PLAB 2 Endocrinology: Mastering Diabetes OSCE Scenarios

Endocrinology stations featuring diabetes are among the most frequently tested scenarios in PLAB 2 OSCE examinations. As an examiner who has assessed countless candidates, I can tell you that diabetes cases offer rich opportunities to demonstrate clinical competence, communication skills, and safe prescribing—all crucial domains in the PLAB 2 marking scheme.

This guide will equip you with the essential knowledge, structured approaches, and practical strategies to confidently tackle diabetes-related OSCE stations.

Why Diabetes Dominates PLAB 2 Endocrinology Stations

Diabetes mellitus affects approximately 4.9 million people in the UK, making it one of the most prevalent chronic conditions you'll encounter as a junior doctor. The GMC recognises this, frequently testing candidates on:

• New diagnosis counselling

• Hypoglycaemia management

• Medication adjustment and insulin initiation

• Complication screening and management

• Lifestyle modification discussions

These scenarios test your ability to combine clinical knowledge with patient-centred communication—the hallmark of a safe and effective practitioner.

Essential Diabetes Knowledge for PLAB 2

Classification at a Glance

Key NICE Guidelines You Must Know

NICE NG28 (Type 2 Diabetes in Adults):

• First-line: Metformin (if HbA1c ≥48 mmol/mol)

• Second-line: Add sulfonylurea, pioglitazone, DPP-4 inhibitor, or SGLT2 inhibitor

• Third-line: Consider triple therapy or insulin

NICE NG17 (Type 1 Diabetes):

• Multiple daily injection (MDI) regimens or continuous subcutaneous insulin infusion (CSII)

• Carbohydrate counting education

• Annual screening for complications

NICE NG19 (Diabetic Foot Problems):

• Risk stratification

• Urgent referral for foot ulcers

Common PLAB 2 Diabetes OSCE Scenarios

Scenario 1: New Diagnosis of Type 2 Diabetes

Station Brief: You are an F2 doctor in primary care. Mrs Patel, 52, has just been diagnosed with Type 2 diabetes following routine blood tests (HbA1c 58 mmol/mol). Explain the diagnosis and initial management plan.

Structured Approach:

1. Open with empathy

   • "I understand this may come as a surprise. Can you tell me what you already know about diabetes?"

2. Explain diagnosis clearly

   • Use simple language: "Your blood sugar levels are higher than normal, which means you have Type 2 diabetes."

   • Avoid jargon; explain HbA1c as "a measure of your average blood sugar over the past 3 months."

3. Discuss initial management

   • Lifestyle modifications first (diet, exercise, weight loss)

   • Medication: Metformin—explain benefits and common side effects (GI upset)

   • Mention the diabetes annual review process

4. Address concerns

   • "What questions do you have?"

   • Reassure: "Many people live full, healthy lives with well-managed diabetes."

5. Safety netting

   • Symptoms of hypoglycaemia (if starting medication)

   • When to seek help

   • Follow-up appointment

Examiner Tips:

• Candidates often forget to assess prior knowledge—always check what the patient understands first

• Discuss driving implications if relevant (DVLA notification for insulin-treated diabetes)

• Arrange diabetic retinopathy screening

Scenario 2: Hypoglycaemia Management

Station Brief: You are the on-call F2 doctor. A nurse alerts you that Mr Thompson, 68 with Type 2 diabetes on gliclazide, appears confused and sweating. His capillary blood glucose is 3.2 mmol/L. Manage this acute scenario.

Immediate Management (15-15 Rule):

If patient is conscious and able to swallow:

• Give 15-20g fast-acting carbohydrate (glucose tablets, Lucozade, glucose gel)

• Recheck blood glucose after 15 minutes

• If still <4 mmol/L, repeat treatment

• Once recovered, give long-acting carbohydrate (biscuit, sandwich)

If patient is unconscious or unable to swallow:

• Do NOT give oral glucose

• Give IV glucagon 1mg OR IV 20% glucose 100ml

• Position in recovery position

• Monitor closely

• Investigate cause and review diabetes medications

Communication Points:

• Reassure the patient once recovered

• Explain what happened and why

• Review medications—consider reducing sulfonylurea dose

• Educate on symptom recognition and self-management

• Discuss sick day rules

Examiner Favourites:

• Candidates who forget to identify the cause (missed meals, incorrect insulin dose, alcohol, infection)

• Those who fail to adjust medications to prevent recurrence

• Not arranging follow-up or education

Scenario 3: Insulin Initiation Counselling

Station Brief: You are an F2 in the diabetes clinic. Mr Ahmed, 45 with Type 2 diabetes, has suboptimal control on maximal oral therapy (HbA1c 75 mmol/mol). The consultant has decided to start insulin. Counsel Mr Ahmed about starting insulin therapy.

Key Discussion Points:

1. Why insulin?

   • Explain that tablets alone are no longer sufficient

   • Emphasise this is a progression of the condition, not patient failure

2. Types of insulin

   • Long-acting (background/basal): Once or twice daily

   • Short/rapid-acting (mealtime/bolus): With meals

   • Explain the regimen chosen (usually basal-bolus or basal-only initially)

3. Injection technique

   • Demonstrate with a dummy pen

   • Sites: Abdomen, thighs, arms—rotate injection sites

   • Storage: Keep in use pen at room temperature; spare pens in fridge

4. Self-monitoring

   • Teach blood glucose checking

   • Target ranges: Fasting 5-7 mmol/L, pre-meals 4-7 mmol/L

5. Hypoglycaemia awareness

   • Symptoms: Tremor, sweating, palpitations, confusion

   • Management: Fast-acting glucose, then slow-acting carbohydrate

6. Sick day rules

   • Continue insulin even if not eating

   • Monitor blood glucose more frequently

   • Check ketones if unwell

7. Driving regulations

   • Must inform DVLA

   • Must test before driving and every 2 hours on long journeys

   • Do not drive if glucose <5 mmol/L

Communication Excellence:

• Address fears about injections (most patients anticipate pain, but modern pens are nearly painless)

• Discuss support available (diabetes specialist nurse, structured education programmes)

• Provide written information

Scenario 4: Diabetic Foot Examination

Station Brief: You are an F2 in the diabetes clinic. Perform a diabetic foot examination on Mr Roberts, 65, who has Type 2 diabetes of 15 years' duration.

Structured Examination (IPCAP):

Introduction and Permission

• Introduce yourself, explain examination, gain consent

• Expose both feet and lower limbs

Clinical Assessment:

1. Inspection

   • Skin: Colour, integrity, ulcers, calluses, fissures

   • Nails: Thickness, fungal infection, ingrowth

   • Deformities: Charcot foot, claw toes, hammer toes

   • Pressure areas

   • Footwear: Appropriate? Signs of rubbing?

2. Palpation

   • Temperature: Compare both feet ( unilateral cold → arterial disease; unilateral warm → Charcot or infection)

   • Pulses: Dorsalis pedis and posterior tibial

   • Capillary refill time

3. Neurological Assessment

   • 10g monofilament: Test at 10 sites on each foot (patient closes eyes, says "yes" when felt)

   • 128Hz tuning fork: Vibration perception at hallux

   • Proprioception: Hallux movement

   • Reflexes: Ankle jerk (may be absent in peripheral neuropathy)

Assessment and Plan:

• Risk stratify (NICE NG19):

Examiner Checklist:

• Did the candidate check for both neuropathy AND vascular disease?

• Did they risk stratify appropriately?

• Did they provide appropriate follow-up and referral?

Scenario 5: Diabetes and Pregnancy Counselling

Station Brief: You are an F2 in the antenatal clinic. Mrs Khan, 32, has Type 1 diabetes and is planning pregnancy. Counsel her about preconception care.

Critical Discussion Points:

1. Glycaemic optimisation

   • Target HbA1c <48 mmol/mol if safe

   • Tight control reduces risk of congenital malformations and miscarriage

2. Medication review

   • Stop: ACE inhibitors, ARBs, statins (teratogenic)

   • Continue: Insulin (safe in pregnancy), metformin (if already on it, discuss with specialist)

   • Folic acid 5mg daily (higher dose for diabetic women)

3. Retinopathy screening

   • Rapid improvement in glucose control can worsen retinopathy

   • Ensure recent retinal screening

4. Antenatal care pathway

   • Joint diabetes-antenatal clinic

   • Increased monitoring frequency

   • Delivery planning (often earlier, around 37-38 weeks)

5. Risks to discuss

   • Macrosomia, neonatal hypoglycaemia, preterm delivery

   • Reassure that good control minimises these risks

Marking Scheme Alignment

Understanding how PLAB 2 OSCEs are scored helps you focus your preparation:

Clinical Assessment (Data Gathering)

• Appropriate history/examination

• Correct interpretation of findings

• Formulating differential diagnoses

Clinical Management

• Appropriate investigations

• Evidence-based treatment plans

• Safety netting and follow-up

Interpersonal Skills

• Patient-centred approach

• Clear explanations without jargon

• Addressing concerns and checking understanding

Practical Skills

• Injection technique demonstration

• Blood glucose meter use

• Foot examination technique

Red Flags and Danger Signs in Diabetes OSCEs

Always mention these to demonstrate safety awareness:

1. Diabetic Ketoacidosis (DKA)

   • Hyperglycaemia, ketosis, acidosis

   • More common in Type 1 but can occur in Type 2

   • Admit, IV fluids, fixed-rate insulin infusion, monitor potassium

2. Hyperosmolar Hyperglycaemic State (HHS)

   • Profound hyperglycaemia (>40 mmol/L), dehydration, altered consciousness

   • More common in Type 2

   • Careful fluid resuscitation, avoid rapid glucose correction

3. Diabetic Foot Emergencies

   • Infected ulcer, spreading cellulitis, Charcot foot

   • Urgent referral to diabetic foot multidisciplinary team

4. Hypoglycaemic Seizure or Unconsciousness

   • Medical emergency

   • IV glucose or glucagon

   • Post-event medication review

Practical Preparation Tips

1. Know Your Guidelines

• Download NICE NG28 (Type 2), NG17 (Type 1), NG19 (Foot), NG3 (Gestational)

• Be familiar with local protocols for DKA and HHS

2. Practice Communication

• Explain diabetes to a layperson using simple language

• Practice demonstrating injection technique with a pen device

• Role-play breaking bad news scenarios

3. Clinical Skills

• Practice foot examination on colleagues or mannequins

• Be comfortable with blood glucose meters

• Know how to calculate insulin doses

4. Time Management

• In PLAB 2, stations last 8 minutes

• Practice completing consultations within time

• Use a structured approach (ICE, ICE, ICE for history)

5. Watch for Hidden Cues

• Simulated patients may give subtle hints about their concerns

• Address psychosocial aspects (impact on work, driving, relationships)

Summary: Your Diabetes OSCE Checklist

Before any diabetes station, mentally run through this checklist:

• [ ] Assess patient's existing knowledge

• [ ] Use simple, jargon-free language

• [ ] Cover diagnosis, management, and follow-up

• [ ] Discuss lifestyle modifications

• [ ] Address driving implications (if on insulin or sulfonylureas)

• [ ] Provide safety netting for hypoglycaemia

• [ ] Arrange appropriate screening (retinopathy, foot, renal)

• [ ] Check patient understanding and address concerns

• [ ] Provide written information and support resources

Final Thoughts

Diabetes OSCE stations in PLAB 2 are opportunities to demonstrate that you are a safe, competent, and compassionate doctor. By mastering the clinical knowledge, practising your communication skills, and understanding what examiners are looking for, you will be well-prepared to excel in these scenarios.

Remember: The examiners are not trying to catch you out—they want to ensure you can practise safely as a junior doctor in the NHS. Approach each station calmly, systematically, and with the patient at the centre of your care.

Good luck with your PLAB 2 preparation!

Dr. [Author]
MRCGP, MRCP (UK)
PLAB 2 Examiner and Clinical Supervisor