Deck 42: Mechanical Ventilators

Question 1

During volume control ventilation, the clinician has control over which of the following?
I)pressure waveform
II)volume waveform
III)flow waveform

A)I or II
B)II or III
C)II
D)I, II, and III

Answer 1

B

Question 2

Which of the following types of ventilators would you select for use during an MRI procedure?
I)electronically controlled
II)pneumatically controlled
III)fluidically controlled
IV)electrically controlled

A)I and IV
B)II and III
C)I, II, and IV
D)I, II, III, and IV

Answer 2

B

Question 3

Which of the following ventilators is the simplest example of a true flow controller?

A)Newport Wave
B)Bear 1
C)Emerson 3-PV
D)Sechrist

Answer 3

D

Question 4

The volume waveform generated by a ventilator remains the same against changing lung mechanics. Which of the following parameters might this device be controlling?
I)volume
II)flow
III)pressure

A)I and II
B)I and III
C)II and III
D)I, II, and III

Question 5

Primary drive mechanisms used by modern ventilators include which of the following?
I) compressed gas or reducing valve
II) hydraulic or fluidic compressor
III) electrical motor or compressor

A)I and II
B)I and III
C)II and III
D)I, II, and III

Question 6

If the pressure waveform of a ventilator remains the same when a patient's lung mechanics change, then what is the ventilator?

A)volume controller
B)pressure controller
C)time controller
D)flow controller

Question 7

According to the equation of motion of the respiratory system, a ventilator can control all of the following variables except:

A)volume
B)resistance
C)pressure
D)flow

Question 8

Which of the following is true of the relationship between flow and volume?
I. Volume is the integral of flow.
II. Volume is the derivative of flow.
III. Flow is the derivative of volume.

A)I and II
B)I and III
C)II and III
D)I, II, and III

Question 9

During mechanical ventilation, what variable causes a breath to begin?

A)limit
B)cycle
C)trigger
D)baseline

Question 10

A ventilator's pressure waveform changes when a patient's lung mechanics change, but its volume waveform remains the same. The device does not directly control the delivered volume. What is this ventilator?

A)volume controller
B)pressure controller
C)time controller
D)flow controller

Question 11

Which of the following ventilators is controlled by fluidic logic systems?

A)Siemens 300
B)Sechrist IV-100B
C)Bird 8400ST
D)Bear 1000

Question 12

A ventilator can derive its input power from which of the following sources?
I)alternating current (AC) electricity
II)battery
III)pneumatic

A)I and II
B)I and III
C)II and III
D)I, II, and III

Question 13

Which of the following are characteristic of a ventilator that functions as a true volume controller?
I. Its pressure waveform changes with changes in lung mechanics.
II. It measures and uses volume to control the volume waveform.
III. Its volume waveform stays constant with changes in lung mechanics.

A)I and II
B)I and III
C)II and III
D)I, II, and III

Question 14

A complete ventilatory cycle or breath consists of which of the following phases?
I)expiration
II)initiation of inspiration
III)inspiration
IV)end of inspiration

A)I and IV
B)II and III
C)I, II, and IV
D)I, II, III, and IV

Question 15

How would a ventilatory support device that uses pressure regulators, needle valves, and balloon valves to regulate most or all of the parameters of ventilation be classified?

A)mechanically controlled
B)electronically controlled
C)fluidically controlled
D)pneumatically controlled

Question 16

During mechanical ventilation, what variable causes a breath to end?

A)limit
B)cycle
C)trigger
D)baseline

Question 17

Which of the following major categories of ventilator function are useful in classifying ventilators?
I)control scheme
II)power conversion
III)ventilator output

A)I and II
B)I and III
C)II and III
D)I, II, and III

Question 18

Types of output control valves used in modern ventilators include all of the following except:

A)pneumatic diaphragm valve
B)proportional valve
C)electromagnetic poppet or plunger
D)linear screw valve

Question 19

For which of the following uses might you consider the use of a purely pneumatically powered ventilator?
I)as a backup to electrically powered ventilators
II)when electrical device cannot be used (e.g., magnetic resonance imaging)III.during certain types of patient transport

A)I and II
B)I and III
C)II and III
D)I, II, and III

Question 20

Which of the following equations best describes the pressure (P) necessary to drive gas into the airway and inflate the lungs?

A)P = (Elastance * Volume) + (Resistance * Flow)
B)P = (Elastance - Volume) + (Resistance ÷ Flow)
C)P = (Volume + Compliance) + (Resistance ÷ Flow)
D)P = (Volume ÷ Compliance) - (Resistance * Flow)

Question 21

A patient receiving time-triggered continuous mechanical ventilation at a preset rate of 10/min stops breathing. Which of the following will occur?

A)The high-pressure limit alarm will sound (if properly set).
B)The patient will continue to receive 10 breaths/min.
C)The low tidal volume (V_T) alarm will sound (if properly set).
D)Ventilation will drop to zero and the apnea alarm will sound.

Question 22

A physician requests that you switch from pressure-triggering a patient to flow-triggering. Which of the following new settings would be appropriate?

A)Base flow = 0 L/min; trigger at 2 L/min
B)Base flow = 10 L/min; trigger at -2 cm H₂O
C)Base flow = 10 L/min; trigger at 2 L/min
D)Base flow = 0 L/min; trigger at 10 cm H₂O

Question 23

A ventilator providing pressure support ventilation to a patient is set to flow trigger on spontaneous breaths (base flow = 10 L/min; trigger = 3 L/min below base flow). While at the bedside, you observe that the ventilator trigger rate is much higher than the patient's spontaneous rate, causing noticeable patient discomfort. Which of the following could be causing this problem?
I)circuit leaks
II)inadequate base flow
III)circuit movement

A)I and II
B)I and III
C)II and III
D)I, II, and III

Question 24

What ventilatory variable reaches and maintains a preset level before inspiration ends?

A)limit
B)cycle
C)trigger
D)baseline

Question 25

When you adjust the pressure drop necessary to trigger a breath on a ventilator, what are you adjusting on the machine?

A)sensitivity
B)pressure limit
C)mode setting
D)positive end-expiratory pressure (PEEP) level

Question 26

Which of the following parameters can serve as the cycle variable during ventilatory support?
I)volume
II)pressure
III)flow
IV)time

A)I and IV
B)II and III
C)I, II, and IV
D)I, II, III, and IV

Question 27

A volume-cycled ventilator has a rate knob for setting the controlled frequency of breathing. If this control is set to 12/min, which of the following other settings will determine the inspiratory and expiratory times?
I)FIO₂
II)flow
III)volume

A)I and II
B)I and III
C)II and III
D)I, II, and III

Question 28

A time-cycled constant flow generator is set up with a flow of 35 L/min and an inspiratory time of 1.7 seconds. What is the approximate V_T?

A)750 ml (0.75 L)
B)1000 ml (1.00 L)
C)1900 ml (1.90 L)
D)1200 ml (1.20 L)

Question 29

Pure time-triggered ventilation is the same as what type of ventilation?

A)assist
B)intermittent mandatory ventilation
C)assist and control
D)proportional assist

Question 30

If a patient initiates a ventilator breath, the trigger variable could be all of the following except:

A)pressure
B)flow
C)time
D)volume

Question 31

When using pressure as the trigger variable, where do you typically set the trigger level?

A)0.5 to 1.5 cm H₂O below the baseline expiratory pressure
B)0.5 to 1.5 cm H₂O above the baseline expiratory pressure
C)2.0 to 3.5 cm H₂O below the baseline expiratory pressure
D)2.0 to 3.5 cm H₂O above the baseline expiratory pressure

Question 32

Compared to using pressure as the trigger variable, what is the major advantage of flow-triggering?

A)decreased work of breathing
B)improved minute ventilation (V_E)
C)decreased physiologic dead space
D)improved arterial oxygenation

Question 33

To describe what happens during the expiratory phase of mechanical ventilation, you must know the value of which variable?

A)limit
B)cycle
C)trigger
D)baseline

Question 34

Which of the following is false about the application of flow triggering on a mechanical ventilator?

A)The ventilator measures both input and output flow.
B)Between patient breaths, input flow exceeds output flow.
C)A relative drop in output flow triggers the machine to turn on.
D)Gas flows continuously through the ventilator circuit.

Question 35

A volume-cycled ventilator provides gas under positive pressure during inspiration until what point?

A)A preselected volume of gas is received by the patient.
B)An adjustable, preselected airway pressure is reached.
C)The inspiratory time equals or exceeds the expiratory time.
D)A preselected volume of gas is expelled from the device.

Question 36

If a ventilator, not the patient, initiates a breath, what is the trigger variable?

A)time
B)pressure
C)flow
D)volume

Question 37

What is the name of a breath where a patient is able to change the inspiratory time?

A)patient cycled
B)patient triggered
C)machine triggered
D)machine cycled

Question 38

In which of the following modes inspiration ends when flow decays to some preset value?

A)intermittent mandatory ventilation
B)pressure support ventilation
C)continuous mandatory ventilation
D)airway pressure release ventilation

Question 39

Flow serves as a limit variable whenever a ventilator controls what?

A)pressure
B)flow
C)time
D)volume

Question 40

You observe that a ventilator reaches a preset pressure early in inspiration but holds it for a specific time, after which inspiration ends. What mode of ventilatory support is in force?

A)time cycled
B)pressure limited
C)pressure cycled
D)volume limited

Question 41

During mechanical ventilation, a spontaneous breath is defined as one that:

A)initiated and terminated by the machine
B)begun by the patient and ended by the machine
C)initiated and terminated by the patient
D)begun by the machine and ended by the patient

Question 42

A ventilator that controls flow and delivers a rectangular flow waveform will also exhibit what waveform?

A)exponential (rise) volume
B)rectangular pressure
C)ascending ramp pressure
D)descending ramp volume

Question 43

While observing a patient receiving ventilatory support, you notice that some delivered breaths are begun or ended by the machine, whereas others are begun and ended by the patient. Which of the following modes of ventilatory support is in force?

A)intermittent mandatory ventilation (IMV)
B)pressure support ventilation
C)continuous mandatory ventilation (CMV)
D)airway pressure release ventilation

Question 44

A ventilator that controls pressure and delivers a rectangular pressure waveform will also exhibit what waveform?

A)exponential (rise) volume
B)rectangular flow
C)ascending ramp pressure
D)sinusoidal flow

Question 45

During volume-targeted ventilation, which of the following settings determine the inspiratory time?
I)volume
II)flow
III)rate

A)I and II
B)I and III
C)II and III
D)I, II, and III

Question 46

Which of the following can be used by a ventilator as a conditional variable?
I)volume
II)pressure
III)flow
IV)time

A)I and IV
B)II and III
C)I, II, and IV
D)I, II, III, and IV

Question 47

What parameter serves as the baseline variable on all modern ventilators?

A)pressure
B)flow
C)time
D)volume

Question 48

Which of the following modes is a good example of adaptive control?

A)intermittent mandatory ventilation
B)airway pressure release ventilation
C)continuous mandatory ventilation (CMV)
D)pressure-regulated volume control (PRVC)

Question 49

What is the default baseline value during mechanical ventilation?

A)positive end-expiratory pressure (PEEP)
B)zero end-expiratory pressure (ZEEP)
C)negative end-expiratory pressure (NEEP)
D)continuous positive airway pressure (CPAP)

Question 50

While observing a patient receiving ventilatory support, you notice that all delivered breaths are initiated or terminated by the machine. Which of the following modes of ventilatory support is in force?

A)intermittent mandatory ventilation
B)partial ventilatory support
C)continuous mandatory ventilation
D)continuous spontaneous ventilation

Question 51

During mechanical ventilation, a mandatory breath is defined as one that is:

A)initiated or terminated by the machine
B)initiated and terminated by the machine
C)initiated and terminated by the patient
D)begun according to a preset time interval

Question 52

What is the primary physiological effect of positive end-expiratory pressure (PEEP)?

A)increase the functional residual capacity (FRC)
B)increase the inspiratory reserve volume (IRV)
C)decrease the compliance of the lung (C_L)
D)increase the length of expiration

Question 53

What is the application of pressure above atmospheric at the airway throughout expiration during mechanical ventilation?

A)positive end-expiratory pressure (PEEP)
B)pressure support ventilation
C)continuous mandatory ventilation (CMV)
D)continuous positive airway pressure (CPAP)

Question 54

Mean airway pressure is highest with what waveform?

A)rectangular flow
B)rectangular pressure
C)ascending ramp flow
D)sinusoidal flow

Question 55

Which of the closed-loop controllers is used by all ventilators?

A)setpoint
B)auto setpoint
C)adaptive
D)servo

Question 56

During volume-targeted ventilation, which of the following settings determine the machine-delivered minute volume?
I)volume
II)flow
III)rate

A)I and II
B)I and III
C)II and III
D)I, II, and III

Question 57

Peak airway pressure is highest with what waveform?

A)sinusoidal flow
B)rectangular flow
C)ascending ramp flow
D)descending ramp flow

Question 58

Mean airway pressure is lowest with what waveform?

A)sinusoidal flow
B)rectangular flow
C)ascending ramp flow
D)descending ramp flow

Question 59

Which of the following ventilator control systems is NOT considered closed loop?

A)orientation based
B)servo
C)adaptive
D)optimal

Question 60

A mode that allows spontaneously breathing patients to breathe at a positive-pressure level, but drops briefly to a reduced pressure level for CO₂ elimination during each breathing cycle is also known as:

A)intermittent mandatory ventilation
B)airway pressure release ventilation
C)continuous mandatory ventilation (CMV)
D)continuous spontaneous ventilation

Question 61

Spontaneous breath modes include all of the following except:

A)pressure support ventilation (PSV)
B)continuous positive airway pressure (CPAP)
C)bilevel CPAP (BiPAP)
D)continuous mandatory ventilation assist-control

Question 62

A patient is receiving continuous mandatory ventilation through a constant flow generator in the control mode at a rate of 20/min with a V_T of 750 mL. The inspiratory time is 1 second. What is the flow?

A)15 L/min
B)30 L/min
C)45 L/min
D)60 L/min

Question 63

Which of the following is the primary parameter used to alter the breath size in pressure controlled?

A)positive inspiratory pressure (PIP)- positive end-expiratory pressure (PEEP)
B)continuous positive airway pressure (CPAP)
C)tidal volume
D)flow

Question 64

What is the mode of ventilatory support in which patient's inspiratory efforts are augmented with a set amount of positive airway pressure?

A)intermittent mandatory ventilation
B)continuous mandatory ventilation (CMV)
C)pressure support ventilation (PSV)
D)positive end-expiratory pressure (PEEP)

Question 65

Which of the following is an advantage of intermittent mandatory ventilation (IMV) over continuous mandatory ventilation (CMV)?

A)IMV does not encourage activity of the ventilatory muscles.
B)CMV allows the patient to set the ventilatory pattern.
C)IMV results in lower pleural pressures for a given V_E.
D)IMV results in a much faster weaning.

Question 66

During volume-targeted ventilation, which of the following settings determine the expiratory time?
I)volume
II)flow
III)rate

A)I and II
B)I and III
C)II and III
D)I, II, and III

Question 67

During volume-targeted ventilation, which of the following settings determine I:E ratio?
I)volume
II)flow
III)rate

A)I and II
B)I and III
C)II and III
D)I, II, and III

Question 68

What is the primary use of pressure support ventilation at low pressure levels?

A)decrease the ventilator circuit-imposed respiratory muscle work
B)increase the functional residual capacity
C)decrease the V_D/V_T
D)restore tone to atrophied respiratory muscles

Question 69

A patient is receiving continuous mandatory ventilation in the control mode at a rate of 15/min. The inspiratory time is 0.8 second. What is the expiratory time?

A)3.2 seconds
B)2.8 seconds
C)2.4 seconds
D)4.2 seconds

Question 70

During volume-targeted ventilation, which of the following settings determine the total cycle time?
I)volume
II)flow
III)rate

A)I and II
B)II and III
C)III only
D)I, II, and III

Question 71

A patient is receiving continuous mandatory ventilation in the control mode at a rate of 15/min. The expiratory time is 2.9 seconds. What is the inspiratory time?

A)1.1 seconds
B)1.3 seconds
C)1.5 seconds
D)1.7 seconds

Question 72

In which of the following situations is volume-controlled ventilation sometimes used?
I.when a precise PaCO₂ has to be maintained (some closed-head injuries)
II.when more even distribution of ventilation is required
III.when ventilating patients with severe, refractory hypoxemia
IV.when ventilating patients with unstable or changing ventilatory drives

A)I and II
B)III and IV
C)I, II, and III
D)I, III, and IV

Question 73

A patient is receiving continuous mandatory ventilation in the control mode at a rate of 10/min. The inspiratory time control is set at 40%. What is the inspiratory time?

A)1.60 seconds
B)1.85 seconds
C)2.40 seconds
D)3.50 seconds

Question 74

A patient receiving continuous mandatory ventilation in the control mode has an inspiratory time of 1.5 seconds and an expiratory time of 2.5 seconds. What is the frequency of breathing?

A)10/min
B)12/min
C)15/min
D)18/min

Question 75

In which of the following situations is pressure-controlled ventilation sometimes used?
I.when a precise PaCO₂ has to be maintained (some closed-head injuries)
II.when more even distribution of ventilation is required
III.when ventilating patients with severe, refractory hypoxemia
IV.when tidal volume in unstable due to leaks

A)I and II
B)III and IV
C)I, II, and III
D)I, III, and IV

Question 76

During pressure-targeted ventilation, which of the following settings determine V_T?
I)pressure difference
II)inspiratory time
III)time constant

A)I and II
B)II and III
C)III only
D)I, II, and III

Question 77

A patient is receiving continuous mandatory ventilation in the control mode at a rate of 20/min. The inspiratory time is 0.75 second. What is the percentage inspiratory time?

A)20%
B)25%
C)30%
D)33%

Question 78

Which of the following modes is commonly selected for patients with neuromuscular disorders?

A)PC-intermittent mandatory ventilation (IMV)
B)VC-IMV
C)airway pressure release ventilation
D)pressure-regulated volume control

Question 79

A patient is receiving continuous mandatory ventilation in the control mode at a rate of 10/min. The inspiratory time control is set at 25%. What is the I:E ratio?

A)1:3
B)1:2
C)1:4
D)1:1

Question 80

A patient is receiving continuous mandatory ventilation in the control mode at a rate of 12/min. The inspiratory time control is set at 33%. What is the expiratory time?

A)1.65 seconds
B)2.45 seconds
C)3.35 seconds
D)3.85 seconds