Demonstration of Bubble CPAP for the Low Resource Environment, by Dr. Traci Wolbrink.
Hi.
My name is Traci Wolbrink, and I'm a clinical fellow in Pediatric Critical Care at Children's
Hospital Boston.
Today I'll be demonstrating how to set up a bubble CPAP system.
CPAP stands for Continuous Positive Airway Pressure.
It can be delivered in several different modalities, including via an endotracheal tube with a
mechanical ventilator, through nasal or mask interface in a CPAP machine, or via a bubble
CPAP system, which I'll be showing you.
I'll be using equipment to set this system up that should be readily available.
However, you may need to modify the equipment and resources based on what you have available
in your institution.
Indications.
Continuous Positive Airway Pressure can be helpful for patients in respiratory distress.
It helps to keep the airways open, and helps to alleviate the work of breathing, thus improving
gas exchange and making it easier for the patient to breathe.
At each institution, you'll need to decide what your indications for using bubble CPAP
will be.
It will depend on the amount of oxygen supplies that you have available and the amount of
supplies to create the circuit.
Additionally, it will depend on your ability to use a mechanical ventilator or other CPAP
systems, and your ability to have a fresh oxygen supply for all the patients that are
necessary.
In some hospitals, they find it helpful to use this on patients that are hypoxemic, which
is refractory to oxygen therapy, or patients with mild to moderate work of breathing.
In those patients, it may be helpful to step up from oxygen therapy and try a bubble CPAP
interface to improve the work of breathing and gas exchange.
Contraindications.
There are several patients that you may not want to put on bubble CPAP.
Those would be patients that have nasal or facial fractures, because you risk causing
pneumocephalus with using the positive airway pressure.
You would also want to caution the use of bubble CPAP in patients that have air leak,
such as pneumothorax or pneumomediastinum.
And you would want to consider other modalities if you have a patient that's in severe respiratory
distress or severely hypoxic, as bubble CPAP may not be enough to help this patient.
Equipment.
I'm now going to go over the equipment that's necessary to set up the bubble CPAP system.
The first thing that you'll need is an oxygen source.
And I have a source here, that's connected to my in-wall oxygen.
I have also attached a humidifier that will allow humidification to the baby, which will
make the system more comfortable for the baby to breathe.
You'll need some sort of tubing to connect this to the system.
You can also use whatever type of oxygen source you have at your hospital, such as an oxygen
cylinder or an oxygen concentrator, as long as you have enough flow to make the system
bubble, which I'll explain in a few minutes.
What you will also need is, you'll need a suction catheter connected to a suction device.
And you'll need a sterile water bottle, which here I have attached a 7 centimeter ruler
to the bottom of this via tape.
I filled the water bottle with sterile water.
And as you can see, the meniscus of the water reaches the top of the ruler.
You should make sure that you change your water at least once a day to help prevent
the spread of infection.
The other pieces of equipment that you'll need-- you'll need a low-resistance tubing,
such as the corrugated tubing that I have here.
You'll need two pieces; one for each limb.
You'll also need a nasal cannula set-up.
This one here is a prepackaged bubble CPAP nasal cannula set-up that you can purchase.
You can also look around your hospital for other pieces of equipment that you can make
such a set-up.
And I've made one here using a regular nasal cannula for which I have cut on either side
of the nasal prongs.
And as you see here, I've cut each side, and then I've attached it to two separate 3-way
stopcocks.
And I have a nasal cannula set-up that looks very similar to what I have here.
You'll notice that the distance between the nasal prongs is different for both of these
interfaces, so you'll need to adapt that to which size patient you're using.
You'll also need to have a 10 mL syringe, which will be used to secure the tubing in
place in your bottle.
And you'll need some way to secure this interface to your patient.
There are many commercially available products, such as a baby bonnet that will go over the
head-- and I'll show you this-- which will allow the system to be secured with either
Velcro, or you can make a securing system with rubber bands and safety pins.
You could also choose to not use a bonnet and instead use some gauze to wrap the system
in place.
Set-up.
Now I'll demonstrate how to set up your bubble CPAP system.
First of all, you'll need to take your oxygen tubing that's connected to your oxygen source,
and you'll need to connect it to one piece of your corrugated tubing, ensuring that you
have a tight fit, and the two tubings are not going to come apart.
You'll then take the other end and insert your nasal cannula end into here, again, making
sure that it fits tightly.
You'll then take your other piece of corrugated tubing inserting that on the other side of
your nasal cannula, again, making sure that's tight.
And this will be your patient interface.
Your next step is going to be to put the end of the corrugated tubing, which is not connected
to your oxygen source, into your sterile water bottle.
So the first thing I'm going to do is unscrew the top of my water bottle, and I'm going
to place the end of the tubing into the bottle, and into the water, to a depth of five centimeters.
You can see the tip of the tubing is at five centimeters.
And I'll take my 10mL syringe, insert it into the top of the bottle.
This will help to secure it in place, and allow the tubing to stay at five centimeters.
You also want to make sure that there's space for air to flow out of the water bottle, and
that you haven't occluded the opening completely.
Now before attaching this to your baby, you're going to want to make sure that you test the
system.
You'll make sure that there are no leaks in the system.
So you'll want to occlude your nasal prongs, and you'll want to look at your water bottle
to make sure that it's bubbling.
This will make sure that there are no leaks in the system, and that everything seems to
be connected properly.
Point of clarification.
It is important to consider the delivered FiO2 to with this set-up.
If the flow meter is connected to a pure oxygen source, then the delivered FiO2 is likely
to be near 100%.
Ideally, the flow meter should be connected to an air-oxygen blender that enables the
clinician to select the desired oxygen concentration from 21 to 100% oxygen.
This is crucial in populations where oxygen toxicity is a risk for the development of
retinopathy of prematurity, especially those born less than 31 weeks gestational age, and/or
in subjects at risk for the development of chronic lung disease.
The next step, and most challenging step, is to connect this to the baby.
So what you'll do is you'll take your nasal prongs and you'll insert them into the nares
of the baby.
Most likely the baby will be crying, and kicking, and squirming around.
So it's helpful to have a parent who can soothe the child, or an assistant to help you connect
that.
And in order to secure the system to the baby's face there are multiple ways we can do this.
I'm just going to show you a simple way using some gauze.
You can take the gauze and wrap it around the system and around the baby's head ensuring
that it's a tight fit.
You want to make sure to avoid the eyes or the mouth.
And you can cut that when it's finished.
This should ensure that the system will stay in place and will not move too far from the
baby.
So I've showed you how to secure the nasal cannula with some gauze, but I'll also show
you how to do it with a baby bonnet.
It's helpful if you put the bonnet on before you begin placing the nasal cannula, as it
can sometimes be a challenge to put on a baby who is moving their head all around.
You can do one of two things to secure this.
You can either use something like Velcro, which you can see I have two pieces of Velcro
here that are sticky on one side and Velcro on the other.
And I will just stick this Velcro on one side of the baby bonnet.
Alternatively, you can use two safety pins and a rubber band to secure each side of the
corrugated tubing.
You'll want to place the safety pins first on the side of the baby's head, and you'll
want to make sure that the tubing will run between the safety pins.
You'll want to be careful when you place these that you're not going through the bonnet all
the way and injuring the baby's skin.
Then you'll take a rubber band, tie a knot in the middle, and you'll have this available
for when you put the nasal cannula set-up on the baby's face.
So I'll set that right there for this moment.
Next, I'm going to place the nasal cannula in the baby's nares as I did previously.
And you can see here that the tubing runs between both sides of the safety pins.
I'll take my rubber band, connect it around the safety pin on one side, and again, I'll
take this, wrap it around the safety pin on the other side, and this will create a resistance
for the tube to move.
Additionally, I'll show you for the sake of demonstration purposes on the other side.
I'll remove the top piece of Velcro, I'll place the nasal cannula set up through the
Velcro, and again attach that.
So there are many ways that you can use to secure the nasal cannula in place to the baby,
but it's just very helpful to secure it.
If this comes dislodged the cannula will come out, and you won't be delivering any of the
positive airway pressure.
Troubleshooting.
So now I'll go over some troubleshooting tips for your bubble CPAP system.
As you look at this system, we can see that the baby is connected to the bubble CPAP system;
however, the bottle is not bubbling.
This is indicating that we have a leak somewhere in our system.
First of all, you may have complications with the circuit itself where some of the parts
may become disconnected.
We did check the system prior to placing it on the baby, and we know that our system is
completely connected, and that there is no leaks in the plastic, and that all of our
connections were tight.
Therefore, we must assume that the leak is with the patient itself, and there are a couple
areas that the patient can leak from.
One is through the nares and the nasal cannula interface, and the other is through the mouth
if the baby's doing open mouth breathing.
First of all, I'm just going to reposition the nasal cannulas to see if we can get a
better fit.
And you can see here, just by making sure that the nasal cannulas are indeed in place
in the nares, you do get bubbling in the system.
So that was the trouble that we had with this baby.
Now if, by placing the cannula in the nares we still weren't getting bubbling, we could
try a couple of things.
The first thing that you notice with this baby is that the baby is open mouth breathing,
and this could also be a loss of positive airway pressure because the pressure is going
in through the nose and coming out of the mouth.
So another thing that you can do to help this baby is to place a chinstrap.
I'm just going to use gauze.
You can use whatever you have at your institution.
I'm just going to wrap this gently around the baby, making sure not to dislodge the
nasal cannula in the process, and I'm going to wrap it around here.
And in a regular baby, this would help to keep the mouth closed.
I'm just going to readjust the nasal cannula in place here, making sure that they're in.
There we go.
And you'll want to make sure that this chinstrap is tight enough so that it closes the baby's
mouth, but not so tight so that the baby is unable to cry, yawn, or vomit, because you
wouldn't want the baby to aspirate if the baby did vomit.
Some other troubleshooting tips: you want to watch for abdominal distension.
As you're providing positive airway pressure into the baby, there is a chance that some
of this airway pressure is not going only to the lungs, but is also going into the stomach.
With that, you may get some gastric distension and the baby may be very uncomfortable with
that.
So you could consider placing an orogastric tube or even a nasogastric tube and use one
nasal cannula side only.
This will help to alleviate some of the abdominal distension.
Many babies will tolerate an orogastric tube.
You may have some plugging of the nasal cannula with secretions, and so it's important that
at least once per shift you take the baby off and clean the nasal cannula, making sure
that the secretions aren't building up in the nasal cannula system.
And the last thing that you'll want to do when you're troubleshooting is to look at
the quantity and quality of your bubbling in your circuit.
As you see here, there's quite a lot of bubbling now that we have an occlusive nasal cannula
in place and a chinstrap on our baby.
So you can dial down your oxygen a bit, to the point where you're getting just a nice
gentle bubbling like you see here.
You'll notice if you turn down the oxygen too much, or even turn it completely off,
you lose the bubbling.
And in this way, you're not delivering enough oxygen to the baby, and the baby may actually
be rebreathing CO2 because they're not able to push the carbon dioxide out the expiratory
limb into the bottle.
So you'll want to make sure that your flow is high enough that you're getting enough
bubbling so that you're able to deliver oxygen into the patient, and that when the baby exhales
through the nasal cannula, they'll exhale in the exhalation loop and exhale carbon dioxide
out into the bottle.
So it's very important that there's adequate amount of bubbling.
The baby may also exhale some carbon dioxide out their mouth, but if you have a chinstrap
in place and you're trying to keep their mouth closed, you may not have enough carbon dioxide
removal.
Complications.
The last thing that I'll discuss is some of the complications you may encounter while
you have a patient on bubble CPAP.
As we discussed previously with the troubleshooting video, if you don't have enough gas flow going
through the patient, you may re-breathe carbon dioxide, which would not be very helpful for
these patients.
You may also develop some nasal breakdown by using the system, especially if your cannula
is moving quite often.
That's why it's very important to secure this to the baby's head.
Also if you have a cannula that is not the right size and is moving around inside the
nares or is very stiff, you may develop more nasal breakdown.
And additionally, if you're using non-humidified oxygen, it may be more uncomfortable and more
drying to the nares, which can promote more nasal breakdown.
So if you have the capabilities to use humidified oxygen, it's generally safer and more comfortable
for the patient.
You may also develop an air leak such as a pneumothorax.
You'll want to watch for that and notice if your baby develops increased work of breathing,
hypoxia, or diminished breath sounds.
You want to make sure that you think about pneumothorax as a possible complication.
Additionally, you may find when you put a patient on nasal cannula CPAP for the first
time that the baby develops a lot of excessive oral secretions.
That's normal, and that's as the positive airway pressure is building in the oral cavity,
some of the secretions are forced out of the mouth.
You can reassure the parents and the patient that this is normal and should go away after
four to six hours.
Finally, you may notice gastric distension, as we discussed in the previous segment, and
you may need to place a nasogastric or an orogastric tube in order to help alleviate
that.
So this concludes the video on bubble CPAP.
I hope that you find it helpful.
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