Lesson 4 - Intro to Anesthesia Equipment

What is characterizes a closed circuit?

total rebreathing occurs

3 multiple choice options

What is characterizes an open circuit?

no rebreathing occurs

3 multiple choice options

What characterizes a partially closed circuit?

some rebreathing occurs

3 multiple choice options

What part of the anesthesia machine allows oxygen to enter the anesthesia machine?

flowmeter

3 multiple choice options

What part of the anesthesia machine sets the flow rate of the carrier gas?

flowmeter

3 multiple choice options

What part of the anesthesia machine reduces the pressure of the gas as it enters the anesthesia machine?

flowmeter

3 multiple choice options

What part of the anesthesia machine displays the pressure within the breathing system and anesthesia machine?

pressure gauge

3 multiple choice options

What part of the anesthesia machine speeds up filling of the breathing system during a machine leak test?

oxygen flush valve

3 multiple choice options

What part of the anesthesia machine rapidly removes inhalant anesthetic from the breathing system?

oxygen flush valve

3 multiple choice options

What part of the anesthesia machine delivers inhalant anesthetic agents to maintain anesthesia?

vaporizer

3 multiple choice options

What part of the anesthesia machine provides an exit point for the mixture of carrier gas and inhalant anesthetic to the breathing system?

common gas outlet

3 multiple choice options

When would we want to close the adjustment pressure limiting valve?

evaluating the anesthesia machine and breathing system for leaks

3 multiple choice options

What occurs when the adjustment pressure limiting valve is open?

waste gases exit to the atmosphere

3 multiple choice options

What part of the anesthesia machine ensures correct flow direction of gas toward or away from the patient?

unidirectional valves

3 multiple choice options

What part of the anesthesia machine indicates the patients breathing?

reservoir bag

3 multiple choice options

What part of the anesthesia machine allows manual ventilation?

reservoir bag

3 multiple choice options

What part of the anesthesia machine serves as a reservoir for oxygen and inhalant anesthetics?

reservoir bag

3 multiple choice options

What part of the anesthesia machine eliminates expired gases to the atmosphere?

scavenging system

3 multiple choice options

What part of the anesthesia machine removes exhaled CO2 through a chemical reaction?

CO2 absorber

3 multiple choice options

What are types of oxygen sources?

1. cylinders

2. oxygen concentrator

3. liquid cryogenic oxygen

Where is the high pressure system of the anesthesia delivery system?

from cylinder to pressure regulator

3 multiple choice options

Where is the intermediate pressure system of the anesthesia delivery system?

from pressure regulator to flowmeter

3 multiple choice options

Where is the low pressure system of the anesthesia delivery system?

downstream of flowmeter to common gas outlet

3 multiple choice options

What is the pressure of oxygen in the high pressure zone?

2000 psi

3 multiple choice options

What is the pressure of oxygen in the intermediate pressure zone?

50 psi

3 multiple choice options

What is the pressure of oxygen in the low pressure zone?

14 psi

3 multiple choice options

What are the carrier gases used?

1. oxygen

2. medical air

3. nitrous oxide

What is nitrous oxide always in combination with when used as a carrier gas?

oxygen

What are the most common sizes of oxygen cylinders used for anesthesia?

size E and size H

3 multiple choice options

What size oxygen cylinder is in the anesthesia machine?

size E

3 multiple choice options

What size oxygen cylinder is in the cylinder bank?

size H

3 multiple choice options

How are oxygen cylinders attached to the anesthesia machine?

hangar yoke

What are some safety rules to keep in mind with oxygen cylinders?

1. do not lubricate with oil or grease

2. do not leave close to open flames

3. store in dry-clean, well ventilated/shaded areas

4. store in upright position

What are the features in place that help avoid accidental delivery of the wrong gas?

1. color-coding and labeling

2. pin index safety system

3. diameter index safety system and quick connect

What color is oxygen?

green or white

What color is nitrous oxide?

blue

What color is medical air?

yellow

What color is carbon dioxide?

grey

What color is entonox?

blue

How does the pin index safety system work?

holes on the cylinder valve must match the pins on the hangar yoke on the anesthesia machine

What is the function of oxygen concentrators?

1. produce concentrate oxygen from air

2. nitrogen and water vapor are removed

What is the maximum achievable concentration of oxygen that can be obtained from an oxygen concentrator?

95%

3 multiple choice options

What pressure do oxygen concentrators work at?

low pressure

What is the function of the liquid cryogenic oxygen?

1. oxygen is stored as a liquid

2. useful in large hospitals with high demand

What is the function of the pressure regulator?

reduce pressure of oxygen from oxygen cylinder

3 multiple choice options

What are the pipelines?

connection between cylinders and anesthesia machine

What safety system is used for the pipelines?

diameter index safety system and color coding

What is the units for the flowmeter?

L/min

What are the types of rotating floats for the flowmeter?

1. balls

2. bobbins

Where do you read the level at with flowmeter ball?

middle of ball

Where do you read the level at with flowmeter bobbin?

at the top

What is a good indicator that something is wrong with the flowmeter with a bobbin?

bobbin isn't spinning when oxygen should be flowing through

What are the cons of excess FGF?

1. waste of oxygen

2. waste of volatile agents

3. potentiates hypothermia

What is very important about the oxygen flush valve?

do not use when a patient is connected to the breathing system because of barotrauma risk

How does the oxygen flush valve work?

delivers oxygen at high flow that bypasses the vaporizer

What pressure system does the oxygen flush valve belong to?

intermediate pressure system

What is the color for sevoflurane?

yellow

3 multiple choice options

What is the color for isoflurane?

purple

3 multiple choice options

What is the color for halothane?

red

3 multiple choice options

What is very important safety rule with the vaporizer?

never tilt or put upside down

What do you need to check with the vaporizer before using it?

1. level of liquid anesthetic

2. filling port is closed

3. dial turns easily

4. properly mounted in the machine

What are the precautions with the vaporizer?

1. keep upright

2. turn off after use

3. turn off if refilling while in use

4. do not fill with the wrong agent

Which statement correctly describes administering 3 L/min of 100% oxygen compared to 0.8 L/min of 100% oxygen?

it delivers the same oxygen concentration, but at a higher flow rate

3 multiple choice options

How to know if a reservoir bag is too small?

1. bag collapses when a patient takes a breath

2. when giving manual breath, unable to expand the chest

How to know if a reservoir bag is too large?

1. difficult to observe movements of the bag

2. slower changes in anesthetic depth

What size reservoir bag is usually used for cats?

0.5 - 1 L

What size reservoir bag is usually used for dogs?

0.5 - 3 L

What size reservoir bag is usually used for horses?

25 - 30 L

What is the pop-off valve?

spring loaded APL valve

Should the APL valve be open or closed during spontaneous ventilation?

always open

1 multiple choice option

What are the types of scavenging systems?

1. active

2. passive

What is an active scavenging system?

uses a slight vacuum to take the gases

What is a passive scavenging system?

1. does not used negative pressure

2. charcoal canister

3. exhaled gases vented to distant site through long tubing

What does the charcoal canister bind to?

only to inhalants

3 multiple choice options

What are the safety checks with the charcoal canister?

1. weigh regularly to check if its exhausted

2. do not occlude holes in the bottom

What rebreathing system uses unidirectional valves?

rebreathing system

What breathing systems use CO2 absorber?

rebreathing system

What does the chemical reaction in the CO2 absorber produce?

heat, change in pH, and water

What is the precaution with sevoflurane and the CO2 absorber?

interacts with granules and produce Compound A which is nephrotoxic in rats

What is the precaution with desflurane and the CO2 absorber?

production of carbon monoxide, mainly in the presence of desiccated absorbers

What is the consequence of closing the APL valve during spontaneous ventilation?

pressure builds up in the breathing system and the lungs

3 multiple choice options

What are the types of breathing systems?

1. open

2. close

3. semi-closed

4. semi-open

What are characteristics of rebreathing systems?

1. expired gas without CO2 returns to patient

2. closed/semiclosed

3. high/low flow of oxygen

What are characteristics of non-rebreathing systems?

1. all exhaled gases are removed

2. no CO2 absorbed

3. no unidirectional valves

What removes the CO2 from the non-rebreathing systems?

high FGF

What results from rebreathing CO2?

1. hypercapnia

2. acidemia

3. hyperkalemia

4. reduced contractility

5. cardiac arrhythmias

What are the rebreathing systems?

1. two-tubing system

2. single-tubing system

Which type of breathing system uses less oxygen and inhalant anesthetics?

rebreathing systems

What are the pros of rebreathing systems?

1. more economical

2. less environmental pollution

3. heat and moist conservation

4. less gas waste

5. gas flow can be changed

What are the cons of rebreathing systems?

1. increased resistance

2. CO2 absorber needs replacing

3. bulky

4. slow changes in anesthetic depth

What are the types of non-rebreathing systems?

1. Magill, Lack

2. Bain

3. Ayre's T-Piece

4. Jackson-Rees T-piece

Where do the exhaled gases go in non-rebreathing systems?

APL valve and scavenging system

What breathing system is suitable for smaller patients <7-10kg?

non-rebreathing system

Why is non-rebreathing system not suitable for large patients?

need high FGF to push out the CO2

What are the pros to non-rebreathing system?

1. reduced work of breathing/resistance

2. good control of inspired gas concentrations

3. no CO2 absorber needed

What are the cons to non-rebreathing system?

1. high FGF required

2. more gas waste

3. moisture and heat loss

4. inefficient in large animals

When do we use high flow in rebreathing systems?

1. first 10 min

2. anesthesia induction

3. anesthesia recovery

What is the metabolic oxygen consumption rate under anesthesia?

6 mL/kg/min

What is the rate for high flow?

40-100 ml/kg/min

What is the rate for low flow?

20-40 ml/kg/min