Mechanical Ventilation

Question 1

What is Mechanical Rate:

Answer 1

Breaths per minute that will be delivered by the ventilator whether or not the patient attempts to breath or not. It can be adjusted up or down based on ABGs, patient mental status, reason for mechanical ventilation.

Question 2

What is the first parameter weaned during attempts to liberate the patient from mechanical ventilation?

Answer 2

mechanical rate

Question 3

What is spontaneous rate?

Answer 3

The breaths per minute that the patient initiates. This may vary widely depending on level of alertness, sedation, respiratory muscle strength, pain/aggitation, disease process

Question 4

What is tidal volume?

Answer 4

It refers to the amount of exhaled breath or the targel tidal volume that was set for mechanical breaths.

Question 5

What measures tidal volume?

Answer 5

The ventilator measures exhaled tidal volume

Question 6

What is the minute ventilation?

Answer 6

= Vt x RR. Minute ventilation is ultimately what determines PaCO2, so in making ventilator adjustments for PaCO2 we are really manipulating the minute ventilation.

Question 7

What is PEEP?

Answer 7

Positive End Expiratory Pressure, Pressure in the lungs that is maintained at the end of expiration.

Question 8

Auto-PEEP:

Answer 8

air trapping caused by incomplete exhalation

Question 9

Applied-PEEP:

Answer 9

amount of pressure set on the ventilator to either reduce atelectasis due to mechanical ventilation or improve alveolar recruitment due to pathological processes.

Question 10

What is pressure support?

Answer 10

Pressure (cm H2O) above the PEEP that the ventilator delivers during a patient-initiated breath to help increase the tidal volume.

Question 11

What is EtCO2?

Answer 11

Measure of the partial pressure of carbon dioxide in the expired air.

Question 12

What is used as a real time guide to ventilation?

Answer 12

EtCO2

Question 13

What is FiO2?

Answer 13

Percentage of oxygen that can be delivered in multiple ways (NC, face mask) but can be very precisely set via the ventilator.

Question 14

What is the Assist Control mode of mechanical ventilation?

Answer 14

All breaths are fully-mechanical. Set number of breaths per minute regardless of patient initiation. Ventilator senses patient initiation and delivers a fully-mechanical breath.

Question 15

What are the advantages of assist control?

Answer 15

Reduced work of breathing

Question 16

What are the disadvantages to assist control?

Answer 16

Decreased patient requirement & Easier, unintended hyperventilation.

Question 17

What is the SIMV mode of mechanical ventilation?

Answer 17

Set number of breaths regardless of patient initiation. PS (cm H2O above PEEP) delivered during patient-initiated breaths.

Question 18

What are the advantages of SIMV?

Answer 18

Patient assumes control respiratory drive and rate.

Question 19

What are the disadvantages of SIMV?

Answer 19

At times, unintended increase in work of breathing.

Question 20

What is the PSV mode of mechanical ventilation?

Answer 20

Zero fully-mechanical breaths. PS and PEEP set – basically an invasive form of BiPAP.

Question 21

What are the advantages of PSV?

Answer 21

Patient assumes drive to breathe.

Frequently more comfortable due to patient control over duration of breath and tidal volume.

Question 22

What are the disadvantages of PSV?

Answer 22

Certain patients may not tolerate due to hypoventilation.

Question 23

What are the methods of delivery for mechanical ventilation?

Answer 23

Volume control
Pressure control
VC+

Question 24

How does volume control work?

Answer 24

Ventilator delivers a set tidal volume to the patient on all mechanical breaths regardless of pressure required.

Question 25

What are the advantages to volume control?

Answer 25

Precise tidal volume delivered.

Question 26

What are the disadvantages to volume control?

Answer 26

Requires the practitioner to adjust flow rates to meet patient demand. Potential for increased pressure to meet target tidal volume.

Question 27

How does pressure control work?

Answer 27

Ventilator delivers a set pressure (in cmH2O) regardless of the volume delivered – remember, we set that pressure.

Question 28

What are the advantages to pressure control?

Answer 28

Precise pressure delivered.

Question 29

What are the disadvantages to pressure control?

Answer 29

Can allow hypoventilation or hyperventilation if the practitioner is not vigilant. Requires repeated adjustment/monitoring depending on patient’s compliance.

Question 30

How does VC+ work?

Answer 30

Allows the practitioner to set a goal tidal volume. The ventilator goes into VC+ startup mode where it delivers several volume control breaths to determine pressure required to meet that volume. The ventilator uses lowest pressure as pressure to be delivered but also does not restrict flow rate (more comfortable). Breath is stopped when goal met (goal + or – 2 standard deviations of desired volume) and will automatically adjust pressure required to reach the goal (good for changing compliance). Also allows a set maximum tidal volume and maximum pressure that it won’t go above.

Question 31

What are the advantages of VC+?

Answer 31

Allows the setting of an inspiratory time that is most appropriate for each time. Typically more comfortable due to automatic adjustment for compliance and flow demand. Helps guard against baro-trauma and volu-trauma via practitioner set safe guards.

Question 32

What are the disadvantages of VC+?

Answer 32

Sometimes does not allow for adequate tidal volumes in certain situations (severe inhalational injury).

Question 33

``` Which of the following is the term for breaths per minute initiated by a patient (on a ventilator)? A.Mechanical Rate B.Minute Ventilation C.FiO2 D.Spontaneous Rate ```

Answer 33

Spontaneous Rate

Question 34

Which method of ventilation uses complete fully-mechanical ventilation? A.Synchronized Intermittent Mandatory Ventilation B.Pressure Support Ventilation C.Assist Control

Answer 34

Assist Control

Question 35

Which method of ventilation uses a set number of breaths regardless of patient initiation and utilizes pressure support? A.Synchronized Intermittent Mandatory Ventilation B.Pressure Support Ventilation C.Assist Control

Answer 35

SIMV

Question 36

Which method of ventilation uses no fully-mechanical breaths? A.Synchronized Intermittent Mandatory Ventilation B.Pressure Support Ventilation C.Assist Control

Answer 36

Pressure Support

Question 37

``` What value is the real time guide for ventilation? A.Minute Ventilation B.Tidal Volume C.FiO2 D.EtCO2 ```

Answer 37

EtCO2

Question 38

Which of the following cases would you NOT use Applied PEEP in? A.Reduce Atelectasis B.COPD C.Improve Alveolar Involvement in Pneumonia D.Alveolar Recruitment in Tension Pneumothorax

Answer 38

COPD

Question 39

``` What ultimately determines PaCO2? A.Mechanical Rate B.Spontaneous Rate C.Auto PEEP D.Minute Ventilation ```

Answer 39

Minute Ventilation

Question 40

``` What is the first parameter weaned during attempts to liberate the patient from mechanical ventilation? A.Mechanical Rate B.Spontaneous Rate C.Applied PEEP D.Pressure Support ```

Answer 40

Mechanical Rate