Friday, April 3, 2009

HOT TIPS FOR MMED


First of all, let me tell you the experience of sitting in a panel of 'MMED exam Vetting'. The panel is led by a senior Professor and members represent lecturers from all the three universities. Each of the University will be given 'assignment' eg. To pick a number of questions on Cardiology, Neurology etc. Each of those questions, be they MCQ, MEQ whatever, will be discussed. Here's how they select the questions.

First, the question must be easily understood by all the members present. If one of the members strongly object a question with good reason, most likely the question will be turned down.

Second, for MCQ for example, it should be 'answerable' by all the members in the panel. Generally if most of them think they can answer 3 out of those 5 items, the question is considered ok.

They will then go on to change wordings and phrasing of the question as necessary.

Where all the members are unable to explain certain doubts, they will either refer to 'Google' the material on the internet, or simply ring the respected specialtists to get clarification.

Sometimes they do change the questions completely, in order to make the question more 'understandable' and 'answerable'.


For MCQ, of course you understand what is called Bloom Taxonomy (I don't really, just know it superficially…). Each question can be given a grade of difficulty and whether it tests comprehension, deduction, logic etc. Good set of MCQs should contain mixtures of those.


What I am trying to put across here, is that, the examiners also have 'difficulty' in creating and finalising questions for the exam. Since all of them are Generalists and Specialists in their field, when it come to subjects beyond their specialty, their knowledge is probably just above an average MMED candidate! (Presumably their vast amount of experience in Medicine help them to understand things in broader sense…). Knowing this could be very useful, since then, you probably think that, no question is really difficult. If you find one as such, it is either you have not been studying (enough!) or that there are certain wordings or terminologies in the question that you need to understand deeper. Once this is overcome, you should be able (as an average performer) to answer at least 60% of the questions correctly. This applies to MCQ, MEQ, Problem solving etc.




Sample of MEQ

Unlike Problem solving, in MEQ information is presented in stage. You should answer each package on itself, ie based on the currently presented information. Basically, step by step approach. It is common that in MEQ, you will not have any clue of what is the final diagnosis till near the end. So, just go by the flow…


Package 1

A 45 year old lady was admitted due to chronic cough and difficulty in breathing. She was well until about three months earlier when she had productive cough and fever. She was admitted to a private hospital and treated as community acquired pneumonia. Her symptoms partially improve after one week admission.

She continued to cough with whitish sputum. There was no haemoptysis. She claimed has normal appetite but has lost about 7kg of weight. She is non-smoker. Her grandfather has pulmonary tuberculosis.

On examination, she was mildly dyspnoeic. She was not pale or cyanosed. Her temperature was 37.5C.There was no lymphadenopathy. There was fine crepitation heard over the right middle and lower zones. The left lung was clear.


  1. Discuss the differential diagnosis

Your differentials should cover broad possibilities like unresolving pneumonia, cryptogenic organising pneumonia, atypical pneumonia, absess/empyema, Pulmonary TB and lung Ca

  1. List 5 investigations that you would like to do at this stage. Give reason

Remember, at this early stage, you are talking about basic investigations that include things like CXR, ABGs, FBC, Blood/sputum cultures, atypical pneumonia titres and perhaps Mantoux


Package 2

A 45 year4 old lady à chronic cough and difficulty in breathing à loss of weight à crepitations over the right middle and lower zones.


The results of investigations were as follows:


  1. Blood count
  2. Hb 9.8
  3. TWBC 8.6
  4. Plt 250,000


2. ESR 110mm/hr


3. Arterial blood gases

pH 7.36

pO2 77

pCO2 38

HCO3 23

O2sat 91


  1. Mantoux test 9mm at 72 hours


CXR:


Comment the above investigation results

Describe the abnormalities seen in the CXR


(Xray showing Alveolar opacification of the right lower zone obscuring the right hemidiaphragm and lower end of the right heart, suggestive of consolidation)


Package 3

A 45 year old lady à chronic cough and difficult in breathing à loss of weight à consolidation over the right lower zone

CT scan of thorax was performed

  1. Describe the abnormalities in the CT scan

Massive right pulmonary consolidation involving right basal segments of the right lower lobe and middle lobe

  1. State the differential diagnosis of the CT findings

Lung Ca, Connective tissue disease

  1. State further investigations that you would like to perform

Autoantibodies, bronchoscopy and transbronchial biopsy


A 45 year old lady à chronic cough and difficulty in breathing à loss of weight à consolidation over the right lower lobe and middle lobe


The screening for connective tissue disease was negative.

Bronchoscopy and transbronchial biopsy was performed. The histology was reported as bronchoalveolar cell carcinoma.


  1. State the stage of her lung cancer

Since it involves both lobes, this is advanced lung Ca stage 4

  1. Outline the management of her lung cancer

Include everything from counseling the patient on diagnosis, counseling the relatives, palliative chemotherapy, treat underlying infection, manages her electrolyte balance etc.


A 45 year old lady à chronic cough and difficulty in breathing à loss of weight à consolidation over the right lower lobe and middle lobe à bronchoalveolar carcinoma


She agreed for palliative chemotherapy. While waiting for chemotheraphy to be administered, she suddenly develop sudden onset of chest pain. It was associated with worsening dyspnoea. On examination she was dyspnoeic and tachypnoeic. The blood pressure was 120/70 and HR 120/m. there was no new respiratory or cardiac findings on examination.


What is the most likely diagnosis?

Didn't know? Has got to be PE


State 3 further investigations that you would like to perform.

CXR, arterial blood gases, D-dimers, CTPA


A 45 year old lady à chronic cough and difficulty in breathing à loss of weight à consolidation over the right lower lobe and middle lobe à bronchoalveolar carcinoma à sudden onset of chest pain


Her ECG revealed sinus tachycardia. She is hypoxaemic. A CTPA confirmed a pulmonary emboli in the right main pulmonary artery.


Outline your management at this stage

This is on how to manage PE. Goes from option for thrombolysis to short and long term anticoagulant. Screen the peripheral limbs for DVT

PROBLEM SOLVING

A 50 year old man presented to the A n E Department. He had been unwell for the past 3 weeks with fever, night sweats, non-productive cough and loss of appetite. He woke up on the morning of admission coughing out red blood, feeling breathless at rest and unable to move his right foot fully.

Examination whowed he had a respiratory rate of 40 breaths per minute. Blood pressure was 140/80 mmHg, pulse 110 regular, temperature 39C. there wer multiple splinter haemorrhages in all fingers of both hands. His maxillary sinuses were tended to palpation. A soft systolic murmur grade 2/5 was heard at the left sternal edge with no radiation. There was bronchial breathing dound in the upper zone of both lungs. Power of right ankle dorsiflexion was 2/5. No rash or peripheral oedema was noted.


Hb 9.7

WCC 6x109

Plt 733x109


Na 138

K 5.5

Urea 29.3

Creatinine 344


Albumin 30

Ca 2.24

Alt 30

ALP 63


Urine analysis

Protein 0.25

Ery 22/ul

Leu 1/ul

Red cell casts found


CXR :

Consolidation with several cavitaging lesions measuring 3-4 cm in both lung apices

Blood cultures x 3 no growth


  1. Give four important interpretations of the investigations shown (8marks)
  2. State one complete unifying diagnosis
  3. Suggest three further investigations to confirm the diagnosis, stating also the results you would expect (6)
  4. Outline your short and long term management of this patient


  1. Acute renal failure (Ca normal)

Glomeruolnephritis (RCC)

Cavitating pneumonia/pneumonitis

No evidence of bacterial infection

Normocytic anemia (1 mark)


  1. Wegener's Granulomatosis (2) with renal (1) and pulmonary (1) involvement with mononeuritis multiplex of the right common peroneal nerve



  1. ANCA testing – positive c-ANCA, positive also for proteinase 3 antigen

Renal biopsy – pauci-immune glomerulonephritis (+- crescents)

Nerve conduction studies – mononeuritis multiplex of right common peroneal nerve

Sural nerve biopsy – vasculitis of vasa nervorum

Echocardiography to rule out presence of vegetations/myxoma


  1. Ensure adequate oxygenation

Fluid resuscitation with central venous monitoring

Careful monitoring of renal function

Renal replacement therapy if needed

High dose corticosteroids (either IV methylpred or oral pred 1mg/kg)

Cyclophosphamide (oral or pulsed intravenous)

Plasmapharesis

IV immunoglobulin



A 27 year old lady, G3P2 at 10 weeks pregnancy complained of acute onset of left sided weakness for 4 days duration. She had history of severe vomiting prior to the weakness. On the day of admission patient initially developed focal seizures involving the left upper limb and lower limb with secondary generalization, which lasted for few hours. Her 2nd child was 6 months of age and she had no family history of epilppsy. Examination showed L hemiparesis. Other systems were unremarkable.


State 2 differential diagnoses

Ischaemic stroke – due to preeclampsis, HPT, SLE, antiphospholipid syndrome

Venous infarcts – due to sagittal sinus thrombosis

Space occupying lesion – tumour, abscess

Intracranial haemorrhage – AVM, aneurysm


State 3 investigations required for this patient

CT brain/MRI

Connective tissue screening

EEG

If CT normal – LP


State your immediate management

Control seizures – IV diazepam/phenytoin

Hydrate patient

Start anticoagulation



As for MCQs, questions that test knowledge per se, should be able to be tackled in a very straight forward way. It is either you know or not! Eg.

Regarding treatment for Heart Failure:

  1. Addition of ARB on ACE-I improves prognosis
  2. Digoxin reduces rate of hospitalization
  3. Betablocker is contraindicated in NYHA functional class III
  4. Calcium channel blocker increases cardiac death
  5. Warfarin reduces risk of stroke

All of the above questions, are derived from clinica studies some of which as old as 15 or 20 years! Though you can make intelligent guest, one who has read reasonably extensively, and perhaps attended some of the cardiovascular symposium would have answers to the above within seconds. Correct answers are TTFTT.


Questions that test knowledge can be very straight forward (if you know) or can be 'difficult' one – if you have not enough grasp. In this case, perhaps you should limit your attempts with what you know, it's mostly safer that way. So, even if they are pure 'recall' test, they are not necessarily easy! Eg

Regarding management of severe sepsis

  1. Clinical trials have failed to consistently demonstrate a difference between colloid and crystalloid in the treatment of septic shock
  2. Norepinephrine has been sown to be superior to dopamine as a vasopressor in patients with persistent hypotension despite fluid resuscitation
  3. Elevated serum procalcitonin levels is a good predictor to distinguish sepsis from nonseptic systemic inflammation
  4. The time to initiation of appropriate antimicrobial therapy is a strong predictor of mortality
  5. Combination therapy has been proven to demonstrate superior overall efficacy compared to monotherapy in gram-negative septicaemia

Like the question on digoxin in heart failure, stem B test our very fundamental grasp on daily clinical practice, since we mostly use NE over dopamine in septic shock. So those clinically orientated people will straight away answer True! However, all of these statements are backed by evidence, so it is either you know the evidence or not. If you don't, better not attempt it. If you know half-half, perhaps you can attempt it…correct answers TFFTF


In general, many of the less common diseases or syndrome for instance, if they are asked, the questions will be of those 'recall' type. They are seen as difficult, but if you have come across them or learn them somewhere, you are the lucky one. Eg

Tuberous sclerosis (err when did I last hear about this?)

  1. Is inherited as autosomal recessive
  2. Is characterised by the development of multiple hamartomas distributed at various sites throughout the body
  3. Tends to affect bone marrow
  4. The earliest visible sign is facial angioma
  5. Mental retardation is a feature

Either you know or not, isn't it? Of note, the vetting committee usually will not allow statement like B to appear, because they are actually a combination of two sentences, therefore, if one part of it is false, the whole sentence becomes false. This is considered unfair to canditates. Same like in C, you will not come across answer like 'Tends to affect the skin, brain, eyes and bone marrow' – since, though this statement appears wholly true, the truth is now 'contaminated' by the eyes!! Correct answers for the above FTFFT.


Another example in rheumatology

Regarding viral infections and inflammatory arthritis:

  1. Parvovirus B19 infection is known to lead to chronic erosive arthritis
  2. The arthralgia of Chikunguya infection responds to corticosteroids
  3. Infection with HIV improves rheumatoid arthritis activity
  4. Infection with HIV improves psoriatic arthritis activity
  5. Symptoms of reactive arthritis will improve is the original viral infection is treated

I hardly could recall the above, but it sounds like B is true, E is false. The rest…guestwork? Correct answers here TTTFF


While some questions test your knowledge plus deduction eg

Transfer of patients with ST-elevation MI to Percutaneous Coronary Intervention Centres should be considered in the following situations

  1. When fibrinolytic therapy is unsuccessful
  2. When cardiogenic shock occurs
  3. Patients presenting less than 3 hours of chest pain onset
  4. In patient presenting with large anterior infarcts, 6 hours from the onset of pain
  5. In asymptomatic patients with late presentation

Some of this information can be obtained directly from the guideline, while others require your logic and deduction, understanding the pathophysiology of acute MI. Correct answers TTFTF


This one tests understanding:

A 78 year old man had sudden onset of right sided hemiparesis two hours ago. The following are true:

  1. Hypertension is the most important risk factor
  2. The presence of dysphasia indicates cortical involvement
  3. Aspirin cannot be given before a CT scan of the brain is done
  4. Recombinant tissue plasminogen activator (r-tPA) is indicated if the CT scan shows the infarct
  5. Blood pressure of 180/90 mmHg should be treated with IV antihypertensive agent

Whatever it is, E definitely sounds false even to orginary laymen…correct answers TTFFF


Some do test mixture of scientific and clinical knowledge, almost a pure recall too, but it calls for your understanding of the subject eg

Regarding COPD

  1. Best documented genetic risk is present of circulating inhibitor of serine protease
  2. The risk for COPD in smokers in dose-related
  3. The pattern of inflammation is characterised by neutrophils, macrophages and B-lymphocytes
  4. Emphysema is most associated with gas exchange abnormalities than with reduced FEV1.
  5. Pneumococcal polysaccharide vaccine is recommended for patients > 65 years old.

Correct answers TTFTT