Anesthesia Machine Flashcards

1
Q

What would result from delivering atmospheric air for anesthesia?

A

Hypoxia- due to hypoventilation and V/Q mismatch caused by anesthetics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Minimum O2 requirement for anesthesia

A

30-35% O2

Atmospheric is 21%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Metabolic O2 requirement

A

5-10mL/kg/min

Represents the minimum O2 flow required

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Gasses

A

O2
Nitrous oxide
Medical air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Two types of O2 cylinders

A

E- usually in singles, attached to machine via a yoke

H- stored in banks, central O2 supply

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Green Cylinders

A

Oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Blue Cylinders

A

Nitrous oxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Yellow Cylinders

A

Medical Air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why are cylinders stored on their sides?

A

To prevent explosion and avoid spontaneous combustion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Cylinder pressure units

A

psi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Breathing system pressure units

A

cmH2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

High Pressure systems

A

100-2200+psi

Gas cylinders, yokes, pressure gauges, regulators

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Intermediate pressure systems

A

50psi

Central O2 supply, post-regulatory, flush valve, input to flowmeter, driving gas for ventilator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Low pressure systems

A

pressure in patients lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

E-cylinder capacity

A

660L (need to memorize)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

H-cylinder capacity

A

6600L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Internal cylinder pressure

A

2200psi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How do you figure out volume left in tank?

A

Boyle’s law

P1V1=P2V2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How do you figure out time left on remaining volume?

A

Minutes = Volume/(flow liters/min)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Can you calculate remaining volume on N2O tanks?

A

NO- exists as both a liquid and a gas in the tanks and the pressure will only read the gas portion

21
Q

Components to the safety systems

A
  1. Colour coding
  2. Labeling
  3. Diameter index safety system
  4. Pin index system
  5. Quick connectors
22
Q

Diameter index safety system

A

Non-interchangeable gas-specific threaded connection system

Universal between equipment cylinder manufacturers

23
Q

Pin index safety system

A

Gas-specific pin patters that only allow connections between appropriate cylinder yokes and E-tanks

Commonly found on yokes and some cylinder-specific regulators/flowmeters

24
Q

Quick connectors

A

Manufacturer-specific

Facilitate rapid connecting/disconnecting of gas hoses

25
Q

Regulator

A

Aka pressure reducing valve

Decreases tank pressure to approximately 50psi and supplies to the flowmeter

Prevents pressure fluctuations as tank empties

26
Q

Flowmeter

A

Controls rate of gas flow through the vaporizer (L/min)

Calibrated for 760mmHg and 20C

27
Q

Flowmeter pressure reduction

A

50psi to 15psi

28
Q

Where do you read the flowmeter?

A

Middle of ball or top of bobbin depending on type

29
Q

Where should the O2 flowmeter be positioned if there are multiple gas flowmeters? Why?

A

Far right, to avoid hypoxic mixtures.

30
Q

Quick flush

A

Delivers intermediate pressure O2 bypassing the vaporizer

31
Q

Flowrate of the quick flush

A

35-75L/min

32
Q

Use for the quick flush

A

Quickly decrease gas percentage in circuit

Emergency or recovery

33
Q

Should the patient be hooked up to the circuit when using the quick flush?

A

NO- results in dangerous pressure in the breathing circuit which could result in pneumothorax

34
Q

Anesthetic vaporizers

A

Change liquid anesthetic into vapor

Deliver selected % of vapor to the fresh gas outlet

35
Q

Vapor

A

Gaseous state of a substance that is liquid at ambient temp and pressure

Eg- halo, iso, sevo, desflurane

36
Q

Gas

A

Exists in gaseous state at ambient T/P

Eg. N20, Xenon

37
Q

Vapor pressure

A

Pressure exerted by vapor molecules when liquid and vapor phases are in equilibrium

Directly related to temperature
Inversely related to boiling point

38
Q

Saturated vapor pressure

A

Maximum administration percentage of vapor

Vaporizers reduce this to clinically useful percentages

39
Q

Modern vaporizer characteristics

A
  • Agent specific
  • Concentration calibrated
  • Variable bypass
  • Flow over
  • Out of circuit
  • High resistance
  • Compensated for temperature, flow, and back-pressure
40
Q

Variable bypass system

A

Delivers a specific concentration by flowing fresh gas over a reservoir of liquid anesthetic and mixing it from carrier gas

41
Q

VOC- precision vaporizer

A

Out of circuit vaporizer which delivers a known percentage of anesthetic

42
Q

VIC- non-precision vaporizer

A

OLD model

Glass jar containing wicking material saturated with anesthetic
Did not deliver a precise percentage of anesthetic

43
Q

Modern vaporizer compensations

A

Temp: Between 15-35C
Achieved using efficient heat conducting materials

Flow rate- 0.5-10 L/min

Back pressure- associated with positive pressure ventilation and flush valve

44
Q

Desflurane vaporizer

A

Boiling point close to room temp

Electronically heated

Commonly used in Human, not in vet

45
Q

Agent-specific key filler port

A

Prevents filling of vaporizers with improper anesthetics

46
Q

Do modern vaporizers require external power?

A

No- except desflurane

47
Q

Vaporizer transportation/orientation

A

Cannot be tipped, must be emptied prior to transport

If tipped run 1L/min O2 with vaporizer off to clear lines

48
Q

What do you do if vaporizers are filled with the wrong anesthetic?

A

Drain and run 1L/min O2 until dry

49
Q

Common gas outlet

A

Where gas exits the vaporizer, connected by a hose to the fresh gas inlet

Universal for rebreathing and non-rebreating units