Medical gases chapter 37

Question 1

Critical temperature

Answer 1

Highest temperature at which a substance can exist as a liquid

Question 2

Critical pressure

Answer 2

Pressure needed to keep substance in liquid state at its critical temperature

Question 3

Critical Point

Answer 3

The critical pressure + the critical temperature of a substance.

Question 4

Oxygen

Answer 4

• colorless, odorless
• Density at STPD = 1.49 g/L (GMW = 32)
• Critical temperature= -118 degrees C
• Critical pressure= 716 PSIG
• Nonflammable but supports combustion
• FDA requires 99% immunity for medical use

Question 5

Purification

Answer 5

Atmospheric air is filtered and dried (get rid of water vapor)

Question 6

Liquefaction

Answer 6

Purified air is liquefied by compressing to high pressures and cooling by rapid expansion

Question 7

Distillation

Answer 7

liquid air is warmed to boil off other gases, oxygen has the highest boiling temperature ( -183 degrees C)

Question 8

Oxygen concentrators

Answer 8

Molecular Sieves, Electric device that separates O2 in room air from nitrogen, pellets inside absorb nitrogen and water vapor from the air. Provides greater than 90% oxygen, 1-2 L/min 92-95%, most cost effective for home use.

Question 9

Air

Answer 9

Colorless, odorless

• Composition- 21% oxygen, 78% nitrogen, 1% trace gases .9% argon and .3% carbon dioxide.
• Density = 1.29 g/L
• medical air must be dry, free or oil and particulate contamination

Question 10

Production of medical air

Answer 10

• capable flows greater then 100 L/minute (heavy duty)

* Generates pressures at 50 psig

Question 11

Portable air compresser

Answer 11

• Home use for aerosol drug delivery
• No reservoir- limited pressure and flow
• Do NOT generate pressures of 50 psig

Question 12

Carbon Dioxide (CO2)

Answer 12

*Colorless, odorless
*Does not support combustion or maintain animal life
*