Week 6 - Anesthesia Equipment Part 2

Question 1

Decreasing temperature causes a ____________ in evaporation

Answer 1

decrease

Question 2

What is vapor?

Answer 2

Molecules in the gaseous phase of a substance that is liquid at room temperature and 1 atm of pressure.

Question 3

Describe latent heat of vaporization

Answer 3

This is the cooling effect of the liquid as the vapor is taking energy (heat) with it. As more of a liquid is vaporized and loses this energy, the liquid becomes cooler.

Question 4

A cool liquid vaporizes _______ than a warmer liquid

Answer 4

less
Vaporization occurs less as the liquid begins to cool

Question 5

How is the latent effect of vaporization prevented in the inhaled anesthetics we give?

Answer 5

Materials such as copper are used to contain liquid anesthetics in vaporizers.
Temperature compensation devices (variable bypass vaporizers), diverts more gas into the vaporization chamber as the anesthetic cools

Question 6

3 things the rate of vaporization depends on

Answer 6

Temperature, vapor pressure of the liquid, and partial pressure of the vapor.

Question 7

What is the splitting ratio within a vaporizer?

Answer 7

The operator can set the concentration of the anesthetic on the vaporizer. This causes a portion of the combined gases from the flowmeter to be channeled down to the vaporizing chamber, while the rest of the gas (majority) doesn’t come into contact with the vaporized anesthetic at all, going through the bypass chamber.

Question 8

Vaporizers are _____ of the breathing circuit

Answer 8

out

Question 9

What makes a Tec 6 vaporizer different from a traditional variable bypass vaporizer?

Answer 9

Tec 6 is used only with Desflurane, where it is heated and pressurized (due to vapor pressure being so close to atmospheric pressure). Heated dual circuit vaporizer where the FGF NEVER comes in contact with the anesthetic vapor. Instead, an appropriate amount of vapor is released from the vaporizer.

Question 10

Going up on FGF causes the Tec 6 vaporized to release _____ anesthetic

Answer 10

More

Question 11

At what heat and pressure does the Tec 6 vaporized keep Desflurane stored at?

Answer 11

39 degrees C, 2 atms (1500 mmHg)

Question 12

What would happen if Desflurane was put into a conventional variable bypass vaporizer?

Answer 12

Hypoxic breathing mixture would develop. This is due to Desflurane completely vaporizing, consisting of nearly 100% of the output.

Question 13

What is the purpose of unidirectional valves within the vaporizer?

Answer 13

Keeps flow unidirectional (toward patient). Prevent back pressure (pumping effect) which would increase vaporizer output.

Question 14

2 types of filling methods within the vaporizer

Answer 14

Funnel type and Keyed filler type

Question 15

What filling method is preferred within the vaporizer?

Answer 15

Keyed filler type. Less likely to add the wrong anesthetic to the wrong vaporizer

Question 16

How should vaporizer be filled?

Answer 16

Turn off, ensure correct vaporizer and anesthetic, then pour or attach

Question 17

How long does the Tec 6 vaporizer need after plugging it in?

Answer 17

10 minutes. This is so it can be heated to 39 degrees C and pressurized to 1500 mmHg.

Question 18

Preoperative checkout for varible bypass vaporizers includes

Answer 18

Checked to determine if they are turned off, whether they are full, if the filling cap is tightly closed, and if the interlock system is functioning correctly.
They also are checked for leaks, ONE BY ONE!

Question 19

Why is tipping the vaporizer hazardous?

Answer 19

Because the liquid anesthetic can enter different portions of the vaporizer where its control can’t be managed. It causes unpredictable effects on its function

Question 20

Should high or low FGF be used during induction?

Answer 20

HIGH, This causes the anesthetic to equilibrate into the patients system much faster.
Do NOT switch to low FGF too early after induction, this can lead to awareness.

Question 21

What is the theory of wash in?

Answer 21

Concept of a time constant.
After 1 time constant this brings a system 63% to equilibrium, 2 = 86% and 3 = 95%

Question 22

Splitting ratio is

Answer 22

Gas entering vaporizing chamber divided by total FGF determined in variable bypass vaporizer by internal resistance to flow.

Question 23

Full saturation of carrier gas is achieved by _______ and _________

Answer 23

wicks, baffles

Question 24

The final concentration of an anesthetic equals

Answer 24

Fully saturated carrier gas diluted with FGF at chamber outlet

Question 25

Setting the vaporizer dial to a higher concentration __________ bypass flow

Answer 25

decreases

Question 26

2 control points of the Tec 6 vaporizer

Answer 26

Setting concentration dial and transducer responsive to FGF