# 190722_Gas Systems Flashcards

1
Q

SOURCES OF GASES

A

Piped in Gas

E-Cylinders

2
Q

DISS - PIPELINE

A

Diameter Index Safety System:

• Provides non-interchangeable connections for the medical gas lines
• Connection consists of a body, nipple, and nut combination
• Only properly mated parts will fit together and allow the threads to engage
• Required for every anesthesia machine
3
Q

PISS - Cylinder

A

PIN INDEX SAFETY SYSTEM:

• Required for every anesthesia machine
• Uses a series of pins to connect associated gas cylinders valves with its matching yoke clamp
- Position of holes on the cylinder valves corresponds with the pins on the yoke attached to the equipment
- Each gas has a unique pin configuration
- Prevents connection of the wrong cylinder to a yoke

4
Q

CO2 PISS

A

1,6

5
Q

Helium US color code

A

Brown

6
Q

Oxygen

A

2000-2200 psi

625-700 L

7
Q

Air

A

1900-2000 psi

625 L

8
Q

N2O*

A

745 psi

1590 L

*Full N2O cylinder would read pressure of 745 psi and have ~1590 liters and stored as a liquid. Pressure does NOT indicate amount left in tank

9
Q

N2O*full weight

A

20.7 lbs

10
Q

N2O*1/2 full weight

A

17.3 lbs

11
Q

N2O*no liquid weight

A

14.2 lbs

12
Q

N2O*empty weight

A

12.9 lbs

13
Q
• Full tank 2200 psi, 650 liters
• Current tank: 750 psi, ??? Liters

Question: Figure out how many Liters you have left in the current tank. Then, if you are running 2 L/min flow, figure out how many minutes you have left to use before you run out. How many hours left?

A

Current tank volume = 650L/2200psi x 750 psi = 221.6L

Time remaining = 221.6L/(2L/min) = 110.8 min = 1.9 hrs

14
Q

Purity of medical gases is specified in the

A

US Pharmacopoeia

15
Q

Purity of medical gases is specified in the US Pharmacopoeia and enforced by the

A

FDA

16
Q

The _______ establishes the requirements for manufacturing, filling, qualification, transportation, storage, handling, maintenance, re-qualification, and disposition of medical gas cylinders and containers.

A

DOT

17
Q

CYLINDER MARKINGS

A

Permanent Markings: The DOT regulations require specific marking on each cylinder

18
Q

CYLINDER LABELS

A

Labeling: Each cylinder must have a label or decal on the side or on the shoulder, but may not cover any permanent markings

19
Q

CYLINDER TAGS

A

Tags: Full, In Use, Empty connected by perforations. Denotes the amount of cylinder contents and is not used for identification purposes.

Once opened tare off Full tag. Once empty tare off In Use tag.

20
Q

SAFE HANDLING PROCEDURES FOR CYLINDERS

A
1. Never stand a cylinder upright without support
2. Never leave empty cylinders on the machine
3. Never leave the plastic tape on the port while installing the cylinder
4. Never rely only on the a cylinder’s color for identification of its contents
5. Never oil valves
6. Before any fitting is applied to the cylinder valve, particles of dust, metal shavings, and other foreign matter should be cleared from the outlet by slowly and briefly “cracking” the valve.
7. The valve should always be fully open when a cylinder is in use.
21
Q

Why is it important to “crack” the valve away from you and/or other personnel.

A

FIRE!!!! and exposure to pressure and gas

22
Q

The valve should always be fully open when a cylinder is in use. Marginal opening may result in…….

A

23
Q

Vaporization is__________

Why is this important?

A

the conversion of liquid to a gas.

The inhalation agents we use today are liquids that must be converted to a vapor to be inhaled.

24
Q

Anesthetic gases are also referred to as __________ because they are liquids that have a ___________ to vaporize into gas form.

A

“Volatile Agents”

high propensity

25
Q

Vaporization is dependent on:

A
• Vapor pressures
• Temperature
• Amount of carrier gas used
26
Q

Molecules of a volatile agent in a closed container are distributed between what phases?

A

liquid and gas

27
Q

The gas molecules bombard the surface of the liquid and the walls of the container creating __________.

A

vapor pressure

28
Q

VOLATILE AGENTS VAPOR PRESSURE:

Sevoflurane

A

160mmHg

Yellow

29
Q

VOLATILE AGENTS VAPOR PRESSURE:

Enflurane

A

172mmHg

Orange

30
Q

VOLATILE AGENTS VAPOR PRESSURE:

Isoflurane

A

240mmHg

Purple

31
Q

VOLATILE AGENTS VAPOR PRESSURE:

Halothane

A

244mmHg

Red

32
Q

VOLATILE AGENTS VAPOR PRESSURE:

Desflurane

A

669mmHg

Blue

33
Q

A

more molecules inter vapor phase (VP increase)

34
Q

VAPORIZATION OF LIQUIDS: Cool

A

more molecules inter liquid phase (VP decrease)

35
Q

Passing carrier gas over the liquid causes

A

shift toward vapor phase

heat of vaporization is supplied by remaining liquid, causing a drop in temperature

36
Q

LATENT HEAT OF VAPORIZATION

A

Number of calories required to change 1 gram of liquid into vapor without a temperature change
*note 1g=1mL

37
Q

The energy for vaporization comes from__________.

A

the liquid itself (or from an outside source)

38
Q

In the absence of outside source of energy, the temp of liquid itself will _______ during vaporization… rate of vaporization will_______. We need some sort of system where temp of liquid……….

A

decrease

further decrease

remains constant

39
Q

The number of calories required to increase the temperature of one gram of a substance by one degree centigrade is known as what?

A

SPECIFIC HEAT

• The substance can be liquid, solid or gas

40
Q

A measure of speed with which heat flow through a substance is known as what?

A

THERMAL CONDUCTIVITY

41
Q

The higher the thermal conductivity, the better the substance __________.

A

conducts heat

42
Q

VAPORIZERS

A
• Agent Specific
• Temperature Compensated
• Variable Bypass
43
Q

KISS

A

key index safety system

44
Q

VARIABLE BYPASS VAPORIZER

A
• A portion of the gas flow will pass into the vaporizing chamber where it will become saturated with vapor.
• This vapor-laden portion then rejoins the gas flow for dilution to deliverable concentrations.

REVIEW SLIDES 29 and 30!!!

45
Q

TEC 6 VAPORIZER

A

REVIEW SLIDES 31 and 32!!!

46
Q

A

computer controlled variable bypass

47
Q

COPPER KETTLE

A
• Measured flow, Bubble Through vaporizer
• Dedicated flowmeter for the kettle (MEASURED FLOW) • Gas comes up through central tube inside of the vaporizer to the LOVING CUP
• Flow of gas is then directed down toward the liquid (BUBBLE THROUGH)
• Highly concentrated vapor then exits the vaporizer and is
• Diluted into the fresh gas flow
48
Q

COPPER KETTLE CALCULATIONS:

Vapor Output

A

Vapor Output = (CG x VP) / (BP – VP)

• Where CG is the flow rate of the carrier gas in lpm, VP is the vapor pressure of the anesthetic agent and BP is the Barometric pressure.

***CG is manipulated to produce desired vapor output

49
Q

COPPER KETTLE CALCULATIONS:

Anesthetic Concentration

A

Anesthetic Concentration =
Vapor output in mL/min Total gas flow in ml/min

***Total gas flow is manipulated to produce desired concentration

50
Q

ALTITUDE increase: EFFECT ON VAPORIZATION

A

Increased altitude – ↓ barometric pressure

51
Q

ALTITUDE decrease: EFFECT ON VAPORIZATION

A

Decreased altitude – ↑ barometric pressure

52
Q

The % delivered is relative to the ____ vapor pressure in comparison to the _______ pressure.

A

agent’s

barometric

• Vaporizer must be re-calibrated to assure accurate % delivered anesthetic gas

53
Q

ALTITUDE: EFFECT ON VAPORIZATION calculated

A

2% agent @ STP (sea level) = 0.02 x 760mmHg = 15.2mmHg (VP agent)

X elevation ambient pressure = 380mmHg
15.2mmHg (VP agent) / 380mmHg = 0.04
= 4% agent at X elevation

54
Q

POTENTIAL VAPORIZER HAZARDS

A
```• Wrong Agent in the vaporizer ??????????
- High VP – Low VP – High Concentration
- Low VP – High VP - Low Concentration
• Contamination
• Tipping
• Overfilling
• Simultaneous Administration of More than One Vapor
• Leaks
• Pumping Effect```
55
Q

Simultaneous Administration of More than One Vapor is avoided by……

A

the interlocking system.