This is just an example of what
can go wrong. So, the slide shows
the diagram at the top is a left
endobronchial tube that has been
pushed too far down into the left mainstem
bronchus. And you can see that the distal cuff,
the cuff at the end of the tube, has
obstructed the left upper area of the lung.
And that portion of the lung will not be ventilated if you're
ventilating through the tube. You'll ventilate the lower
lobe of the lung and the lingula of the lung,
but you won't ventilate the left upper lobe.
And if you've got bad lungs, that'll be
insufficient lung area to maintain
oxygenation. In the lower picture, you
have a right sided endobronchial
tube that is misplaced. And it's misplaced
again because it's been pushed too deeply
into the right mainstem bronchus. And what's
happened here is that, the proximal
cuff, the tracheal cuff, has occluded the right
mainstem bronchus at the level
of the carina. And the hole in the distal
cuff has passed the right upper lobe bronchus.
This makes it very difficult to get
even ventilation through the lung. And through serendipity
more than anything else, in the picture there is a suggestion
that there is some gas making it into the right upper
lobe. But you can see there's also a leak right at
the tracheal cuff, so it's probably extremely
difficult to ventilate. The problem with placing
a right endobronchial tube is trying
to make sure that the hole in
the distal cuff is adjacent to the hole for
the right upper lobe bronchus. And it's hard
to see that. You use a fiber optic bronchoscope,
you look down, you try to look through the hole in
the cuff, and try to identify the right upper lobe
bronchus. But it's very difficult to do because
the right upper lobe bronchus is not terribly big and it's easy
to miss it. And it's very hard to turn the tip of the bronchus,
go completely into a right angle and go up
through the hole in the distal cuff.
So, many, as I mentioned, many anesthesiologists
prefer to always use a left sided cuff.
Here's another option however. If you don't want to use
an endobronchial tube, you can use a standard endotracheal
tube, which is what is shown in this
slide, and a bronchial blocker.
So the bronchial blocker in this case has been
pushed down into the left mainstem bronchus
and has occluded the left mainstem bronchus. This is
all done under direct vision using fiber optic bronchoscope.
When that blocker's in place, it's impossible
to ventilate the left lung. It's completely isolated
from the right lung. And that's probably what the anesthesiologist
wants. If they get to a point where they want
to ventilate the left lung, they have to pull the blocker back.
They cannot ventilate that lung unless the blocker's
out of the way. They can deflate the cuff in the blocker
and try to ventilate that way. But the normal thing is to deflate
the cuff and pull the blocker back. And if you have to replace it,
go back down with your fiber-optic scope and reposition
under that direct vision. Some anesthesiologists
who do a lot of thoracic work,
prefer this technique to using an endobronchial tube.