Monash HealthFellowship practice exam2016.1 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 • Temp38.2oC • HR 60bpm • BP 150/80 mmHg A CT brain is shown in the prop booklet, page 4.
i) List 3 abnormal findings(accept ring enhancement as separate finding) Descriptions of: • Features of lesion(s) • Solitary • Location – parietal / temporal • Shape • Ring of contrast enhancement • Oedema (Vasogenic) • White matter hypodense • Loss grey-white junction • Effacement sulci • Mass effect • Ventricle • Midline shift
DDx ring enhancing lesion on CT brain MAGICDR or MAGICALDRGiven 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 groupI 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 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 • 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
Thoughts on LP/ CSF? • Possible contraindications in this case? • Reduced GCS • Mass effect on CT • HR low, BP high • etcetc • 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
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 …
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 groupI 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; • Antibiotics • Analgesia • 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