Scavenging Systems

Question 1

State the definition of scavenging

Answer 1

Collection of excess gases from equipment used to administer anesthesia or exhaled by the patient & the removal of these gases to an appropriate place of discharge outside the work environment

Question 2

Gas-collecting assembly

Answer 2

Captures gases at site of emission
Function: Collects excess gases & delivers them to the transfer means
Design: 30-mm male fitting for outlet connection

Question 3

Transfer tubing

Answer 3

Carry collected gases to interface

Question 4

Interface

Answer 4

Provide positive (& sometimes negative) pressure relief & may provide reservoir capacity
19 or 30-mm male connector
Positioned as close to gas-collecting assembly as possible

Question 5

Gas-disposal tubing

Answer 5

Carry gases from interface to gas disposal system

Question 6

Gas disposal system

Answer 6

Carries gases to point where they are discharged

Question 7

List the order of the components of the scavenging system

Answer 7

(1) Gas collection assembly (2) Transfer tubing (3) Interface (4) Gas disposal tubing (5) Gas disposal system

Question 8

Gas Collecting Assembly Locations:

Answer 8

Breathing systems
Ventilators
Respiratory gas monitors
Leak sites

Question 9

Details of the design of Transfer Tubing

Answer 9

A length of tubing with a connector at either end
As short as possible
Wide enough to carry high flows without significant pressure increase
19 or 30-mm inlet/outlet fittings
Resistant to kinking & occlusion
Easy to see & disconnect
Different color than breathing system

Question 10

Components of the interface

Answer 10

Positive pressure relief
Negative pressure relief
Reservoir capacity

Question 11

Types of Interfaces

Answer 11

Open

Closed

Question 12

Features of Open Interface

Answer 12

Has 1 or more openings to atmosphere
Contains no valves
Reservoir needed to hold gas surges
Reservoir allows disposal system flow rate to be above gas-collecting assembly flow rate
Should only be used with active disposal
Safety depends on patency of vents to atmosphere

Question 13

Flow of the open interface

Answer 13

Anesthetic gases from transfer means enter at the top of the reservoir & are conducted to base where they are dispersed

Question 14

design of open interface

Answer 14

Parallel tubes inside canister
1 carries waste gases to bottom
1 carries gases from bottom to disposal system
Open ports at top of canister provide positive & negative pressure relief
A flow control valve regulates scavenging flow
A flowmeter measures amount of vacuum applied to interface by the active disposal system

Question 15

Features of Closed interface

Answer 15

Connects to atmosphere thru valves
Positive pressure relief valve always required
Negative pressure relief valve required only with active disposal system
Reservoir not required

Question 16

Closed Interface

Answer 16

Positive Pressure Relief Only
Used only with a passive disposal system
Positive relief valve remains closed unless there is problem downstream of interface

Positive & Negative Pressure Relief
Used only with active disposal system