An Emergency Department doctor tells you that he feels the patient can be discharged. He tells you this because he shows you the D-Dimer result, which is “negative”. The result is shown below.

Which of the following statements is true about D-Dimer testing in general patients with a suspected DVT?

a. Following a clinical assessment, clinicians should not rely on the test as a basis to ‘discharge’ or ‘investigate’

b. It is of no use in patients who have had recent surgery (e.g. within the last 12 weeks)

c. It is of no clinical use in patients with malignancy and secondary metastases

d. It can be used to discharge patients based on their underlying estimated clinical risk score

e. None of the listed answers are correct.

Which of these symptoms of hypoadrenalism will distinguish between primary adrenal failure and secondary (pituitary) adrenal insufficiency?

a. Postural Hypotension
b. Weight Loss
c. Fatigue
d. Hypoglycaemia
e. Skin Pigmentation

Symmetrical disease?
Erosions?
This is classical of RA X-ray changes that include

1. Erosions
2. Reduced joint space
3. Peri-articular osteoporosis
4. Nodules

So from the initial history of disease [small joints, both hands], the likely diagnoses would be

• RA
• PsA
• (less likely) gout.

Erosive changes are not specific to RA however but the findings were symmetrical

• both gout and PsA tend to be asymmetrical

Don’t be put off by the fact he’s male, although RA is roughly 3x commoner in women. You dont get a mention of which joints are affected here: RA has a penchant for the wrists and MCP joints. Erosions of the ulnar styloid are very common.

Common x-ray changes of the different arthritides are shown below:

Non Inflammatory

Primary OA: Asymmetrical

There are classically 4 signs of OA on an X-ray: Occurs in classic joints eight bearing e.g. Hips& Knees. May not be symmetrical.

1. Subchondral bone sclerosis
2. Cystic Change
3. Osteophytes
4. Reduced Joint Space

Charcot Joints:

1. Destruction of the joint
2. Disorganisation (bones not arranged in the correct /usual arrangement through gross destruction e.g. cuniforms of the foot.
3. Increased density (sclerosis)
4. Debris (boney debris from a destroyed joint: often with well defined margins
5. Dislocation

Secondary OA

As per primary OA but occurring in a joint that has been previously damaged from any other disease process (inflammatory disease etc)

Inflammatory

Gout: Asymmetrical

The classical signs of gout on an Xray are: Erosions with sclerotic margins. Asymmetrical.

1. A relatively preserved joint space
2. Minimal periarticular osteoporosis
3. Nodules (these are in fact tophi)

Psoriatic Arthritis: Asymmetrical

The X-ray Changes are similar to rheumatoid but they differ in their distribution, and the formation of pencil in cup deformities along with osteolysis.

1. Asymmetrical distribution of disease
2. Often affects PIP and DIP joints
3. relative absence of peri-articular osteoporosis
4. Erosions seen at the distal interphalangeal joints joints
5. Reduced joint space
6. Pencil in cup deformity (arthritis mutilans with telescoping of the fingers)- this is a result of osteolysis
7. Loss of the terminal tufts of the phalanges (acro-osteolysis)
8. Sacroiliac and spondylitic changes (similar to those of Ank. Spond.)

Rheumatoid Arthritis: Symmetrical

1. Erosions
2. Reduced joint space
3. Periarticular osteoporosis
4. Nodules

Septic Arthritis: Asymmetrical

1. Periarticular osteoporosis
2. Loss of joint space
3. Deformity/subluxation
4. Erosions
5. Effusion
6. Usually just 1 joint

EMQ’s are being increasingly used in research and papers have recently been published on their success in the USMLE. Its likely that many medical schools will adopt this N from many approach. An EMQ is simple: its a series of typically 6-10 answers, used a number of times with different question stems.They first cropped up in 1993 after work by Case and Swanson. Read more about EMQ’s and their development here.

Distracters

Distracters are being used to throw students off the scent, and in some ways discriminate from good and bad students. An example would be describing a history of a rash affecting the flexor surfaces and giving on e of the answers as psoriasis. Seeing the two together can lead to the assumption this is the correct answer. This is an example of a good discriminator, but EMQs can easily be written in such a way that the more capable student gets it wrong!

Take an example EMQ from our new section dedicated to them on the login site.

“A 64 year old homeless man presents after being found exposed under a bush shelter by paramedics. He is ‘tided over the night’ by the emergency department staff with an IVI of 5% dextrose. The next morning he is confused, and ataxic. On examination he has nystagmus. Which of the following is treatment is most likely to be effective?”

Students classically then have to pick from a range of answers:

• Aciclovir
• Ciprofloxacin
• Buscopan
• Omeprazole
• Gluten free diet
• Peg Interferon alpha
• Mesalazine
• Vitamin B Complex

Here’s the Answer from the main site:

“Nystagmus, and ataxia are features of cerebellar disease, with the addition of confusion this triad is suggestive of Wernickes Encephalopathy (vitamin B1 deficiency- thiamine). Risk factors: poor nutrition (+/- alcohol).

Thiamine is important in carbohydrate metabolism and the Krebs cycle: it’s vital to remember that dextrose presents a carbohydrate load, the excess of which cannot be effectively metabolised , leading to cell death.

Hence the treatment: Vitamin B complex: initially this is given as Intravenous Pabrinex © for 48-72 hours.”

The EMQ here does a number of things: You could use your knowledge of drugs alone to answer the question: An antiviral (acivlovir), quinalone antibiotic (ciprofloxacin), an antispasmodic (buscopan), a Proton pump inhibitor (omeprazole) a gluten free diet (!), etc.

Aciclovir would initially seem attractive for a possible encephalitis- there are some things that fit: confusion, other CNS signs? This is a form of a distracter-look at the history, and the role of the glucose drip.Here the answer has been worked through by correctly recognise the triad of opthalmoplegia, confusion and ataxia that isin keeping with the diagnosis of Wernickes.

So, we can see that EMQs look initially pretty intuative, but more are being written, and expect them to be coming to an exam near you soon.

You can work through some examples of EMQ’s to prepare for your medical finals with different question structures on the subscription section of our site.