E3 - Anesthesia Machine II Flashcards

1
Q

A ventilator is an automatic device that will provide what two things to the patient?

A

ventilation and oxygenation

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2
Q

On the anesthesia workstation, ventilators essentially replace what component?
A. bellows
B. reservoir bag
C. circle system
D. APL valve

A

B. reservoir bag

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3
Q

What was a downside of the older ventilators?
A. only CMV
B. no PEEP
C. couldn’t provide high enough PIP
D. all of the above

A

D. all of the above
* provided only controlled mandatory ventilation (which was volume control)
* No PEEP
* Couldn’t provide high enough PIP

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4
Q

Barotrauma is an injury that results from ___.
A. high airway pressures
B. low airway pressures
C. flail chest
D. high fresh gas flows

A

A. high airway pressures

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5
Q

What is compliance?

A
  • Ratio of a change in volume to a change in pressure (delta V/ delta P)

make schmidt proud

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6
Q

A decrease in compliance in breathing system causes a decrease in __.
A. Vt
B. PIP
C. work of breathing
D. inspiratory effort

A

A. Vt (tidal volume) as volume is used to expand system

newer vents alter volume delivered to compensate for system compliance

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7
Q

Name the valve that opens to allow driving gas to exit the bellows housing on inhalation.

A

Exhaust Valve

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8
Q

What is the idea of Fresh Gas Compensation?
A. FGF can be decreased whenever
B. FGF can only affect Vt on expiration
C. a way to prevent FGF from affecting Vt
D. Vt increases when FGF increases

A

C. a way to prevent FGF from affecting tidal volume
by measuring tidal volume and adjusting the volume of gas delivered by the ventilator.

older vents would increase Vt as FGF increase

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9
Q

The time in which lungs are held inflated at a fixed volume and pressure is called:

A

Inspiratory pause time aka inspiratory plateau

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10
Q

What is I:E ratio?
Normal I:E?

A

Ratio of the inspiratory phase time to the expiratory phase time
Normal: 1:2

usually spend longer time in expiration, just chillin

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11
Q

What is inverse ratio ventilation?
A. inspiratory phase time is shorter than the expiratory phase time
B. inspiratory phase time is longer than the expiratory phase time
C. the 2 phases are the same time

A

B. Inspiratory phase time is longer than the expiratory phase time

so inverse ratio ventilation would be using an I:E ratio of 2:1

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12
Q

What is the sum of all tidal volumes in one minute?

A

Minute volume

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13
Q

Define peak pressure:

A

The maximum inspiratory pressure

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14
Q

The spill valve in the ventilator allows excess gases:
A. to spill
B. to be sent to scavenging system during inspiration
C. to exit bellows housing
D. to be sent to scavenging system during exhalation

A

D. The valve in the ventilator that allows excess gases to be sent to scavenging system during exhalation

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15
Q

The energy that the patient/ventilator expends to move gas in and out of the lungs

A
  • Work of breathing
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16
Q

What are factors that affect ventilation: Select 2
A. compliance
B. I:E ratio
C. leak
D. FGF

A

A. Compliance (patient or system)
C. Leak

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17
Q

How does a leak affect delivered tidal volume?
A. increased Vt by ventilator compensation
B. decreased Vt but ventilator compensated
C. increased Vt w/ no vent compensation
D. decreased Vt with no ventilator compensation

A

D. Leaks will cause a decrease tidal volume that can’t be compensated by the ventilator

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18
Q

What are some components to the bellows ventilator? Select 3
A. gas is only oxygen
B. plunger of syringe
C. driving gas supply
D. only high-pressure alarms
E. pressure-limiting mechanism
F. housing

A

C. Driving gas supply
E. Pressure-limiting mechanism
F. Housing
and:
* Controls
* Alarms (high AND low pressure alarms)
* Bellows (accordion-like device)
* Exhaust Valve

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19
Q

What does the driving gas do to the bellows?
A. squeezes gas out of bellows into lungs
B. causes bellows to ascend
C. allows for exhalation
D. refills bellows on exhalation

A

A. The driving gas is the gas external to the bellows that squeezes gas out of bellows into the lungs.

driving gas is what causes bellows to collapse

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20
Q

What is the most common cause of low-pressure ventilator alarms?
A. kinking of ETT
B. mucus plug
C. leak within circuit
D. disconnection of a circuit

A

D. Disconnection of a circuit

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21
Q

What are examples of high-pressure ventilator alarms? Select 2
A. disconnection of circuit
B. kinking of the ETT
C. cuff leak
D. mucus plug

A

B. Kinking of the ETT
D. mucus plug

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22
Q

What is a good set point for the pressure limit of the inspiratory pressure?
A. 15 cmH2O above peak pressure
B. 15 cmH2O above average inspiratory pressure
C. 10 cmH2O above average inspiratory pressure
D. 10 cmH2O above peak pressure

A

D. 10 cmH2O above peak pressure with desired Vt

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23
Q

What is the purpose of the housing for bellows ventilators? select 2.
A. allows CRNA to see movement of bellows
B. forces FGF to refill bellows on inspiration
C. drives gas into bellows
D. provides rough estimate of Vt

A

A. Allows movement of bellows to be observed
D. Has scale on side for rough estimation of tidal volume

housing is the clear, plastic cylinder w/ bellows inside it

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24
Q

What are the two kinds of bellows?

Which one is safer?

A
  1. Ascending (standing) Bellows = safer
  2. Descending (hanging) Bellows
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25
Q

Why are ascending bellows considered safer if there is a disconnection in the circuit?
A. they will continue to rise on exhalation
B. they will fail to rise on exhalation
C. they will rise on inspiration
D. they will to continue to rise on inspiration

A

B. If there is a disconnection in the circuit, the ascending (standing) bellows will fail to rise on exhalation, which will trigger the CRNA to know something is wrong.

descending (hanging) bellows will continue to descend even if there is a disconnection.

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26
Q

What are 3 problems with bellows?
A. waste gases vented to room if scavenging system is closed
B. both types will refill even with disconnection
C. entrain room air during leaks
D. inadequate ventilation if bellows aren’t seated properly
E. barotrauma if there’s a hole in bellows
F. alveolar hypoinflation

A

A. waste gases vented to room if scavenging system is closed
D. inadequate ventilation if bellows aren’t seated properly
E. barotrauma if there’s a hole in bellows because driving gas will just blow straight into patient (if driving gas is AIR, then pts FiO2 will go down…)

if hole in bellows and the driving gas is OXYGEN, pts FiO2 goes up so not as problematic

27
Q

What are some components of piston ventilators? Select 2
A. no driving gas
B. use more gas than bellows
C. mechanically driven motor
D. very loud

A

A. no driving gas
C. mechanically driven motor
Also:
* uses dramatically less gas
* no visual ventilation (unlike bellows which you can clearly see)
* very quiet

28
Q

What is the most commonly used mode of ventilation?

A
  • Volume control
29
Q

Controlled Ventilation Modes:

Describe volume control: Select 2.
A. fixed pressure delivered
B. fixed volume delivered
C. could cause excessive PIP
D. changes Vt on every breath depending on pt’s condition

A

B. Preset tidal volume is delivered (fixed parameter)
C. could cause excessive PIP!

problematic b/c machine will give a set tidal volume regardless of the patient’s condition

30
Q

Volume control mode will have which 3 things set?
A. Vt
B. FGF
C. inverse ratio
D. RR
E. I:E ratio

A

A. Tidal Volume
D. RR
E. I:E Ratio

31
Q

In what conditions would pressure control not be beneficial for the patient? Select 3
A. supine procedures
B. trendelenberg/lithotomy procedures
C. obese/pregnant pts
D. pts with restrictive lung disease
E. COPD pts
F. reverse trendelenberg procedures

A

Conditions with decreased compliance and FRC such as:
B. Trendelenburg/Lithotomy procedures
C. Obese/Pregnant patients
D. pts with restrictive lung disease (bc they already decreased compliance)

and:
* Patients with lung pathology
* Patients that need to be weaned from the vent

could cause hypoventilation and atelectasis

32
Q

How much tidal volume should be delivered to a patient on a ventilator?

A
  • 4-6 mL/kg
33
Q

Describe pressure control ventilation: Select 2
A. fixed pressure
B. fixed volume
C. preset pressure is quickly achieved during inspiration
D. preset volume is quickly achieved during inspiration

A

A. fixed pressure, and volume can change depending on when set pressure is reached
C. Preset pressure is quickly achieved during inspiration.

Set PIP, RR, and I:E Ratio

34
Q

What occurs to tidal volume with pressure control ventilation?
A. does not vary with compliance change
B. varies regardless of compliance
C. varies with resistance and compliance changes

A

C. Tidal volume varies with resistance and compliance changes

like with the pt in tberg or obese/pregnant patient

35
Q

In pressure control:

What will insufflation of the abdomen do to inspiratory pressure? And what does this cause?
A. decreased PIP; high Vt
B. increased PIP; high Vt
C. decreased PIP; low Vt
D. increased PIP; low Vt

A

D. Increased inspiratory pressure, which will cause a low tidal volume.

36
Q

What is the good thing about pressure control ventilation?
A. protects lungs from mucus plugs
B. protects lungs from barotrauma
C. prevents a decreased Vt
D. prevents atelectasis

A

B. Pressure control protects lungs from barotrauma

37
Q

What is the bad thing about pressure control ventilation? Select 2
A. set RR cannot be altered
B. pressure delivered might not be enough for large enough Vt for the patient
C. preset pressure takes a long time to be achieved during inspiration
D. increased risk of atelectasis

A

B. The pressure delivered in this mode might not develop enough tidal volume for the patient.
D. Increased risk for atelectasis and hypoventilation

38
Q

What are ways to deliver more tidal volume in pressure control ventilation mode to patients with low lung compliance? Select 2.
A. increase PIP
B. use inverse I:E ratio
C. decrease RR
D. decrease I:E ratio
E. increase RR

A

A. Increase PIP
B. Use Inverse I:E ratio = longer inspiratory than expiratory time. The body will have time to adapt to increased pressure.

39
Q

Describe Volume Guarantee Pressure-Control (PRVC). Select 2
A. delivers set Vt, PIP, RR, and I:E ratio
B. maintains Vt by adjusting PIP over several breaths
C. causes sudden Vt changes w/ resistance and compliance
D. prevents sudden Vt changes from loss of compliance w/ insufflation

A

B. Maintain Tidal Volume by adjusting PIP over several breaths.
D. Prevents sudden Tidal Volume changes d/t compliance lost with insufflation (so this mode will increase PIP to deliver set Vt)

so this mode is good for insufflation cases

40
Q

Assisted/Supported Vent modes

What is the main thing that defines Assist Control (A/C) ventilation?
A. positive pressure will trigger breaths
B. breath is at preset PIP
C. pt’s effort is required to trigger breath
D. mandatory ventilator breaths are set

A

C. Predetermined negative pressure (pt’s inspiratory effort) will trigger breath!
Breath is at a preset TIDAL VOLUME

so RR, I:E ratio, and PIP could all be variable on breath-to-breath basis depending on pt’s inspiratory (negative) pressure

41
Q

Assisted/Supported Vent modes

What describes Intermittent Mandatory Ventilation (IMV)?
A. does not allow breath stacking
B. PIP and inspiratory time set
C. additional breaths are at set Vt
D. mandatory ventilator breaths are set

A

D. Mandatory ventilator breaths are set

And:
* Additional native breaths at variable tidal volume

IMV Allows breath stacking!

42
Q

Assisted/Supported Vent modes

What is true about Synchronized Intermittent Mandatory Ventilation (SIMV)?
A. there is no inspiratory delay between another breath
B. synchronizes vent-driven breaths w/ spontaneous breaths
C. pt won’t be able to take their own spontaneous breaths
D. similar to IMV because it allows breath stacking

A

B. Synchronizes ventilatory-driven breaths with spontaneous breaths so provides backup to weaning ventilator

also, forces an inspiratory delay between another breath so it prevents breath stacking

Best for weaning!

43
Q

Assisted/Supported Vent modes

Pressure Support has what two things preset?
A. I:E ratio
B. Vt
C. PIP
D. RR
E. I-time
F. E-time

A

C. PIP
E. inspiratory time

tidal volume is variable b/c it equates to patient’s native effort

Need apnea alarm!! cause RR would also be variable based on pt effort

44
Q

What are solutions to use a ventilator during an MRI?
A. MRI compatible machines
B. Anesthesia machine kept outside in hallway
C. Machine bolted to wall
D. Aluminum tanks or pipeline gas supply
E. All of the above

A

E. all of the above

  • MRI compatible machines
  • Anesthesia machine kept outside in hallway
  • Machine bolted to wall
  • Aluminum tanks or pipeline gas supply
45
Q

General Hazards:

What can cause ventilation failure? Select 2
A. extremely low FGF
B. disconnection from power supply
C. leaking bellows housing
D. dry circuits

A

B. Disconnection from power supply
C. Leaking bellows housing

And:
* Extremely high FGF
* Fluid in electronic circuitry

46
Q

General Hazards:

How can there be a loss of breathing system gas? Select 2.
A. failure to occlude spill valve
B. losing cylinders
C. leaking bellows
D. disconnection from power

A

A. Failure to occlude spill valve
B. Losing cylinders
and:
* Leak in the system
* Losing pipeline pressure

Need to do daily anesthesia machine check

47
Q

General Hazards:

What can cause incorrect ventilator settings?
A. extremely high FGF
B. vent turned off for xrays
C. leak in system
D. failure to occlude spill valve

A

B. Ventilator turned off for xrays (cholangiogram)
And some obvious reasons:
* Inadvertent bumping
* Not adjusted for new case
* Not adjusted for position/pressure changes

48
Q

Pick 3 advantages of a ventilator:
A. more regular rr, rhythm, Vt
B. increased “feel”
C. crna can be hands free
D. super user-friendly
E. decreases fatigue
F. more sporradic rr, rhythm, Vt

A

A. Produces more regular rate, rhythm, and Vt
C. Allows anesthesia provider to devote energy to other tasks (free hands)
E. Decreases fatigue

49
Q

What are some disadvantages of a ventilator? Select 3
A. can’t be hands-free
B. bellows leak often
C. can’t give high FGF
D. loss of “feel”
E. not super user-friendly
F. hard to clean

A

D. Loss of “feel” (reservoir bag)
E. Lack user-friendliness
F. Components are hard to clean or fix
And:
* Older versions may not have all the desired modes
* Noisy or too quiet
* May require high-flow driving gases…expensive

50
Q

Trace gas concentrations are concentration of a gas that is:
A. higher than needed for anesthesia
B. not detected by smell
C. far below that needed for anesthesia or detected by smell

A

C. Concentration of a gas far below that needed for anesthesia or detected by smell

51
Q

Trace concentration units

A

PPM (parts per million)

52
Q

100% of gas is how many PPM?

A

1,000,000 PPM

53
Q

1% of gas is how many PPM?

A

10,000 ppm

54
Q

Higher levels of trace gas concentration are seen in which 3 places?
A. dental surgery
B. ICU
C. hemo/onc
D. pediatric anesthesia
E. well vented PACUs
F. poorly vented PACUs

A

A. Dental surgery
D. Pediatric anesthesia
F. Poorly vented PACU’s

55
Q

What can cause OR contamination of trace gas concentrations? select 3
A. failure to turn off vaporizer
B. high FGF
C. poorly fitting masks
D. underfilled vaporizers
E. use of uncuffed ETT
F. using o2 flush

A

A. Failure to turn off vaporizer
C. Poorly fitting masks
E. Use of uncuffed ETT (like with pedi cases)
And:
* Flushing circuit into room
* Filling vaporizers and causing a spill
* Scavenging system leaks

56
Q

For years, what did old studies conclude about trace gas exposure?

A
  • Spontaneous abortions
  • Spontaneous abortion in spouses
  • Infertility
  • Birth defects
  • Impaired performance
  • Cancer/mortality
  • Liver disease
  • Cardiac disease

These negative side effects of gas exposure has been mitigated with the scavenger system

57
Q

What is the function of the scavenging system?

A
  • Removes the collection of gases from equipment used to administer anesthesia or exhaled by the patient.
58
Q

Describe the passive scavenging system. Select 2
A. attached to central vacuum system
B. attached to room ventilation system
C. disposal tubing from the anesthesia machine is attached to the exhaust grill and removed with room air.
D. must be able to provide high volume

A

B. attached to room ventilation system
C. Disposal tubing from the anesthesia machine is attached to the exhaust grill and removed with room air.

Entire volume is exhausted to the atmosphere.

very economic but uncommon

59
Q

The active scavenging system is attached to ____.
A. room ventilation system
B. central vacuum system
C. suction system
D. anesthesia machine

A

B. central vacuum system

  • Must be able to provide high volume (30 L/min!)
  • Need plenty of suction outlets and close to anesthesia machine
60
Q

How can we alter work practices to help the scavenging system?
A. turn off vaporizer during intubation
B. make sure mask fits
C. place anesthesia machine as close to exhaust grill as possible
D. 100% washout at end of case
E. all but A
F. only b and c
G. all of the above

A

E. all but A

entire list:
* mask fit
* place anesthesia machine as close to exhaust grill (passive system) as possible
* 100% washout at end of case
* turn off gas flow (NOT vaporizer) during intubation
* prevent liquid spills

61
Q

How does hypoventilation occur on the ventilator?

A
  • Insufficient gas
  • Obstruction
  • Leaks
  • Main machine power off
  • Breathing system leaks (disconnections)
62
Q

How can the ventilator cause hypercapnia?
A. hyperventilation
B. absorbent failure
C. leak in o2 flow meter
D. incorrectly installed outlets

A

B. Absorbent failure

And:
* Hypoventilation (for multiple reasons like insufficient gas, breathing system leaks, obstruction)
* Excessive dead space
* Defect coaxial system (seen in mapleson A & D circuits if coaxial tubing gets kinked)

63
Q

How can an anesthetic agent overdose occur? Select 2
A. high FGF
B. underfilled vaporizer
C. vaporizer accidentally on
D. interlock system failure
E. CO2 absorbent failure

A

C. Vaporizer accidentally on
D. Interlock system failure
And:
* Incorrect agent in vaporizer
* Tipped vaporizer
* Overfilled vaporizer

64
Q

What are ways to prevent inadvertent exposure to volatiles?
A. Change breathing system hoses and bag
B. Change fresh gas supply hose
C. Change absorbent
D. Use very high oxygen flows to flush the machine
E. Remove vaporizers
F. Don’t use the axillary flowmeter for supplemental oxygen
G. All but F
H. All of the above

A

G. all but F
* Change breathing system hoses and bag
* Change fresh gas supply hose
* Change absorbent
* Use very high oxygen flows to flush the machine
* Remove vaporizers
* Use an axillary flowmeter for supplemental oxygen