Free PLAB 1 mock test — 180 SBAs, 3 hours, UKMLA content map 🇬🇧

8 original practice questions written by Myndaq in the PLAB 1 / UKMLA AKT style. They are not taken from this mock paper or from official past papers. Try each one, then open the answer.

1. Question 1CardiovascularOne correct answer

   A 76-year-old man attends his GP surgery after a 48-hour ambulatory ECG, arranged for intermittent palpitations, showed several episodes of atrial fibrillation lasting up to 3 hours. He has hypertension treated with ramipril. He has no history of bleeding, does not drink alcohol and weighs 82 kg. His pulse is 74 bpm and regular, and his BP is 136/82 mmHg. His eGFR is 68 mL/min/1.73m² and his full blood count is normal. Which is the most appropriate treatment to reduce his risk of stroke?

   1. A. Apixaban 5 mg twice daily
   2. B. Aspirin 75 mg once daily
   3. C. Clopidogrel 75 mg once daily
   4. D. No antithrombotic treatment because the atrial fibrillation is paroxysmal
   5. E. Warfarin with a target INR of 3.5
   Show answer and explanation

   Answer: A

   Paroxysmal atrial fibrillation carries a stroke risk similar to persistent AF, so it is assessed in the same way. He scores 2 for age 75 or over and 1 for hypertension, a stroke-risk score of 3 (the same whether or not a point is given for sex). NICE advises offering a direct oral anticoagulant to anyone with a score of 2 or more, after assessing bleeding risk, which is low here.

   Apixaban 5 mg twice daily is the correct dose: the reduced dose of 2.5 mg twice daily is used only when at least two of age 80 or over, weight 60 kg or less and serum creatinine 133 micromol/L or above are present, and he has none.

   Aspirin or clopidogrel alone should not be used for stroke prevention in AF, as they are less effective and still cause bleeding. Warfarin is an alternative only when a DOAC is unsuitable, and the target INR in AF is 2.5 (range 2 to 3), not 3.5.

2. Question 2RespiratoryOne correct answer

   A 23-year-old woman with asthma comes to the emergency department with 2 days of increasing breathlessness after a cold. She can speak only in short phrases. Her respiratory rate is 28/min, pulse 124 bpm and BP 118/74 mmHg. Her peak expiratory flow is 160 L/min; her best recorded value is 420 L/min. Oxygen saturation is 91% on room air. There is widespread expiratory wheeze and she is alert. Which finding indicates that this is a life-threatening attack?

   1. A. Inability to complete sentences
   2. B. Oxygen saturation of 91% on room air
   3. C. Peak expiratory flow of 38% of her best
   4. D. Pulse of 124 bpm
   5. E. Respiratory rate of 28/min
   Show answer and explanation

   Answer: B

   In UK asthma guidance, an attack is life-threatening if any of these is present: SpO2 below 92%, PEF below 33% of best or predicted, PaO2 below 8 kPa, a PaCO2 in the normal range (4.6 to 6.0 kPa), silent chest, cyanosis, poor respiratory effort, arrhythmia, exhaustion, altered consciousness or hypotension. A raised PaCO2 indicates near-fatal asthma. Her SpO2 of 91% meets this threshold, so she needs controlled oxygen to reach 94 to 98%, an arterial blood gas and senior review alongside nebulised salbutamol, ipratropium and steroids.

   The other findings define an acute severe attack only: PEF 33 to 50% (160/420 is 38%), respiratory rate 25/min or more, heart rate 110 bpm or more and inability to complete sentences in one breath.

3. Question 3PaediatricsOne correct answer

   A 4-week-old boy is brought to the emergency department with 5 days of vomiting. The vomit is milky, never green, and shoots across the room within minutes of every feed, after which he roots eagerly for more. His birth weight was 3.9 kg and he now weighs 3.6 kg. He has had only two wet nappies today, his anterior fontanelle is slightly sunken and his capillary refill time is 3 seconds. Which set of blood results is most likely?

   1. A. Hyperchloraemic metabolic acidosis with hyperkalaemia
   2. B. Hypochloraemic metabolic alkalosis with hypokalaemia
   3. C. Hypochloraemic metabolic acidosis with hypokalaemia
   4. D. Normal anion gap metabolic acidosis with hyperkalaemia
   5. E. Respiratory alkalosis with hypernatraemia
   Show answer and explanation

   Answer: B

   Repeated forceful non-bilious vomiting in a hungry, dehydrated infant aged 2 to 8 weeks suggests infantile hypertrophic pyloric stenosis, most often in boys.

   Vomiting pure gastric contents loses hydrochloric acid, which causes hypochloraemia and a metabolic alkalosis. Volume depletion activates the renin-angiotensin-aldosterone system, so the kidneys retain sodium at the cost of potassium and hydrogen ions, which causes hypokalaemia and sometimes a paradoxically acidic urine.

   Acidosis would suggest another cause, such as sepsis, severe dehydration from diarrhoea or a metabolic disorder, and there is no reason for a primary respiratory alkalosis. The diagnosis is confirmed by abdominal ultrasound. Fluid and electrolyte problems must be corrected with IV fluids before pyloromyotomy, because anaesthesia is unsafe while the alkalosis persists.

4. Question 4Mental healthOne correct answer

   A 52-year-old woman with bipolar affective disorder has taken lithium for 6 years; her levels have been stable at 0.6 to 0.8 mmol/L. She now has 3 days of coarse tremor, vomiting, loose stools, an unsteady gait and increasing drowsiness. Her serum lithium level is 2.1 mmol/L. Over the past 2 weeks she has started lansoprazole for indigestion and amoxicillin for a chest infection, and has been taking paracetamol, codeine phosphate and ibuprofen for a painful knee. Which medicine is most likely to have caused the rise in her lithium level?

   1. A. Amoxicillin
   2. B. Codeine phosphate
   3. C. Ibuprofen
   4. D. Lansoprazole
   5. E. Paracetamol
   Show answer and explanation

   Answer: C

   Her symptoms and a level of 2.1 mmol/L (usual target 0.4 to 1.0 mmol/L) show lithium toxicity. Lithium is cleared almost entirely by the kidneys. NSAIDs such as ibuprofen reduce renal prostaglandin synthesis, lower lithium clearance and can raise the level sharply, so the BNF advises avoiding them or monitoring levels closely. ACE inhibitors, angiotensin receptor blockers and thiazide diuretics act in the same way, and dehydration from her vomiting and diarrhoea will make it worse.

   Paracetamol is the preferred painkiller for patients taking lithium. Codeine, lansoprazole and amoxicillin have no clinically important effect on lithium levels.

   Management: stop lithium and the NSAID, give IV fluids, monitor renal function and lithium levels, and discuss with a poisons service. Haemodialysis is considered if toxicity is severe or kidney function is poor.

5. Question 5Emergency medicineOne correct answer

   A 29-year-old man is brought into the emergency department 15 minutes after eating a meal containing peanut sauce. His lips and tongue are swollen, his voice is hoarse and he has a widespread itchy rash. His respiratory rate is 30/min with audible wheeze, pulse 128 bpm, BP 82/50 mmHg and SpO2 90% on room air. High-flow oxygen has been started. Which is the most appropriate next drug treatment?

   1. A. Adrenaline 1 mg IV (10 mL of 100 micrograms/mL) as a rapid bolus
   2. B. Adrenaline 500 micrograms IM (0.5 mL of 1 mg/mL) into the anterolateral thigh
   3. C. Chlorphenamine 10 mg IV
   4. D. Hydrocortisone 200 mg IV
   5. E. Salbutamol 5 mg nebulised
   Show answer and explanation

   Answer: B

   Sudden airway swelling, bronchospasm and hypotension after exposure to a likely allergen is anaphylaxis. Resuscitation Council UK guidance is to give IM adrenaline at once: 500 micrograms (0.5 mL of 1 mg/mL) for an adult, into the anterolateral thigh. This can be repeated after 5 minutes if there is no improvement, while IV access is secured and a fluid bolus is given for the hypotension.

   An IV bolus of 1 mg adrenaline is the cardiac arrest dose. In a patient with a pulse it can cause severe hypertension, arrhythmias and myocardial ischaemia. IV adrenaline infusions are given only by experienced specialists for refractory anaphylaxis.

   Antihistamines treat only skin symptoms and come after adrenaline. Corticosteroids are no longer routinely advised for the emergency treatment. Nebulised salbutamol may help wheeze that persists after adrenaline but does nothing for the swelling or shock.

6. Question 6Ethics and professionalismOne correct answer

   A 44-year-old man who works as a van driver had an unprovoked generalised seizure 3 weeks ago. You have explained, on two occasions and with a written record, that he must not drive and must tell the DVLA. At today's review he says he cannot afford to stop working, has not contacted the DVLA and drove to the appointment. He has capacity and refuses to change his mind after further discussion. What is the most appropriate action?

   1. A. Ask his partner to take away his car keys
   2. B. Continue to keep his information confidential, as he has capacity
   3. C. Inform him that you will notify the DVLA, then do so
   4. D. Report him to the police so that his driving can be stopped
   5. E. Write to his employer explaining that he is unfit to drive
   Show answer and explanation

   Answer: C

   GMC confidentiality guidance says that patients are responsible for telling the DVLA about conditions that may affect safe driving. If a patient cannot be persuaded to stop driving, or is known to be driving against advice, the doctor should contact the DVLA promptly and disclose the relevant information, in confidence, to its medical adviser. This disclosure is justified in the public interest because he could cause serious harm to others. He should be told beforehand that you intend to do this (unless that would be unsafe), and he should be told in writing afterwards that it has been done.

   Having capacity does not outweigh the risk to other road users, so staying silent is wrong. The DVLA, not the police, is the body that decides on fitness to drive. Telling his employer or his partner would be a disproportionate breach of confidentiality and would not deal with his licence.

7. Question 7RenalOne correct answer

   A 67-year-old man with stage 4 chronic kidney disease and heart failure takes ramipril and spironolactone. He comes to the emergency department with 2 days of generalised weakness. His pulse is 48 bpm and BP 124/70 mmHg. Serum potassium is 7.2 mmol/L (a repeat sample without haemolysis confirms this), creatinine 318 micromol/L and venous bicarbonate 19 mmol/L. The ECG shows peaked T waves, flattened P waves and a broad QRS complex. Which is the most appropriate first treatment?

   1. A. Calcium gluconate 10%, 30 mL IV over 5 to 10 minutes
   2. B. Calcium polystyrene sulfonate 15 g orally
   3. C. Salbutamol 10 mg nebulised
   4. D. Sodium bicarbonate 8.4%, 50 mL IV
   5. E. Soluble insulin 10 units with 25 g glucose IV
   Show answer and explanation

   Answer: A

   Severe hyperkalaemia (6.5 mmol/L or above) with ECG changes can cause a fatal arrhythmia at any moment. The first step is IV calcium, which stabilises the cardiac cell membrane within minutes but does not lower potassium. UK Kidney Association guidance recommends 30 mL of 10% calcium gluconate (or 10 mL of 10% calcium chloride), repeated if the ECG does not improve, with cardiac monitoring.

   Insulin with glucose, and then nebulised salbutamol, should follow straight away to move potassium into cells; they come second because they take 15 to 30 minutes to work. Oral potassium binders act over hours to remove potassium from the body. UK Kidney Association guidance uses sodium zirconium cyclosilicate for this later step and no longer recommends calcium polystyrene sulfonate for acute hyperkalaemia. Neither should be the first treatment when the ECG shows changes. IV bicarbonate is not routine and should not be given through the same line as calcium, because they precipitate. Ramipril and spironolactone must be stopped.

8. Question 8Obstetrics and gynaecologyOne correct answer

   A 31-year-old woman attends her booking appointment at 9 weeks of gestation in her first pregnancy. Her BMI is 37 kg/m² and her BP is 124/78 mmHg. She has no history of hypertension, kidney disease, diabetes or autoimmune disease, and her mother and sisters had no problems in pregnancy. Urinalysis is normal. Which is the most appropriate advice?

   1. A. No preventive medication is needed; routine antenatal care only
   2. B. Take aspirin 75 to 150 mg once daily from 12 weeks until the baby is born
   3. C. Take aspirin 75 mg once daily from 28 weeks until the baby is born
   4. D. Take labetalol 100 mg twice daily from 12 weeks until the baby is born
   5. E. Take low molecular weight heparin from now until 6 weeks after the birth
   Show answer and explanation

   Answer: B

   NICE advises aspirin 75 to 150 mg daily from 12 weeks until the birth for women with one high-risk factor for pre-eclampsia, or with more than one moderate-risk factor. The moderate-risk factors are a first pregnancy, age 40 or over, more than 10 years since the last pregnancy, BMI 35 kg/m² or more at the first visit, a family history of pre-eclampsia and a multiple pregnancy. She has two: this is her first pregnancy, and her BMI is 37. So aspirin is indicated.

   Starting aspirin at 28 weeks is too late for it to help placental development. Labetalol treats hypertension, which she does not have, and does not prevent pre-eclampsia. Obesity alone is only one risk factor for venous thromboembolism, which is not enough for antenatal heparin. Routine care alone misses the combined moderate-risk factors.