Anesthesia Flashcards
(103 cards)
1
Q
What are some examples of the high-pressure system?
A
Hanger yoke
Yoke block with check valves
Cylinder pressure gauge
Cylinder pressure regulators
2
Q
What are some examples of intermediate-pressure?
A
Pipeline inlets
Pressure gauges
Oxygen pressure failure device
Oxygen second stage regulator
Ventilator power inlet
Flowmeter valves
3
Q
What are examples of a low pressure system?
A
Flowmeter tubes
Vaporizers
Check valve
Common gas outlet
4
Q
What are the components to the SPDD model?
A
Supply: pipeline/cylinder
Processing: vaporizers
Delivery: breathing circuit
Disposal: scavenging system
5
Q
What are the 5 tasks of oxygen in the anesthesia gas machine?
A
O2 pressure alarm
O2 pressure device
O2 Flowmeter
O2 flush valves
Ventilator drive gas
6
Q
What is the PISS system?
A
Pin Index Safety System
(Prevents the wrong cylinder from being attached to the machine)
7
Q
What is the DISS system?
A
Diameter index safety system
(Prevents the wrong pipeline hose from being attached to the machine)
8
Q
What is oxygens PISS configurations?
A
2,5
9
Q
What is air’s PISS configuration?
A
1,5
10
Q
What is Nitrous Oxide’s PISS configuration?
A
3,5
11
Q
What is the max psi and Liters for a tank of O2?
A
660L
2000 psi
12
Q
What is the max psi and liters for a tank of air?
A
625
1900L
13
Q
What is the max psi and liters for a tank of Nitrous oxide?
A
1590 L
745 psi
14
Q
What is the most delicate portion of the cylinder?
A
Cylinder valve
15
Q
When should the oxygen cylinder be turned on?
A
Daily machine check and when you are NOT using pipeline gas
16
Q
What is the only way of determining cylinder content?
A
By reading its LABEL!
17
Q
What are the standard US colors for gases?
A
Oxygen: green
Air: yellow
Nitrous: Blue
18
Q
What are the World Health Organization’s colors?
A
Oxygen: white
Air: white and black
Nitrous: blue
19
Q
What two gases exist as a liquid inside their cylinder?
A
CO2
Nitrous
20
Q
What is the fire triad?
A
Oxidizer, fuel, and igniter
21
Q
What are some examples of a safety relief device? For cylinders in the event of a fire
A
Fusible plug
A valve that opens under high pressures
Frangible disk
22
Q
What is Wood’s metal typical maker of?
A
BLT- with cheese
B: Bismuth
L: Leas
T: Tin
Cheese: cadmium
23
Q
What sets the standard for compressed gas cylinders?
A
United States department of transportation
24
Q
Who sets the standards for acceptable occupational exposure to volatile anesthetics?
A
Occupational safety and Health Administration
25
Who created the 1993 anesthesia machine pre-use checkout procedures?
Food and Drug Administration
26
Who sets the standard for the required components of the anesthesia machine?
American society for Testing and Materials
27
What are the 7 things required on a gas cylinder label?
1. Government agency
2. Type of metal used to constraint cylinder
3. Max filling pressures (psi)
4. Serial number
5. Manufacturer
6. Owner
7. Date of last inspection
28
At what PSI does the threshold alarm (for the oxygen pressure failure device) sound?
<28-30 psi
29
What what pressure does the pneumatic device stop the flow of nitrous oxide? (In the oxygen pressure failure device)
< 20 psi
30
What are two ways you can still produce a hypoxic mixture with a failsafe?
Oxygen-pipeline crossover
Flowmeter leak.
31
What device prevents you from setting a hypoxic mixture with the flow control valves?
The hypoxia prevention safety device (proportioning device)
Limits N2O flow to 3 x O2 flow (N2O max is 75%)
32
What is the minimum FiO2 permitted by the proportioning device?
25%
33
At low flows, what type of flow is it and what is it dependent on?
Laminar flow
Dependent on gas’s viscosity
34
At high flows, what type of flow is it and what is it dependent on?
Flow is turbulent
Dependent on the gas’s density
35
Where is the oxygen Flowmeter placed in US anesthesia machines?
On the far RIGHT!
36
What is the equation to Reynold’s number?
Density x diameter x velocity / viscosity
37
How do you determine the delivered FiO2 using a nasal cannula?
Add 4% for each liter of oxygen administered (to a max of 44% at 6L/min)
0:21%
1L : 24%
2 L: 28%
3 L: 32%
4 L: 36%
5 L: 40%
6 L: 44%
38
What should you do if the vaporizer is tripped?
Run high FGF for 20-30 mins
39
What is the latent heat of vaporization?
Number of calories that is needed to convert 1 g of liquid into vapor without a change in temperature.
40
What is the pumping effect?
Anything that causes gas that has already left the vaporizer to reneged the vaporizing chamber. (Usually due to positive pressure ventilation or the oxygen flush valve)
41
How do you calculate how long your agent will last? What is the equation?!
mL of liquid anesthetic used per hour = vol% x FGF (L/min) x 3
42
What is the “T” setting on the vaporizer?
Transport mode. It eliminates the worry of tipping the vaporizer during transport or removal
43
What is the TEC 6 heated to and pressurized to?
2 atmospheres
39 degrees C
44
Does the TEC 6 compensate for changes in elevation?
No
45
What is the equation to account for pressure when determining the output of Desflurane at a different atmosphere?
Required dial setting = (normal dial setting % x 760) / ambient pressure mmHg
46
What happens to Desflurane’s output of anesthesia takes place at a HIGHER elevation?
Atmospheric pressure is lower at higher elevation —> partial pressure in the circuit with be lower (less anesthesia delivered)
47
What happens to Desflurane’s output of anesthesia takes place at a lower elevation?
Less elevation = higher ambient pressure
Partial pressure in the breathing circuit will be HIGHER than expected.
48
What is deemed the last line of defense against a hypoxic mixture?
Oxygen analyzer (found in inspiratory limb)
49
What are the two things you must do if an oxygen pipeline crossover is assumed!?
Disconnect pipeline (you must disconnect!)
Open O2 tank.
50
What is the pressure and/or flow of the oxygen flush valve?
Flow: 35-75 L/min
Pressure: 50 psi
51
What are two complications caused by the overuse of the oxygen flush valve?
Awareness
Barotrauma
52
When does an ascending bellows rise and fall?
Rises during expiration
Falls during inspiration
53
When does a descending (hanging) bellows rise and fall?
Remember this is upside down
Falls with expiration
Rises with inspiration
54
Will a piston ventilator consume tank oxygen in the event of a oxygen pipeline failure?
No.
55
What are the two pressure relief valves on a piston ventilator?
Positive pressure relief valve: opens at 75 cm H2O
Negative pressure relief valve: opens at -8 cm H2O
56
Which ventilator mode adds intrinsic peep?
Gas driven adds 2-3 cm H2O of peep
Piston ventilators do NOT
57
What are some traits about volume controlled ventilation?
Delivers a preset tidal volume over a predetermined time
Inspiratory pressure will vary as a fx of patient pulmonary compliance
If airway resistance rises or lung compliance decreases, PIP will rise
Inspiratory flow is held constant during inspiration
***flow waveform looks like a square
58
What are some traits about pressure controlled ventilation?
Delivers a preset inspiratory pressure over a predetermined time
Vt and inspiratory flow will vary as a function of the patient’s pulmonary compliance
If airway resistance rises or lung compliance decreases, then the Vt will decrease.
Inspiratory flow uses a decelerating pattern. Begins high to achieve inflation pressure and then slows to maintain constant pressure
***flow waveform looks like a triangle
59
What is fixed and what is variable in a volume controlled ventilator setting?
Fixed: tidal volume, inspiratory flow rate, inspiratory time
Variable: peak inspiratory pressure
60
What is fixed and what is variable in a pressure controlled ventilator setting?
Fixed: peak inspiratory pressure, inspiratory time
Variable: tidal volume, inspiratory flow
61
What are the advantages of PCV?
Larger tidal volume for a given pressure
Inspiratory flow pattern may improve gas exchange
Reduces risk of VALI
Useful in patients with low compliance where high PIP is dangerous
62
What are some disadvantages of PCV?
Increased airway resistance or decreased lung compliance reduces tidal volume
Requires extra attempting in conditions that alter pulmonary mechanics (increased resistance or compliance)
63
In PCV, what conditions will decrease your tidal volume?
Pneumoperitoneum
T-berg
Bronchospasm
Kinked ETT
64
In PCV, what conditions will increase your tidal volume?
Release of pneumoperitoneum
Going from t-berg to supine
Bronchodilator therapy
Removing airway secretions
65
What are some conditions where PCV is better than VCV?
Pt with low compliance: preg, obesity, laparoscopy, ARDs
High PIP would injure patient: LMA, neonate, emphysema
Need to compensate for a leak: LMA, uncuffed ETT in kiddos
66
What are some traits about controlled mandatory ventilation?
Machine initiates breaths and delivers preset Vt and RR on a fixed schedule
Does not compensate for patient initiated breaths (risk for asynchrony)
**best for apneic patients
67
What are some traits about assist control?
Machine initiated breaths deliver preset Vt and RR
Spontaneous breaths receive the full preset volume.
Patient that over breathes is at risk for hyperventilation and resp alkalosis
68
What are some traits about SIMV?
Machine delivers preset Vt and RR, BUT this still allows patient to breathe spontaneous b/t delivered breaths
If patient breathes before the initiated breath is due, the timing will adjust and coordinate
Promotes synchrony
Spontaneous breaths can be augmented with support
Guarantees a min minute vent.
Useful for weaning or LMA
69
What are some traits about PCV-VG?
Benefits of pressure control, BUT also guarantees a predetermined tidal volume
70
What are some traits about PSV?
Augments spontaneous breaths with pre-set pressure amount
No machine intimated breaths UNLESS a back up mode is in place (I.e. PSV-Pro)
Use for weaning/LMA
71
What are some traits about PSV- Pro?!? Highlight on the pro.
Pro means protect.
Receives benefit of PSV, BUT if patient becomes apneic, will switch to PCV, and will switch back and forth
72
What are some traits of CPAP?
Continuous amount of pressure is applied to breathing circuit.
Two benefits: augments pts spontaneous breaths and reduces airway collapse during expiration
(PSV only applies pressure during inspiration, NOT expiration)
73
What are some traits of Bipap?
Similar to CPAP, but a DIFFERENT pressure is set between inspiration and expiration. P1 is the pressure set to augment for inspiration and P2 is the pressure set for expiratory.
**useful for patients when CPAP is not quite enough
74
What are some traits of Airway Pressure Release Ventilation (APRV)?
Used for spontaneous breaths
Like bipap, but there is a high level of CPAP through most of the resp cycle. This pressure is released at pre-set intervals.
**great for ARDS
75
What are some traits about Inverse Ratio Ventilation? (IRV)
This type of setting reverses the I:E ration by allocating more time during inspiration.
**REQUIRES A PARALYZED PT
Useful for ARDs and pts with small FRC
Risk of auto peep
76
What are some traits about high-frequency ventilation?
Delivers a tidal volume below anatomical dead space in conjunction with a high RR. Gas transport occurs by molecular diffusion, coaxial flow, and high-velocity flow
(Includes oscillation, jet ventilation, and percussive ventilation)
77
At what pH does the ethyl violet turn purple?
10.3
78
What is the reaction of carbon dioxide with soda lime? Full…
CO2 + H2O —> H2CO3
H2CO3 + 2NaOH —> Na2CO3 + 2 H2O + heat
Na2CO3 + Ca(OH)2 —> CaCO3 + 2 NaOH
79
How many liters of CO2 can soda line absorb per 100g of absorbent?
26L
80
What is the ideal balance of mesh granules used in carbon dioxide absorbents?
4-8 mesh granules
81
Small granules in CO2 absorbents have what?
Increased surface area
BUT also increased resistance
82
Large granules in CO2 absorbents have what?
Lower surface area
And a lower airflow resistance
83
What volatile anesthetics have the highest rate of CO production with desiccated soda lime?
Des > Iso > Sevo
84
What can Sevo produce in the presence of desiccated soda lime?
Compound A baby!
85
What conditions increase the formation of compound A?
Low FGF rates
High absorbent temp
Desiccation
High concentration of Sevo
86
What are the final products of the carbon dioxide and soda lime reaction? Aka final part of the equation
CaCO3 (calcium carbonate)
2NaOH (2 Sodium hydroxide)
87
Why is silica added to soda lime?
It provides hardness and minimizes dust production
88
What are the major drawbacks of using calcium hydroxide instead of soda lime?
More expensive
Requires more replacements
Absorbs 1/2 of what soda lime can
89
What is an active scavenger system?
Active uses suction
90
What is a passive scavenger system?
Passive system relies on the positive pressure of fresh gas leaving the interface
91
What is a closed scavenger system?
Uses valves
92
What is an open scavenger system?
Open to the atmosphere
93
Which scavenger system has a higher change of exposing OR staff to waste gas?
Open system
94
What is the most common cause of low circuit pressure? What is the second most common?
1st: circuit disconnect
2nd: leak around the CO2 absorbent
95
What are the 4 ways to detect a circuit disconnect?
Pressure
Volume
EtCO2
Vigilance
96
What are 4 cardiovascular consequences caused by excessive pressure in the breathing circuit?
Decreased venous return
Decreased CO
Hypotension
Cardiovascular collapse
97
What are the OSHA’s recommendations for anesthetic gas exposure?
Nitrous oxide alone should not exceed 25 ppm
Halogenated agents alone should not exceed 2 ppm
Halogenated agents with Nitrous oxide should be less than 0.5 ppm and 25 ppm respectively
98
What is the minimum recommended pressure when performed a high-pressure leak test in the anesthesia gas machine?
30 cm H2O
(Think how you have to turn the APL valve to 30-70)
99
What are the types of breathing systems and their classification?
Open: no rebreathing/no reservoir
Semi-open: no rebreathing with reservoir
Semi-closed: partial rebreathing with a reservoir
Closed: complete rebreathing with a reservoir
100
What are examples of an open system?
Insufflation
Simple face mask
Nasal cannula
Open drop ether
101
What are examples of a semi open system?
Mapleson circuit
Circle system (FGF > minute vent)
102
What are examples of a semi closed system?
Circle system (FGF < minute ventilation)
103
What are examples of a closed system?
Circle system with very low FGF and APL closed
