Deck 7: Mechanical Ventilator Theory and Classification

Question 1

A differential pressure transducer can measure flow if the pressure ports are connected to a:
I. venturi pneumotachometer
II. at the inlet and outlet of a flow delivery valve
III. at the pressure ports of a pneumotachometer

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

Answer 1

I, II, and III only

Question 2

A common fluidic element often applied to control the phase of ventilation (inspiration or expiration) is a:

A) AND/NAND gate
B) OR/NOR gate
C) Schmidt trigger
D) flip-flop element

Answer 2

D

Question 3

Which of the following may serve as a drive mechanism for a mechanical ventilator?
I. bellows
II. piston
III. proportional solenoid valve (pneumatic)

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

Answer 3

I, II, and III only

Question 4

A variable that rises to a preset value during inspiration and is held at that value until exhalation is termed a:

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

Question 5

Which of the following may be used as trigger variables?
I. pressure
II. flow
III. time
IV. manual

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

Question 6

Unlike a simple solenoid valve, a proportional solenoid valve can:

A) open and close faster
B) open in increments
C) lock in the open or closed position
D) none of the above

Question 7

A type of valve that responds to a patient's sub-ambient pressure generation and opens is a:

A) solenoid valve
B) proportional scissor valve
C) proportional solenoid valve
D) demand valve

Question 8

For both positive and negative pressure ventilators, exhalation:

A) is active
B) is assisted by the ventilator
C) is passive
D) none of the above

Question 9

Which of the following are used by fluidic logic elements in their operation?

A) venturi principle
B) electronic elements
C) Bernoulli's principle
D) the Coanda effect

Question 10

To be classified as a control variable:

A) the variable is monitored only during one phase of ventilation
B) the variable must be measured and used as feedback to control output
C) the variable must be measured only during inspiration
D) the variable must be measured only during exhalation

Question 11

Which of the following are control variables?
I. volume
II. pressure
III. flow
IV. time

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

Question 12

Solenoid valves on mechanical ventilators may be:

A) manually activated
B) automated
C) pressure activated
D) all of the above

Question 13

The ventilator's input power refers to:

A) the power source for the ventilator
B) the system used to convert the power to ventilatory work
C) the system used to control rate or tidal volume
D) the gas pressure powering the ventilator

Question 14

The drive mechanism of a ventilator refers to:

A) the power source for the ventilator
B) the system used to convert the power to ventilatory work
C) the system used to control rate or tidal volume
D) the gas pressure powering the ventilator

Question 15

A fluidic element that is commonly used to sense negative (sub-ambient) pressure is the:

A) AND/NAND gate
B) OR/NOR gate
C) Schmidt trigger
D) flip-flop element

Question 16

The trigger variable best describes:

A) how the ventilator changes from inspiration to exhalation
B) how the ventilator delivers gas during inspiration
C) how a breath is initiated
D) what happens to pressure during exhalation

Question 17

A fluidic element used by the Monaghan 225/SIMV ventilator to power the exhalation valve is the:

A) AND/NAND gate
B) OR/NOR gate
C) Schmidt trigger
D) flip-flop element

Question 18

Which of the following may provide input power sources for mechanical ventilators?
I. electricity
II. pneumatic
III. hydraulic
IV. magnetic

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

Question 19

The control circuit of a mechanical ventilator refers to:

A) the power source for the ventilator
B) the system used to convert the power to ventilatory work
C) the system used to control rate or tidal volume
D) the gas pressure powering the ventilator

Question 20

A ventilator that uses proportional scissor valves is the:

A) CareFusion Avea
B) Puritan Bennett840
C) Siemens SERVO
D) Newport Medical e360

Question 21

Which of the following are common morphologies (shapes) for pressure output waveforms?
I. rectangular
II. exponential
III. sinusoidal
IV. oscillating

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

Question 22

Which of the following are classified as input power alarms?
I. loss of electrical power
II. ventilator inoperative
III. high pressure
IV. loss of oxygen

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

Question 23

A variable that describes what happens to pressure during exhalation is best termed a:

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

Question 24

Which of the following modes of ventilation allows spontaneous breathing?
I. continuous mandatory ventilation (CMV)
II. assist/control (A/C)
III. synchronized intermittent mandatory ventilation (SMIV)
IV. continuous positive airway pressure

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

Question 25

Which of the following are common morphologies (shapes) of flow output waveforms?
I. ascending ramp
II. descending ramp
III. sinusoidal
IV. rectangular

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

Question 26

When comparing a Downs' and a Boehringer PEEP valve, an advantage of a Downs' valve would be:

A) it provides more accurate pressure regulation
B) it is smaller and more compact
C) it doesn't require water
D) it can operate in any position

Question 27

Which of the following are common morphologies (shapes) of volume output waveforms?
I. ascending ramp
II. descending ramp
III. sinusoidal
IV. oscillating

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

Question 28

Which of the following PEEP devices may be used in any position?
I. Downs' valve
II. Boehringer valve
III. magnetic valves

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

Question 29

Which of the following may serve as cycle variables?
I. pressure
II. flow
III. volume
IV. time

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

Question 30

A ventilator in which the gas that drives the ventilator is delivered to the patient is termed a:

A) drive-circuit ventilator
B) double-circuit ventilator
C) main-circuit ventilator
D) single-circuit ventilator

Question 31

A variable that describes how inspiration is terminated is best termed a:

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

Question 32

A ventilator in which the gas delivered to the patient is independent from the gas that powers the ventilator is termed a:

A) drive-circuit ventilator
B) double-circuit ventilator
C) main-circuit ventilator
D) single-circuit ventilator

Question 33

Which of the following pressure output waveforms is commonly produced by high-frequency ventilators?

A) rectangular
B) exponential
C) sinusoidal
D) oscillating

Question 34

A mode of ventilation in which all breaths are mandatory, pressure limited, and time cycled with an inverse I:E ratio is termed:

A) airway pressure release ventilation (APRV)
B) volume-controlled inverse-ratio ventilation (VCIRV)
C) pressure-controlled inverse-ratio ventilation (PCIRV)
D) volume-assured pressure support

Question 35

Which of the following alarms is classified as a control-circuit alarm?

A) loss of electrical power
B) ventilator inoperative
C) high pressure
D) loss of oxygen

Question 36

A mode of ventilation in which all breaths are mandatory and volume cycled with an inverse I:E ratio is termed:

A) airway pressure release ventilation (APRV)
B) volume-controlled inverse-ratio ventilation (VCIRV)
C) pressure-controlled inverse-ratio ventilation (PCIRV)
D) volume-assured pressure support

Question 37

A mode of ventilation in which the patient is able to breathe spontaneously between mechanical (mandatory) breaths is termed:

A) assist control (A/C)
B) pressure support
C) synchronized intermittent mandatory ventilation (SIMV)
D) pressure control

Question 38

Which of the following are classified as output alarms?
I. low pressure
II. low exhaled tidal volume
III. low-minute ventilation
IV. high respiratory rate

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

Question 39

Which of the following may serve as limit variables?
I. pressure
II. flow
III. volume
IV. time

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

Question 40

A mode of mandatory ventilation in which all breaths are pressure limited and time cycled is termed:

A) assist control (A/C)
B) pressure support
C) synchronized intermittent mandatory ventilation (SIMV)
D) pressure control

Question 41

You are using a ventilator circuit that has a tubing compliance of 3 mL/cmH₂O. The peak pressure is 30 cmH₂O, and the measured exhaled volume is 760 mL. What is the corrected volume?

A) 760 mL
B) 757 mL
C) 730 mL
D) 670 mL

Question 42

The pathology of your patient changes such that more secretions are produced and bronchospasm occurs. Airway caliber decreases by one-half. What happens to airway resistance?

A) It stays the same.
B) It increases by one-half.
C) It doubles.
D) It increases by sixteen times.

Question 43

Resistance is defined as:

A) pressure divided by volume
B) volume divided by pressure
C) pressure divided by flow
D) flow divided by pressure

Question 44

Compliance is defined as:

A) pressure divided by volume
B) volume divided by pressure
C) pressure divided by flow
D) flow divided by pressure

Question 45

Which of the following modes of ventilation maintains spontaneous breathing?

A) volume control - CMV
B) volume control - SIMV
C) pressure control - SIMV
D) pressure control - APRV

Question 46

During pressure control, which of the following variables are set by the clinician?
I. Volume
II.Pressure
III.Flow
IV.Inspiratory time

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

Question 47

Which of the following are considered drive mechanisms:
I. pistons
II. bellows
III. compressors
IV. pneumatic circuits

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

Question 48

The diaphragm is responsible for what percentage of the thoracic volume increase during inspiration?

A) 25%
B) 50%
C) 75%
D) none of the above

Question 49

The load required that a mechanical ventilator must overcome includes which of the following: Elastic properties of the lungs
Resistance properties of the lung
The compliance of the lung

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

Question 50

The primary difference between pressure support and CPAP is:

A) CPAP only provides pressure during inspiration
B) Pressure support augments spontaneous breaths with a set pressure
C) CPAP unlike pressure support allows the clinician to set a baseline pressure
D) Pressure support allows the clinician to set a rate

Question 51

A mode of ventilation in which two CPAP levels are set and the patient may breathe spontaneously from both CPAP levels is termed:

A) pressure support
B) pressure ventilation
C) airway pressure release ventilation (APRV)
D) bilevel positive airway pressure (BiPAP)

Question 52

During normal quiet ventilation, pleural pressures change by approximately:

A) 46 - 50 cmH₂O
B) 36 - 40 cmH₂O
C) 14 - 16 cmH₂O
D) 3 - 6 cmH₂O

Question 53

Which of the following is/are the primary muscle(s) of ventilation? Diaphragm
External intercostals
Scalene
Pectoralis major

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

Question 54

During volume control, which of the following variables are set by the clinician?
I. Volume
II.Pressure
III.Flow
IV.Inspiratory time

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

Question 55

The pressure difference between the mouth and alveoli is termed the:

A) transairway pressure
B) transpulmonary pressure
C) transthoracic pressure
D) drive pressure

Question 56

You are using a ventilator circuit that has a tubing compliance of 4 mL/cmH₂O. The peak pressure is 30 cmH₂O, and the measured exhaled volume is 760 mL. What is the corrected volume?

A) 760 mL
B) 756 mL
C) 730 mL
D) 640 mL

Question 57

The pressure difference between the alveoli and the pleural space is termed the:

A) transairway pressure
B) transpulmonary pressure
C) transthoracic pressure
D) drive pressure