Module 4 Scavenger Systems

Question 1

Barotrauma

Answer 1

Injury resulting from high airway pressure

Question 2

Compliance

Answer 2

The ratio of a change in volume to change in pressure. Most commonly used in reference to the lungs and chest wall.

Question 3

Continuous Positive Airway Pressure (CPAP)

Answer 3

Airway pressure maintained above ambient.

Question 4

Which factors affect delivered tidal volume?

Answer 4

1) Fresh gas flow
2) Leaks
3) Compliance and compression volumes

Question 5

What is the difference between ascending and descending bellows?

Answer 5

Ascending bellows “ascend” during the expiratory phase, whereas the descending bellows “descend” during the expiratory phase.

Question 6

What is scavenging?

Answer 6

Scavenging is the collection and the subsequent removal of waste anesthetic gases from the OR.

Question 7

What is the NIOSH recommendation for maximum safe level of exposure of halogenated agents?

Answer 7

2 ppm

Question 8

What are the two major causes of waste gas contamination in the OR?

Answer 8

1- The anesthetic technique employed.

2- Equipment issues.

Question 9

What are the components of a scavenger system?

Answer 9

1- the gas-collecting assembly.
2- the transfer means
3- the scavenging interface
4- the gas-disposal assembly tubing
5- an active or passive gas-disposal assembly.

Question 10

What is the most important component of the scavenger system?

Answer 10

the scavenging interface

Question 11

What is an “open interface”?

Answer 11

An open interface has no valves and is open to atmosphere, allowing both positive and negative-pressure relief.

Question 12

Should you use an open interface with a passive disposal system?

Answer 12

NO. Open interfaces should be used ONLY with active disposal systems that use a central evacuation system.

Question 13

What is a “closed interface”?

Answer 13

Is a system that communicates with the atmosphere through valves.

Question 14

How many types of closed interface systems are there?

Answer 14

2. • Positive pressure relief only
   • Positive and negative pressure relief

Question 15

What are the characteristics of the positive pressure relief only system?

Answer 15

1- A single positive-pressure relief valve designed to be used ONLY with passive disposal systems.
2- A reservoir bag is not required.

Question 16

What are the characteristics of the positive and negative pressure relief system?

Answer 16

1- A positive-pressure relief valve, and at LEAST one negative-pressure relief valve.
2- It has a reservoir bag.
3- it is used with active disposal systems

Question 17

What are the types of gas-disposal systems?

Answer 17

1- Active

2- Passive

Question 18

Active gas-disposal system

Answer 18

• Most common.
• An interface with a negative pressure relief valve is MANDATORY.
• A reservoir is highly recommended

Question 19

Passive gas-disposal system

Answer 19

• Doesn’t require the mechanical flow-induced device.
• Positive pressure relief is MANDATORY.
• Negative pressure relief and reservoir not needed.

Question 20

Exhaust valve

Answer 20

A valve in a ventilator with a bellows that when open allows driving gas to exit the bellows housing.

Question 21

Expiratory flow time

Answer 21

Time between the beginning and end of the expiratory flow.

Question 22

Expiratory Pause Time

Answer 22

Time from the end of expiratory flow to the start of the inspiratory flow.

Question 23

The time between the start of expiratory flow and the start of the inspiratory flow. It is the sum of the expiratory flow and expiratory pause times.

Answer 23

Expiratory Phase Time

Question 24

What is a possible problem with piston ventilators?

Answer 24

Air entrainment with a disconnection. In this case, the machine will not alarm and the patient will continue to be ventilated, but air will be entrained, resulting in lower oxygen concentration and anesthetic agents.

Question 25

What is the relationship between fresh gas flow, tidal and minute volume?

Answer 25

When the fresh gas flow is increased, the tidal and minute volume will increase. When the gas flow is decreased, tidal and minute volume will decrease as well

Question 26

What is the ventilator driving gas?

Answer 26

Oxygen

Question 27

What are the three types of alarms?

Answer 27

1- High priority (cannot be silenced)- immediate action 2- Intermediate priority- prompt action 3- Low priority- operator awareness but not necessarily action.

Question 28

What will prevent barotrauma?

Answer 28

Setting the pressure 10 cm H20 above the peak pressure achieved with the desired tidal volume.

Question 29

Trace gas levels in OR depends on...

Answer 29

``` 1- fresh gas flow 2- the ventilation system 3-the length of time the anesthetic agents have been administered. 4- the measurement site 5- the anesthetic technique ```

Question 30

What are some problems attributed to trace gas?

Answer 30

* Spontaneous abortions * Infertility * Birth defects * Impaired performance * Cancer * Liver disease

Question 31

Scavenging is...

Answer 31

the collection of excess gases from equipment used to administer anesthesia or exhaled by the patient and the removal of these gases to an appropriate place of discharge outside the work environment. Dorsch CH 13.

Question 32

What is the purpose of the gas-collecting assembly?

Answer 32

It collects excess gases and delivers them to the transfer means.

Question 33

Conveys gas from the collecting assembly to the interface when the interface is not an integral part of the gas-collecting assembly

Answer 33

Transfer tubing

Question 34

COPD, Asthma, emphysema

Answer 34

Pathologies that will benefit from prolonged expiratory time.

Question 35

Monitor drive pressure and will alarm if pressure falls below 25 psig. It ensures that driving pressure is within a set safe parameter

Answer 35

Regulated Pressure Transducer

Question 36

How often do you calibrate the oxygen sensor?

Answer 36

Every morning at 21%. | Every month at 100%

Question 37

Y-piece

Answer 37

the most common site of disconnection

Question 38

Tubing Sizes

Answer 38

Scavenger: 19 or 30mm Common gas outlet: 15 mm Breathing circuit: 22 mm

Question 39

Protocol for mechanical ventilator failure

Answer 39

1- manually ventilate with the circle system. 2- bag with oxygen or room air 3- try to pass a suction catheter through the tracheal tube 4- visualize the hypopharynx and cords, or reintubate

Question 40

What is the NIOSH recommendation for maximum safe level of exposure of halogenated agents with nitrous oxide?

Answer 40

0.5 ppm

Question 41

What is the NIOSH recommendation for maximum safe level of exposure of nitrous oxide alone?

Answer 41

25 ppm