1. What is the max exposure 8 hour average of halogenated agents? N2O?
    • Halogenated agents = 2ppm
    • N2O = 25 ppm
  2. What should you do if you smell anesthetic gas during a case?
    Investigate. This is not normal.
  3. What is the purpose of a scavenging system?
    to control occupational exposure to waste anesthetic gases
  4. What are the 2 most important factors in reducing waste anesthetic gases?
    • 1) Scavenger System
    • 2) Operating Room Ventilation
  5. 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
  6. What is the potential danger to the patient of an active scavenging system?
    • 1) negative pressure to patient
    • 2) positive pressure to patient
  7. What is the potential danger to the patient of a passive scavenging system?
    positive pressure buildup
  8. 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
  9. Is the Open or Closed interface safer for the patient?
  10. Can you have an Open Passive system?
    No - all open systems must be active
  11. 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.
  12. How do you gauge the intensity of vacuum on the open system? closed system?
    • Open: flowmeter with ball in-between lines
    • Closed: Resorvior bag not distended but not completely flat
  13. If you are using a closed system and hear a hissing noise what does it mean?
    The positive pressure relief valve is open
  14. 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
  15. What is the purpose of the reservoir bag?
    To handle fluctuations in intake vs output
  16. If you increase your FGF, what else can you expect to increase?
    suction on your scavenging system
  17. 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
    • 3) Barotrauma¬†
    • 4) Misassembled system (uses 19 or 30 mm connectors)
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