Final Exam Review Flashcards
What is an aneroid gauge?
A gauge without liquid
What is a bourdon gauge?
A type of aneroid gauge; no liquid inside
A bourdon gauge measures ___ and is seen on what types of tanks?
Gas pressures (specifically measures pressure difference between the pressure exerted by the gas in the compressed cylinder vs. atmospheric pressure)
Seen on O2, air, and N2O tanks
When the bourdon gauge reads ‘0’, is there any pressure left in the tank?
YES—once it reads 0, it still has the equivalent of atmospheric pressure in there (14 psi of atmospheric pressure remains)
A tank of gas has a gauge that reads 45 psi. If the atmospheric pressure at that time is 14 psi, how much gas is really in the tank?
P total = P gauge + P atmosphere
P total = 45 + 14 = 59 psi
1 atm = ___ psi
14 psi
1 atm = ___ torr = ___ mm Hg
1 atm = 760 torr = 760 mm Hg
Barometer is an instrument used to measure ___
Atmospheric pressure
Manometer is an instrument used to measure ___
Pressure differences
What law is the basis of pulse oximetry?
Beer Lambert’s Law
Pulse ox measures the difference between background absorption in ___ and peak absorption during ___
Diastole; systole
Infrared light— ___ nm; measures ___; corresponds with ___% sat
940 nm; measures oxyhemoglobin; corresponds with 100% sat
Red light— ___ nm; measures ___; corresponds with ___% sat
660 nm; measures deoxyhemoglobin; corresponds with 50% sat
Carboxyhemoglobin— ___ binds to hemoglobin instead of O2; shows SPO2 reading of ___; use ___
CO; SPO2 reading of 100% (inaccurate); use co-oximeter
Methemoglobin
Fe 2+ converts to Fe 3+ form; O2 cannot be transported by iron in hemoglobin
Methemoglobin is caused by what (6) things?
- Nitrates
- Nitrites
- Sulfonamides
- Benzocaine spray
- Nitroglycerin
- Nitroprusside
Methemoglobin absorbs ___ at both wavelengths
Equally
Methemglobin shows sat of ___%
85%
Treatment for methemoglobinemia
Methylene blue or ascorbic acid
What two things do NOT affect pulse ox readings?
Fetal hemoglobin and bilirubin
___ is the basis behind non-invasive blood pressure technology
Oscillometry
___ is used in pressure monitoring with transducers
Piezoelectric technology
Electricity is defined as the effects produced by ___
Moving charges
Proton =
Positive charge
Electron =
Negative charge
Fundamental principle of charge interaction—opposite charges ___; like charges ___
Opposite charges attract; like charges repel
Electric current is the amount of…
Charge flowing per unit of time
What substances allow electrons to move easily from one atom to the next?
Conductors (i.e.: metals—electron shells mostly empty)
What substances do NOT allow electrons to move easily from one atom to the next?
Nonmetals
What is the point of CO2 absorption (soda lime) in the anesthesia gas machine?
To remove/rebreathe CO2 from the patient’s exhaled air; goal is to conserve O2, agent, as well as heat
How many L of CO2/100g of absorbent?
23 L CO2/100 g of absorbent
What is the soda lime reaction that takes place when CO2 is reabsorbed?—CO2 chemically combines with ___ to form __
CO2 combines with H2O to form carbonic acid
Soda lime contains ___ that are capable of neutralizing carbonic acid
Hydroxide salts
What are the (3) reaction end products of CO2 reabsorption?
Heat, water, and calcium carbonate
What color does soda lime turn when exhausted?
Purple
Which inhalation agent forms compound A when degraded by soda lime?
Sevoflurane
CO2 reabsorption has the potential to generate ___
Carbon monoxide
What should you do with your flows when the anesthesia machine is NOT in use?
Turn off all gas flows!
What is the unit of flow rate?
M^3/s (cubic meters per second)
Narrowing causes speed to ___ tremendously
Increase
Narrowing causes flow rate to ___
Remain the same
Which principle does this describe?—as the speed of a fluid increases, the pressure exerted by the fluid decreases
Bernoulli’s principle—pressure of a fluid varies inversely with speed
Bernoulli—an increase in speed = ___ in pressure
Decrease in pressure
Bernoulli—a decrease in speed = ___ in pressure
Increase in pressure
Bernoulli—pressure is ___ in the narrow part of the tube
LOWER in the narrow part of the tube because speed is greatest there (inverse relationship between speed and pressure)
The Venturi flow meter was originally used to measure ___; today, it’s the idea behind ___
Used to measure the speed of fluid in a pipe; today, it’s the idea behind nebulizer treatments
What type of change is this?—no change in the chemical makeup (i.e.: melting ice)
Physical change
What type of change is this?—always makes a chemically different substance (i.e.: 2H2O —> 2 H2 + O2)
Chemical change
What type of property is this?—may be observed/measured without changing the chemical makeup
Physical property
What are two types of physical properties?
- Intensive
- Extensive
What type of physical property is this?—integral to the material, regardless of amount (i.e.: color)
Intensive physical property
What type of physical property is this?—depends on the sample size (i.e.: volume)
Extensive physical property
What type of property is this?—describes the type of chemical changes the material tends to undergo (i.e.: flammable)
Chemical property
The following is an example of what type of change?—boiling water to steam
Physical change
The following is an example of what type of property?—liquid
Intensive physical property
The following is an example of what type of property?—mass
Extensive physical property
What is kinetic energy?
Energy of a mass in motion
What is potential energy?
Stored energy
What is the unit of measurement for energy?
Joules
What is internal energy?
The sum of the kinetic and potential energies in a system
What does STP stand for?
Standard temperature and pressure; unless stated otherwise, follow these conditions
What is standard temperature?
T = 273 K (0 degrees C)
What is standard pressure?
1 atm = 760 mm Hg
One mole of ideal gas has a volume of ___ L
22.414 L (or 22.7 according to new literature)
___ forces determine how molecules interact
Intermolecular
Intermolecular forces arise because of the attraction of ___ forces—what law does this describe?
Opposite forces—Coulomb’s Law
What type of substance does this describe?—intermolecular forces are strong enough to hold molecules rigidly in place with respect to each other
Solid
What type of substance does this describe?—molecules are held in a condensed phase, not strong enough to prevent molecules from sliding past each other
Liquid
What type of substance does this describe?—neither definite shape nor volume; intermolecular forces are essentially zero
Gas
___ are formed from metals and nonmetals
Ionic compounds
___ are formed from oppositely charge ions; generally stronger than covalent bonds; most commonly solids
Ionic bonds
What is the relative concentration of solutes in osmotic systems?
Tonicity
Equal concentrations of particles =
Isotonic
Greater concentration of particles =
Hypertonic
Lower concentration of particles =
Hypotonic
Diffusion of water is ___
Osmosis
Diffusion always occurs from ___ concentration to ___ concentration
High concentration to low concentration
What law explains why the surface tension on a blood vessel wall depends on the radius of that vessel?
LaPlace’s law
LaPlace’s law states that for cylinders, T (wall tension) =
T = Pr
T = wall tension P = pressure R = radius
LaPlace’s law—wall tension is directly proportional to ___
The radius of the vessel; as the radius increases, so does wall tension (and vice versa)
___ has greater wall tension than a capillary
Aorta > capillary
What in our bodies helps to decrease surface tension?
Surfactant
Water has a ___ (low/high) surface tension
HIGH
What is the closed path through which a charge flows?
Electric circuit
Direct current circuit—current flows in ___ direction
One direction only
Alternating current circuit—current ___ direction
Reverses
A short circuit is a ___ path resulting in a large current
Low resistance path
If current from a short circuit is NOT limited by a fuse or circuit breaker, the resulting heat from the high current can lead to ___
A fire
Series circuits—batteries or resistors are connected in ___; the voltages and resistances are ___
Connected in series; added (R total = R1 + R2)
Parallel circuits—current flows through each resistor ___; voltages/resistances are added ___
Independently; added inversely (1/R total = 1/R + 1/R)
We pay for ___, NOT electrical power
Electrical energy—power x time
What type of shock is this?—large amounts of current conducted through a patient’s skin or other tissues; extent of injury depends on the amount of current and the duration of exposure
Macroshock
What type of shock is this?—delivery of small amounts of current directly into the heart
Microshock
With Microshock, very small currents < ___ milliamps can produce V Fib
< 50 milliamps
What provides a low resistance pathway for leakage current and constitutes the major source of protection against Microshock?
Ground wire
Can you touch (simultaneously) an electrical device and a saline filled CVP line or pacing wires?
NO!!! Must wear rubber gloves
What are 3 types of safety features used to prevent electrical shock?
- Polarized plugs
- Three prong grounded plugs
- Ground fault circuit interrupter (GFCI)
Three prong grounded plug—grounded third prong is wired directly to ___
The casing of the electrical device
Three prong grounded plug—if for some reason a high potential wire comes into contact with the case, the current will flow directly to the ___ instead of ___
Directly to the third prong instead of through your body
Polarized plugs have one narrow prong (___ potential) and one wide prong (___ potential)
Narrow prong = high potential
Wide prong = low potential
Casing in polarized plugs is connected to the ___ prong
Wide prong—low potential
GFCIs are used in circuits near ___
Water sources
What do GCFIs do if a change in current is detected?
Immediately disrupt flow
What is a disadvantage of GFCIs?
They interrupt power without warning—problematic when using life support equipment
Modern electrical circuits are typically ___ but can still pose a risk to humans—why?
Grounded
Humans at ground potential only have to touch a single object to complete the circuit, resulting in electrical shock
In the OR, electrical systems are isolated from the grounded electrical supply through the use of ___
Isolation transformers
Isolation transformers rely on magnetic inductance to transfer current from the ___ electrical system to an ___ secondary system WITHOUT ___
Grounded electrical system; an ungrounded secondary system; without the two systems touching each other
Ungrounded systems in the operating room prevent ___ from simply touching a single live wire
Accidental shocks
The line isolation monitor alarms when ___ occurs
Fault in an ungrounded system occurs
When the line isolation monitor alarms, does current still flow?
Yes, current still flows
Line isolation monitor—if live wires contact a ground, a ___ has occurred
Fault
Line isolation monitor—if a second fault occurs, it can result in ___
Shock
Line isolation monitor is set to alarm between ___ mA
2-5 mA
If the line isolation monitor is between 2 and 5 mA, there is ___
Too much equipment plugged into the circuit
If the line isolation monitor > 5 mA…
Then there is a faulty piece of equipment plugged in; unplug things until the alarm is silenced
If the line isolation monitor system alarms, make sure it is a ___
True fault—either too much equipment plugged in or a faulty piece of equipment present
Line isolation monitor is NOT designed for protection against ___
Microshock
The main objective of electrical safety is to make it difficult for current to pass through ___
People
Electrosurgery involves ___ currents; do not excite ___ cells
High frequency currents; do not excite contractile cells
Electrosurgery cannot be safely operated unless the energy is routed from the unit through the patient and back to the unit via a ___
Large surface area dispersive electrode
ESU—if the return plate is improperly applied to the patient or if the cord connecting to the return plate is broken, then high frequency electrical current will seek ___
An alternate return path (aka shock the patient)
Most important factor in preventing patient burns from the ESU is ___
Proper application of the return plate
Which gas law states the following?—pressure is directly proportional to temperature if volume is constant
Gay-Lussac’s Law
If temperature goes up, then pressure goes up (if volume is constant)
Name this gas law—if temperature goes up, then pressure goes up (if volume is constant)
Gay-Lussac’s Law
