Monash HealthFellowship practice exam

2016.1

SAQ 2 J.Brookes

Eastern Health

QUESTION 2 (19 marks) 6 minutes(Note the clinical information, which guides answers to question ii and iii)

A 35 year old man presents with 2 weeks of worsening

headache and confusion.

On examination his observations are as follows:

• GCS 13• Temp 38.2 oC• HR 60 bpm• BP 150/80 mmHg

A CT brain is shown in the prop booklet, page 4.

2 Images Note +C

i) List 3 abnormal findings(accept ring enhancement as separate finding)

Descriptions of:1.Features of lesion(s)

– Solitary – Location – parietal / temporal– Shape– Ring of contrast enhancement

2.Oedema (Vasogenic)– White matter hypodense – Loss grey-white junction – Effacement sulci

3.Mass effect – Ventricle – Midline shift

DDx ring enhancing lesion on CT brain MAGICDR or MAGICALDR

Given clinical information, the underlined items help direct my answer to question ii)…

• Metastasis • Abscess • Gliomas• Infarct • Contusion• AIDS• Lymphoma • Demyelination• Radiation necrosis

Teaching point - DDx ring enhancing lesionReview of 221 cases by Schwartz et al.

• Causes– 40% gliomas– 30% metastases– 8% abscesses– 6% demyelinating disease.

• Single lesions in– 45% of metastases & 77% of gliomas

– Versus multiple lesions in 75% of abscess cases & 85% of MS cases.

List three (3) abnormal findings on the images provided.

• Main omissions– Failure to mention anything at all about size • 3 x 3 cm • Large • Etc

– Failure to identify Mass effect

ii) List and justify six (6) further investigations.These are all investigations suggested by group

I would have chosen from the underlined to try and show my grasp of DDx + clinical context + be able to well justify …but revise the topic then debate which six investigations you would pick…

Pathology

• FBE / CRP / ESR• UEC • Ur/CR• Glucose• Coags• LFT• VBG/ABG• G+H• Urine FWT/MCS• Serology e.g. HIV, Hepatitis, Toxoplasmosis• PCR e.e. viral, bacterial (Str Pneum etc)• Blood Cultures / x 2-3 / including AFB• Sputum / Mantoux test• PSA• CSF/LP

Imaging

• MRI• MRA• CXR• Echocardiography / TTE• CTB with contrast (?)• CT other

– CTA Brain– CT Face – CT chest, abdo, pelvis

• OPG• PET scan• Bone scan• Skeletal XR

Other• ECG

Thoughts on LP/ CSF?

• Possible contraindications in this case?• Reduced GCS• Mass effect on CT• HR low, BP high• etc etc

• i.e. potentially unsafe practice

• NB there are many options for ED Ix and I would have avoided mention of LP – if mentioned, needed to indicate risk

Should you get a point for writing a test alone?

• i.e. Complete ALL sections of table

Investigation (6 marks) Justification (6 marks)

1 FBE It is hard to think this list alone should gain any of 6/12 marks

Providing a list alone hasn’t demonstrated the required standard of knowledge

2 UEC

3 Blood culture x 3

4 Serology e.g. HIV

5 CXR

6 MRI

• Many answers had very poor justifications

…Particularly given the wealth of Investigations and rationale for these in a febrile, young man with altered conscious state and a large ring enhancing lesion on CT scan …

Investigation Insufficient Justification

Comment

FBE WCC General / generic

FBE Raised markers

FBE Infection

Blood culture Fever

CXR or MRI For other lesions What sort of “lesions”? Understanding the DDx is one point of the Question!

LFT or Renal function

Baseline Not very contributory / doesn’t demonstrate understanding of the case

HIV Complication Which complications in this case…?

Coags or Platelets

Pre-op (surgery or LP(?))

This is a default answer..There are much better choices of Ix / justifications which convey a better understanding of the issues in this question

Please consider: Did your choice of Investigation/justification demonstrate your

understanding of:

• The DDx given the CT findings– Particularly abscess and tumour

• Cause• Complications• Clinical context– Young man, fever, ?immunocompetent

Great examples from candidates• FBE

– Neutrophilia (> 15,000), eosinophilia or neutropenia may influence DDx and Rx

• Na– Possible SIADH in intracerebral mass, malignancy

• Ca– malignancy complicated by hypercalcemia

• Serology HIV/TB– causative in brain abscess

• Blood culture - at least 2– urgent prior to immediate empiric ABs, allows tailored AB Rx later

(Less great examples from me…)

• MRI • Increased delineation for DDx abscess vs tumour, may identify

multiple lesions

• CXR• DDX of 2o tumour or abscess warrants search for primary tumour /

focus of infection in lung

• HIV serology • Complications of HIV e.g. TB, Toxoplasmosis, lymphoma (= DDx

ring enhancing lesion)

• Blood cultures x 3 • prior to empirical BS AB Rx / consider bacteraemia and

endocarditis in cerebral abscess

iii)Outline 4 treatment priorities for this patient (4 marks)These are the list of Treatment priorities suggested by group

I would have chosen from the underlined to try and show my grasp of issues – but revise the topic and debate which four you would select…

• Antibiotics - BS, empiric• Anti viral • Antifungal• Steroids• Mannitol • Analgesia • Seizure prophylaxis• Antipyretic• Anti emetic • Sedation • HIV Rx

• IV fluids • ICP related

– Reduce ICP– Prevent 2O injury – Neuroprotective strategies

• Airway – Monitor, secure, intubate if…

• Consultations/Admission– Neurosurgery – ICU – Infectious Disease

• Other – Seek and RX electrolyte/glucose

disturbance– Communicate with family

Examples which don’t convey sufficient information

Simply writing;1.Antibiotics2.Analgesia3.Monitor airway

• Scanty - lack sufficient example or detail, do not show sufficient knowledge

• A good answer will provide some detail or example e.g.

• BS AB cover for range of pathogens in cerebral abscess

• Drug, dose, route• Example of neuroprotective

measures

Suggestions for making progress…

• Revise topic then answer these questions again• Practice similar questions for various images – e.g. Other CT scans, CXR

• Practice choosing investigations and justifying them for varied clinical contexts e.g. – Suspected PE– Fever in returned traveller – First trimester bleeding

Good luck!