A Cuff Leak or a Leak Around the Cuff?

Recently, a colleague approached me with a situation that I actually run into fairly regularly, especially with some of the younger
RT’s. This colleague, one who is still a fairly ‘young’ RT, told me
that one of his intubated patients’ has a cuff leak and asked me if I
would assist him with the pilot balloon repair kit. He’s never actually
used one and was a little uncomfortable. I’m always willing to lend a
helping hand, especially to those who are still willing to learn a few
things.


Being a rather “old” RT I have seen these scenarios many times before so I am already asking
myself if this is an actual cuff leak or simply a leak around the cuff.
Each requires prompt attention but they are very different situations.
For now I decided to keep that thought to myself and see how this plays
out.

When we arrived at the patient’s bedside I noticed that the patient was well awake,
although confused and moving his head back and forth – looking all
around the room. I also noticed the unmistakable sound of air leaking
from the patents’ mouth with each positive pressure breath from the
ventilator. I thought to myself “yup, there’s a leak alright”. Now I
have to ask myself a very important question again; “Is there a cuff leak or is this simply a leak around the cuff”?

From this point there are 2 things that need to be looked at. First and foremost you
must look at your patient to make sure they are stable and in no
immediate danger of respiratory compromise. The second thing you should
do is feel the ET tube pilot balloon. Is there still air in the pilot
balloon? If the answer is “yes” then you are not looking at a
true cuff leak. What you are more than likely looking at is a displaced
ET tube, and that’s exactly what I was looking at.What happened with my colleague is something that happens more often
than not, even with experienced RT’s. He heard an air leak from around
the ET tube and assumed that there was a cuff leak that needed to be
repaired. That assumption was compounded when he added air to the pilot
balloon and there was still air coming from the patients’ mouth with
each positive-pressure machine breath. Over the years I have even seen
patients get re-intubated due to a cuff leak that was later discovered
to be non-existent. So, I ask again. Is it a true cuff leak or is it a displaced ET tube causing a leak around the cuff?

How can we tell the difference? A true cuff leak is when an air leak causes the ET tube
balloon to deflate. If you have a true cuff leak then the pilot balloon
simply will not hold air. If you check the pilot balloon and it is
holding air then you do not have a cuff leak. If you add 2.0cc of air to
the ET tube pilot balloon and still have air leaking from around the ET
tube you more than likely have a displaced ET tube. A displaced ET tube
is actually far more common than a true cuff leak.There is some
risk to damaging the soft plastic of the ET tube cuff during the process
of an endotracheal intubation, but once the patient is intubated, and
the ET tube is secured, that risk is pretty much gone. There is nothing
in the tracheal wall that can spontaneously create a leak in the cuff.


However, what CAN happen is the tiny spring valve within the ET tube pilot balloon can become weakened over time. This can cause an air leak
and the cuff to deflate spontaneously. In this situation a pilot balloon
repair kit is a wonderful tool that works very well.

Can these situations be avoided? Well, there is no way avoid a displaced ET tube 100% of the time but there are things you can do to minimize the risk.
One of the best ways to prevent a displaced ET tube is to be certain
that the ET tube is in a safe position at all times. This is a little
more involved than checking for tube placement at the level of the lip
or teeth. There are 2 more things that you must be aware of to be
certain that the ET tube is in a SAFE position.When a patient is
intubated there are several tasks that must be performed immediately to
be certain that the ET tube is in the trachea and not in the esophagus.

1. Visualization of the ET tube passing through the vocal cords.
2. Capnography or ETCO2 detection to verify tracheal intubation vs. an esophageal intubation.
3. Visualization of bilateral chest rise and fall.
4. Auscultation of bilateral lung sounds.

Once these are done and we are certain that the ET tube is in the trachea then the next step is to obtain the golden-nugget of tube placement verification; a STAT portable chest X-Ray. This is done for two reasons.

1. So we can document by diagnostic image that the ET tube is in the trachea.
2. So we can be certain that the ET tine is in a SAFE position within the trachea.

We’re always told that proper ET tube placement is between 2 and 4 centimeters above the carina so many of us go by that soft rule. Some clinicians use the clavicular heads as a land mark for ET tube placement, and others use the aortic arch (one of my personal favorites) as a placement land mark. The purpose behind them is to be certain that
we are ventilating both lungs and are at no risk of a right main-stem
intubation. While these are all acceptable practices they are only
showing us part of the picture. The tip of the ET tube in relationship
to the carina, the clavicular heads, and the aortic arch can all be seen
on the chest X-Ray but there are a couple of things that cannot be seen
that are of equal or greater importance.

1. The vocal cords
2. The ET tube cuff
3. The distance between the ET tube cuff and the vocal cords

Measuring the distance between the tip of the ET tube and the carina is a very good practice but it only tells us half of what we need to know.
Measuring the distance between the top of the ET tube cuff and the level
of the vocal cords is also very important. It tells us if there is a
risk of accidental ET tube displacement. An ET tube placed at 4.0cm
above the carina may be a safe position for some patients but it is not a
safe position for all patients. Consider the patients who have a
shorter thorax. In these patients an ET tube placed at 4.0cm above the
carina might place the ET tube cuff right at the level of the vocal
cords. This might be okay for a patient in the operating room who is
paralyzed and under general anesthesia but a patient in the ICU is a
different story. They are being moved on a regular basis. The bedding
gets changed, the patients get bathed, patients get repositioned, etc…
Something as simple as a pillow getting placed under the patients head
to make them comfortable can easily displace the ET tube. We must keep
in mind that often times when the head looks downward the ET tube can
actually migrate upward. Optimally there should be at least 2.0cm
between the top of the ET tube cuff and the level of the vocal cords,
but if we can’t actually see these things on the X-Ray how can we safely
place the tube?

Consider this. Most facilities use ET tubes from one manufacturer. Get to know your
tubes. Measure them. On most adult sized ET tubes the top of the cuff is
approximately 6.5 – 7.0cm above the tip of the tube. There is some
variation to this so measure your ET tubes to be certain. If your
facility uses a digital imaging system there is more than likely a ruler
tool that will allow you to draw a line from the tip of the ET tube
upward to 6.5cm above it. That line now represents the ET tube cuff. The
next step is to locate the approximate level of the vocal cords. It is
actually fairly simple. Draw a line (you can even eyeball this if you
are comfortable with it) from shoulder to shoulder – NOT the bones, the
actual top of the patients shoulder. They can usually be seen on the
X-Ray. That straight line now represents the approximate level of the
vocal cords. (You can try this on yourself. While looking in the
mirror use your hand and “draw” a straight line from one shoulder to the
other. Stop when you get to your neck and you’ll notice that you are
just about at the level of your own vocal cords). Now you can using
the systems ruler tool you can measure the distance between the top of
the ET tube cuff and the approximate level of the vocal cords.

You’ll notice in the image of the ET tube above that there is also a radio opaque marker
and a hole just above it. The ET tube in the image has a subglottic
suction port. The marker is present so the location of the suction port
can be seen on chest X-Ray. Coincidentally the marker also happens to be
right at the top of the ET tube cuff. If you use these tubes at your
facility then finding the top of the cuff is even easier and all you
have to do now is look for the level of the vocal cords and measure the
distance.In
my experience most intubated patients have a portable chest X-Ray taken
every morning. At the beginning of each shift it is a good practice to
view the most recent chest X-Ray and check for ET tube placement,
measuring not only the distance between the tip of the ET tube and the
carina, but also the distance between the top of the cuff and the
approximate level of the vocal cords. This is a very simple task, it is
almost foul-proof, and it only takes a couple of minutes. It sure seems
worth it to me…

NOTICE from the Author: No Medical Advice: These writings are my own personal words based solely
on my own personal clinical experiences, education, and research. I am
NOT a Physician and therefore DO NOT give out medical advice under any
circumstance. The writings within BreathSounds, BreathSounds Media, and
BreathSounds.Org are in no way intended to be taken as medical advice of
any kind.

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