1. Medical Gases/Cylinders

Question 1

What’s the equation to determine the duration or time remaining in a cylinder?

Answer 1

[(Gauge Pressure - 500psig) x Conversion Factor] / Flow Rate

Question 2

What’s the equation to determine the ‘cylinder factor’? and what’s the unit for it?

Answer 2

Cylinder Factor (L/psig) = [Cubic feet x 28.3] / Pressure of a full cylinder in psig

Question 3

What’s the conversion factor for an E cylinder (hundredths)?

Answer 3

E Cylinder = 0.28 L/psig

Question 4

What’s the conversion factor for an H/K cylinder (hundredths)?

Answer 4

H/K Cylinder = 3.14 L/psig

Question 5

What’s the cu/ft for D Cylinder?

Answer 5

D cylinder = 12.6 cu/ft

Question 6

What’s the cu/ft for E Cylinder?

Answer 6

E cylinder = 22 cu/ft

Question 7

What’s the cu/ft for G Cylinder?

Answer 7

G cylinder = 187 cu/ft

Question 8

What’s the cu/ft for H/K Cylinder?

Answer 8

H/K Cylinder = 244 cu/ft

Question 9

Where did the 28.3 came from in the Cylinder Factor equation?

Answer 9

28.3 L = 1 cu/ft

Question 10

How many pounds equals 1 Liter of Liquid O2?

Answer 10

1 L Liquid O2 = 2.5 lbs

Question 11

How do you find how many Liters of Liquid O2 given Liquid O2 weight (in lbs)?

Answer 11

Liter of Liquid O2 = Liquid O2 (lbs) / 2.5 lbs

Question 12

What’s the equation for determining the Duration or Time remaining of a Liquid System given Liters of Liquid O2, Gauge Reading, and Flow Rate?

Answer 12

Duration of Liquid System = [Liters of Liquid O2 x 860 x Gauge Reading (%decimal form)] / Flow Rate

Question 13

What does the 860 mean in the Duration of Liquid O2 equation?

Answer 13

An O2 gas occupies 860 times the volume of liquid O2

Question 14

How do you find Liters of O2 gas, given Liters of Liquid O2?

Answer 14

Liters of Liquid O2 x 860 = Liters of O2 Gas

Question 15

What’s the equation to calculate the Duration or Time Remaining of a Liquid System, given Pounds of Liquid O2 and the Flow Rate?

Answer 15

Duration of a Liquid System = [ (Pounds/2.5lbs) x 860 ] / Flow Rate

Question 16

When do we subtract 500 psi from the gauge pressure and when do we not subtract?

Answer 16

We don’t subtract if the question asks “when will the cylinder be EMPTY”. We subtract when it either doesn’t say or when the cylinder should be changed, for safety/cushion purposes.

Question 17

What’s the equation to find the Air to Oxygen Ratio?

Answer 17

[ 100 - % of O2 ] / [% of O2 - 21]

Question 18

If the FiO2 = 40% -> Air to Oxygen ratio is 3:1, how would you explain what 3:1 means?

Answer 18

3 L(parts of air): 1 L(part of oxygen)
For every 1 Liter of Oxygen you dial in a flowmeter, you are entraining 3 Liters of Room Air. 
So if you're dialing 5 L of O2 for example, you are entraining 15 Liters of Air. It would still maintain an FiO2 of 40%

Question 19

What’s the equation to find the FiO2 when given the Air to Oxygen ratio?

Answer 19

[(Air Flow x 21) + (Oxygen Flow x 100)] / (Air Flow + Oxygen Flow)

Question 20

What’s the equation to find the absolute flow rate in Liters/Minute/Part, given a total flow and FiO2?

Answer 20

First, using the Air to Oxygen ratio equation, find the ratio for the FiO2 and add the parts together to get the Total Parts.
Then, the equation is Total Flow / Total Parts

Question 21

What are the US Color coding for these Medical Gases: Oxygen, Air, CO2, Nitrous Oxide, Helium, Nitrogen, Cyclopropane, Ethylene, Nitric Oxide, HeliOx

Answer 21

Oxygen=green, Air=yellow, CO2=gray, Nitrous Oxide=blue, Helium=brown, Nitrogen=black, Cyclopropane=orange, Ethylene=red, Nitric Oxide=baby blue, HeliOx=brown/green

Question 22

What’s the main difference compared to Canada color coding?

Answer 22

In Canada, Oxygen=white, Air=black/white, and N2/O2=Pink. like HeliOx would be Brown and White

Question 23

What’s purity of most gases, and which gas is the different purity?

Answer 23

99.0 purity for most gases. Only Nitrous Oxide (N2O) has a purity of 97.0