Mechanical Ventilation

Question 0

What are the 2 different driving mechanisms for ventilators?

Answer 0

1. Bellows - pneumatic

2. Piston - electric

Question 1

What is the waste gas scavenging system?

Answer 1

• Prevents atmospheric contamination
• Collects all the extra gas and vapor from the system so you don’t get contamination of the air with volatile agents, etc.

Question 2

The Bellows type ventilator is pneumatically driven. What does this mean?

Answer 2

• a pneumatic force compresses the bellows, which empties its contents (gas from flowmeters and vaporizer) into the circuit
• Gas goes into the bellow and fills it up and then gas comes outside the bellows and drives it down.

Question 3

For the bellow type ventilator, what drives the bellows?

Answer 3

• Have to have an external gas source to drive the bellows

- The driving gas is oxygen, air, or a venturi mix of O2 and air

Question 4

What drives the piston type ventilators?

Answer 4

• They do not need a driving gas

- They are electronically controlled and pneumatically driven

Question 5

Bellows ventilators will not work without…?

Answer 5

Electrical power

Question 6

All ventilators have backup batteries, how long will they last?

Answer 6

30 min

Question 7

For ascending bellows, they go ______ during exhalation and _______ during inhalation.

Answer 7

up, down

Question 8

Describe “hanging bellows” or descending bellows.

Answer 8

• Same concept as ascending bellows except they are upside down
• During exhalation they fall down due to a weight.

Question 9

What is a possible safety hazard with “hanging bellows” or descending bellows?

Answer 9

• The bellows fall no matter what because of the weight, so if you have a disconnection or leak in the system you would not know

Question 10

In ascending bellows, filling is dependent on ______…?

Answer 10

• exhaled gases from a tight circuit

Question 11

Piston ventilators do not require _____…?

Answer 11

• A driving gas

Question 12

Piston ventilators are driven by ________…?

Answer 12

• Compression from an electric motor

Question 13

In regards to piston ventilators, tidal volume =?

Answer 13

• The surface area of the piston X the distance the piston moves to ventilate the patient

Question 14

What are 4 advantages/disadvantages of piston type ventilators?

Answer 14

1. Quiet
2. No baseline PEEP
3. Greater precision
4. No gas needed to drive it

Question 15

What is an advantage of bellow type ventilators?

Answer 15

1. Able to see and detect disconnection from bellows falling

Question 16

What is physiological PEEP?

Answer 16

3 or so

Question 17

What does mandatory ventilation mean?

Answer 17

• Means that the patient will get ventilated no matter what, it doesn’t sense what the patient is doing

Question 18

What are the 3 modes of mandatory ventilation?

Answer 18

1. Volume control
2. Pressure control
3. Pressure control volume guarantee

Question 19

What do you set for Volume Control?

Answer 19

• you set the tidal volume and respiratory rate

Question 20

What varies in Volume Control?

Answer 20

Peak pressures (due to patient compliance)

Question 21

What remains constant in Volume Control?

Answer 21

Minute ventilation remains constant

Question 22

How should tidal volume be calculated?

Answer 22

8-10 cc per Kg of the ideal body weight

Question 23

What do you set for Pressure Control Ventilation?

Answer 23

• You set the peak pressure and RR

Question 24

What varies in Pressure Control?

Answer 24

- Tidal volume | - Minute ventilation

Question 25

What is Pressure Control - Volume Guarantee?

Answer 25

- "Smart mode" that delivers the desired tidal volume with the lowest possible pressure using a decelerating flow pattern - The ventilator automatically adjusts the pressure to achieve the volume that you would like to achieve

Question 26

Specifically, how does Pressure Control - Volume Guarantee work?

Answer 26

- The first breath is a volume control breath, the patients compliance is determined and then the inspiratory pressure level is established for the subsequent breaths. - It is anesthesia ventilation tailored to the patient's compliance

Question 27

What is Synchronized Intermittent Mandatory Ventilation (SIMV)?

Answer 27

- Combination of spontaneous breathing and mandatory ventilation - Machine breathes are delivered to the patient at set intervals - Meant to supplement patient's own respiratory efforts - mechanical breaths are "synchronized" with respiratory effort

Question 28

What are the 2 SIMV modes?

Answer 28

- SIMV - VC: you set the TV and RR | - SIMV - PC: you set the pressure and RR

Question 29

What is Pressure Support Ventilation (PSV)?

Answer 29

- Used for patients who are spontaneously breathing - You set the pressure support for the machine to deliver during spontaneous breathing - Once the ventilator senses an inspiratory effort from the patient, the ventilator provides constant pressure to the airway to relieve work of breathing.

Question 30

What is PSV- Pro?

Answer 30

- Back up ventilation incase patient stops breathing (30 sec apnea alarm) - Back up mode is SIMV-PC + PS * You set a minimum mandatory RR and pressure * In between mandatory breaths, the patient receives pressure support