Breathing Circuits Flashcards
What are the 4 types of breathing circuits?
Open
Semi-open
Semi-closed
Closed
What circuit does not have rebreathing and does not have a reservoir? Examples?
Open
Insufflation
NC
Simple face mask
Open drop ether
What circuit does not have rebreathing and does have a reservoir? Examples?
Semi-open
Mapleson (FGF dependent on design)
Circle (FGF>MV)
What circuit has partial rebreathing and does have a reservoir? Examples?
Semi Closed
Circle system (FGF<MV)
What circuit has complete rebreathing and does have a reservoir? Examples?
Closed
Circle with low flow and APL closed
What should you do if the End Tidal does not return to baseline?
Increase FGF to greater than the MV
Replace absorbent
What is unique to the circle system?
Has two unidirectional valves and CO2 absorbent
What is an example of a semi-open circuit? (what is FGF set at)
FGF > MV
Ex: 10L during induction
What is an example of a semi-closed circuit? (what is FGF set at)
FGF < MV
Ex: 2L after intubation
What is an example of a circuit? (what is FGF set at)
Just enough to support O2 consumption
What benefits does the reservoir bag provide?
-Exhaled gas accumulates in the bag so allows patient to rebreathe the gas and use lower FGF
-Monitor for spontaneous ventilation
-Allows you to control positive pressure
-Must not exceed internal pressure of 60 cm h2o
What is the function of the APL valve?
Controls how much pressure can be generated during the bag mode
Other names for APL?
Pressure relief
Relief valve
Overspill valve
Popoff valve
etc
What are two causes of inspired CO2
Failure of unidirectional valve
Co2 absorbent exhaustion
What is the best Mapleson for a spontaneous breathing patient? Worst?
A
B
What is the best Mapleson for controlleD? Worst?
D (controlleD)
A
What is not present in Mapleson systems?
Unidirectional valves
CO2 absorbent
Which Mapleson does not have Corrugated tubing?
C
(corrugated starts with c)
Which Mapleson does not have a reservoir bag or APL valve?
E
Which Mapleson is the only circuit with the fresh gas inlet NEAR the bag?
A
Which Mapleson is the only circuit with the APL away from the patient?
D
What are the pros to Mapleson circuits?
Less airway resistance (good for peds)
Convenient
Easily scavenged
What is the pro to a Bain system?
Prevents heat loss
What is another name for the Bain system?
Mapleson D
How does the Bain system warm fresh gas coming in?
By exhaled gas
When using a Bain circuit, the FGF should be at least how many times higher than the MV?
2.5x
What test should be performed on the Bain system? How is the test interpreted?
Pethick
If the inner tubing is patent the reservoir bag will collapse and is okay to use
If the inner tubing is occluded, the reservoir bag will remain inflated and not okay to use
