with that or not. And it’s also used when
acid-base disorders may be present.
Right, so moving on from testing lung function,
I’m now going to talk about bronchoscopy.
Bronchoscopy is a test involving an endoscope
where we can actually directly visualise the
bronchial tree. As you can see here on this
picture, that’s the carina of the bronchi
breaking off from there further down in the
lungs. So you can see if there is a visible
abnormality in the bronchial tree. You can
also obtain samples from deep within the lung.
It requires only a degree of local anaesthesia
and light sedation. It takes about 15-20 minutes
to do. And therefore it’s a very easy procedure
to use to access the central airways of the
lung. As well as visualising abnormalities,
we obtain different types of samples, bronchial
washes – which is fluid washed over a bronchial
abnormality – brushings – where you get
a sort of a wire brush and brush it over the
bronchial abnormality – biopsies of the
bronchial mucosa, something called a bronchoalveolar
lavage – where in fact we get fluid from
deep within the lung which represents the
alveolus. And, occasionally, we do transbronchial
biopsies where we pass the needle through
the lung tissue to try and get some interstitial
material for the histopathologist to assess
for interstitial lung diseases for example.
And more recently, the mediastinal lymph nodes
have been biopsied using ultrasound control.
This is becoming a routine test now in respiratory
medicine. It has made a major advance in our
ability to assess what’s going on with mediastinal
lymph nodes without doing surgery.
So we use bronchoscopies when we’ve got
somebody with a new lung shadow and we’re
worried that it may be cancer, especially
is that shadow is in the central area and
therefore could be in one of the airways.
So, for example, this a bronchoscopy photograph.
What it shows is a normal bronchus and then,
at the end there, there is a tumour which
is blocking that bronchus.
We use it to assess lobar collapse. This collapse
of the lobe is due to something blocking the
bronchus. And it might be a tumour – as
is shown in this picture – or it might be
a sputum plug or it could be a foreign body
such as an inhaled tooth or something like
We use it for haemoptysis – to investigate
haemoptysis because you can actually visualise
where the bleeding’s coming from using the
And the samples that we can obtain – the
lavages, the biopsies – are useful when
you’re diagnosing people with interstitial
lung disease and can be used for patients
with difficult lung diseases – lung infections
such as TB in immunocompromised patients with
pneumonia etc., etc.
The problem with bronchoscopies: well, the
main one is actually the patient coughs a
loss. You’re passing a thin tube down through
their throat and it can make them cough a
lot during the actual procedure. And that
coughing rubs the back of the throat against
the bronchoscope so they often have a sore
throat after the procedure.
More importantly, if you biopsy something
it may leak blood and haemoptysis is a potential
complication. Usually that will stop but,
if somebody has a reason to bleed more – they
have low platelets, abnormal clotting – then
there’s going to be a major problem with
haemoptysis and you have to avoid doing biopsies
in those sorts of patients.
Bronchoscopy requires sedation in general
and that can be a problem in patients with
respiratory disease because type-II respiratory
failure, for example, actually is already
a sedating situation. And if you give people
sedation in those circumstances, it can exaggerate
the respiratory failure. And there’s a temporary
decrease in your oxygen during the procedure
and that can be a problem with patients who
really are struggling to maintain their oxygen
levels. Some people get an infection and,
if you do a transbronchial biopsy, you can
get a pneumothorax in about 10% of people.
So I’ll talk about the radiology of the
lung but I’ll be relatively brief about
this because that could be the subject of
entire lectures by itself.
But clearly x-rays are a vital modality for
investigating lung disease. And there are
multiple various types of x-rays than can
be done. But for the lung disease, the most
important are chest x-rays and CT scans. We
do use ultrasound and radionucleotide scans
and magnetic resonance imaging sometimes but,
in general, we get away with just doing chest
x-rays and CT scans.