Right. Just a brief now, we discussed asbestos
exposure in pleural disease because another
cause of the pleural thickening is asbestos
exposure. Occupational exposure asbestos used
to become in the ‘70s and the early ‘80s
mainly in the building trades but also engineers,
Dockers and shipbuilders as asbestos was used
as a heat prevention or heat protection substance
in those industries. Inhaled asbestos fibres
actually readily reached the alveoli, penetrate
through the alveoli, and reached the pleural
lining where they cause inflammation. And the
consequences of that are three or four-fold.
One is that you get pleural plaques and this
show off on a chest X-ray frequently in patients
who’d been exposed to asbestos. In fact,
really don’t mean much for the health but
do identify patients who’ve had pleural
who have been exposed to asbestos.
Benign pleural thickening where you get a
layer of thickening around the lungs and that
can cause restrictive lung defects. As I mentioned
earlier, you can get benign exudated pleural
effusions due to asbestos exposure. And the
last thing that pleural asbestos can cause
is a malignant mesothelioma which I discussed
in the lecture of malignancy. Asbestos inhalation
also can cause pulmonary fibrosis, and that’s
called asbestosis, and that’s discussed
in the lecture on Interstitial Lung Diseases.
So to summarize the main learning points of
pleural disease; pleural effusions are common
and are divided into exudates in which the
pleural is abnormal and transudates in which
the pleura is normal, but there are other
systematic reasons why pleural fluid is forming
such as cardiac failure. Investigation of
pleural fluid is best done using ultrasound
as they identify exactly where the fluid is.
You can see loculations, and you see whether
there are any abnormalities of pleural suggestive
of cancer, etc. There are multiple different
causes of pleural effusions, but the most
important are malignancy either secondary
metastasis or mesothelioma or pleural infection,
TB or bacterial infection. If somebody has
recurrent effusions and that
occurs frequently in patients with metastatic
disease affecting the pleura, then these can
be prevented by pleurodesis where you fuse
the visceral and the parietal pleura together.
If somebody has loculated pleural fluid, that
suggests strongly that they have pleural infection
and requires active treatment and investigation.
Pneumothoraces, air in the pleural space could
be primary young people with no underlying
lung disease, but spontaneous holes appearing
in the visceral pleural allowing air out into
the pleural space or secondary where they
actually have an underlying lung disease such
as COPD or cystic fibrosis.
Pneumothorax can be relatively easily treated
in most cases, but the serious problem is
the tension pneumothorax which is a medical
emergency with a high pressure in the pleural
spaces causing hypertension and can lead to
cardiac arrest. That needs immediate treatment
by insertion of wide bore canula into the second intercostal
space, midclavicular line which equalizes the high pressure
in the pleural space without atmospheric.
And thank you for listening.