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HKMLE Part III study materials
HKMLE Part III study resources

HKMLE Part III practice questions

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Question 1Professional knowledge and clinical practice (unspecified by source)

A 58-year-old man with type 2 diabetes has an eGFR of 28 mL/min/1.73 m². Which oral glucose-lowering agent requires dose reduction or avoidance at this level of renal function because of an increased risk of lactic acidosis?

  1. Sitagliptin
  2. Empagliflozin
  3. Metformin Correct answer.
  4. Gliclazide

Explanation

Metformin is renally excreted and accumulates when eGFR falls, raising the risk of metformin-associated lactic acidosis; in Hong Kong practice it is generally avoided once eGFR is below 30 mL/min/1.73 m². The other agents listed have different elimination or safety profiles in renal impairment.

Question 2Professional knowledge and clinical practice (unspecified by source)

A 30-year-old woman has a blood pressure of 152/96 mmHg on two occasions. Which single finding on urinalysis most suggests an underlying glomerular cause of her hypertension rather than essential hypertension?

  1. Trace glycosuria
  2. A few hyaline casts
  3. Dysmorphic red cells with red cell casts Correct answer.
  4. Isolated proteinuria of 0.2 g/day

Explanation

Dysmorphic red cells and red cell casts indicate glomerular bleeding and point to glomerulonephritis as a secondary cause of hypertension. Hyaline casts, mild isolated proteinuria and glycosuria are non-specific or suggest other processes.

Question 3Professional knowledge and clinical practice (unspecified by source)

A 72-year-old man presents with sudden painless loss of vision in the right eye. Fundoscopy shows a pale, oedematous retina with a cherry-red spot at the macula. What is the most appropriate immediate management priority?

  1. Topical beta-blocker to lower intraocular pressure
  2. Urgent assessment for thrombolysis and stroke risk factors Correct answer.
  3. Intravitreal anti-VEGF injection
  4. Oral acetazolamide and head-up positioning

Explanation

The picture is central retinal artery occlusion, an ocular stroke; management focuses on urgent stroke evaluation and secondary prevention of vascular risk. Lowering intraocular pressure is sometimes attempted but is not the primary priority, and anti-VEGF is used for venous occlusion or neovascularisation.

Question 4Professional knowledge and clinical practice (unspecified by source)

A 26-year-old woman has a 6-week history of palpitations, weight loss and heat intolerance. TSH is suppressed and free T4 is elevated. She has a smooth goitre and no eye signs. Which treatment is most appropriate first-line for symptom control while definitive therapy is planned?

  1. Subtotal thyroidectomy
  2. Radioactive iodine
  3. Levothyroxine
  4. Carbimazole Correct answer.

Explanation

Thionamides such as carbimazole are first-line to control hyperthyroidism while awaiting definitive therapy. Radioactive iodine and surgery are definitive options reserved for selected patients, and levothyroxine would worsen thyrotoxicosis.

Question 5Professional knowledge and clinical practice (unspecified by source)

A 65-year-old man with chronic obstructive pulmonary disease has an arterial blood gas showing pH 7.32, PaCO2 62 mmHg, PaO2 55 mmHg and bicarbonate 31 mmol/L. How is this acid-base disturbance best described?

  1. Mixed metabolic acidosis and respiratory alkalosis
  2. Respiratory alkalosis with metabolic compensation
  3. Compensated respiratory acidosis with hypoxaemia Correct answer.
  4. Uncompensated metabolic acidosis

Explanation

A raised PaCO2 with acid pH indicates respiratory acidosis, and the elevated bicarbonate reflects metabolic compensation. The low PaO2 confirms hypoxaemia, consistent with chronic COPD.

Question 6Professional knowledge and clinical practice (unspecified by source)

A 24-year-old man is brought in after a night of heavy drinking and is drowsy. Capillary glucose is 2.1 mmol/L. After intravenous glucose administration, which additional step is most important to prevent recurrence?

  1. Give intravenous glucagon
  2. Give a longer-acting carbohydrate and monitor glucose Correct answer.
  3. Restrict oral intake for 12 hours
  4. Give intravenous insulin

Explanation

Alcohol-induced hypoglycaemia occurs because ethanol inhibits gluconeogenesis; after correcting acute hypoglycaemia, a sustained carbohydrate source and monitoring prevent recurrence. Insulin would worsen hypoglycaemia, and glucagon is less useful when glycogen stores are depleted.

Question 7Professional knowledge and clinical practice (unspecified by source)

A 45-year-old woman has generalised anxiety with prominent somatic symptoms. Which class of medication is recommended first-line pharmacotherapy for generalised anxiety disorder in most guidelines?

  1. Beta-blockers as first-line
  2. Antipsychotics as first-line
  3. Benzodiazepines as long-term monotherapy
  4. Selective serotonin reuptake inhibitors Correct answer.

Explanation

SSRIs are first-line pharmacotherapy for generalised anxiety disorder because of efficacy and a favourable long-term safety profile. Benzodiazepines are reserved for short-term use, and antipsychotics or beta-blockers are not first-line.

Question 8Professional knowledge and clinical practice (unspecified by source)

A 34-year-old woman at 10 weeks' gestation presents with fever, dysuria and flank pain. Which antibiotic is most appropriate empirically for acute pyelonephritis in pregnancy?

  1. Ceftriaxone Correct answer.
  2. Ciprofloxacin
  3. Tetracycline
  4. Trimethoprim-sulfamethoxazole in the first trimester

Explanation

A third-generation cephalosporin such as ceftriaxone is safe in pregnancy and provides appropriate cover for pyelonephritis. Fluoroquinolones and tetracyclines are avoided in pregnancy, and trimethoprim is avoided in the first trimester because it is a folate antagonist.

Question 9Professional knowledge and clinical practice (unspecified by source)

A 3-year-old child has a barking cough, inspiratory stridor and hoarse voice following a coryzal illness. Which condition is most likely?

  1. Foreign body aspiration
  2. Croup Correct answer.
  3. Bronchiolitis
  4. Epiglottitis

Explanation

Croup (laryngotracheobronchitis) classically causes a barking cough, hoarse voice and inspiratory stridor after a viral upper respiratory illness in young children. Epiglottitis causes drooling and toxicity, bronchiolitis causes wheeze, and aspiration gives sudden onset without coryza.

Question 10Professional knowledge and clinical practice (unspecified by source)

A 55-year-old man has sudden severe epigastric pain radiating to the back with vomiting. Serum lipase is three times the upper limit of normal. Which single factor is most important to assess for severity and aetiology at presentation?

  1. Serum amylase level
  2. Abdominal plain film
  3. Faecal occult blood
  4. Serum calcium and triglyceride levels Correct answer.

Explanation

Hypercalcaemia and hypertriglyceridaemia are recognised causes of acute pancreatitis, and both also affect severity assessment and management. Amylase adds little once lipase is diagnostic, and plain film is not central to severity assessment.

Question 11Professional knowledge and clinical practice (unspecified by source)

A 68-year-old woman on warfarin for atrial fibrillation has an INR of 7.5 and no bleeding. What is the most appropriate immediate management?

  1. Withhold warfarin and give oral vitamin K Correct answer.
  2. Continue warfarin at the same dose
  3. Give intravenous heparin
  4. Give fresh frozen plasma immediately

Explanation

With an INR above 5 without bleeding, warfarin should be withheld and low-dose oral vitamin K given, with monitoring until the INR falls. Fresh frozen plasma is reserved for major bleeding or urgent surgery, and heparin is not a reversal agent.

Question 12Professional knowledge and clinical practice (unspecified by source)

A 30-year-old man is diagnosed with acute myeloid leukaemia. A peripheral blood film shows many blasts. Which single feature on bone marrow examination best supports the diagnosis of acute myeloid leukaemia over acute lymphoblastic leukaemia?

  1. Presence of Auer rods only in ALL
  2. Terminal deoxynucleotidyl transferase positivity
  3. Myeloperoxidase positivity of blast cells Correct answer.
  4. CD3 positivity

Explanation

Myeloperoxidase positivity indicates myeloid lineage and supports acute myeloid leukaemia. Auer rods are a feature of AML, not ALL, and CD3 and TdT positivity are lymphoid markers.

Question 13Professional knowledge and clinical practice (unspecified by source)

A 40-year-old woman has a 3-month history of fatigue, arthralgia and a photosensitive facial rash. Which single autoantibody is most specific for systemic lupus erythematosus?

  1. Rheumatoid factor
  2. Anti-histone antibody
  3. Anti-double-stranded DNA Correct answer.
  4. Antinuclear antibody

Explanation

Anti-double-stranded DNA is highly specific for systemic lupus erythematosus and correlates with disease activity and nephritis. Antinuclear antibody is sensitive but not specific, and rheumatoid factor and anti-histone antibodies occur in other conditions.

Question 14Professional knowledge and clinical practice (unspecified by source)

A 60-year-old man has a serum creatinine of 200 µmol/L. Using the Cockcroft-Gault formula, which factor besides age and weight must be adjusted for to estimate creatinine clearance?

  1. Sex Correct answer.
  2. Height
  3. Blood urea
  4. Body mass index

Explanation

The Cockcroft-Gault equation includes age, weight, serum creatinine and sex, because the formula applies a sex-specific factor. Height, body mass index and blood urea are not variables in the equation.

Question 15Professional knowledge and clinical practice (unspecified by source)

A 70-year-old man has an acute exacerbation of COPD with increased sputum purulence and breathlessness. Which single intervention has the strongest evidence for reducing mortality in this setting when hypoxaemia is present?

  1. Chest physiotherapy alone
  2. Intravenous theophylline
  3. High-flow oxygen to target saturation of 100%
  4. Controlled oxygen therapy to a target saturation of 88–92% Correct answer.

Explanation

Controlled oxygen to a target saturation of 88–92% in at-risk COPD patients prevents hypercapnia while correcting hypoxaemia and improves outcomes. Uncontrolled high-flow oxygen can worsen hypercapnia, and theophylline and physiotherapy alone do not reduce mortality.

Question 16Professional knowledge and clinical practice (unspecified by source)

A 28-year-old woman has recurrent episodes of severe abdominal pain, and her urine turns dark on standing. Which diagnosis should be considered?

  1. Hereditary haemochromatosis
  2. Wilson disease
  3. Acute intermittent porphyria Correct answer.
  4. Alpha-1 antitrypsin deficiency

Explanation

Acute intermittent porphyria presents with recurrent abdominal pain and neurovisceral symptoms, and urine may darken on standing due to porphobilinogen oxidation. The other conditions present with different patterns of liver, neurological or metabolic disease.

Question 17Professional knowledge and clinical practice (unspecified by source)

A 50-year-old man has a painless testicular swelling. Ultrasound shows a solid intratesticular mass. Which tumour marker is most useful for a non-seminomatous germ cell tumour?

  1. CA 19-9
  2. Carcinoembryonic antigen
  3. CA 125
  4. Alpha-fetoprotein Correct answer.

Explanation

Alpha-fetoprotein is elevated in non-seminomatous germ cell tumours such as yolk sac tumours and is useful for diagnosis and monitoring. CA 19-9, CA 125 and CEA are used for pancreatic, ovarian and colorectal tumours respectively.

Question 18Professional knowledge and clinical practice (unspecified by source)

A 62-year-old woman with atrial fibrillation on dabigatran presents with major gastrointestinal bleeding. Which agent is the specific reversal treatment?

  1. Idarucizumab Correct answer.
  2. Vitamin K
  3. Fresh frozen plasma as the specific antidote
  4. Protamine sulfate

Explanation

Idarucizumab is a monoclonal antibody fragment that specifically reverses dabigatran. Protamine reverses heparin, vitamin K reverses warfarin, and fresh frozen plasma is supportive but not a specific antidote.

Question 19Professional knowledge and clinical practice (unspecified by source)

A 5-year-old boy has periorbital oedema, generalised oedema and frothy urine. Urinalysis shows 4+ protein with no red cells, and serum albumin is 20 g/L. What is the most likely diagnosis?

  1. Alport syndrome
  2. IgA nephropathy
  3. Minimal change nephrotic syndrome Correct answer.
  4. Acute post-streptococcal glomerulonephritis

Explanation

Heavy selective proteinuria, hypoalbuminaemia and oedema without haematuria in a young child fit minimal change nephrotic syndrome, the commonest nephrotic syndrome in children. The other conditions typically present with haematuria or a different clinical course.

Question 20Professional knowledge and clinical practice (unspecified by source)

A 35-year-old woman is 32 weeks pregnant and presents with a blood pressure of 165/110 mmHg and 3+ proteinuria. Which medication is most appropriate for immediate blood pressure control?

  1. Sublingual nifedipine as first-line
  2. Oral ramipril
  3. Intravenous labetalol Correct answer.
  4. Oral candesartan

Explanation

Intravenous labetalol is a standard first-line agent for severe hypertension in pregnancy because of its rapid onset and safety. ACE inhibitors and angiotensin receptor blockers are contraindicated in pregnancy, and sublingual nifedipine is not recommended due to unpredictable falls in blood pressure.

Question 21Professional knowledge and clinical practice (unspecified by source)

A 45-year-old man has sudden severe headache described as the worst of his life, with neck stiffness. A non-contrast CT head is normal 6 hours after onset. What is the next most appropriate investigation?

  1. Carotid Doppler ultrasound
  2. MRI brain with contrast
  3. Repeat CT head in 24 hours
  4. Lumbar puncture for xanthochromia Correct answer.

Explanation

Subarachnoid haemorrhage can be missed on CT within the first day, and lumbar puncture for xanthochromia remains the next step when CT is negative and suspicion is high. Contrast MRI and carotid Doppler do not directly confirm subarachnoid blood.

Question 22Professional knowledge and clinical practice (unspecified by source)

A 70-year-old woman has a hip fracture and is scheduled for surgery. Which single factor most increases her perioperative risk of venous thromboembolism?

  1. Prolonged immobility Correct answer.
  2. Mild hypertension
  3. Controlled type 2 diabetes
  4. Mild renal impairment

Explanation

Prolonged immobility and major orthopaedic surgery are strong Virchow triad risk factors for venous thromboembolism. Hypertension, controlled diabetes and mild renal impairment are less influential than immobility for VTE risk.

Question 23Professional knowledge and clinical practice (unspecified by source)

A 40-year-old man has a 6-month history of low mood, anhedonia and early morning waking. He has never had a manic episode. Which diagnosis is most consistent with this presentation?

  1. Schizoaffective disorder
  2. Persistent depressive disorder with psychotic features
  3. Major depressive disorder Correct answer.
  4. Bipolar I disorder

Explanation

Low mood and anhedonia for more than two weeks without any manic or hypomanic episode is characteristic of major depressive disorder. Bipolar I requires a manic episode, and schizoaffective disorder requires psychotic symptoms meeting criteria for schizophrenia.

Question 24Professional knowledge and clinical practice (unspecified by source)

A 55-year-old woman has a thyroid nodule. Fine-needle aspiration shows a follicular lesion of undetermined significance. Which single next step is most appropriate?

  1. Observation with no further action
  2. Diagnostic hemithyroidectomy Correct answer.
  3. Radioactive iodine ablation
  4. Repeat fine-needle aspiration in 1 year

Explanation

Follicular lesions of undetermined significance cannot be reliably distinguished as benign or malignant by cytology alone, so diagnostic surgery (usually hemithyroidectomy) is needed for histology. Simple observation or delayed repeat aspiration risks missing malignancy.

Question 25Professional knowledge and clinical practice (unspecified by source)

A 65-year-old man with heart failure with reduced ejection fraction is on maximal tolerated doses of an ACE inhibitor and beta-blocker but remains symptomatic. Which single additional agent has been shown to reduce mortality in this setting?

  1. Digoxin
  2. Amlodipine
  3. Furosemide
  4. Spironolactone Correct answer.

Explanation

Mineralocorticoid receptor antagonists such as spironolactone reduce mortality in symptomatic heart failure with reduced ejection fraction when added to ACE inhibitors and beta-blockers. Furosemide relieves congestion but does not reduce mortality, and digoxin reduces hospitalisation rather than mortality.

Question 26Professional knowledge and clinical practice (unspecified by source)

A 58-year-old man with type 2 diabetes and a history of myocardial infarction is reviewed in clinic. His blood pressure is 138/86 mmHg, HbA1c 7.4%, and eGFR 72 mL/min/1.73m². Which single medication has the strongest evidence for reducing cardiovascular mortality in this patient?

  1. Pioglitazone
  2. Empagliflozin Correct answer.
  3. Gliclazide
  4. Sitagliptin

Explanation

SGLT2 inhibitors such as empagliflozin have demonstrated a significant reduction in cardiovascular mortality in patients with type 2 diabetes and established cardiovascular disease in large randomised trials. This benefit is independent of glucose lowering and is now a standard consideration in such patients.

Question 27Professional knowledge and clinical practice (unspecified by source)

A 72-year-old woman presents with sudden onset of painless loss of vision in her right eye. Fundoscopy reveals a pale retina with a cherry-red spot at the macula. Which single artery is most likely occluded?

  1. Central retinal vein
  2. Central retinal artery Correct answer.
  3. Ophthalmic artery
  4. Posterior ciliary artery

Explanation

Central retinal artery occlusion classically produces sudden painless monocular vision loss with a pale, oedematous retina and a cherry-red spot at the fovea, where the choroidal circulation remains visible through the thin macula. Central retinal vein occlusion instead causes a blood-and-thunder fundus with haemorrhages.

Question 28Professional knowledge and clinical practice (unspecified by source)

A 28-year-old woman at 10 weeks' gestation is diagnosed with Graves' disease. She is symptomatic with a heart rate of 110 beats/min. Which single antithyroid drug is most appropriate in the first trimester?

  1. Carbimazole
  2. Radioactive iodine
  3. Propylthiouracil Correct answer.
  4. Methimazole

Explanation

Propylthiouracil is preferred in the first trimester because methimazole and carbimazole are associated with embryopathy, including aplasia cutis and choanal atresia. Radioactive iodine is absolutely contraindicated in pregnancy.

Question 29Professional knowledge and clinical practice (unspecified by source)

A 45-year-old man presents with a 6-month history of episodic palpitations, sweating and headache. He has a blood pressure of 180/110 mmHg. Biochemical testing confirms phaeochromocytoma. Which single pre-operative medication is essential to prevent intraoperative hypertensive crisis?

  1. Hydralazine
  2. Atenolol
  3. Propranolol
  4. Phenoxybenzamine Correct answer.

Explanation

Alpha-blockade with phenoxybenzamine is required before surgery to control blood pressure and prevent intraoperative hypertensive crises from catecholamine release. Beta-blockade must never be used before alpha-blockade because unopposed alpha stimulation can precipitate a hypertensive crisis.

Question 30Professional knowledge and clinical practice (unspecified by source)

A 62-year-old woman with rheumatoid arthritis has been on long-term prednisolone 10 mg daily. She presents with a low-trauma wrist fracture. Which single medication should be considered to reduce her fracture risk?

  1. Raloxifene
  2. Cholecalciferol alone
  3. Calcium carbonate alone
  4. Alendronate Correct answer.

Explanation

Glucocorticoid-induced osteoporosis is best managed with a bisphosphonate such as alendronate, along with calcium and vitamin D supplementation. Bisphosphonates reduce fracture risk in patients on long-term glucocorticoids.

Question 31Professional knowledge and clinical practice (unspecified by source)

A 30-year-old man presents with a 2-day history of fever, headache and neck stiffness. A lumbar puncture shows a neutrophil predominance, low glucose and high protein. Which single organism is the most likely cause?

  1. Neisseria meningitidis Correct answer.
  2. Listeria monocytogenes
  3. Haemophilus influenzae type b
  4. Streptococcus pneumoniae

Explanation

In a young adult with community-acquired bacterial meningitis, Neisseria meningitidis is a leading cause, although Streptococcus pneumoniae is also common. The CSF profile is typical of bacterial meningitis, and empirical therapy should cover both until culture results are available.

Question 32Professional knowledge and clinical practice (unspecified by source)

A 68-year-old man with a history of hypertension and diabetes presents with sudden onset of severe epigastric pain radiating to the back. CT angiography shows a dissection flap in the descending aorta. Which single finding is most consistent with this diagnosis?

  1. Subcutaneous emphysema
  2. Pulsatile abdominal mass
  3. Elevated serum amylase
  4. Blood pressure difference of >20 mmHg between arms Correct answer.

Explanation

Aortic dissection often presents with a blood pressure difference between arms due to involvement of the subclavian artery. This is a classic finding that helps distinguish dissection from other causes of severe chest or back pain.

Question 33Professional knowledge and clinical practice (unspecified by source)

A 55-year-old woman presents with a 3-month history of fatigue, weight gain and cold intolerance. Examination reveals a diffuse goitre. Thyroid function tests show TSH 10 mIU/L and free T4 8 pmol/L. Which single antibody is most likely to be positive?

  1. Anti-thyroid peroxidase Correct answer.
  2. TSH receptor antibody
  3. Anti-nuclear antibody
  4. Anti-thyroglobulin

Explanation

Hashimoto's thyroiditis is the most common cause of hypothyroidism in iodine-sufficient areas and is characterised by positive anti-thyroid peroxidase antibodies. Anti-thyroglobulin antibodies are also present but are less sensitive and specific.

Question 34Professional knowledge and clinical practice (unspecified by source)

A 35-year-old woman at 34 weeks' gestation presents with a blood pressure of 160/110 mmHg and 3+ proteinuria. She has a platelet count of 90 × 10⁹/L and elevated liver enzymes. Which single medication is most appropriate for seizure prophylaxis?

  1. Phenytoin
  2. Diazepam
  3. Magnesium sulfate Correct answer.
  4. Labetalol

Explanation

Magnesium sulfate is the drug of choice for prevention and treatment of eclamptic seizures in pre-eclampsia. It is more effective than phenytoin or diazepam and is standard care in severe pre-eclampsia.

Question 35Professional knowledge and clinical practice (unspecified by source)

A 40-year-old man presents with a 4-week history of a painless penile ulcer. Dark-field microscopy is positive for spirochaetes. He has no known allergies. Which single treatment is recommended?

  1. Intravenous ceftriaxone
  2. Intramuscular benzathine penicillin G Correct answer.
  3. Oral azithromycin
  4. Topical imiquimod

Explanation

Primary syphilis is treated with intramuscular benzathine penicillin G, which is the standard and most effective therapy. Azithromycin resistance is now common, and ceftriaxone is reserved for neurosyphilis or penicillin allergy.

Question 36Professional knowledge and clinical practice (unspecified by source)

A 70-year-old man with atrial fibrillation is on warfarin. His INR is 8.0 and he has no bleeding. Which single management is most appropriate?

  1. Continue warfarin and recheck INR in 1 week
  2. Give fresh frozen plasma
  3. Withhold warfarin and give oral vitamin K Correct answer.
  4. Give intravenous vitamin K

Explanation

For an INR above 8.0 without bleeding, warfarin should be withheld and low-dose oral vitamin K given to reduce the INR. Intravenous vitamin K is reserved for major bleeding or very high INR with bleeding risk.

Question 37Professional knowledge and clinical practice (unspecified by source)

A 25-year-old woman presents with a 2-day history of dysuria and frequency. Urine dipstick is positive for nitrites and leucocytes. She has no allergies. Which single antibiotic is first-line for uncomplicated cystitis?

  1. Amoxicillin
  2. Ciprofloxacin
  3. Doxycycline
  4. Nitrofurantoin Correct answer.

Explanation

Nitrofurantoin is a first-line agent for uncomplicated lower urinary tract infection because of its efficacy and low resistance rates. Fluoroquinolones are reserved for more complicated infections due to concerns about resistance and adverse effects.

Question 38Professional knowledge and clinical practice (unspecified by source)

A 60-year-old man presents with a 3-month history of progressive dysphagia to solids and weight loss. Endoscopy shows a mass in the lower oesophagus. Which single histological type is most common in this location in Western countries?

  1. Small cell carcinoma
  2. Lymphoma
  3. Adenocarcinoma Correct answer.
  4. Squamous cell carcinoma

Explanation

Adenocarcinoma of the oesophagus typically arises in the lower third and is associated with Barrett's oesophagus and gastro-oesophageal reflux disease. It is now more common than squamous cell carcinoma in Western populations.

Question 39Professional knowledge and clinical practice (unspecified by source)

A 45-year-old man presents with sudden onset of severe headache, neck stiffness and photophobia. CT scan is normal, but lumbar puncture shows xanthochromia. Which single complication should be monitored for?

  1. Hydrocephalus
  2. All of the above
  3. Rebleeding Correct answer.
  4. Hyponatraemia

Explanation

Rebleeding is a major early complication of subarachnoid haemorrhage and carries a high mortality. Hydrocephalus and hyponatraemia can also occur, but rebleeding is the most immediate life-threatening complication to monitor for.

Question 40Professional knowledge and clinical practice (unspecified by source)

A 30-year-old woman at 8 weeks' gestation presents with severe hyperemesis gravidarum. She is dehydrated and has ketonuria. Which single electrolyte abnormality is most likely?

  1. Hyperkalaemia
  2. Hypokalaemia Correct answer.
  3. Hypernatraemia
  4. Hypercalcaemia

Explanation

Prolonged vomiting in hyperemesis gravidarum leads to loss of potassium and hydrogen ions, resulting in hypokalaemia and metabolic alkalosis. Hyperkalaemia and hypernatraemia are not typical.

Question 41Professional knowledge and clinical practice (unspecified by source)

A 55-year-old man with chronic obstructive pulmonary disease presents with an acute exacerbation. He has increased sputum purulence and breathlessness. Which single antibiotic is recommended first-line?

  1. Ciprofloxacin
  2. Co-trimoxazole
  3. Azithromycin
  4. Amoxicillin Correct answer.

Explanation

Amoxicillin is recommended as first-line for acute exacerbations of COPD with increased sputum purulence, as it covers common respiratory pathogens such as Streptococcus pneumoniae and Haemophilus influenzae. Macrolides or tetracyclines are alternatives in penicillin allergy.

Question 42Professional knowledge and clinical practice (unspecified by source)

A 40-year-old woman presents with a 6-month history of low mood, anhedonia and early morning waking. She has never had a manic episode. Which single class of antidepressant is first-line?

  1. Selective serotonin reuptake inhibitors Correct answer.
  2. Monoamine oxidase inhibitors
  3. Benzodiazepines
  4. Tricyclic antidepressants

Explanation

SSRIs are first-line for major depressive disorder due to their favourable safety profile and tolerability compared with tricyclics and MAOIs. Benzodiazepines are not antidepressants and are used short-term for anxiety.

Question 43Professional knowledge and clinical practice (unspecified by source)

A 65-year-old man with heart failure with reduced ejection fraction is on maximal tolerated doses of an ACE inhibitor and beta-blocker. He remains symptomatic with an ejection fraction of 30%. Which single medication has been shown to reduce mortality in this setting?

  1. Digoxin
  2. Eplerenone Correct answer.
  3. Ivabradine
  4. Furosemide

Explanation

Mineralocorticoid receptor antagonists such as eplerenone reduce mortality in patients with heart failure with reduced ejection fraction who remain symptomatic despite ACE inhibitor and beta-blocker therapy. Furosemide provides symptomatic relief but does not improve mortality.

Question 44Professional knowledge and clinical practice (unspecified by source)

A 50-year-old man presents with a painless testicular swelling. Ultrasound shows a solid intratesticular mass. Which single tumour marker is most likely to be elevated in a non-seminomatous germ cell tumour?

  1. Alpha-fetoprotein Correct answer.
  2. Lactate dehydrogenase
  3. Beta-human chorionic gonadotropin
  4. Carcinoembryonic antigen

Explanation

Alpha-fetoprotein is elevated in non-seminomatous germ cell tumours, particularly yolk sac tumours. Beta-hCG can also be elevated but is more characteristic of choriocarcinoma and some seminomas.

Question 45Professional knowledge and clinical practice (unspecified by source)

A 28-year-old woman presents with recurrent episodes of severe abdominal pain and dark urine on standing. Which single diagnosis is most likely?

  1. Acute intermittent porphyria Correct answer.
  2. Variegate porphyria
  3. Hereditary coproporphyria
  4. Lead poisoning

Explanation

Acute intermittent porphyria classically presents with neurovisceral symptoms including severe abdominal pain and dark urine due to porphobilinogen. It is not associated with cutaneous photosensitivity.

Question 46Professional knowledge and clinical practice (unspecified by source)

A 70-year-old woman presents with a hip fracture after a fall. She is scheduled for surgery. Which single factor most increases her perioperative risk?

  1. Serum creatinine of 90 µmol/L
  2. Age over 70 years Correct answer.
  3. Body mass index of 25
  4. Haemoglobin of 11 g/dL

Explanation

Advanced age is a significant independent risk factor for perioperative complications and mortality in hip fracture surgery. Other factors such as anaemia and renal impairment also contribute but are less consistently predictive.

Question 47Professional knowledge and clinical practice (unspecified by source)

A 60-year-old man presents with sudden onset of severe abdominal pain and distension. He has a history of atrial fibrillation. CT scan shows ischaemic bowel. Which single vessel is most likely occluded?

  1. Coeliac trunk
  2. Superior mesenteric artery Correct answer.
  3. Renal artery
  4. Inferior mesenteric artery

Explanation

Acute mesenteric ischaemia due to superior mesenteric artery occlusion is a classic complication of atrial fibrillation and presents with severe pain out of proportion to examination findings. The inferior mesenteric artery is less commonly affected and usually causes ischaemic colitis.

Question 48Professional knowledge and clinical practice (unspecified by source)

A 35-year-old woman presents with a 2-week history of fever, arthralgia and a new murmur. Blood cultures are positive for Staphylococcus aureus. Which single investigation is most appropriate to confirm endocarditis?

  1. Electrocardiogram
  2. Chest X-ray
  3. Transoesophageal echocardiography
  4. Transthoracic echocardiography Correct answer.

Explanation

Transthoracic echocardiography is the initial imaging test for suspected infective endocarditis, although transoesophageal echocardiography is more sensitive and used when the transthoracic study is inconclusive or when there is a high clinical suspicion.

Question 49Professional knowledge and clinical practice (unspecified by source)

A 45-year-old man presents with a 3-day history of severe epigastric pain radiating to the back. Serum lipase is elevated. Which single finding on ultrasound is most suggestive of gallstone pancreatitis?

  1. Pericholecystic fluid
  2. Gallstones in the gallbladder Correct answer.
  3. Dilated common bile duct
  4. Thickened gallbladder wall

Explanation

Gallstone pancreatitis is caused by the passage of gallstones through the biliary tree, and ultrasound may show gallstones in the gallbladder or a dilated common bile duct. The other findings are more suggestive of cholecystitis.

Question 50Professional knowledge and clinical practice (unspecified by source)

A 25-year-old woman presents with a 2-week history of fever, sore throat and lymphadenopathy. Blood film shows atypical lymphocytes. Which single test is most appropriate to confirm infectious mononucleosis?

  1. Monospot test Correct answer.
  2. Cytomegalovirus PCR
  3. Epstein-Barr virus viral capsid antigen IgM
  4. Throat swab culture

Explanation

The Monospot test (heterophile antibody test) is the standard initial test for infectious mononucleosis and is highly specific. EBV VCA IgM is more sensitive but is used when the Monospot is negative and clinical suspicion remains high.