Module 6 Flashcards
No worker should be exposed to halogenated concentrations greater than
2ppm; 0.5ppm with nitrous oxide & no more than 25ppm of nitrous oxide based on a time weighted 8 hour average
Is there a universal standard for waste gas exposure?
No
What happens when there is no attempt to scavenge gases like nitrous?
Is found at 400-600ppm & there is 5-10ppm of halogenated agents
How are standards of scavenged gases met?
Providing a leakage of 2.5L every 5 min of nitrous
What are the 5 sources of gas contamination?
APL Valve
Anesthesia Machine
Ventilator
Exhaled Gases
Anesthetic Technique
In a non rebreathing system, large volumes of anesthetic gases are discharged through what?
The relief valve
In a high pressure system (anesthesia machine), what is the range of nitrous oxide?
26-750 PSI
Leaks are common from
Defective connectors or tank yolks
Quick connectors are easily
Brokendown & leak easier
This gas leaks due to normal wear & tear and due to absorbent granules impeding the seal
Carbon Dioxide
The higher the pressure in the breathing circuit, the
More gas can escape through a leak
Where is an area where exhaled anesthetics can accumulate?
PACU; concentrations as high has 10ppm
What is a list of things that can cause a leak?
Anesthesia Technique
Turing on Vaporizer & Flow Meters
Preparing the patient
Poorly fitted face mask/LMA
Disconnection
The sampling line of the anesthesia circuit draws in
1-300mL of gas/min
How many exchanges are recommended per hour in the OR?
15/hour
How is the air removed in the OR?
Recirculating ventilation filters & recirculates, which can affect the distribution of airborne particles, creating turbulence
What are the 4 properties of the scavenging systems?
- Relief Valves
- Conducting Tubing
- Scavenging Interface
- Disposal Linee
What are the 2 types of scavenging systems?
Active & Passive
What is the flow of gas ini passive systems?
Flows under their own pressure
What is the flow of gas ini active systems?
Negative pressure is applied & gas is sucked away
Joint commission requires all waste gases to be
Actively scavenged
When the ventilator is off, how does scavenging gases leave?
Via APL valve
When the ventilator is on, how does scavenging gases leave?
Via ventilator pressure relief valve
The exhaust port is how big?
19mm male
In the interface system, where are the relief valves located?
Between the breathing circuit & the hospital vacuum to protect the patient from negative pressure caused by suction or from positive pressure
Interface systems can either be
Closed or Open reservoir
What happens when vacuum system is insufficient?
Build up within the reservoir causing the positive pressure relief valve to open, ventilating waste gas into the room
Valves are set to open at what cm of water
10
What acts as a visual indicator of the scavenging system function?
Reservoir bag
What happens if the hospital generates too much negative pressure
The pop off or sub-atmospheric relief valve will open & allow air to be drawn into the reservoir
Open reservoir scavenging. system is _________& uses relief ports that are open to the atmosphere
valveless, avoiding positive & negative
Where is the gas sampling port
Typically comes from the Y port
Name 2 places waste gas should go
Conducted to waste gas scavenging Returned gas to breathing system for scavenging
When should scavenging system be checked?
With abnormal pressures
What happens with inadequate ventilation
Oxygen can build up & when combined with heat & fuel could cause a fire
Reasons for scavenging mishaps
User error
Incorrect connection
Negative pressure relief valve can fail t open
Exhaust port can be occluded
Does the ASA demand routine monitoring when regular maintenance/daily checks
No
What are the recommendations for waste gas
- Scavenging
2.Appropriate work practices - Education
What variables determine the reduction in waste anesthetic gases in the OR?
- Room ventilation
- Anesthesia equipment conditions
- Scavenging effectiveness
- User techniques
The scavenging interface can be either
Open or Closed
What is the most important component of the scavenger system?
The interface between the breathing circuit & wall suction
Closed interface depends on the
Bag
When is closed interface useful?
When passive scavenging is used (active required in the US)
What is required when using a closed interface system?
Must be a way to relieve positive or negative pressure, which is the relief valve ( will be released into the OR)
What should be adjusted in the closed system so the scavenging reservoir bag is neither flat nor over distended
Suction
Since relief valves can fail, what is supplied on all new workstations?
An open scavenging interface
The open interface is opened to
The atmosphere
Why is suction important ini open system?
If it is inadequate, all waste gases will be released into the OR
What is the threshold for smelling volatile agents
5-300ppm
