NZREX Clinical Diagnosis & Management 1 β Questions and Answers
Question 1: A 60-year-old man presents with sudden onset crushing central chest pain radiating to the left arm, diaphoresis, and nausea. His ECG shows ST elevation in leads II, III, and aVF. Which artery is most likely occluded?
- Right coronary artery (Correct answer)
- Left anterior descending artery
- Left circumflex artery
- Left main coronary artery
Correct answer: Right coronary artery
ST elevation in leads II, III, and aVF indicates inferior STEMI, which is most commonly caused by occlusion of the right coronary artery (RCA), which supplies the inferior wall of the left ventricle in most patients.
Question 2: Which of the following is the first-line treatment for anaphylaxis?
- Intramuscular adrenaline 0.5 mg (1:1000) (Correct answer)
- Intravenous hydrocortisone 200 mg
- Intravenous antihistamine
- Nebulised salbutamol
Correct answer: Intramuscular adrenaline 0.5 mg (1:1000)
IM adrenaline (epinephrine) 0.5 mg of 1:1000 solution into the anterolateral thigh is the life-saving first-line treatment for anaphylaxis. Antihistamines and corticosteroids are adjuncts only.
Question 3: A 35-year-old woman presents with a 6-month history of weight loss, heat intolerance, palpitations, and a smooth goitre. TSH is suppressed with elevated free T4. What is the most likely diagnosis?
- Graves' disease (Correct answer)
- Hashimoto's thyroiditis
- Toxic multinodular goitre
- De Quervain's thyroiditis
Correct answer: Graves' disease
Graves' disease is the most common cause of hyperthyroidism in young women, caused by TSH receptor antibodies. It presents with a diffusely smooth goitre, ophthalmopathy, and hyperthyroid symptoms.
Question 4: Which investigation is the gold standard for diagnosing pulmonary embolism?
- CT pulmonary angiography (CTPA) (Correct answer)
- V/Q scan
- D-dimer
- Chest X-ray
Correct answer: CT pulmonary angiography (CTPA)
CTPA is the gold standard investigation for diagnosing pulmonary embolism, providing direct visualisation of clot within the pulmonary vasculature with high sensitivity and specificity.
Question 5: A 55-year-old with known cirrhosis presents with confusion, asterixis, and fetor hepaticus. Ammonia is elevated. What is the most appropriate immediate management?
- Lactulose orally or via nasogastric tube (Correct answer)
- IV thiamine followed by dextrose
- Sodium bicarbonate infusion
- Rifaximin IV loading dose
Correct answer: Lactulose orally or via nasogastric tube
Lactulose reduces ammonia absorption from the gut by acidifying colonic contents and promoting ammonia excretion. It is first-line for hepatic encephalopathy. Rifaximin is used as adjunct or maintenance.
Question 6: A 72-year-old woman is found to have a serum potassium of 6.8 mmol/L with peaked T waves on ECG. What is the most urgent first step?
- IV calcium gluconate (Correct answer)
- IV insulin and dextrose
- Calcium resonium orally
- Salbutamol nebuliser
Correct answer: IV calcium gluconate
IV calcium gluconate stabilises the cardiac membrane immediately without lowering potassium, protecting against arrhythmia. This is the most urgent step. Insulin/dextrose and salbutamol are then used to shift potassium into cells.
NZREX Clinical Diagnosis & Management 1
A 60-year-old man presents with sudden onset crushing central chest pain radiating to the left arm, diaphoresis, and nausea.
His ECG shows ST elevation in leads II, III, and aVF.
Which artery is most likely occluded?