Module 4: Physical Principles Of Respiratory Care And Storage And Delivery Of Medical Gases

Question 1

What a re the three primary states of matter?

Answer 1

Solids, liquids, and gases.

Question 2

What are the components that make up ”solids?”

Answer 2

Solids:
-Have high degree of internal order
-Fixed volume and shape
-Strong mutual attractive force between atoms
-Molecules have the shortest distance to travel before collision
-This collision is referred to as the “jiggle”

Question 3

What are the components that make up “liquids?”

Answer 3

Liquids:
-Have fixed volume, but adapt to shape of their container
-Atoms exhibit less degree of mutual attraction compared with solids
-Shape is determined by numerous internal and external forces

Question 4

What components make up “gases?”

Answer 4

Gases:
-Gas molecules in constant motion exhibit rapid, random motion with frequent collisions
-Exhibit the phenomenon of flow, expand to fill their containers, and have minimal forces of attraction

Question 5

What is heat transfer?

Answer 5

First law of thermodynamics.
When two objects of different temperature coexist, heat will move from hotter to cooler object until both are equal.

Question 6

How can heat transfer occur?

Answer 6

Conduction: is the transfer of heat by the direct interactions of atoms or molecules in a hot area with atoms or molecules in a cooler area, requires direct contact between two substances.

Question 7

How can heat transfer occur?

Answer 7

Convection: involves the mixing of either liquid or gas molecules (fluids) at different temperatures, requires direct contact between two substances.

Question 8

How can heat transfer occur?

Answer 8

Radiation: Requires no direct contact between the warmer and cooler substances.

Question 9

How can heat transfer occur?

Answer 9

Evaporation: is a change of state from liquid to gas; heat is taken from the air surrounding the liquid, cooling the air.

Question 10

273 Celsius =

Answer 10

Kinetic molecular activity stops= 0 (K)elvin

Question 11

C=

Answer 11

(F - 32) divided by 1.8

Question 12

F=

Answer 12

(1.8x C) + 32

Question 13

Cohesion

Answer 13

Attractive force between like molecules= cohesion

Question 14

Adhesion

Answer 14

Attractive force between unlike molecules= adhesion

Question 15

Surface tension

Answer 15

Force exerted by like molecules at liquids surface.

Question 16

What is surface tension responsible for?

Answer 16

This force is responsible for the spherical shape of liquid droplets and their ability to keep this shape when placed into an aerosol suspension.

Question 17

What is capillary action?

Answer 17

Liquid in a small tube that moves upwards against the force of gravity

Question 18

What forces are involved with capillary action?

Answer 18

Adhesive and surface tension forces.

Question 19

What are some examples of capillary action?

Answer 19

Capillary stick blood samples, absorbent humidifier wicks, and certain surgical dressings.

Question 20

What is vaporization?

Answer 20

Liquid-to-vapor phase changes

Question 21

What are the two types of vaporization?

Answer 21

Boiling and Evaporation

Question 22

What is boiling point?

Answer 22

Boiling point- heating liquid to temperature at which its vapor pressure exceeds atmospheric pressure.

Question 23

What is evaporation?

Answer 23

Evaporation: when liquid changes into gas at temperature below its boiling point, the adjacent air is cooled

Question 24

What is absolute humidity?

Answer 24

A.K.A water vapor content
Actual amount (or weight) of water vapor in gas
Air (gas) that is fully saturated with water vapor has absolute humidity of 43.8 mg/L at 37• C, 760 mmHg, and water vapor pressure of 47 mmHg

Question 25

What is relative humidity?

Answer 25

RH: 100% when the ga is fully saturated, this occurs when the water vapor content of a volume of gas equals its capacity

Question 26

What is molar volume?

Answer 26

A quantity of matter that contains 6.02 x 10(23) molecules, atoms or ions at STPD is known as a mole.

Question 27

What does 1 mole of gas equal to?

Answer 27

1 mole (Mol) of a gas at STPD= 22.4 L

Question 28

How much of space does 1 mole of gas occupy?

Answer 28

1 mole of any gas occupies 22.40 liters of space

Question 29

What results in entraining the greatest amount of air in an air injector?

Answer 29

A small offrice jet (from an oxygen gas source) and a large entrainment port (from atmospheric or room air) would result in entraining the greatest amount of air in an air injector.

Question 30

What are the characteristics of medical gases: Oxygen (O2)

Answer 30

Colorless, odorless, transparent, and tasteless

Question 31

What are the characteristics of (O2) at standard temperature, pressure and dry (STPD)?

Answer 31

Oxygen has a density of of 1.429 g/L Slightly heavier than air (1.29 g/L) Not very soluble in water, at room temperature and 1 atm pressure, only 3.3 ml of O2 dissolves in 100 mL of water.

Question 32

What percentage (of purity) does medical oxygen need to be at according to the FDA?

Answer 32

99%

Question 33

How can oxygen accelerate combustion?

Answer 33

Burning speed increases with either an increase in O2 percentage at a fixed total pressure or an increase in total pressure O2 at a constant gas concentration.

Question 34

How are most LARGE quantities of medical O2 produced?

Answer 34

Produced by fractional distillation of atmospheric air

Question 35

How are small quantities of concentrated O2 produced?

Answer 35

By physical separation of O2 from air, which is the method of O2 production commonly used in the home care setting

Question 36

What is hydrostatic testing and what is it used for?

Answer 36

Hydrostatic testing for leaks and expandability is done every 5-10 years by the Department of Transportation (DOT)

Question 37

How can you identify a gas cylinder?

Answer 37

A positive identification of the contents of a medical gas cylinder is made by reading the cylinder label and not only by the color of the tank.

Question 38

How can you distinguish the cylinder sizes and content?

Answer 38

The key difference between small compressed gas cylinders (sized AA-E) and their larger counter parts (sizes F to K) is that small gas cylinders use a yoke (non-threaded) connector

Question 39

What does the plus symbol stand for on a gas cylinder?

Answer 39

A plus (+) symbol marking on the shoulder of the tank indicates the gas cylinder can be filled to 10% in excess of service pressure (2000 psig + 10% = 2200 psig)

Question 40

Duration of Flow=Content/Flow Equation

Answer 40

Duration of Flow= Pressure Tank x Cylinder Factor ——————————————————————— Flow Rate (L/min)

Question 41

Cylinder Factor (E)

Answer 41

0.28

Question 42

Cylinder Factor (G)

Answer 42

2.41

Question 43

Cylinder Factor (H & K)

Answer 43

3.14

Question 44

What are the three systems used to ensure correct gas source?

Answer 44

American Standard Safety System (ASSS) Pin-Index Safety System (PISS) Diameter- Index Safety System (DISS)

Question 45

American Standard Safety System (ASSS)

Answer 45

For large cylinders (sizes F-H/K) and their attachments and prevents accidental misconnections

Question 46

Pin-Index Safety System (PISS)

Answer 46

For small cylinders (Sizes AA-E) and their attachments Cylinders have yoke type connection Uses a post valve and yoke connection. In order to work, the yoke nipple has to seat in the recessed valve outlet

Question 47

What are the exact positions for pins and pinholes for PISS?

Answer 47

2-5 for oxygen 1-5 for air There are six pin positions an 10 possible pin/hole combinations

Question 48

Diameter Index Safety System (DISS)

Answer 48

For low pressure gas connections (<200 psig) Located at the outlets of pressure reducing valves attachment to cylinders, at the station outlets of central piping systems, and at the inlets of blenders, flow meters, ventilators, and other pneumatic equipment

Question 49

Flowmeter

Answer 49

Flowmeter is used to control flow to patient

Question 50

Regulator

Answer 50

Regulator is used to control both pressure and flow

Question 51

Thorpe Tube Flowmeter

Answer 51

Used to deliver oxygen to a patient directly from a bedside outlet station. Measures true flow, controls flow by using variable orifice, constant pressure flowmeter device.

Question 52

What does increasing the size of a orifice do to gas flow?

Answer 52

Increase gas flow

Question 53

What always attached to a Thorpe Tube Flowmeter?

Answer 53

50 psig gas source

Question 54

What is the purpose of the compensated flowmeter? (Thorpe Tube Flowmeter)

Answer 54

Is used to accurately measure flow when using a jet nebulizer

Question 55

Thorpe Tube Flowmeters with Heliox What are the gas densities?

Answer 55

Oxygen: 1.429 g/L Air: 1.293 g/L 80:20 Heliox: 0.429 g/l 70:30 Heliox: 0.554 g/L

Question 56

80:20 Heliox flows?

Answer 56

Will be 1.8 times the meter reading. Helium must always be combined with at least %20 oxygen

Question 57

70:30 helium flows..?

Answer 57

Will always be 1.6 times the meter reading