Apex- Breathing Circuits Flashcards
Difference b/t semi-open and semi-closed circuits
Both have reservoirs
Both can be accomplished with the circle system
> semi open = FGF > MV (no rebreathing)
> semi closed = FGF < MV (partial rebreathing)
semi-open system is also a mapleson circuit
What kind of circuit is a mapleson system : open, semi-open, semi-closed, or closed?
semi- open (FGF depends on design)
+resevior
no rebreathing
What 3 ways can the cicle system be configured?
- Semi-open: FGF > mV
- Semi-closed: FGF < mV
- Closed: FGF only replaces gas cosnumed by the patient (closed APL)
What does the APL valve determine?
how much gas remains in the circuit and how much is directed to the scavenger
What are the 2 most common circle-system related causes of rebreathing
- exhausted CO2 absorbent
- an incompetent unidirectional valve
malfunction of either valve converts the region between the y-piece and the affected valve to apparatus dead space
What happens when the unidirectional valves malfunction in the circle system - stuck open vs stuck closed (airway obstruction vs rebreathing)
stuck open = rebreathing
stuck closed = airway obstruction
The American Society for Testing and Materials (ASTM) requires that the pressure inside an adult-sized (3L) reservoir bag does not exceed an internal pressure of what if the bag is inflated up to 4x its size
60cm H20
T/f- closing hte APL valve during mask ventilation is useful when theres a leak around the mask
True
When the unidirectional valves in the circle system are working properly, dead space begins and ends where?
begins at the y- piece (bi-directional flow)
ends at the terminal bronchials (conduit for gas flow, no exhcange)
How does a fault unidirectional valve lead to a high inspired co2?
if the inspiratory valve isnt working, when the pt exhales, the exhaled co2 and gases will distribute to both the expiratory AND inspiratory limbs
>the expired gas in the inspirtaory limb now goes back to the patient on the next breath
if the expriatory valve isnt working, then the pt inhales, they will get cleaned gas , as well as excess gas from the expiratory limb that hasn’t been thru the absorbant yet
What is the BEST mapleson circuit for a spontaneously ventilating patient?
A, B, C, or D
which is the worst?
A
B
What is hte best mapleson circuit design for controlled ventilation?
which is the worst?
D
A
Which Mapleson is the only circuit where the fresh gas inlet is near the bag?
A
best for the spontaneously ventilationg pt
worst for controlled
Which mapleson circuit is the only circuit with no corrugated tubing
C
C = no Corrugated
Which mapleson circuit is the only circuit with the APL valve away from the patient
D
closest to you
well i guess F too - is (Jackson-Rees)
Which is the only mapleson circit without a reservoir bag?
E
Ayers T-Piece
No APL valve either
Which maplleson doesnt have an APL valve
E
ayeres-T-piece
no reservoir mag either
List in order form best to worst of mapelsons to use for spontaneous ventilation
mneumonic
A > DFE > CB
All Dogs Bite
List in order from best to worst of mapelosns to use for controlled ventilation
mneumonic
DFE > BC > A
Don’t Be Arrogant
The Bain circuit: (Select 2):
-is tested with the Pethick test
-is a modified Mapleson A
- delivers FG through the inner tube
- is best for spontaneous but not controlled ventilation
-is tested with the Pethicktest
-delivers fresh gas through the inner tube
Bain is a modification of Mapleson D and can be used for spontaenous and controlled ventilation
What is the Bain system a modification of?
Mapleson D circuit
coaxial design:
gresh gas is delivered to the pt thru the inner tube
exhaled gas travels through the outer tube (the corrugated tubing)
*Pethick test to check for inner tube kinking and disconnection
T/F: the bain circuit can be used for both spontaneous and contolled ventilation
True
To prevent rebreathing with the bain system, FGF should be what?
2.5x minute ventilation
What test is used to test the integrity of hte bain circuit during pre-anesthetic checkout ?
Pethick test
- occlude the elbow at the pt end of the circuit
- close the APL valve
- use the o2 flush valve to fill the circuit
- remove the occusion at the elbow while flushing circuit
-if hte inner tube is patent, the venturi effect will cause the bag to collapse (safe)
-if its kinked or disconnected, the bag will remain inflated and is not safet to use
