NAC OSCE Emergency Medicine

Question 1

A 45-year-old male presents to a Canadian ED with crushing substernal chest pain radiating to the left arm, diaphoresis, and an ECG showing 2 mm ST elevation in leads II, III, and aVF. What is the MOST time-critical intervention target?

Accepted Answer

Door-to-balloon time <90 minutes for primary PCI, or fibrinolysis within 30 minutes if PCI is unavailable

Answer

Canadian Cardiovascular Society STEMI guidelines mandate door-to-balloon time <90 minutes for primary PCI; if PCI cannot be achieved within 120 minutes, fibrinolysis should be given within 30 minutes of ED arrival.

Question 2

A 28-year-old woman is brought to the ED after ingesting an unknown quantity of acetaminophen 4 hours ago. Which investigation is MOST critical to guide treatment?

Accepted Answer

Serum acetaminophen level at 4 hours post-ingestion plotted on the Rumack-Matthew nomogram

Answer

The Rumack-Matthew nomogram uses the serum acetaminophen level at 4 hours post-ingestion to determine whether N-acetylcysteine (NAC) is indicated; earlier or later levels are not reliably predictive.

Question 3

According to Canadian Triage and Acuity Scale (CTAS), which level is assigned to a patient presenting with severe respiratory distress, SpO₂ 88%, and inability to complete sentences?

Accepted Answer

CTAS 1 — Resuscitation (immediate life threat)

Answer

CTAS 1 (Resuscitation) applies to conditions with immediate threat to life such as severe respiratory failure; the patient requires immediate physician assessment and intervention.

Question 4

A 55-year-old male presents in anaphylactic shock after a bee sting. What is the FIRST-line treatment according to Canadian Emergency Medicine guidelines?

Accepted Answer

IM epinephrine 0.3-0.5 mg (1:1000) into the anterolateral thigh

Answer

IM epinephrine into the anterolateral thigh is the first-line treatment for anaphylaxis per Canadian guidelines; antihistamines and corticosteroids are adjuncts that do not replace epinephrine.

Question 5

A 65-year-old woman presents with sudden onset of the worst headache of her life. CT head is negative. What is the next MOST critical investigation?

Accepted Answer

Lumbar puncture for xanthochromia and red blood cell count (or CT angiography if available)

Answer

A thunderclap headache with normal CT requires LP to detect xanthochromia (present 2-12 hours to 2 weeks post-SAH) or elevated RBCs, as CT misses 2% of SAH; CT angiography may be used in some Canadian centres as an alternative.

NAC OSCE Practice Test

NAC OSCE Practice Test

NAC OSCE Emergency Medicine