Week 3 (Voice over) Vaporizers

Question 1

Modern vaporizers are accurate over a wide range of temperatures and ___ ____ ___.

Answer 1

Fresh gas flows

Question 2

SVP is what?

Answer 2

A measure of the volatility of the liquid anesthetic in the carrier gas.

Question 3

Heat of vaporization is the amount of calories required to what?

Answer 3

1 G of liquid to vapor without temperature change in the remaining fluid.

Question 4

A substance’s specific heat (SH) is what?

Answer 4

The quantify of heat required to raise the temperature of one gram (1 ml) of a substance by 1 degree C.

Question 5

What are the factors that potentially affect vaporizer output?

Answer 5

FGF (fresh gas flows), temperature, carrier gas composition, and ambient pressure.

Question 6

Increasing contact are between gas and liquid in a vaporizer increases what?

Answer 6

The efficiency of the vaporization (baffles, spiral tracks or wicks).

Question 7

Three characteristics of modern vaporizers include what?

Answer 7

Agent-specificity (keyed filling port required), temperature compensation, and flow-over.

Question 8

Vaporizer interlock is a safety feature that does what?

Answer 8

Only allows one vaporizer on at a time.

Question 9

The basic operating premise of variable-bypass vaporizers states what?

Answer 9

That FGF (fresh gas flows) enters the vaporizer and splits into carrier gas (much less than 20%) and bypass gas (80%).

Question 10

Output is relatively constant over a wide range of flows, what are these flow rates?

Answer 10

250 ml/min to 15 L/min

Question 11

What is the “Pumping Effect”?

Answer 11

It describes the affect on vaporizer output from intermittently fluctuating pressure in the breathing system.

Question 12

ASTM established standards in 1988 that included what?

Answer 12

FGF limits (15 L/m), unidirectional rotation for concentration increase, concentration calibration of vaporizers, and temp/pressure effects.

Question 13

Hazards associated with vaporizers include what?

Answer 13

Using the wrong agent, tipping, overfilling, and emptying.

Question 14

Safety features of vaporizers include what?

Answer 14

Agent specific keyed fillers, secured vaporizers, interlocks and counterclockwise rotation of dial for an increase in % of agent.

Question 15

Compared to newer vaporizers (Tec 6, 7, etc), Tec 5 vaporizers require FGF close to what?

Answer 15

5 L/m. They are also more affected by pumping.

Question 16

Desflurane is heated to 39 C (above boiling point)…

Answer 16

As large amounts are vaporized and over-pressurized to 1300 mmHg

Question 17

Where is the electronic control mechanism?

Answer 17

In the aladin cassette, is in the anesthesia machine.

Question 18

Vapor 2000 vaporizers may be tipped as long as they are in what setting?

Answer 18

“T” setting.

Question 19

If the wrong agent is used, what do you do?

Answer 19

First, discard contents of the vaporizer, then run at 5L oxygen flow until no agent is detected. Typically about 20 minutes.

Question 20

Boiling points for contemporary agents?

Answer 20

Isoflurane - 48.5 C
Halothane - 50.2 C
Sevoflurane - 58.5 C
Desflurane - 22.8 C (requires a special vaporizer due to the lower boiling point.)

Question 21

Vaporizers are made from metals that are good conductors of what?

Answer 21

Heat - help transfer heat from surroundings into the liquid. Metals are very THICK.