivalent, this relates the?
human tissue absorption to the effective biological damage of the radiation
the yearly maximum radiation exposure is ___ rem
5 rem
the yearly maximum exposure for the fetus of a pregnant worker is ___ rem or ___ rem/month
0.5
or
0.05 rem/month
in the non-pregnant person, the ___ and ____ are the most susceptible to injury from radiation on the body.
eye and thyroid
in the pregnant person, who is most suseptible to injury the mother or the fetus?
the fetus
how can you protect yourself from radiation? 3 ways
distance
duration
shielding
the minimum safe distance is ___ feet from the radiation source.
6 feet
the amount of exposure is _____ proportional to the square of the distance of the source
inversely
six feet of air confers the same protection from radiation as ___ inches of concrete or ___ mm of lead
9 inches of concrete
2.5 mm of lead
a lead apron is usually ___ mm thick
0.25 to 0.5 mm
what is the measuring device for radiation exposure?
dosimeter
where should a pregnant provider where her second dosimeter?
under her apron
where should a provider wear a dosimeter?
on the shirt collar near the thyroid gland.
