hi everyone this is lee here from abc's of anesthesia and today i'm going to talk about
what you can do a simple really simple step you can do if your anaesthetic machine
fails for some reason so let's get started
now the ansing machine is a really complicated device i mean when you look at it it's got this
massive console here that's all for the delivery of positive pressure oxygen it also has volatile
gases that you can run through through the circuit into an outlet the expiratory end and that goes
into the patient it then recycles gases back and it goes through the sodium to take away your co2
and then you can also switch it from a manual mode and also a ventilator which happens and ventilates
mechanically so you can use that positive pressure to fill up this bag to inflate the lungs and that
way you can kind of dial up this pressure using this apl valve here and that way you can inflate
the lungs of a patient that you're ventilating likewise you can flip the switch and you can
have the ventilator going as well so it's got a number of ways you can ventilate the patient
now this machine gets a bit more complicated because we've got all these complicated monitors
blood pressure ecg and tidal co2 as well um as well as sats monitoring and then you can
dial up all these settings on these fancy screens and look at the monitor reading
now one of the things we always talk about in anaesthetic training is what happens if this
very complicated device goes wrong and there's one simple solution after your initial troubleshooting
steps if you simply can't find a solution all you do is go to your ambu bag which is this device
over here so you might be thinking how can this simple looking little device possibly replace
this entire machine and it's quite simple as we mentioned before this is pretty much a device to
deliver positive pressure to inflate the patient's lungs it has a lot of other additions which makes
it complicated and really good for having the patient safely ventilated and oxygen oxygenated
over a long period of time and it's very hands off i can just set my machine and monitor the patient
and i don't really need to be there with my hands doing all the ventilation myself
now this device also does that it's able to deliver positive pressure through a very simple
mechanism i think the most phenomenal part of this is that this bag is self-inflating so if i was to
compress it like this it then just inflates by itself it doesn't actually have to be connected
to oxygen to inflate itself whereas with my anesthetic machine this bag here which i can
use to manually ventilate the patient requires gas for oxygen or air or whatever else to inflate
that bag so right there it's not self-inflating whereas this device is so that's probably one of
the most remarkable things about this bag the fact that it self-inflates so i don't need to
connect it to oxygen if all of my piping failed or the oxygen failed if the machine failed if there
was a problem with the circuit any part of this there's a problem with this can essentially solve
that problem in the in the immediate term you can solve it for a short period of time and therefore
i can keep the patient safe and alive so let's go through each aspect of this air viva or dell bag
so first of all i can attach a mask and this particular mask has a little port here so you
can inflate it and that means that you can get a really nice bouncy seal here which means it
can form to the face and try to cover any gaps that might be left so really great for making a
seal it then attaches to this little device here and this is essentially a couple of connections
and a valve now you might be able to see here as i inflate you can see that that fish mouth valve
actually opens up and it so it only allows air really to travel in one direction
this port here now that's a blow-off valve so generally speaking that can blow off at low
pressures but you can also put this little cap on which generates a very high pressure
seal so i think up to 60 centimeters water or six kilopascals that means if i have a patient with
restrictive lung disease or severe obstructive lung disease i can still use that to ventilate
the patient now notice that in my anaesthetic machine that valve really is this function here
so this function here this apl valve allows me to change the pressure whereby this circuit blows off
air so i'll often change the doesn't bag in your patient it won't be possible to do that with this
mask so what i've got to do is be really in tune with the patient and if i feel like there's too
much pressure in the circuit as i'm holding the mask on the patient's face i can just let air
escape if that's required and that means that i'm going to avoid theratron so really important that
with these devices that you're really attuned to what is happening with the patient for example
if this cap was off and i start ventilating the patient as normal if i realize that there's no
rise and fall of the chest or if there's no fogging of the mask or no end tidal co2
that means that chances i'm not ventilating the patient so in that sense i'd probably put this on
to make sure that i've got a higher pressure and then i'd start ventilating once i've got rise and
fall of the chest i then know that the patient's going to be safe and as soon as i feel too high
a pressure maybe my seal's really good maybe the patient's now gas trapping and overfilling with
oxygen then i just do this and use the mask as a valve to let air out it's a really simple device
but also doesn't have all the complexities of a circuit so you do have to be really in tune with
the patient as we mentioned before it leads into this two liter reservoir which can hold
you know two liters of oxygen and then you've got here this reservoir bag so that's where any excess
oxygen can go so this will fill up slowly during your ventilation of the patient which means that
once you compress and release the oxygen and do that this provides the reservoir by which all the
oxygen will then get back and train into this to fill it up almost instantly with oxygen therefore
if you have the right circuit device here and a really good seal you can deliver
up you know up to 100 oxygen pretty much i think the manufacturer says 98 oxygen if
you have the proper closed circuit using this expiratory valve as well next important thing
and this is really important if you want to deliver oxygen you really have to connect this end
to an oxygen source um so pretty much connecting it to one of the burial of variable orifice flow
meters just like that and turning on and if i've got a patient who i'm really worried about
i'll turn this up to 15 liters straight away and that means that the patient's gonna be safe
as long as i'm ventilating oxygenating this patient one of the traps you'll find in a
lot of your research situations is that this can easily become disconnected so always making sure
that you've got oxygen flow and you can hear the oxygen flow you can see that the um the fogging of
the mask is going away because of the oxygen flow it's one of those things that you know things can
go wrong if you're not really in tune with what's happening around the patient as well now the final
piece of this puzzle is this little exploratory valve so this is such a great device because with
this little addition which is a screwed valve you're able to apply different layers of p so
so you might be able to see some numbers there if i just screw this on i go from five of peak
to 10 fp then 15 even up to 20 feet all by just screwing this cap on which means that
now you've got positive end expiratory pressure which again can be really great for sick lungs
if i want to take all the peep off i simply put it all the way up and unscrew it all the way up
now you might be wondering why it's called so many different names like for example it's called an
ambu bag a ladel bag an air viva and pretty much it's from all the different manufacturers
so the first person to make this self-inflating you know rescue rescue ventilation device was a
dangerousness called henning ruben he called it the ambu bag he made it in 1957 so quite a long
time ago now another inventor asman liddell he was actually a toy manufacturer made another
version of this which he called the ledell bag now asman liddell was initially a toy manufacturer
but then ended up going to the medical space and created one of these another company called the
commonwealth industrial gases an australian australian company made another device called
the airbus that's why you hear so many different names for this self-inflating
auctionation device so that's probably all i need to talk about now every anesthetic machine should
have one of these it's such a great device because it simplifies and solves a lot of the problems
that you might not be able to solve immediately by troubleshooting an anaesthetic machine so any
problems with the anaesthetic machine you can always attach the circuit the endotracheal tube
or just put the face mask onto the patient to ventilate them with this simple device
and it's because it doesn't require an oxygen source necessarily and it's self-inflating without
positive pressure you can apply positive pressure in any other situation where
you're whether you're out in the field or in the wards in the emergency in icu or even anesthetics
so thanks very much for watching if you have any questions or comments please write below
and share with anyone who might be interested thanks so much for watching see you next time
you