NAC OSCE Clinical Reasoning & Diagnosis

Question 1

A 25-year-old woman presents with acute onset pleuritic chest pain, dyspnoea, and a history of oral contraceptive use. Which investigation should be ordered FIRST according to Canadian guidelines?

Accepted Answer

CT pulmonary angiography (CTPA) after pre-test probability assessment using the Wells PE score

Answer

Canadian guidelines recommend calculating the Wells PE score first; if score is high or D-dimer is elevated in low/intermediate probability, CTPA is the first-line imaging choice.

Question 2

A 60-year-old male smoker has a 3-month history of haemoptysis, weight loss, and a right upper lobe opacity on CXR. What is the MOST appropriate next investigation?

Accepted Answer

CT chest with IV contrast followed by bronchoscopy or CT-guided biopsy

Answer

A suspicious lung mass in a smoker requires tissue diagnosis; CT chest provides detailed characterisation and guides biopsy strategy, consistent with Canadian lung cancer screening and diagnosis guidelines.

Question 3

A 45-year-old woman presents with fatigue, weight gain, cold intolerance, and constipation. Which single test is MOST appropriate to confirm the suspected diagnosis?

Accepted Answer

TSH (thyroid-stimulating hormone)

Answer

TSH is the most sensitive first-line test for hypothyroidism, consistent with Canadian guidelines; a high TSH with low free T4 confirms primary hypothyroidism.

Question 4

In a diabetic patient presenting with fever, flank pain, and costovertebral angle tenderness, what complication must be urgently ruled out?

Accepted Answer

Emphysematous pyelonephritis requiring urgent CT and possibly nephrectomy

Answer

Emphysematous pyelonephritis is a life-threatening gas-forming infection of the renal parenchyma occurring predominantly in diabetics; CT abdomen is required urgently, and management may include percutaneous drainage or nephrectomy.

Question 5

A newborn has persistent cyanosis that does not improve with supplemental oxygen. Which congenital cardiac lesion should be MOST suspected?

Accepted Answer

Transposition of the great arteries (TGA)

Answer

TGA causes parallel rather than series circulation, so supplemental oxygen does not improve saturations; this hyperoxia test (nitrogen washout test) distinguishes cardiac from pulmonary causes of cyanosis.

NAC OSCE Practice Test

NAC OSCE Practice Test

NAC OSCE Clinical Reasoning & Diagnosis