Master Internal Medicine
for SMLE

What the SMLE Tests in Internal Medicine

The SMLE Internal Medicine section tests the ability to manage common adult medical presentations in ambulatory and inpatient settings. Candidates must demonstrate knowledge of diagnostic criteria (e.g., American College of Rheumatology/EULAR for lupus, KDIGO for CKD), first-line pharmacotherapy (e.g., ACE inhibitors for diabetic nephropathy, beta-blockers for stable angina), and acute care decisions (e.g., when to start IV antibiotics for sepsis, criteria for thrombolysis in stroke). Emphasis is on evidence-based guidelines from NICE, ESC, and BTS. Questions often present a history, examination findings, and basic investigations (ECG, chest X-ray, bloods), requiring selection of the next step in diagnosis or management. Rare diseases are not tested; instead, focus on complications and comorbidities of common conditions like diabetes, hypertension, COPD, and heart failure.

High-Yield Concepts

• Community-Acquired Pneumonia Severity (CURB-65): Score 1 point each for Confusion (AMTS ≤8), Urea >7 mmol/L, Respiratory rate ≥30/min, BP systolic <90 or diastolic ≤60 mmHg, age ≥65. Score 0-1: treat at home; 2: consider hospital admission; 3-5: severe pneumonia, admit and consider ICU. First-line antibiotics: amoxicillin 500 mg TDS for mild; co-amoxiclav PLUS clarithromycin for severe.
• Heart Failure with Reduced Ejection Fraction (HFrEF): Diagnosis requires LVEF ≤40% on echocardiography. First-line disease-modifying therapy: ACE inhibitor (e.g., ramipril) OR ARNI (sacubitril/valsartan) PLUS beta-blocker (bisoprolol, carvedilol, nebivolol) PLUS MRA (spironolactone or eplerenone). Add SGLT2 inhibitor (dapagliflozin or empagliflozin) regardless of diabetes status. Loop diuretics (furosemide) for congestion only.
• Diabetic Ketoacidosis (DKA) Management: Diagnosis: glucose >11 mmol/L, ketones ≥3 mmol/L or ++ on urine, pH <7.3, bicarbonate <15 mmol/L. Fixed-rate IV insulin infusion 0.1 units/kg/hour after fluid resuscitation (1 litre 0.9% saline over 1 hour, then 1 litre over 2 hours, then 1 litre over 4 hours). Replace potassium: if K+ <5.5, add 40 mmol/L to fluids. Aim for ketone reduction 0.5 mmol/L/hour.
• Chronic Kidney Disease (CKD) Staging and Referral: Use eGFR and ACR (albumin:creatinine ratio). Stage 1: eGFR ≥90 with ACR ≥3; Stage 2: eGFR 60-89 with ACR ≥3; Stage 3a: eGFR 45-59; Stage 3b: eGFR 30-44; Stage 4: eGFR 15-29; Stage 5: eGFR <15. Refer to nephrology if eGFR <30, ACR >70, or rapid decline (>5 ml/min/1.73m²/year). First-line BP target <130/80 mmHg; use ACEi/ARB if ACR >3.
• Acute Coronary Syndrome (ACS) – NSTEMI Management: Diagnosis: troponin rise with chest pain but no ST elevation. Start dual antiplatelet therapy (aspirin 300 mg loading, then 75 mg OD; plus ticagrelor 180 mg loading, then 90 mg BD). Anticoagulate with fondaparinux 2.5 mg SC OD. Risk stratify using GRACE score; high-risk (GRACE >140) requires early angiography within 24 hours. Add beta-blocker (metoprolol) and statin (atorvastatin 80 mg).
• Asthma Stepwise Management (BTS/SIGN): Step 1: SABA as needed. Step 2: add low-dose ICS (e.g., beclometasone 200 mcg BD). Step 3: add LABA (e.g., formoterol) – if poor response, consider MART (maintenance and reliever therapy). Step 4: increase ICS to high dose (beclometasone 2000 mcg/day) plus consider LTRA (montelukast). Step 5: add oral prednisolone and refer to specialist. Acute exacerbation: give 100% oxygen, salbutamol 5 mg nebulised, prednisolone 40-50 mg PO for 5 days.
• Systemic Lupus Erythematosus (SLE) Diagnosis (ACR/EULAR 2019): Requires at least one clinical criterion (e.g., malar rash, arthritis, serositis, renal) plus ANA ≥1:80. Add weighted points: fever (2), thrombocytopenia (2), renal class III/IV (10), anti-dsDNA (6), low C3/C4 (3). Total ≥10 = definite SLE. First-line for mild disease: hydroxychloroquine 200-400 mg/day. For moderate-severe: mycophenolate mofetil or cyclophosphamide plus high-dose steroids.
• Venous Thromboembolism (VTE) – PE Risk Stratification: Use Wells score: clinical signs of DVT (3), PE as likely diagnosis (3), heart rate >100 (1.5), immobilisation/surgery within 4 weeks (1.5), previous DVT/PE (1.5), haemoptysis (1), cancer (1). Score >4: PE likely; do CTPA. If PE confirmed, assess severity: sBP <90 mmHg = high-risk (massive) PE, requires thrombolysis (alteplase 50 mg bolus). Non-massive: start LMWH (enoxaparin 1.5 mg/kg SC OD) and warfarin (target INR 2-3) or DOAC (apixaban 10 mg BD for 7 days, then 5 mg BD).

Common Traps in Internal Medicine Questions

• Confusing CURB-65 with qSOFA for sepsis: qSOFA uses altered mental status, RR≥22, SBP≤100, not urea or age.
• Assuming all heart failure is HFrEF: HFpEF (LVEF ≥50%) management differs, with no proven mortality benefit from ACEi/beta-blockers; treat comorbidities and diuretics.
• In DKA, forgetting to stop the insulin infusion if glucose falls below 14 mmol/L without switching to IV dextrose – leads to hypoglycaemia.
• Using fondaparinux in STEMI: it is contraindicated; use heparin or enoxaparin instead.
• In asthma, prescribing LABA without ICS – increases mortality risk; always ensure ICS is co-prescribed.
• In SLE, checking ANA alone for diagnosis: ANA positive in many conditions; require specific autoantibodies (anti-dsDNA, anti-Smith) and clinical criteria.

How to Revise Internal Medicine for the SMLE

Prioritise high-prevalence conditions: diabetes, hypertension, ischaemic heart disease, COPD, asthma, pneumonia, UTI, and anaemia. Questions often use a vignette with a single abnormal lab value (e.g., eGFR 35) and ask for the next step (e.g., refer to nephrology). Memorise key cut-offs: CURB-65 ≥3, eGFR <30, LVEF ≤40%, HbA1c ≥48 mmol/mol for diabetes, and BP targets. Practice interpreting ECGs for ACS (ST depression, T inversion) and chest X-rays for pneumonia and heart failure. Be comfortable with step-up algorithms (asthma, hypertension). Drug interactions: warfarin with antibiotics, ACEi with NSAIDs causing AKI. Time management: do not spend more than 90 seconds per question; if unsure, eliminate one wrong answer and guess.

Practise it: MedLumen has 50 Internal Medicine questions for the SMLE, each with a full explanation and references.