IHS WAG 33
What is the max exposure 8 hour average of halogenated agents? N2O?
Halogenated agents = 2ppm
N2O = 25 ppm
What should you do if you smell anesthetic gas during a case?
Investigate. This is not normal.
What is the purpose of a scavenging system?
to control occupational exposure to waste anesthetic gases
What are the 2 most important factors in reducing waste anesthetic gases?
1) Scavenger System
2) Operating Room Ventilation
What are the 2 types of Scavenging Systems? What are the differences?
1) Active - uses suction
2) Passive - gases passively leave via tubing to OR ventilation system or outside
What is the potential danger to the patient of an active scavenging system?
1) negative pressure to patient
2) positive pressure to patient
What is the potential danger to the patient of a passive scavenging system?
positive pressure buildup
What are the two types of scavenging interfaces? What are the differences?
1) Open - pressure relief is an opening to the atmosphere
2) Closed - communication to the atmosphere is only through valves
Is the Open or Closed interface safer for the patient?
Can you have an Open Passive system?
No - all open systems must be active
What would you do if you were using an open scavenging interface and you heard a hissing noise during the case?
Nothing - this is normal. The danger though is there is no audible indicator of gas leaks - must rely on nose.
How do you gauge the intensity of vacuum on the open system? closed system?
: flowmeter with ball in-between lines
: Resorvior bag not distended but not completely flat
If you are using a closed system and hear a hissing noise what does it mean?
The positive pressure relief valve is open
When does the negative pressure relief valve open during closed system scavenging? How can you know if this has happened?
- 0.25 cm H2O
scavenging back will be completely flat
What is the purpose of the reservoir bag?
To handle fluctuations in intake vs output
If you increase your FGF, what else can you expect to increase?
suction on your scavenging system
What are the hazards of scavenging? (4)
1) Obstruction distal to interface --> barotrauma or excess negative pressure (disconnect gas collection tube from APL valve and turn off suction)
2) Occupational Exposure
4) Misassembled system (uses 19 or 30 mm connectors)
IHS WAG 33