Mechanical Ventilation

Question 1

Name 4 reasons the airway is no longer protected and intubation may be indicated:

Answer 1

1. Altered mental status
2. Obstruction (angioedema/edema)
3. Surgical intervention of naso/oropharynx
4. Increased secretions requiring frequent auctioning

Question 2

These three events are evidence of acute respiratory failure on an arterial blood gas and may indicate the need for intubation

Answer 2

1. A pH of 7.25 or less with and elevated CO2
2. A PaO2 of 60% with a patient on 60% fio2 or more
3. A PaCO2 of >60 in a non CO2 retaining patient

Question 3

Alterations in respiratory mechanics that may indicate the need for intubation are: (5)

Answer 3

1. A spontaneous tidal volume of less than 5ml/kg of IBW
2. A RR of >35 or 10
3. A vital capacity of

Question 4

What does a negative inspiratory force (NIF) that is low indicate?

Answer 4

That a patient is unable to draw in an adequate tidal volume

Question 5

What causes an elevated minute ventilation?

Answer 5

A deep TV and breathing fast- can be caused by an obstructive lung disease or severe sepsis or kussmauls respiration so where they are attempting to breathe off acidosis

Question 6

What are goals of intubation? (6)

Answer 6

1. Airway protection
2. Secretion managment
3. PaO2- 60-100
4. SpO2 > 90%
5. FiO2

Question 7

Signs of optimal ventilation are: (4)

Answer 7

1. A PaCO2 of 35-45
2. A pH of 7.35-7.45
3. Acceptable airway pressures (peak pressure

Question 8

What are two adjustments on the vent that improve oxygenation?

Answer 8

FiO2 and the PEep

Question 9

What is peep?

Answer 9

Airway pressure in the lungs at end expiration

Question 10

What is physiological peep

Answer 10

Less than or equal to 5

Question 11

What are the two reasons to increase Peep above 5? (Not disease processes but what you are trying to do within the lungs)

Answer 11

1. Restore functional residual capacity

2. Improve oxygenation without increasing FiO2 by stabilizing and recruiting alveoli and preventing further collapse

Question 12

What is the functional residual capacity?

Answer 12

FRC- the amount of air in the lungs after a normal exhalation

Residual volume + expiration reserve volume

Question 13

What are 4 complications of peep?

Answer 13

1- increased pressure in chest
2- decreased cardiac output
3- increased intrapulmonary shunting
4- barotrauma causing decreased lung compliance

Question 14

How do we alter ventilation on a vent?

Answer 14

The minute ventilation or the respiratory rate x tidal volume

Question 15

What are some other ways to improve ventilation on patients besides changing vent settings?

Answer 15

1. Sedate and paralyze
2. Treat fever
3. High-fat and low carbohydrate nutrition (a byproduct of carbohydrate metabolizing is CO2 production)
4. Decrease dead space ventilation by avoiding dehydration, exceeding peep, or ventilator tubing)

Question 16

Explain the difference between pressure and volume-cycled ventilation

Answer 16

Pressure-cycled- a set pressure is delivered with mandatory breaths and the volume varies.

Volume cycled- a set volume is delivered with mandatory breaths and pressure varies

Question 17

What is assist control ventilation?

Answer 17

This is the most common used volume-cycled ventilation. The patient receives a set volume at a set frequency or rate.

If the patient initiates a spontaneous breath, he receives the preset tidal volume

Question 18

What are the strengths of AC mode ventilation?

Answer 18

1. You get what you set
2. Allows the patient to control the rate of breathing (above the set rate) while ensuring that every breath is supported
3. Decreases WOB

Question 19

What are the limitations of AC mode ventilation?

Answer 19

Can cause patient and ventilator dyssynchrony

Auto peep and barotrauma

Muscle atrophy

Question 20

What is SIMV mode?

Answer 20

Volume ventilation with preset tidal volume similar to AC, however the patients spontaneous breaths will allow their own tidal volume with pressure support

Question 21

What are the 3 strengths of SIMV mode ventilation?

Answer 21

1. Widely used and understood mode of ventilation
2. The patient performs a variable amount of work with security of preset mandatory ventilation
3. Decreased iatrogenic respiratory alkalosis because the patient can set their own minute ventilation

Question 22

What are the limitations of SIMV mode?

Answer 22

1. Can increase WOB
2. If rate too low the patient can fatigue
3. Desynchronous at times

Question 23

What is pressure support ventilation?

Answer 23

It is a patient-triggered mode with each spontaneous breath and gives pressure support

Question 24

What are the strengths of pressure support ventilation

Answer 24

1. Decreased WOB
2. Patient sets own minute ventilation
3. Weaning mode of ventilation
4. Improved synchrony
5. Useful in patients slow to wean

Question 25

Limitations of PSV is what?

Answer 25

1. It does not ensure a tidal volume or respiratory rate | 2. Unstable patients should have a back-up up mandatory rate

Question 26

CPAP mode supports the patient how?

Answer 26

Continuous airway pressure is maintained throughout the breathing cycle. Used as a weaning mode where the patient is responsible for all phases of the respiratory cycle.

Question 27

What is pressure control ventilation?

Answer 27

No preset tidal volume. Pressure is set to achieve a desired tidal volume with a set rate. I:E ratio is controlled

Question 28

Pressure control ventilation strengths are what?

Answer 28

1. Peak airway pressures are controlled 2. Peak pressures can be minimized while maintaining mean airway pressures 3. Decrease in ventilator induced lung injury

Question 29

Plateau pressure is what?

Answer 29

Plateau pressure represents peak alveolar pressure and is obtained during end-inspiratory breath hold.

Question 30

How to you check compliance and plateau pressures in the lungs?

Answer 30

By performing an inspiratory hold maneuver to assess what the plateau pressure is

Question 31

What is the peak inspiratory pressure?

Answer 31

The max amount of pressure in the lungs during a full inspiration

Question 32

In an ARDS patient what should the TV be set to?

Answer 32

TV of 6ml/kg of IBW (less than usual)

Question 33

What are some ventilator-induced lung injury causes from pressure control ventilation?

Answer 33

1. Barotrauma- over expansion of alveoli due to high ventilation pressures 2. Atelectrauma- shear stress induced injury caused by unstable alveoli recruiting and derecruiting 3. Biotrauma- inflammatory injury that occurs due to the tissue damage caused by both volutrauma and atelactrauma

Question 34

Why are vasopressors often needed more with pressure ventilation?

Answer 34

Increase pressure can cause cardiovascular compromise, necessitating increased use of vasopressors

Question 35

What is APRV mode on a ventilator?

Answer 35

This is a mode of pressure ventilation good for patients with poor lung compliance. The patient is allowed spontaneous breaths at any point in the cycle It has a pressure high and pressure low setting Pressure high (plateau pressure) should be 20-30 Pressure low (peep) should be 5-10 Then there is the time high and low which is your inspiratory and exploratory times. Time high is time spent at pressure high and time low is time spent at pressure low

Question 36

What are the strengths for APRV?

Answer 36

1 lower peak and plateau pressures 2. Decrease use of sedation and paralytics 3 increase perfusion to dependent lung regions 4. Increase cardiac output 5. Increased functional residual capacity 6. Can cause less cardiac compromise and decrease vasopressors use

Question 37

What are the limitations of APRV mode?

Answer 37

1. People don't know how to use it 2. MV must be monitored and is calculated differently 3. Takes 8-16 hours to see benefit from this ventilator 4. Not for patients with severe airflow obstruction

Question 38

NIPPV has survival advantages for these types of patients in respiratory distress:

Answer 38

1. COPD exacerbation 2. CHF exacerbation 3. Hypoxia respiratory failure associated with immunosuppressive state (Oncology and transplant patients) 4. Hypoxia respiratory failure after major thoracic or abdominal surgery

Question 39

What are parameters that indicate readiness for extubation?

Answer 39

1. RR 15 | 6. FIO2

Question 40

Systemic indications the patient is ready for extubation:

Answer 40

1. Original reason the patient was intubated has resolved 2. Good Abg and or SpO2 3. Hemodynamic stability 4. Free from continuous sedation 5. No major fluid overload or electrolyte abnormality

Question 41

What is an RSBI?

Answer 41

The rapid shallow breathing index takes the respiratory rate and the tidal volume and calculates it to determine if the extubation will be successful. An RSBI of

Question 42

How often and for how long should a SBT be attempted?

Answer 42

A SBT should be attempted once daily and should last 30minutes to 2 hours

Question 43

What medication has been shown to be superior to other agents in reducing ventilator associated ICU days (sedation)

Answer 43

Propofol

Question 44

What medication is associated with fewer ventilator days (sedation), experienced less delirium, tachycardia, and hypotension

Answer 44

Dexedetomidine (precedex)

Question 45

When should you not perform a sedation holiday?

Answer 45

``` FIO2 > 60% Peep > 7.5 Increased ICP HR > 140 MI in the last 24 hrs ECMO On NMBA Active ETOH withdrawal ```