Lots of lymphocytes might suggest that the
patient has tuberculosis. The other test that
we use to identify the cause of pleural effusion
is a pleural biopsy. Now this is a way of obtaining
a sample of the actual pleura. And it’s
the second line test for investigating the
more difficult cases of exudated pleural effusion.
There is no need to do a pleural biopsy in somebody
with a transudate effusion normally. This is done
to identify tumours or tuberculosis
in general. So for example, the sensitivity of
the pleural biopsy for identifying a pleural
metastasis in somebody who has breast cancer
or GI malignancy or lung cancer is about 90%.
The sensitivity of mesothelioma, the primary
pleural cancer is actually less than that
because the interpretation of the histopathology
of mesothelium is quite difficult.
Pleural biopsies are also very useful for identifying
pleural tuberculosis as they will show granulomas
infiltrating through the pleura in about three-quarters
of cases, and that’s a much more sensitive
way of identifying pleural TB than in trying
to identify the presence of the bacteria.
So the second line test for investigating
patients with more difficult case of exudated
pleural effusions would be a pleural biopsy.
Pleural biopsies are not necessary for patients
presented with transudate effusions. Pleural
biopsies can be obtained either blindly using
an Abrams needle, but this is largely out
of date now. In fact, for most patients, we
do a pleural biopsy under a CT or ultrasound
guidance. And that allows us to target the
biopsy to the areas which were abnormal. For
example, an ultrasound may show in somebody
who has metastatic cancer affecting the pleura
little areas which are abnormal with apparent
lumps, and that means that you can use
the ultrasound to put the needle directly
into those areas to get the maximum chance
of identifying the presence of a cancer.
The other method of doing a pleural biopsy
is thoracoscopy. This can either be a surgical
or medical procedure, and it involves inserting
an instrument inside the pleural space so
that you can visualize the pleural space and
using that to guide your biopsies in abnormal
areas. With thoracoscopy, you can actually
combine that procedure with doing a pleurodesis
as well. So, how do you treat pleural
Well, firstly and most obviously, you need to treat
the underlying cause. So somebody with transudate
due to heart failure, they will need diuretics.
If there’s an exudate and it’s due to
a tumour, then actually, treatment of the
tumour might make the pleural effusion go
away. If somebody has systemic lupus erythematosus
causing a pleural effusion, then anti-inflammatories
may be necessary in their suppression and if
somebody has got PE, obviously, they need
anticoagulation. The other thing you need
to consider is whether
the patient can cope with the pleural fluid
or not. So when you have a large pleural effusion,
it makes you breathless. And pleural aspiration,
which is similar to the pleural tap, and instead
of just taking 50 ml, you take off a litre or
1.5 litres, can considerably improve the
patients, how they feel, and reduce that breathlessness.
And that could be done as a one-off procedure
in a few minutes to try and improve their
ability to cope with the effusion.
With persisting large effusions, then you
may need to drain them to dryness to allow
the patient the maximum chance to improve.
Now, this requires inserting a pleural drain,
letting that drain off all the fluid and that
will normally take a few days, and therefore,
require hospital stay. Recently, we’ve been
starting to use more semi-permanent tunnelled
drains which we actually insert under the
skin and leave inside the pleural space and
the patient can go home and that allows us
to have long-term drainage of a persisting
pleural effusion in patients, for example,
The ultimate treatment for pleural effusion
that keeps coming back, and in fact, patients
with cancer, once you've drained an effusion,
it will return in most patients.
Therefore, recurrent effusions is a significant problem
with metastatic disease. The ultimate treatment
for that would be a pleurodesis. Now, that
is where you fuse the visceral and the parietal
pleural together so you actually obliterate
the pleural space, and that prevents a pleural
fluid forming in the first place. This can
be done medically via a drain or surgically
during a thoracoscopic procedure. The basic
principle is to inflame both layers
of the pleura using talc or other agents. Surgeons
often use a physical abrasion, which means
that the inflamed visceral and parietal pleura
will stick together and eventually form adhesions,
and therefore, obliterate the pleural space.
The efficacy of these procedures is a little
variable. It’s about 70% for medical pleurodesis
rising to 80%, 90% for surgical pleurodesis.