Nurs 613 Principles Exam 1

Front 1

What does the O2 flush valve deliver? and where does it go?

Back 1

35-75L/min of 100% O2; to the Common Gas Outlet

Front 2

Whats the purpose of the Fail Safe system? How does it work?

Back 2

-halts the flow of all gasses except Oxygen in the event of O2 failure.
-valve/"gate" held open by pressure in O2 line. Only allows flow of other gases if O2 pressure is sufficient.

Front 3

When using Piston Ventilators, will the TV delivered by affected by variation in O2 pipeline pressure?

Back 3

NO- piston ventilators use electric motors to compress bellows and deliver TV.

Front 4

Function of the proportioning system is...

Back 4

Prevent delivery of hypoxic mixture (makes sure ratio of N2O to O2 is not more than 3:1). Links N2O and O2 mechanically or pneumatically, to prevent final O2 concentration less than 25%. If N2O increased beyond max allowed there is a proportional increase in O2. If O2 flow lowered, proportional decrease in N2O.

Front 5

In what 4 situations could a hypoxic mixture be delivered despite use of hypoxic safeguard?

Back 5

1) wrong supply gas in tank or pipeline
2)defective pneumatics or mechanics
3)leaks downstream of flow control valve
4)inert gas admin (ex. 3rd gas like helium)

Front 6

Rate of vaporization depends on what factors?

Back 6

1) temperature
2) vapor pressure of the liquid
3)partial pressure of the vapor above the evaporating liquid

Front 7

What is the splitting ratio?
How is it determined?

Back 7

It's the gas entering the vaporizer chamber divided by the FGF.
-automatically determined in variable bypass vaporizers by internal resistance to flow when a specific % is selected

Front 8

During Sevoflurane administration an unusually delayed rise or unexpected decline of inspired concentration comparted to vaporizer setting may be associated with what?

Back 8

Excessive heating of the CO2 absorbant cannister

Front 9

Resistance in a breathing circuit can be minimized by...

Back 9

-reducing circuit length
-increasing diameter of tubing
-avoiding use of sharp bends (keep angles less than 20 deg)
-eliminating valves
-maintaining laminar flow

Front 10

Advantages of rebreathing

Back 10

-economical
-Increase or maintain tracheal warmth and humidity
-decrease potential for exposure of gasses to OR personnel
-maintain pt temp
-prevent soda lime granules from drying out

Front 11

Rebreathing of exhaled Nitrogen slows induction true or false?

Back 11

True

Front 12

Common features of Non-rebreathing systems include:

Back 12

-Lack unidirectional valves
-Lack CO2 absorbant
-Amount of rebreathing is HIGHLY dependent on FGF rate
-Resistance is kept to a minimum

Front 13

Two common reasons for an increase in inspired CO2 with circle system?

Back 13

1) Exhausted absorbant granules
2) Faulty unidirectional valves

Front 14

True or False: Incompetence of inspiratory or expiratory valves turns the entire corrugated limb into dead space.

Back 14

True

Front 15

How do you convert a closed circle system to a semi open configuration and why would you do this?

Back 15

-Increase FGF to 5-8L/min and open APL valve
-Do this if inspired CO2 of more than 1-3mmHg is detected on capnograph

Front 16

True/False: Oxyhemoglobin absorbs a greater amount of Red light.

Back 16

False: it absorbs a greater amount of infrared light at 960nm.

Front 17

True/False: Methemoglobin has the same absorption coefficient at both red (660) and infrared light (940).

Back 17

True

Front 18

True/false: Carboxyhemoglobin and Oxyhgb absorb light at 660nm identically.

Back 18

True

Front 19

Name a situation in which a patients sat of 90% MAY indicate a PaO2 of LESS than 65mmHg.

Back 19

-hypothermia
-alkalosis
-decreased 2,3 DPG
-hypocarbia
(shift to the Left on Oxyhgb dissociation curve)

Front 20

Laminar flow occurs at------- Reynolds numbers, where
------forces are dominant.

Back 20

Laminar flow at LOW reynolds numbers, where VISCOUS forces are dominant.

Front 21

What kind of flow would you expect to see at HIGH reynolds numbers?

Back 21

Turbulant flow, dominated by inertial forces

Front 22

For any sized tube transition from laminar straight to turbulent flow occurs when the Re number reaches what value?

Back 22

Reynolds number of 2100

Front 23

Flow through an abrupt orifice (ie. flowmeter) becomes turbulent at Re # of what?

Back 23

Less than 100

Front 24

What 3 functions does a hanger yoke serve?

Back 24

1) orients cylinders
2)provides gas tight seal
3) ensures undirectional flow

Front 25

Whats the calculation to determine how long an O2 cylinder will last?

Back 25

remaining contents (L)/gauge pressure (psi)=capacity (L)/service pressure (psi)

As oxygen is expended, the cylinder’s pressure falls in proportion to its content
1000psig = E cylinder that is half full =330L at atmospheric pressure and a temp. of 20°C
3L/min= empty in 110 min.

Front 26

which absorbs more light:
Oxyhemoglobin or deoxyhemoglobin

Back 26

deoxyhemoglobin- (dark so absorbs more light)

Front 27

infrared light wave length

Back 27

960 nm

Front 28

red light wave length

Back 28

660 nm

Front 29

if more 660 light is absorbed...

Back 29

more deoxyhemoglobin

Front 30

if more 960 light is absorbed...

Back 30

more oxygenated hemoglobin

Front 31

Will the N2O cylinder pressure change as N2O is used?

Back 31

NOT until the liquid is gone in which case it is more than 3/4 empty. b/c 745psig is the vapor pressure

Front 32

5 pathways of O2 in the Anesthesia Gas Machine are?

Back 32

1) FGF flowmeter.
2) Powers O2 flush valve
3) Activates fail safe
4) activates o2 low pressure alarm
5)Compresses bellows of mechanical ventilator.

Front 33

What does the ASA standard 1 say?

Back 33

A qualified anesthetist must be present at all times.

Front 34

What does ASA standard II say?

Back 34

oxygenation, ventilation, circulation and temperature will be monitored at all times.

Front 35

Ventilation is assessed by?

Back 35

-pt assessment (chest rise, breath sounds etc)
-volume of gas (spirometry)
-alarms
-metabolic end products like CO2

Front 36

Where will you find the most common disconnect in the breathing circuit?

Back 36

The Y piece

Front 37

What does ENDCO2 tell us?

Back 37

Expired level of CO2
-gold standard for evaluating ETT placement
-tells us if the heart is pumping
-helps to determine the quality of ventilation

Front 38

Name 3 ways to determine CO2?

Back 38

1) Mass spectrometry
2) Infrared absorption
3) Colorimetric detection

Front 39

True or False: Hemodynamic instability is associated with hypothermia.

Back 39

True

Front 40

What absorbs more light? oxygenated or deoxygenated blood
And at what wavelength?

Back 40

Deoxygenated (660 nm)
Oxygenated (940 nm)

Front 41

what causes the oxygen to be released from hemoglobin

Back 41

enzyme 2,3-DPG

Front 42

carboxyhemoglobin toxicity

Back 42

cherry red appearance

Front 43

methemoglobinemia

Back 43

blue appearance
SpO2 reading 85%

Front 44

true or false: If one extremity is above the other, pulse amplitude and SpO2 will be greater in the upper than dependent hand

Back 44

true

Front 45

What happens to normal saturations as altitude above sea level decreases?

Back 45

It decreases

Front 46

Oxidation product of hemoglobin that forms a reversible complex with oxygen and impairs unloading of oxygen to tissues

Back 46

Methemoglobin

Front 47

Whats the reversal agent for Methemoglobinemia?

Back 47

methylene blue IV 1mg/kg

Front 48

Signs and symptoms of Methemoglobinemia?

Back 48

brownish grayish cyanosis
tachypnea
Metabolic acidosis
headache
irritability

Front 49

What substances may interfere with pulse oximetry and cause erroneous readings?

Back 49

Black, blue and green nailpolish
Methylene blue, indigo carmine, indocyanine green dyes

Front 50

How does colorimetric detection work?

Back 50

exhilation gas expired contains moisture which interacts with CO2 liberating H+ causing acidification which in turn causes the color change from purple to yellow.
-tells you that CO2 is present
-No data to evaluate ventilation.

Front 51

name 2 reasons capnography waveform would not return to baseline level of 0 with inspiration?

Back 51

1) pt is rebreathing CO2
2)an obstruction at small airways just proximal to alveoli.

Front 52

True or False: A good alveolar plateau greatly increases the chances that the EtCO2 reading is a reliable estimate of the level

Back 52

True

Front 53

Alterations in ENDTCo2 can be the result of:

Back 53

Rebreathing CO2
Hypoventilation
Increased CO2 production (hypermetabolic state, MH)

Front 54

List the basic components of the anesthesia machine.

Back 54

A source of compressed gases
Flow meters
Vaporizers
A method to manually and mechanical ventilate
scavenger system

Front 55

List Functions of the Anesthesia Machine.

Back 55

-Receives medical gases from a gas supply
-Controls the flow of desired gases reducing their pressure
-Vaporize volatile anesthetics into the final gas mixtures
-Deliver the gases to the breathing circuit

Front 56

Pipeline gas is delivered at what pressure? and by what system?

Back 56

45-55 psig (pressure on starting machine)
DISS system (Diameter Index Safety System)

Front 57

What is the purpose of PISS and what does it stand for?

Back 57

to prevent misconnection of cylinder to the wrong yoke.
PISS (Pin Index Safety System)

Front 58

Cylinger pressure regulators convert the pressure from what to what?

Back 58

From Cylinder pressure of 2200psig to 45 psig

Front 59

Describe the PISS system configuration for the following gasses.
-O2, N2O, air

Back 59

-O2= 2,5
-N2O= 3,5
-air= 1, 5

Front 60

Describe 3 functions of the check valve located in the cylinder yoke.

Back 60

1.   Minimize trans-filling
2.   Allow change of cylinders during use
3. Minimize leaks to atmosphere if a yoke is empty

Front 61

Describe the Bourdon gauge?

Back 61

- It measures cylinder pressure
It is a flexible tube within this gauge straightens when exposed to gas pressure, causing a gear mechanism to move a needle pointer

Front 62

What is the purpose of a secondary regulator? What does it reduce pressures to in the Anesthesia machine?

Back 62

To further decrease pressures.
Decreases oxygen to 20 psig and nitrous oxide to 38 psig

Front 63

Whats the function of Proportioning system and how does it work?

Back 63

Links nitrous oxide and oxygen flows, mechanically or pneumatically, to prevent final inspired oxygen concentration less than 25%

Front 64

What is another name for the Oxygen supply failure protection device?

Back 64

Fail safe

Front 65

To reduce back flow

What Promotes unidirectional flow and is
found on both wall and cylinder gas flow?

Back 65

Check valves

Front 66

What happens when you push the O2 flush valve?

Back 66

-delivers HIGH flow 35-75L of 100% O2 directly to pt.
-dilutes your anesthetic which could potentially lead to awakening

Front 67

High pressure system consists of what 4 parts?

Back 67

-parts which receive gas at cylinder pressure (O2=2200psi)
-Hanger yoke (including filter and unidirectional valve)
-Yoke block
-Cylinder pressure gauge
-Cylinder pressure regulators

Front 68

Intermediate pressure system consists of what parts?

Back 68

-Receives gases at low constant pressures (37-55 psig, which is pipeline pressure) (Receive gases from regulators or pipeline and delivers to flow controls or oxygen flush valve)
-Pipeline inlets and pressure gauges
-Ventilator power inlet
-Oxygen pressure-failure device (fail-safe) and alarm
-Flow meter valves
-Oxygen second-stage regulator
-Oxygen flush valve

Front 69

Low Pressure circuit consists of what components?

Back 69

-includes components distal to the flow meter needle
-Valves
-Flow meter tubes
-Vaporizer
-Check valves (if present)
-Common gas outlet
(Takes gas from flow control valves to common gas outlet)

Front 70

name 3 types of vaporizers?

Back 70

-Measured flow: Copper kettle, vernitrol
-Blender: electronic (Ohmeda Tec6-Desflurane vaporizers, Aladin cassette vaporizers)
-modern conventional vaporizer (eg. Variable Bypass Vaporizer)

Front 71

True or False: Only some of the air flow passing through Copper kettle vaporizer comes in contact with the anesthetic agent.

Back 71

False: ALL the air that passes through this type of vaporizer comes in contact with anesthetic liquid.

Front 72

Copper Kettle system is based on what?

Back 72

FLOW of the anesthetic liquid. Adjust flow on dedicated flow meter up or down to alter concentration of agent.

Front 73

Name some charachteristics of a Modern Conventional vaporizer.

Back 73

-Agent specific
-Capable of delivering a constant concentration
Regardless of temperature -changes or flow through the vaporizer occur by
turning a single calibrated control knob counterclockwise to desired percentage

Front 74

What is the minimum flow recommended on most flow meters and what pressur does it deliver it under?

Back 74

200-300cc/min
at 16 psig (some books say 20 psig)

Front 75

Name some potential causes of flow meter malfunction.

Back 75

-dirt,
-vertical misalignment
-sticking of float at the top of a tube
-leaving flow meter on when machine is turned off then next time machine is turned on float excelerates to top damaging flow meter.

Front 76

Name the parts of a Thorpe tube?

Back 76

ie. flow meter, constant pressure variable orifice flow meter.
-Parts: needle valve, indicator float, knobs, valve stops

Front 77

A secondary regulator drops the pressure to a N2O flow meter to what?

Back 77

- N2O to 38 psig

Front 78

Describe what will happen if you attempt to manually ventilate a pt with the APL valve open.

Back 78

The bag will not fill properly preventing you from getting a seal and delivering manual breaths.

Front 79

True or False: You can cause Barotrauma if you attempt to manually ventilate your patient with a closed APL valve.

Back 79

True

Front 80

Name 3 hazards associated with the APL valve.

Back 80

-Can cause barotrauma
-accidental activation
-sticking in the on position

Front 81

Name the components of the Circle system.

Back 81

-Fresh Gas Flow
-I/E unidirectional valve
-I/E tubing
-Y – connector
-Pop off (overflow)
-Reservoir bag
-CO2 absorbent

Front 82

What will happen if the inspiratory valve is stuck open on the circle system?

Back 82

Rebreath CO2 b/c it wont close allowing what pt expires to back flow.

Front 83

ratings

Back 83

An assessment of a representative's voting record on issues important to an interest group

Front 84

What is the current minimum flow recommendation when administering Sevofluratne?

Back 84

not recommended at total fresh gas flows less than 1 L/min for more than 2 MAC-Hours

Front 85

What does the scavagening system consist of?

Back 85

Scavenger System consists of: 1) gas collecting assembly,
2) a transfer means,
3) the interface,
4) gas disposal tubing,
5) gas disposal assembly. (some or all components may be combined). ASTM standard fitting size for scavenger hoses 19 mm ( international standard 30mm)

Front 86

What is the function of the scavenger interface?

Back 86

It protects the breathing circuit from excess positive or negative pressure. Must contain a positive pressure relief to vent excess gasses in the event of an obstruction.

Front 87

What are the National Institutes for Safety and Health's recommendations as far as limiting room concentrations of gasses?

Back 87

Nitrous oxide to 25ppm
Halogenated agents to 2ppm
Halogenated agents with nitrous 0.5ppm

Front 88

What does Phase III of the Capnography waveform represent?

Back 88

The alveolar plateau- emptying of distal alveoli.

Front 89

American National Standards Institute

Back 89

Organization who set the stds for the Anesthesia machine

Front 90

Cylinder pressure regulator

Back 90

Converts high (~2200), variable pressure to a constant pressure of ~45-47psi downstream of the regulator.

Front 91

3 types of valves and their functions

Back 91

Free floating: Moves by gas pushing it (DISS/Hangar Yolk System). Prevents leaking of gas.
Ball and Spring: Permits gas flow by adjoining two pieces (male to female) displacing the ball
Diaphragm Valve:
seen on the 1st/2nd stage regulators
They reduce pressure

Front 92

Check valve position and purpose (Jackie said to know)

Back 92

To reduce back flow
Promotes unidirectional flow
Found on both wall and cylinder gas flow

Front 93

Copper Kettle vaporizer (how works, classified)

Back 93

Classified as:
A measured flow vaporizer or flow meter-controlled vaporizer
The amount of carrier gas bubbled through the volatile anesthetic is controlled by a dedicated flow meter
All of the gas entering the vaporizer passes through the anesthetic liquid and becomes saturated with vapor

Front 94

Bourdon Gauge purpose and how it works

Back 94

Cylinder pressure is measured by the Bourdon gauge
It is a flexible tube within this gauge straightens when exposed to gas pressure, causing a gear mechanism to move a needle pointer

Front 95

If the lipid solubility of an agent is high then the MAC of the agent is: a. High b. Low

Back 95

b. low (from sweat book 334)

Front 96

Potency of an inhalational agent is directly related to its
a. MAC.
b. blood solubility.
c. lipid solubility.
d. vapor pressure.

Back 96

c. lipid solubility (sweat book 334)

Front 97

MAC is:
a. inversely related to potency.
b. directly related to potency.
c. inversely related to vapor pressure.
d. directly related to blood solubility.

Back 97

a. inversely related to potency (sweat book 334)
Potency is directly related to lipid solubility. The oil (o1ive):gas partition coefficient provides a quantitative measure of lipid solubility (olive oil resem-
bles membrane lipids)
The minimum alveolar concentration (MAC) is the alveolar concentration of an inhalational agent at which 50%of patients do not move in response to skin incision or similar noxious stimulus;MAC is inversely related to potency.

Front 98

If an agent is highly blood soluble, then the blood:gas partition coefficient is:
a. low.
b. high.
c. the same as oil:gas partition coefficient.
d. may be high or low depending on the patient.

Back 98

b. high (sweat book 334)
Blood solubility determines the speed at which the partial pressure of the agent builds up in the blood and subsequently in the brain. It also determines the speed at which an agent is eliminated from the blood and the brain
The blood:gas partition coefficient provides a quantitative measure of blood solubility

Front 99

Blood solubility determines:
a. speed of uptake of agent by the brain.
b. MAC.
c. potency.
d. the degree of hypotension the agent will produce

Back 99

a. speed of uptake of agent by the brain (sweat book 334)
Blood solubility determines the speed at which the partial pressure of the agent builds up in the blood and subsequently in the brain. It also determines the speed at which an agent is eliminated from the blood and the brain
The b1ood:gas partition coefficient provides a quantitative measure of blood solubility

Front 100

Circle system Unidirectional valves other names

Back 100

aka flutter valves, one way valves, check valves, directional valves, dome valves. Found on Inspiratory and Expiratory flow ports

Front 101

Most common ventilator problems

Back 101

Disconnect most common at y-piece
Precordial
etCO2
Occlusion of breathing circuit: may lead to barotrauma
kinked tube
APL tight when masking
Managing a problem:
Attempt to manual ventilate
Ambu on O2 without machine

Front 102

The medical gas commonly used are:

Back 102

Oxygen (green cylinder)
Nitrous oxide (Blue)
Air (Yellow)
Nitrogen (black)
Please note; while technically not a gas, vacuum exhaust for anesthetics waste gas disposal and surgical suction are considered important to the medical gas system

Front 103

What breathing system is associated with the least amount of resistance?

Back 103

Open (Insufflation)
eg. Old ether screen

Front 104

Where is the most resistance located in an intubated patient?

Back 104

connection between ETT and circuit connector/Y-piece

Front 105

What is the source of the most resistance in an Unintubated patient?

Back 105

at expiratory valve in semi-closed system

Front 106

Density of gas determines flow at ______ flow rates

Back 106

HIGH

Front 107

Viscosity of gas determines flow at _____ flow rates

Back 107

LOW

Front 108

If you increase the length of tubing what happens to the flow?

Back 108

You DECREASE the flow
(Poiseulilles Law)

Front 109

delivery of gases from anesthesia machine via a circuit or mask held above patient’s face

Back 109

Insufflation

Front 110

Alternate names for the APL valve

Back 110

-overflow
-exhaust

Front 111

Name some advantages of the semi-open system.

Back 111

-simple design,
- ability to change anesthetic depth rapidly
-portability
- lack of rebreathing (provided fresh gas flow is adequate)
- low resistance

Front 112

Identify disadvantages of the Semi-open system.

Back 112

-loss of heat and humidity,
-limited ability to scavenge gases (pollution),
- high gas flow requirements 
-less economical

Front 113

What are the two main features that CRNA's need to know regarding medical gas systems in order to prevent pt endangerment

Back 113

Sources of the gases & means of delivery are necessary to prevent and detect medical gas depletion or supply line misconnection

Front 114

Department of Transportation (DOT) role in Anesthesia

Back 114

responsible for the regulation of contents of compressed gas cylinders. Must contain: Serial #, service pressure, DOT specification number

Front 115

What markings are required by DOT?

Back 115

Serial #, service pressure, DOT specification number

Front 116

Standard Organizations in Anesthesia

Back 116

Department of transportation (DOT)
Food & Drug Administration (FDA) National Fire Prevention Association (NFPA)
Compressed Gas Association (CGA)
JCAHO
American Society for testing and Materials (ASTM)

Front 117

JCAHO role in Anesthesia

Back 117

Requires preop assessment in all pts - never to OR with no preop assessment

Front 118

Characteristics of Medical GAS

Back 118

O2 - 625-700 L capacity, 1800-2200 psi Pressure, USA color-green, international color-white, form-gas
Air - 625-700 L capacity - 1800-2200 psi Pressure, color USA-yellow, color international-white&black, form-gas
N2O-1590 L capacity, 745 psi pressure, USA&intern'l color-blue, form-liquid

Front 119

oxygen how manufactured, stored

Back 119

Manufactured by fractional distillation of liquefied air
Stored as a compressed gas at room temperature or refrigerated as a liquid
Stored in banks of H – cylinders connected to a manifold
Manifolds contains valves that reduce cylinder pressure to line pressure
Automatically switch banks when one group is exhausted
Liquid: Must be stored below it’s critical temperature -119°C
The anesthesia provider must always have an emergency (E-cylinder) supply of oxygen available on the anesthesia machine

Front 120

Nitrous Oxide Characteristics, manufacture, storage, critical temp

Back 120

Most commonly used anesthetic gas (analgesia & sleepy)
Fills spaces in body (i.e. N/V-prevent via antiemetics)
Manufactured by heating ammonium nitrate
Stored in large high pressure cylinders
Critical temperature 36.5°C
Kept liquid without refrigerator system
If rises above critical temperature it will revert to gaseous phase

Transformation into gaseous phase is not accompanied by great rise in pressure

Front 121

Relief Valve: other name and what it's designed to do

Back 121

(aka rupture disk)
Prevent explosion of unexpected high gas pressure
(Ie, designed to rupture at 3300 psig)
Volume of the tank is not proportional to the pressure
Only reliable way to determine residual is to weigh the cylinder
Higher reading indicates:
Gauge malfunction, overfill or cylinder containing a gas other than NO

Front 122

Air in Anesthesia (reasons for use, critical temp)

Back 122

Becoming more frequent in anesthesia: keeps integrity of Alveoli d/t nitrogen in air while 100% O2 leads to atelectasis. Also, air used to prevent fire in trach insertion with bovie use.
Critical temperature is – 140.6°C
Pressures fall in proportion to their content

Front 123

If you tighten your APL valve what do you do to pressure and resistance?

Back 123

Increases resistance

Front 124

Normal adult minute volume

Back 124

5-8L/min

Front 125

VA (Alveolar ventilation)+ DV(dead space ventilation)=

Back 125

Minute volume or Minute ventilation

Front 126

True or False: The higher the minute volume the less carbon dioxide (CO2) the person is releasing.

Back 126

FALSE: higher the minute volume the more CO2 the patient is releasing.

Front 127

Do soda lime granules create resistance in the breathing circuit?

Back 127

Yes. All absorbants add some resistance to the breathing circuit.

Front 128

Vacuum in OR

Back 128

Consist of two independent suction pumps
Traps located at every user site which helps to prevent contamination of the system

Front 129

Effects of environmental temp in OR

Back 129

Cold pts slow to wake up, wound infection, blood loss, coagulation issues.

Front 130

Environmental factors of OR

Back 130

Temperature:
Hypothermia: wound infection, blood loss, coagulation issues
Neurological protection (Crani or CPB); 24°C burn patients
Humidity
Static
Flammable vs nonflammable
Ventilation
Air flow: decreases contamination of the surgical site
Noise
Detrimental on human cognitive functions

Front 131

Pressures at cylinder, pipeline and fail safe system

Back 131

2200 psi; 45-55 psi; O2 drops below 25 psi

Front 132

Max leak current in OR

Back 132

10 micro Amps

Front 133

Line isolation Monitor:

Back 133

determines the degree of isolation between two power wires and the ground and predicts the amount of current that could flow if a short circuit develops. Alarm activates if too high current. Power not interrupted. Upon activation of alarm, last electrical equipment plugged in should be unplugged.

Front 134

When is there a risk of electrocution in regard to a circuit

Back 134

Two conductive materials at different voltage potentials may complete a circuit

Front 135

Protection from electric shock in OR

Back 135

Isolated transformer: OR power supply isolated from ground
Line isolation monitor: determines the degree of isolation between two power wires and the ground and predicts the amount of current that could flow if a short circuit develops

Front 136

Another name for a semi-open breathing system.

Back 136

Flow controlled breathing system.

Front 137

In a Semi-open breathing system when will rebreathing occur?

Back 137

When the inspiratory flow exceeds the fresh gas flow.
FLOW is key

Front 138

Advantages of the Mapleson system.

Back 138

-Minimal dead space
-Low resistance (great for fragile airway/peds)
-Can be used w/mask and ETT
-Inexpensive

Front 139

Which Mapleson is Characterized by placement of APL valve near the patient and separation of gas reservoir bag from valve by corrugated tubing?

Back 139

mapleson A (Magill)

Front 140

Which Mapleson is most efficient for CO2 elimination for a spontaneously breathing patient?

Back 140

Mapleson A

Front 141

Surgical Diathermy: Electrosurgical Units (ESU) names and interaction

Back 141

Bovie pad: return electrode or exit pathway for electrical current generated through the cautery tip - grounds the pt to prevent spark. placed on muscle. Completes the circuit to the machine
Pacemaker - place bovie pad away from pacemakers
Malfunction of ESU
Bipolar - bovie that has ground contained in tip

Front 142

Fires & explosions prevention in the OR

Back 142

~100 fires/yr, most involve face (i.e. chloraprep not dried), suction could be used in the folds of the drape to prevent collecting of gases. Burn injuries include warmed IV bags (burning of vessel), warming blankets.

Front 143

Vapor Pressure (VP)

Back 143

Created by molecules in the vapor phase bombarding the walls of a container

Front 144

Saturated Vapor Pressure (SVP)

Back 144

Gas phase above the liquid usually at 20°C
↑Temp → ↑SVP
VP is independent of atmospheric pressure if the temperature remains constant

Front 145

Boiling point

Back 145

The temperature at which the vapor pressure equals atmospheric pressure

Front 146

Units of Vapor Concentration

Back 146

Absolute pressure (mmHg)
Volumes percent

Front 147

Dalton's law of Partial Pressures

Back 147

The total pressure exerted by a gas mixture is the sum of the individual pressures of its constituents

Front 148

Latent Heat of Vaporization

Back 148

The # of cal required to change 1 g of liquid into vapor without a temp change

Front 149

Specific Heat

Back 149

The # of cal required to increase the temp of 1 g of a substance by 1°C

Front 150

Isoflurane

Back 150

MAC 1.15%

Front 151

Sevoflurane

Back 151

MAC 1.7 %

Front 152

Desflurane (MAC, vaporizer needs)

Back 152

MAC 6-7.25; Requires an external heat source
4-9 times more Des is required than other IA
Absolute amount of Des vaporized is much higher than other IA which would cause excessive cooling
Irritating to mucous membranes - LMA-may stimulate lead to laryngospasm d/t sleep and try to cough but not able & chords may spasm.
Traditional vaporizers could not compensate adequately
VP of 669 mmHg – near 1 atm
Traditional vaporizer would cause an anesthetic overdose
Des = 735 ml/min opposed to Iso = 47 ml/min

Front 153

Differences btw measured flow vaporizers and Variable Bypass vaporizers

Back 153

Measured Flow: Carrier gas (CG) bubbles through agent
Manual Temp. conversion
Multi-agent
Operator determines CG split
No longer manufactured (but still present on field machines)
Variable Bypass: CG flows over agent
Auto adjust for Temp & Pressure
Agent specific
Auto CG split
Higher safety standards

Front 154

Temperature Regulation in vaporizers

Metals with high specific heat and high thermal conductivity are used to minimize heat loss
Close to wicks etc
Bypass chamber receives less flow with _______ temperatures
Bypass chamber receives more flow with _______ temperatures

Back 154

Metals with high specific heat and high thermal conductivity are used to minimize heat loss
Close to wicks etc
Bypass chamber receives less flow with 'Lower' temperatures
Bypass chamber receives more flow with 'higher' temperatures

Front 155

What is the effect of Temperature regulation thru the vaporizer?

Back 155

↓Temperature → ↓Vapor Pressure
Sluggish/not hitting the sides of the vaporizer
More flow must go through the vaporizing chamber so that the patient receives the same concentration of agent
↑Temperature → ↑Vapor Pressure
Hitting the sides of the vaporizer rapidly
Less flow must go through the vaporizing chamber so that the patient receives the same concentration of agent

Front 156

Effx of varied altitudes on Tec 6 Desflurane Vaporizer

Back 156

Requires manual adjustments of the concentration dial with changes in barometric pressure
It is a pressurized vaporizer
It works at an absolute pressure
Partial pressure of Des changes with changes in ambient pressure
Required setting = Normal setting (%) X 760 mmHg/ambient pressure (mm Hg)

Front 157

Tec 6 Carrier Gas composition effx on viscosity with gas other than O2

Back 157

Decreased concentration output can occur with low flows of gases other than oxygen due to changes in viscosity
Vaporizer output is 20% less with nitrous than with oxygen
Nitrous oxide is less viscous than oxygen resulting in a lower working pressure at the differential pressure transducer
Take home – May have to increase dialed concentration with low flow anesthesia
Careful with low FIO2

Front 158

Hazards with vaporizers

Back 158

Incorrect agent
Simultaneous agent administration
Free Standing
Overfilling
Tipping

Front 159

Vaporizer Safety Mechanisms

Back 159

Push/Turn
Interlock-only one vaporizer at a time to be opened
Color Codes
“Keyed” filler system

Front 160

How many PPM when you can smell the agent

Back 160

5-300ppm

Front 161

Oximetry

Back 161

oximetry is produced by passing radiation through a sample and measuring the amount of absorbed radiation from a compound of interest. Msmt of a light source (radiation/heat/energy) absorbed by a substance.

Front 162

Pulse Oximetry

Back 162

Mandatory AANA/ASA standard monitor to aid in detecting hypoxemia
Noninvasive measurement of oxygen saturation (SpO2) in arterial blood
Sensor consists of 2 light emitting diodes (LED) and a light detector (a photocell/photodiode); a microprocessor analyzes the info and displays the SpO2
Placed across a pulsatile arterial bed (finger, toe, earlobe or any other perfused tissue)

combo of oximetry and plethysmography. Arterial pulsations are identified by plethysmography.