Anesthesia Machine Flashcards

1
Q

SPDD

A

supply, processing, delivery, and disposal model.

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

Supply

A

Pipeline and Cylinders

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

Processing

A
How gasses are prepared before delivery to the patient. 
Fail-safe
Flowmeters
Oxygen flush
Low pressure alarms
vent-driving gas
proportioning system
oxygen second stage regulator
Vaporizers
Check valves distal to vaporizors
Common Gas Outlet (CGO)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Delivery

A

Interaction with the patient is controlled and monitored; Breathing circuit

Gas delivery hose from CGO to circuit
nonrebreathing or circle
CO2 absorption
vent
monitors; O2 analysis; disconnect; spirometry
Vent alarms
PEEP
Humidification
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Disposal

A

How are gasses disposed of? : Scavenger
Closed: active v. passive or open
Scavenger flowmeter

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

High pressure components

A

Receives gasses from the high pressure E cylinders attached to the back of the anesthesia machine (2000 psi for O2, 745 psi for N2O)
Consists of:
Hanger Yoke (reserve gas cylinder holder)
Check valve (prevent reverse flow of gas, or gas leaks)
Cylinder Pressure Indicator (Gauge)
Pressure Reducing Device (Regulator)
Usually not used, unless pipeline gas supply is off

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

Intermediate Pressure components

A
Receives gasses from the regulator or the hospital pipeline at pressures of 40-55 psig (common is 50psi)
Consists of:
Pipeline inlet connections
Pipeline pressure gauges 
Piping
Ventilator power inlet
Master switch
Oxygen pressure-failure devices
Oxygen flush valve
Additional reducing devices
Flow control valves
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Low pressure components

A
Extends from the flow control valves to the common gas outlet
Consists of:
Flowmeter tubes
Vaporizer mounting device
Check valves
Common gas outlet
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Pressure fail-safe devices

A

This valve is controlled by the O2 supply pressure and shuts off or proportionately decreases the supply pressure of all other gasses as the O2 supply pressure decreases

Historically there are 2 kinds of fail-safe valves
Pressure sensor shut-off valve (Ohmeda) (O2 opens if psi>20)
Oxygen failure protection device (Drager) (The pressure of all gases controlled by the OFPD will decrease proportionately with the oxygen pressure)

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

Oxygen Flush Valve

A

Receives O2 from pipeline inlet or cylinder reducing device and directs high, unmetered flow directly to the common gas outlet (downstream of the vaporizer)
Machine standard requires that the flow be between 35 and 75 L/min
The ability to provide jet ventilation
Hazards
May cause barotrauma
Dilution of inhaled anesthetic

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

Proportioning systems

A

Maintains N2O:O2 ratio 3:1, with a minimum of 25% O2.

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

5 tasks of oxygen

A

1: proceeds to fresh gas flowmeter
2. powers the O2 flush
3. activates failsafe mechanism
4. activates O2 low-pressure alarms
5. Compresses bellows of mechanical vents

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

Managing oxygen pipeline supply Failure

A

Always have Ambubag and O2 tank
If pipeline pressure fails or PaO2 drops:
1: Don’t try to fix analyzer
2: Turn on tank, disconnect pipeline
If FiO2 doesn’t increase, use ambubag with RA
3: Low flow of O2. Keep going with volatile
4: Turn off vent, ventilate manually
5: Call for help, get more O2 tanks, calculate remaining time on current tanks
6: How long will failure last? make a plan
7: Don’t reconnect until pipeline is tested
8: If circle isn’t working, use BVM with O2 or RA, and TIVA.

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

E-cylinder O2

A

1900 psi, 660L

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

N2O

A

745 psi, 1590 L (Needs to be weighed, don’t go off psi)

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

Air

A

1900 psi, 625 L

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

Path of gases (Ox, N2O, air)

A

supply ->fail-safe valve-> flowmeter -> common manifold (O2 is added to all gases at this point) -> vaporizor -> CGO

18
Q

Oxygen flush

A
35 - 75 L/min
Fill circuit quickly
jet ventilation
AVOID DURING INHALATION
proceeds directly from supply to the CGO
19
Q

Inspired oxygen analysis

A

o Ensure that oxygen is present in the pipeline or cylinder
o required in EVERY GETA
o Function checked every time

20
Q

Variable-bypass

A
allows a small portion of FGF to come into contact with liquid and pickup the vapor. 
Sevoflurane, Isoflurane
Splits total fresh gas flow into 2 portions:
First portion (20%) passes into vaporization chamber, becomes saturated with vapor
Second portion passes into bypass chamber , they mix at patient outlet
Delivers known concentration of gas 
Temperature sensitive strip expands and contracts to offset temperature changes due to evaporation
Splitting Ratio = flow through vaporizing chamber/flow through bypass chamber
21
Q

Vaporizer

A

Agent specific, outside breathing circuit.
Vaporization depends on temperature, VP of liquid, and partial pressure of vapor above the evaporating liquid
Tilting or tipping must be avoided; if this is done, vaporizer is not usable until serviced!
Air flow “carrier gas” carries vapor to patient
Variables include molecular make-up of vapor (vapor pressure) and temperature

22
Q

Tec-6

A

Desflurane ONLY
o Flow not split; vapor “injected” into fresh gas
Amount of Des released depends on:
Concentration setting set on control dial
Fresh gas flow rate
Des is heated to 39OC, this maintains desired vapor pressure for delivery
Separate electrical supply

23
Q

Dead Space

A

Anatomical dead space:
Areas of the tracheal/bronchial tree not involved in gas exchange
Includes equipment dead space: ETT and tubing distal to Y connector of circuit
Alveolar dead space:
Alveoli that do not participate in gas exchange due to lack of blood flow
Total dead space reflects the above sum; most pathologically significant changes in dead space represent changes in alveolar dead space

24
Q

Circle system advantages

A

Most popular in USA
Advantages:
Cleanses CO2 but allows rebreathing of all other gases
Conservation of respiratory moisture and heat
Decreases ppm of vapors in the OR
Lower resistance

25
Q

Circle System Disadvantages

A

Disadvantages:
Increased dead space
Uni-directional valves may malfunction
Increased resistance to valves and CO2 absorber
Bulky, can be partially eliminated with co-axial circle (Bain system)
Relatively complex, increased opportunity for malfunction

26
Q

CO2 reabsorption

A

Chemical reaction makes it possible to rebreathe volatile gases.
White to purple when exhausted
If hypercarbia occurs d/t exhausted absorbent, increase the FGF, and replace CO2 right away after the case.

27
Q

Prep machine for MH Patient

A

Oxygen flush: 10L/min for 20 min.
Change breathing circuit and soda lime
Treatment: Dantrolene

28
Q

Vent disconnect

A

Loss of capnogram
Unable to ventilate, loss of volume
Manually ventilate, troubleshoot starting at ETT

29
Q

Disposal of Scavenging gases

A

Gas to be disposed of comes from:
APL valve if bag/vent selector switch is set to “bag”
Ventilator relief valve is switch is set to “vent”

30
Q

2 types of scavenging

A

Active:
Connected to hospital’s vacuum system and gases are drawn from the system
Passive:
Connected to the hospital’s ventilation system and waste gases flow out on their own.

31
Q

Scavenging obstruction

A

Increase positive pressure -> barotrauma

32
Q

Hanger yoke for E cylinder:

A

Orients cylinder, one-way flow (no transfilling to lower pressure tank); Gas-tight seal.

33
Q

Your oxygen tank pressure reads 1200 psi and you are giving the patient 3L of oxygen per minute. How long will this tank last you?

A

About 2 hours. (O2 is 1900 psig/660L. 1200 x 660 / 1900 = 416 / 3L/min = 139 minutes)

34
Q

Wood’s metal

A

Melts at elevated temp on E cylinder valve; if fire or increase pressure safety release valve releases O2 in controlled manner, not explosion.

35
Q

Tipped vaporizer

A

DON’T Use. Can OD Pt. Get to biomed ASAP.

36
Q

Vaporizor

A

Can be overfilled

37
Q

Open system

A

Can’t rebreathe.

38
Q

Mapleson F (Jackson Reese)

A

Requires high Flow to prevent rebreathing

39
Q

What law describes O2 monitor?

A

Beer-Lambert

40
Q

CO2 Gas flows:

A

Flow of the gases opens the inhalation valve
On inspiration the gas flows through the inhalation check valve & soda lime
Gas flows down through the soda lime, directly from the common gas outlet, and from the rebreathing bag

41
Q

Adrienne’s law

A

If you do not work hard and study, memorize, and understand your anesthetic curricular content, you will fail boards!!!