Anesthesia Lab Final

Question 1

What would delivering anesthetic gas in air (21%O₂) lead to in the patient? Why?

Answer 1

Hypoxemia due to hypoventilation & V/Q mismatch induced by anesthetics themselves

Question 2

What is the minimum acceptable % of O₂ delivered for people & small animals?

Answer 2

30-35% (FiO₂ = 0.30-0.35)

Question 3

what is the metabolic requirement for oxygen?

What is the minimum O2 flow required?

Answer 3

5-10mL/kg/min

This would be the minimum O2 flow required!

Question 4

how are E cylinders usually attached to anesthesia machine?

Answer 4

directly via a yoke

Question 5

How is cylinder pressure usually measured

Answer 5

PSI (pounds per square inch)

Question 6

How is breathing system pressure measured?

Answer 6

cmH2O (centimeters water)

Question 7

Where is the low pressure in an anesthetic machine system?

Answer 7

between flowmeter output & common gas outlet

Question 8

What is considered the breathing system pressure

Answer 8

the pressure in patients’ lungs

Question 9

What is the capacity of E cylinder?

Answer 9

660 L

Question 10

What is the capacity of H cylinder?

Answer 10

6600 L

Question 11

What are both the E & H cylinder filled to a pressure of?

Answer 11

2200 psi

Question 12

How to calculate remaining O2 in a tank?

Minutes remaining?

Answer 12

Question 13

What is DISS

Answer 13

Diameter index safety system

Non-interchangeable gas-specific threaded connection system

Question 14

What is a regulator

Answer 14

AKA prssure-reducing valve

decreases tank pressure to a safe working pressure (approx. 50 psi) which is supplied to flowmeter

Question 15

Where do you read the flow in a flowmeter

Answer 15

MIddle of ball

Top of bobbin

Question 16

Where should O2 flowmeter be when there are multiple flowmeters?

Answer 16

On far right (downstream of all other gases) to prevent delivery of a hypoxic gas mixture

Question 17

At what rate does the quick flush deliver gas when used?

Answer 17

Between 35-75 L/min directly to patient circuit

Question 18

When is it appropriate to use the quick flush?

What type of gas mix will be flushed?

What precaution must be taken if quick flush is to be used?

Answer 18

To quickly decrease anesthetic gas % in the circuit

No mix! this is pure O2 that has bypassed the vaporizer

Patient should be disconnected from the circuit temporarily before the O2 flush valve is utilized

Question 19

What is a possible complication of use of the quick flush?

Answer 19

Barotrauma = PNEUMOTHORAX

Question 20

What do anesthetic vaporizers do

Answer 20

Deliver selected % of anesthetic vapor to fresh (common) gas outlet

“volumes percent”

Question 21

What is vapor pressure

Answer 21

pressure exerted by vapor molecules when liquid & vapor phases are in equilibrium

Question 22

What is saturated vapor pressure

Answer 22

maximum administration percentage of a vapor

Question 23

How do vaporizers work

Answer 23

a specific concentration is created by variable-bypass system, where fresh gas flows over a reservoir of liqui anesthetic & mixes with carrier gas

Question 24

What is a common feature of all modern vaporizers?

What type is it if the anesthetic % is known?

Answer 24

They are out-of-circuit (VOC)

precision vaporizer

Question 25

What were vaporizers in the past considered?

Answer 25

VIC - vaporizers in circuit

Non-precision

cannot produce a known anesthetic %

NOT RECOMMENDED CURRENTLY

Question 26

What must you not do before transporting a vaporizer

Answer 26

Cannot be tipped - must be emptied before transporting

Question 27

What is the common gas outlet?

Where is it

Answer 27

where gas exits the vaporizer

connected by a hose to the fresh gas inlet

Question 28

What are the 2 types of pt breathing systems & examples of each type?

Answer 28

Re-breathing system

• circle
• Universal F

Non-rebreathing system

• Bain (modified Mapleson D)
• Mapleson F

Question 29

Advantages of rebreathing system?

Disadvantages?

Answer 29

Advantages: Lower fresh gas flow rate required

• pt breathes warm, humidified gases
• saves $
• decr environmental pollution

Disadvantages:

• higher resistance to breathing due to valves
• changes in anes gac conc occur slowly d/t lower fresh gas flow
• more components→more leak potential

Question 30

Advantages of non-rebreathing system?

Disadvantages?

Answer 30

Advantages:

• Light, minimal dead space, minimal resistance to ventilation (use for small pts <3kg)
• Anes gas conc changes rapidly d/t high fresh gas flow & sm circuit volume
• fewer components→less potential for leaks

Disadvantages:

• pt breathes cold, dry gas
• more $
• incr envionmental pollution

Question 31

How to calculate tidal volume (TV) & reservoir bag size for rebreathing system

Answer 31

Tidal volume = 15mL/kg

Bag size = TV x 6 round up to nearest L

For horses usually 30 L bag or 20 L ventilator capacity