Chemistry, Physics & OR Safety Flashcards
what are the Building block that makes up matter?
atom
what are the positively charged particles in an atom?
protons
where are protons located?
in the nucleus
what are the neutrally charged particles in the atom?
neutrons
where are neutrons located?
inside the nucleus
what are the negatively charged particles located in the atom?
electrons
where are electrons located?
orbit the nucleus in the electron cloud
describe the orbital shell around the nucleus?
each shell has a predefined number of electrons, and each shell must be complete before electrons can begin to fill the next shell
the electrons in the outermost shell are called?
valence electrons
an incomplete shell allows what to happen?
an atom to react with another atom
a full shell makes the atom?
nonreactive
an atom with have a neutral charge if?
electrons are equal to protons
an atom will have a positive charge if?
there are less electrons than protons
an atom will have a negative charge if?
there are more electrons than protons
an ions is an atom that?
carries a positive or negative charge
an atom with a positive charge is called?
a cation
an atom with a negative charge is called?
an anion
metals tend to ____, which non metals do not.
ionize
when two or more atoms are bonded together this is called a?
molecule
describe an ionic bond?
when a complete transfer of valence electrons occurs.
describe the two atoms following an ionic bond?
the transfer leaves one atom with a negative charge and the other with a positive charge.
what is the law that electricity in the OR follows
Ohm’s law: electromotive force (voltage) = current X Impedance
describe covalent bonding?
equal sharing of valence electrons
a single covalent bond is created when?
one pair of electrons is shared
a double covalent bond is created when?
two pairs of electrons are shared
a triple covalent bond is created when ?
three pairs of electrons are shared
describe polar covalent bonding?
unequal sharing of valence electrons, meaning the electrons remain closer to one atom over the other
polar covalent bonds creates a _____ molecule, meaning?
polar
meaning where one area of the molecule is relatively positive and the other is relatively negative
why does water dissolve hydrophilic molecules?
because the polar molecule is attracted to other polar molecules
however, water (polar molecule) does not dissolve hydrophobic substances like oil and fat?
because they are non-polarized
describe van der waals forces?
a very weak intermolecular force that holds molecules of the same type together
electrons are constantly orbiting a molecule which creates temporary partial positive and negative charges at different parts of the molecule at any given time.
Thus, electron rich areas of a molecule will be attracted to electron poor areas of another molecule
a base is a species that accepts a ______ ion from an acid
hydrogen
voltage=
current=
impedance=
Voltage= driving pressure current = flow impedance = resistance
surgical electrocautery device delivers a high frequency current of ______ that is used to cut, coagulate, dissect or destroy tissue
500,000 to 1 million Htz
the current of cautery return must not pass across the
pacemaker
differentiate energy pathways for monopolar vs bipolar electrocautery
mono: uses a pin that enters that body
Bi: will not need a grounding pad
___ is placed on a patient to allow for the exit point of a return current
grounding pad (functional return electrode)
a fault in the return electrode places that patient at a risk for
burns
if the return electrode is malfunctioning, the electrical current will find another pathway to exit the body including
EKG electrodes
temperature probe
metal components of sx table
the smaller that are that the electricity exits the body, the
greater the intensity of the burn
a hydrogen ion is a _____
proton
acid-base pairs differ by one ?
hydrogen ion
the charge on the conjugate acid is always One _________ than the charge on its conjugate base.
greater
acid and bases react to give?
salts and water
the salt solution is actually a solution that contains the?
conjugate acid or base of some other acid or base
the pH of a salt solution depends on the acid/base strength of the?
acid or base from which it was derived.
salts of strong acids/bases, their conjugate bases have?
no base strength
what it the primary purpose of the Line isolation monitor
to alert the OR staff of the first fault (it does not protect personnel or patients from macro-micro shocks)
salts of weak acids are?
bases
the conjugate base of salts of weak acids?
have some appreciable base strength
salts of weak acids ____ the pH of a solution
increase
salts of weak bases are
acids
alkaloids are naturally occurring weak _____ organic compounds
basic
to prevent burns at the return pad site, the entire surface of the return electrode should
be in indirect contact with the patients skin (do not place over bony prominence or metal implants) for babies put it on their back
the electrode gel should be inspected for
dryness (if its too dry, the current wont have a direct path to the return electrode and will find another way to exit the body)
the electrocautery, in an oxygen rich environment can cause
a spark and cause a fire
for a bipolar electrocautery, the tip of the bipolar electrosurgical device (forceps) contain
the active and return electrode, therefore no return pad is needed
the current of cautery return must not pass across the
pacemaker
for a current to flow, there has to be a ____ difference across an ______
voltage difference (driving pressure) across an impedance
if a closed circuit exists, then exposure to a live electricity source provides a
electromotive force (voltage) that pushes the current through an impedance
an impedance is
can be either you or the patient
to receive a shock, a person must become a part of and complete an
electrical circuit
an electrical current that enters the body will exit the body along the
path of least resistance
what are the three consequences of electrical injury
- -cardiac arrhythmias
- -nerve injury (diaphragmatic paralysis)
- -thermal injury (damage to internal organs may be more extensive that damage observed on skin)
Macroshock is a
larger amount of current that is applied to external surface to the body
the impedance of skin offers a higher resistance for macroshock, so it takes
larger current to induce Vfib
Microshock is a
smaller amount of current applied directly to the myocardium
what are examples of direct conductive pathways to the heart
central lines, PA catheters, pacing wires, which will increase the patients susceptibility to micro shocks
the electrical systems in the OR are designed to reduce the risk of electrical shock because (2)
- the OR power supply is not grounded
2. each piece of equipment is grounded
____ assesses the integrity of the ungrounded power system in the OR
Line Isolation monitor
what it the primary purpose of the Line isolation monitor
to alert
If the LIM alarm sounds, what should occur
the last piece of equiptment that was plugged in should be unplugged
At what level will the LIM alarm go off
2-5 mA of leak current is detected
what are the voltages in microshocks for max allowable current leak in the OR and ventricular fibrillation
max allowable leak in OR: 10 uA
Ventricular fibrillation: 10 uA
macroshocks voltage:
- threshold for touch perception of electrical shock
- maximum current for a harmless electrical shock
- let go current occurs before sustained contraction
- loss of conciousness
- ventricular fibrillation
- ) 1 mA
- ) 5 mA
- ) 10-20 mA
- ) 50 mA
- ) 100 mA
CRNAs are at greater risk for exposure to
ionizing radiation (anywhere fluoroscopy is used)
ionizing radiation can remove electrons from atoms causing
free radicals (which is damaging on the cellular level including tissue injury, chromosomal, malignancy)
most exposure is as a result of
scattered X-rays, not direct exposure
the Roentgen is used to
quantify exposure
dalton’s law of partial pressures states that the total gas pressure in a container is equal to ?
the sum of the partial pressures exerted by each gas
what is the yearly maximum radiation exposure
5 rem
what is the yearly maximum exposure for the fetus of a pregnancy worker
0.5 rem or 0.05 rem/month
for a non-pregnant person, what two body parts are most susceptible to injury
eye and thyroid
in the pregnancy person, what is most susceptible to injury
fetus
what are the different ways to protect yourself from radiatoin
- distance
- duration
- shielding
distance is an easy way to protect (minimum is 6 week away from radiation source)
5. radiation exposure obeys inverse square law
what is the inverse square law for radiation exposure
the amount of exposure is inversely propositional to the square of the distance of the source
many medications are organic amines, or _______.
alkaloids
alkaloids are not very water soluble, they are converted to their conjugate acid by reacting with a?
strong acid
Non ionized molecule is usually _____ soluble and can diffuse across the cell membrane. such as the blood brain barrier, renal tubular epithelium, gastrointestinal epithelium, placenta, hepatocytes
lipid
the non-ionized form of the drug that is pharmacologically _____.
active
the degree of drug ionization is a function of its ____ and ____ of the surrounding fluid.
dissociation constant (pK) and the pH
when the pK and pH are identical, ____% of the drug exists in both the ionized and nonionized form
50%
Acidic drugs tend to be highly ionized at an ________ pH
alkaline
what is the joule-thompson effect?
a gas stored at high pressure that is suddenly released escapes from its container into a vacuum. it quickly loses speed as well significant amount of kinetic energy , resulting in a fall in temperature. Conversely, rapid compression of a gas intensifies its kinetic energy, causing the temperature to rise.
acidic drugs examples
barbiturates
critical temperature is the highest temperature a gas can?
exist as a liquid
acidic drugs are usually supplied in a _____ solution to make them more soluble in water.
basic
basic drugs are supplied in _____ solution to make them more soluble in water
acidic
describe the boiling point?
the temperature at which a liquid’s vapor pressure equals atmospheric pressure (760 mmHg or 1 ATM)
increase in atmospheric pressure will ______ the boiling point
increase
what is an example of increased atmospheric pressure?
HBO chamber
decreased atmospheric pressure results in a _____ boiling
decreased
give an example of a decreased atmospheric pressure area?
high altitude
what is specific heat?
the amount of heat required to increase the temperature of 1 gram of a substance by 1 degree of celsius
explain what vapor pressure is?
in a closed container, molecules from a volatile liquid escape the liquid phase and enter the gas phase. the molecules in the gas phase exert a pressure on the walls of the container.
vapor pressure is primarily dependent on the liquid’s ______.
temperature
liquid temperature and vapor pressure are _______ proportional.
directly
increase in liquid temperature leads to a ______ in vapor pressure
increase
at body temperature, the vapor pressure of water is _____ mmHg
47
altitude ______ affect vapor pressure
does not
define vaporizaiton
the process by which a liquid is converted to a gas
vaporization requires _____ .
energy (heat)
what is latent heat of vaporization?
the number of calories required to convert 1 gram of liquid to vapor without a temperature change
what is sevoflurane vapor pressure?
157 torr
what is the isoflurane vapor pressure?
138 torr
what is the halothane vapor pressure?
243 torr
what is desflurane vapor pressure?
659 torr