Week 7 Medical Gas Systems

Question 1

Using the link proportioning system, how is a hypoxic gas mixture defined?

Answer 1

• oxygen concentration of < 25%
• ratio of nitrous:oxygen of > 3:1 or 75% : 25% because anything more would dilute the oxygen to less than 25%

Question 2

What is the PISS?

Answer 2

• Pin Index Safety System
  
  • used for gas cylinders
• uses series of pinks to connected associated gas cylinder’s valves with its matching yoke clamp
  
  • position of holes on the cydlinder correspond with pins on the yoke attached to the equiment
  • prevents connection of the the wrong cylinder to a yoke
    
    • misconnection unlikely, but not impossible
    • where this is a will there is a way, so be diligent in checking and not forcing
• **Required for every anesthesia machine**
• **use only ONE washer when connecting**

Question 3

A full tank of nitrous weighs _____ lbs, contains ______ L, and reads a pressure of about _____ psi.

Answer 3

20.7; 1590; 750

Question 4

Name one reason that it is important to leave the E-cylinders on the anesthesia machine completely closed/off.

Answer 4

If the E-cylinder remains open, and pipeline pressure falls, your E-cylinder will drain without your knowledge, and when it runs out you will have no back up oxygen ready to go.

Question 5

When are the two times that you will open your E-cylinders on the anesthesia machine.

Answer 5

1. morning machine check
2. for back up or emergency use

***otherwise they should remain closed***

Question 6

The Department of Transportation establishes the requirements for __________, __________, __________, __________, __________, _________, ___________, __________, and ____________ of medical gas cylinders and containers.

Answer 6

• manufacturing
• filling
• qualification
• transportation
• storage
• handling
• maintenance
• re-qualification
• disposition

Question 7

Purity of medical gases is specified in the ______________ and enforced by the ______.

Answer 7

US Pharmacopoeia; FDA

Question 8

In a tank of oxygen, as the volume in the tank decreases, the pressure in the tank ________.

Answer 8

decreases

Question 9

Name 4 possible errors that could cause the link proportioning system to fail.

Answer 9

• pipeline crossover or incorrect gas in cylinder
• mechanical issue
  
  • defective pueumatic part, defective chain
• leaks distal to the flow meter
• If you add a 3rd gas
  
  • you risk diluting hte partial press or concentration of gases in the mix you are administering
  • i.e. if you have 75% nitrous and 25% oxygen and you had helium, you will dilute out your oxygen to less than 25% and deliver a hypoxic mixture to your patient.

Question 10

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

Answer 10

Department of Transportation (DOT)

Question 11

State the standard color associated with oxygen, air, nitrous, helium, and nitrogen.

Answer 11

• oxygen - green
• air - yellow
• nitrous - blue
• helium - bronw
• nitrogen - black

**never judge a tank by its color**

Question 12

This label shows the Compressed Gas Association (CGA) marking system.

• The diamond shape denotes the __________.
• To the left is the name of the ___________.
• To the right is the __________, with statements of hazars and measure to be taken to avoid injury.

Answer 12

• hazard class (non flammable)
• contained gas (carbon dioxide)
• signal word (caution)

Question 13

What is the link proportioning system on the anestha machine?

Answer 13

• fail safe mechanism
• 3:1 protection
  
  • 3 parts nitrous : 1 part oxygen
  • never going to have more than 75% nitrous going to patient
• If you begin to dial up the nitrous, the oxygen will automatically dial up to 25%
• oxygen flowmeter works independly of nitrous dial, but nitrous dial is always proportioned with oxygen dial

Question 14

Name the pin locations, for oxygen, nitrous oxide, air, carbon dioxide, and entonx.

Answer 14

Question 15

Distinguish between all eight specified markings on the cyclinder.

Answer 15

1. cylinder specification - regulatory type (DOT), cylinder type of material, service/working pressure in psi
2. serial number
3. date of manufacturer - MM/YY
4. neck ring identification - original owner of cylinder
5. retest markings - Month/Facility/Year + symbol - cylinder qualified for 10% overfill. star - meets qualifications for a 10 year retest, instead of the usual 5.
6. barcode label - provides a unique cylinder identifier and is used by computer systems to track cylinders throughout the fill process
7. cylinder manufacturer’s inspection marking
8. cylinder tare weight - may be preceded by “TW”

Question 16

Differentiate between the volumes and pressures of full tanks of oxygen, air, and nitrous.

Answer 16

Question 17

Do all cylinders need to have a cylinder label? Where does the label go?

Answer 17

Yes, each cylinder must have a label or decal on the side or on the shoulder, but may not cover any permanent markings.

Question 18

Name the seven safe handling procedures for cylinders.

Answer 18

1. Never stand a cylinder upright without support.
2. Never lave empty cylinders on the machine (poor form, consider changing when less than 1/2 full)
3. Never leave the plastic tape on the port while installing the cylinder (could occlude gas flow)
4. Never rely only on the cylinder’s color for identification of its contents (Never judge a cylinder by its color)
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 fromthe outlet by slowly and briefly “cracking” the valve away from you and/or other personnel. WHY?! 1) fire prevention - as gas recompresses as it passes through the cylinder outlet, it can generate a lot of heat and the particles can serve as fuel for the heat. 2) dont want particles traveling into machine
7. The valve should always be fully open when a cylinder is in use. Marginal opening may result in failure to deliver adequate gas.

Question 19

What is the DISS?

Answer 19

• Diameter Index Safety System
  
  • used for pipeline gases
• provides non-interchangable connections of the medical gas lines
• only properly mated parts will fit together and allow the threads to engage
• consists of body, nipple, and nut combinations
• *Required* for every anesthesia machine