Tuesday, 21 September 2010

MRCP revision battle 17.1: DIC

Lots of short battles from a variety of specialities today so buckle up for a ride through some haematology, neurology, endocrinology, respiratory and dermatology.  Yeee-hhaaaa!

MRCP revision battle 17.1: DIC
MRCP revision battle 17.2: Jugular foramen syndrome
MRCP revision battle 17.3: Thyroid cancer
MRCP revision battle 17.4: Legionella infection
MRCP revision battle 17.5: Pleural calcification
MRCP revision battle 17.6: Pseudoxathoma elasticum

MRCP revision battle 17.1: DIC

Disseminated intravascular coagulation (=DIC) is the pathalogical widespread activation of coagulation.

Blood tests will show:
  • prolonged PT
  • prolonged aPTT
  • massively raised d-dimer levels
  • low platelets
  • low fibrinogen
  • schistocytes

Of these, it is the level of fibrinogen which best correlates to the severity.

Causes of DIC include:
  • obstetric
  • crush injury
  • septicaemia
  • malignancy
  • transfusion reaction

The treatment is:
  • treat the cause
  • give platelets if platelets <50
  • cryoprecipitate
  • FFP
  • activated protein C if septic.

Now lets canter onwards to jugular foramen syndrome....

MRCP revision battle 17.2: Jugular foramen syndrome

Jugular foramen syndrome, also known as Vermet's Syndrome, is a condition arising from the compression of the cranial nerves that run through the jugular foramen.

Now just in case they aren't quite on the tip of your tongue, the nerves that run through the jugular foramen are IX, X and XI.

The syndrome is therefore characterised by:
  • loss of taste to posterior 1/3 of tongue (CN IX)
  • dysphagia (CN X)
  • sternocleidomastoid and trapezius paralysis (CN XI)

Anything that compresses the jugular foramen can cause this syndrome.  The commonest cause is a paraganglioma.

Now we've acquired a bit more esoteric MRCP knowledge, lets gallop on to discover some details about thyroid cancer...

MRCP revision battle 17.3: Thyroid cancer

Under 5% of thyroid lumps are malignant, and in general those with a malignant mass will be euthyroid.

There are 4 main types of thyroid cancer:
  1. papillary - 70% - mainly affects young females, excellent prognosis
  2. follicular - 20% 
  3. medullary - 5% - associated with MEN-2 (more on MEN tomorrow)
  4. anaplastic - 1% - very poor prognosis and resistant to treatment.

Rarely a patient can have lymphoma of the thyroid - this usually follows hashimotos disease.

The mainstay of treatment for thyroid cancer is surgery.

Lets break into a canter as we head on to legionella...

MRCP revision battle 17.4: Legionella

Legionella is a gram negative bacteria which causes legionella disease/pneumonia and in MRCP questions is most likely found living in a cruise ship/hotel's water tank or airconditioning system.

The symptoms of legionella disease are:
  • flu-like
  • dry cough
  • dypnoea
  • GI upset

Complications of legionella which may show up in the blood results include:
  • SIADH - low sodium
  • hepatitis - deranged LFTs

Legionella is killed above 60c, cannot multiply between 50 and 60c and are happiest between roughly 35 to 45 c

Males are more affected than females, 3:1

CXR may show bibasal consolidation.

Treatment is with antibiotics which achieve a high intracellular concentration, such as clarithromycin, rifampicin or fluroquinolone.

Legionella has a 10% mortality.

Lets now trot on to pleural calcification...

MRCP revision battle 17.5: Pleural calcification

Pleural calcification pops up both in real life and in MRCP questions intermittently.

The commonest cause is asbestosis. 
This tends to be bilateral and spare the costophrenic angles

So, if the pleural calcification is unilateral consider:
  • previous haemothorax
  • previous TB pleuritis
  • previous empyema

Other differentials to consider are:
  • previous radiotherapy/radiation exposure
  • post talc pleurodesis, which will mimic calcification.

Lets return to a full-speed gallop to our last battle of the day, pseudoxanthoma elasticum

MRCP revision battle 17.6: Pseudoxanthoma elasticum

Pseudoxanthoma elasticum is fragmentation and calcification of elastic fibres.

It is an autosomal recessive condition, found on chromosome 16.

Its various associations are:
  • a characteristic 'plucked chicken' skin (google it, memorise it, get ready to spot it in part 2)
  • angioid streaks in retina/vision problems
  • rarely GI bleeds
  • claudication/cardiovascular problems.

There is no treatment so management is symptomatic only.

Thats all for today, proceed to the war if you are up to.

MRCP questions: War 16

As with previous 'wars' after 'battles' these are just a few quick questions to see if your brain cells have retained the information provided in battles 16.1 to 16.7.

Grab a piece of paper, jot down your answers then compare them to my answers here

Question 1:
List 8 symptoms/signs of pagets disease

Question 2:
Which oral medication would you give to treat pagets disease?

Question 3:
Which medication would you use to treat PCP?

Question 4:
A patient has muscle weakness that gets worse on exercise.  What medication would you give them?

Question 5:
A patient tells you they have weak muscles which get better on exercising.  They state they believe its due to their lung cancer.  What condition do they have?

Question 6:
]What is the commonest cause of hemiballismus?

Question 7:
What is the medical treatment for hyperprolactinoma?

Question 8:
'Waiters tip' is associated with which palsy?

The answers are here