reservoir bag empty

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lakersbaby

lakersbaby

Full Member
15+ Year Member
LMA in on PS of 6 patient breathing ~400 tidal volumes rate of 14. partner flips out because green reservoir bag is basically collapsed on itself and has no air in it. flows are at 2L/min. If the machine is delivering pressure support of 6 and patient receiving adequate tidal volume whats the difference if reservoir bag is empty? Guy just looked at the bag and goes you gonna do something here? I was like i guess i can turn up the flows but whats the point.
 
lakersbaby said:
LMA in on PS of 6 patient breathing ~400 tidal volumes rate of 14. partner flips out because green reservoir bag is basically collapsed on itself and has no air in it. flows are at 2L/min. If the machine is delivering pressure support of 6 and patient receiving adequate tidal volume whats the difference if reservoir bag is empty? Guy just looked at the bag and goes you gonna do something here? I was like i guess i can turn up the flows but whats the point.
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If the patient is on the vent, which I assume since the patient is on pressure support, the reservoir bag should be bypassed on most machines.
 
lakersbaby said:
LMA in on PS of 6 patient breathing ~400 tidal volumes rate of 14. partner flips out because green reservoir bag is basically collapsed on itself and has no air in it. flows are at 2L/min. If the machine is delivering pressure support of 6 and patient receiving adequate tidal volume whats the difference if reservoir bag is empty? Guy just looked at the bag and goes you gonna do something here? I was like i guess i can turn up the flows but whats the point.
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Your partner needs to dust off a copy of Baby Miller and read the first chapter or two again.
 
Tell him get the **** out of your room and go back to school.
No offense but unless you have some very unusual ventilator that doesn't bypass the manual bag, you're not exactly filling anyone with confidence either...

You are staff?
 
This is probably a lapse in my knowledge somewhere, but on our machines (drager apollo) when on the vent the APL is bypassed but if there is a large enough leak in the system, the bag will collapse.
 
I once had a resident that was using obnoxiously high flows on PSV because the reservoir bag was collapsed.:bang:
 
In the new Drager Perseus, the volume of the bag is taken into account and will collapse and alarm if you don't fill the circuit with enough air to fill the bag (or if your leak > your flow). FYI.

But your machine doesn't sound like a drager perseus and your partner sounds like a jackass. but we're supposed to have thick skin :poke:
 
i did know that the bag was bypassed by the machine but he made me second guess myself. guess im a dumba$$
 
The breathing bag is not bypassed on modern anesthesia machines while on the vent. The APL valve is bypassed. Just watch as the bag moves with the ventilator! Look up the circuit diagram in Miller, there’s a fresh gas flow decoupling valve, and the breathing bag acts as a resivor while the ventilator is in the inspiratory phase. I think if the bag is collapsed, there is a significant leak. I would look for the leak if it’s that significant or turn up the flows. It would probably be fine, but I don’t want to mess around with not giving enough volatile during the case because of a simple problem.
 
dipriMAN said:
The breathing bag is not bypassed on modern anesthesia machines while on the vent. The APL valve is bypassed. Just watch as the bag moves with the ventilator! Look up the circuit diagram in Miller, there’s a fresh gas flow decoupling valve, and the breathing bag acts as a resivor while the ventilator is in the inspiratory phase. I think if the bag is collapsed, there is a significant leak. I would look for the leak if it’s that significant or turn up the flows. It would probably be fine, but I don’t want to mess around with not giving enough volatile during the case because of a simple problem.
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That’s only true on Draegers. On GE machines the bag is excluded and does not move while on the vent.
 
dipriMAN said:
The breathing bag is not bypassed on modern anesthesia machines while on the vent. The APL valve is bypassed. Just watch as the bag moves with the ventilator! Look up the circuit diagram in Miller, there’s a fresh gas flow decoupling valve, and the breathing bag acts as a resivor while the ventilator is in the inspiratory phase. I think if the bag is collapsed, there is a significant leak. I would look for the leak if it’s that significant or turn up the flows. It would probably be fine, but I don’t want to mess around with not giving enough volatile during the case because of a simple problem.
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Are you actually serious?

Throw miller in the bin and actually look at the machine you use every day
 
As several people have said, on Drager machines the bag is part of the ventilator circuit. These machines use fresh-gas-flow decoupling and divert flow to the bag while the ventilator is in inspiration, so that your tidal volume doesn't get topped up by the fresh gas. You can tell this is happening because the bag moves a bit while on the ventilator (a bit disconcerting if you're used to GE machines!)

In these machines, an empty reservoir bag is the equivalent of the bellows not refilling and indicates a circle leak.

I think it's a reasonable criticism if the LMA isn't sitting right and there's a leak you have to compensate for by increasing FGF. But usually the machine would be complaining - so it might be that your colleague is used to Dragers and you're using a GE?

addit: Mention of the how the FGF decoupling works in the FAQ for Drager piston ventilators: https://www.draeger.com/Library/Content/9049447_the_anesthesia_ventilator_8seitig_en_101209_fin.pdf
 
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IkeBoy18 said:
This is probably a lapse in my knowledge somewhere, but on our machines (drager apollo) when on the vent the APL is bypassed but if there is a large enough leak in the system, the bag will collapse.
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Looks like I learned something new today, I've look this up and indeed on some Draeger Machines the bag will stay in circuit even if it is switched from manual to the vent.

My institution uses various generations of the GE machines, and I guess that's what I am used to and what I am used to remembering from Baby Miller
 
You can take the bag off the older draeger and nothing will happen. You can squeeze the bag and nothing will happen. This is not true for the new perseus.
 
Psai said:
You can take the bag off the older draeger and nothing will happen. You can squeeze the bag and nothing will happen. This is not true for the new perseus.
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I do not know about GE machines, but it sounds like the bag is be completely excluded on the vent. If you can take the bag off and the ventilator doesn’t alarm, it’s probably excluded. However, just because you can squeeze the badge and nothing happens while on the vent doesn’t mean the bags excluded, there might just be a valve between the bag and the ventilator.
 
It's a fun trick to play on junior residents on machines where it is bypassed, deflating the bag while they're out for lunch relief and watching them freak out about it once they notice.
 
Ronin786 said:
Does it really matter as long as your Et FiO2 and volatile anesthetic concentration are fine and the person isn't desaturating?
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The LMA slid in perfectly had ~400 tidal volumes with patient breathing at a rate of 12 with PS of 6. EtCO2 35-40 100% O2 sat. Reservoir bag flat as a pancake. Did not see a problem and did not hear, feel, smell a leak. Switched to manual ventilation after a bit and patient finished the case breathing sponatneously and all went well.
 
guess I am that guy tonight

Datex-Ohmeda Aespire

It doesn't usually do this
 

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