Professional and Linguistic Assessments Board (PLAB) Medicine and Acute Care Syllabus

What scoring system is used to assess severity of community-acquired pneumonia, and what do the components stand for?

CURB-65: Confusion (AMT $\leq 8$/new disorientation), Urea $> 7$ mmol/L, Respiratory rate $\geq 30$, Blood pressure ($< 90$ systolic or $\leq 60$ diastolic), age $\geq 65$. Each scores 1; 0-1 home treatment, 2 consider hospital, $\geq 3$ severe/consider ICU.

What are the most common causative organisms of community-acquired pneumonia, and which is most common overall?

Streptococcus pneumoniae is the most common overall. Others: Haemophilus influenzae, Mycoplasma pneumoniae (atypical, younger patients), Staphylococcus aureus (often post-influenza), Legionella pneumophila (hyponatraemia, recent travel), and Chlamydophila species.

How does Light's criteria differentiate an exudative from a transudative pleural effusion?

An effusion is an exudate if any one applies: pleural/serum protein ratio $> 0.5$; pleural/serum LDH ratio $> 0.6$; or pleural LDH $>$ two-thirds the upper limit of normal serum LDH. Transudates (e.g. heart failure, hypoalbuminaemia) fail all criteria; exudates suggest infection, malignancy or inflammation.

What are the components of the Wells score for PE outcome categories, and how do PERC and D-dimer fit in?

Wells $> 4$ (PE likely) $\to$ CTPA; Wells $\leq 4$ (PE unlikely) $\to$ D-dimer, with CTPA only if positive. Items include clinical DVT signs, PE most likely diagnosis, HR $> 100$, immobilisation/surgery, prior DVT/PE, haemoptysis, and malignancy. The classic ECG finding $S_1Q_3T_3$ is uncommon; sinus tachycardia is most frequent.

What is the most common type of lung cancer overall, and which type is most strongly associated with paraneoplastic syndromes such as SIADH and ectopic ACTH?

Adenocarcinoma is the most common type overall (and commonest in non-smokers). Small cell lung cancer (SCLC) is most associated with paraneoplastic syndromes: SIADH, ectopic ACTH (Cushing's), and Lambert-Eaton myasthenic syndrome.

Which lung cancer is classically associated with hypercalcaemia via PTH-related peptide secretion?

Squamous cell carcinoma of the lung — it secretes parathyroid hormone-related peptide (PTHrP), causing hypercalcaemia. It is also associated with cavitating lesions and is typically central.

Name the occupational lung disease associated with asbestos exposure that affects the pleura, and its hallmark.

Mesothelioma — a malignancy of the pleura with a long latency (often 30-40 years) after asbestos exposure. It presents with chest pain, dyspnoea and a unilateral pleural effusion; asbestos also causes pleural plaques and asbestosis (interstitial fibrosis).

What is the characteristic HRCT and spirometry pattern of idiopathic pulmonary fibrosis (interstitial lung disease)?

HRCT shows a usual interstitial pneumonia pattern: bibasal, peripheral, subpleural reticulation with honeycombing and traction bronchiectasis. Spirometry shows a restrictive pattern: reduced FEV₁ and FVC with a preserved or increased $\text{FEV}_1/\text{FVC}$ ratio ($> 0.7$) and reduced transfer factor (TLCO).

What is the immediate management of a haemodynamically unstable patient with an acute upper GI bleed?

ABCDE resuscitation: two large-bore cannulae, fluid/blood resuscitation, correct coagulopathy, and use the Blatchford score to assess risk. Urgent endoscopy within 24 hours (immediately after resuscitation if unstable). For variceal bleeds add terlipressin and prophylactic antibiotics.

What scoring systems are used before and after endoscopy in upper GI bleeding?

Glasgow-Blatchford score (pre-endoscopy) assesses need for intervention/admission — a score of 0 may allow outpatient management. The full Rockall score (post-endoscopy) estimates the risk of rebleeding and mortality.

Compare the typical distribution and histological features of ulcerative colitis versus Crohn's disease.

Ulcerative colitis: continuous inflammation from the rectum proximally, limited to the colon, mucosa/submucosa only, with crypt abscesses and no granulomas. Crohn's disease: skip lesions anywhere mouth-to-anus, transmural inflammation, non-caseating granulomas, and a cobblestone appearance; associated with fistulae and strictures.

What is the first-line investigation and a characteristic blood finding in autoimmune (chronic) liver disease screening?

Liver screen autoantibodies: anti-mitochondrial antibody (AMA) for primary biliary cholangitis; anti-smooth muscle and anti-LKM antibodies for autoimmune hepatitis; raised IgG in autoimmune hepatitis and raised IgM with AMA in PBC. ANCA (pANCA) and MRCP (beaded ducts) suggest primary sclerosing cholangitis.

What scoring systems quantify the severity and prognosis of liver cirrhosis?

Child-Pugh score uses bilirubin, albumin, INR, ascites and encephalopathy to grade A-C. MELD score uses bilirubin, INR and creatinine (and sodium in MELD-Na) to predict mortality and prioritise transplantation.

What is the gold-standard scoring system for acute pancreatitis severity, and name common causes via the mnemonic.

The Glasgow (or modified Glasgow/Imrie) and APACHE II scores assess severity. Causes — 'I GET SMASHED': Idiopathic, Gallstones, Ethanol, Trauma, Steroids, Mumps, Autoimmune, Scorpion sting, Hypercalcaemia/Hypertriglyceridaemia, ERCP, Drugs. Gallstones and alcohol are the two commonest.

What constitutes Charcot's triad and Reynolds' pentad in biliary disease?

Charcot's triad (ascending cholangitis): right upper quadrant pain, fever/rigors, and jaundice. Reynolds' pentad adds hypotension (shock) and confusion (altered mental status), indicating severe suppurative cholangitis requiring urgent biliary decompression.

What are the Rome IV diagnostic criteria principles for irritable bowel syndrome (functional GI disorder)?

Recurrent abdominal pain on average $\geq 1$ day/week in the last 3 months (onset $\geq 6$ months prior), associated with $\geq 2$ of: pain related to defecation, change in stool frequency, or change in stool form/appearance. It is a positive diagnosis after excluding red flags (weight loss, bleeding, anaemia).

Which gene mutations and screening pathway are central to hereditary colorectal cancer syndromes?

Familial adenomatous polyposis (FAP): APC gene mutation, hundreds of polyps, near-100% cancer risk. Lynch syndrome (HNPCC): DNA mismatch repair gene mutations (MLH1, MSH2 etc.) causing microsatellite instability and right-sided tumours. The UK uses faecal immunochemical testing (FIT) for screening/symptomatic triage.

How does the typical presentation of right-sided versus left-sided colorectal cancer differ?

Right-sided (caecum/ascending): iron-deficiency anaemia, weight loss, occult bleeding, and a palpable mass — often presents late. Left-sided (descending/sigmoid/rectum): change in bowel habit, PR bleeding/blood mixed with stool, tenesmus, and obstruction.

What are the KDIGO criteria for diagnosing acute kidney injury (AKI)?

Any of: rise in serum creatinine $\geq 26 \, \mu\text{mol/L}$ within 48 hours; rise in creatinine $\geq 1.5\times$ baseline within 7 days; or urine output $< 0.5 \, \text{mL/kg/h}$ for $> 6$ hours. Causes are classified as pre-renal, intrinsic (renal), and post-renal (obstructive).

What ECG changes and emergency treatment are associated with severe hyperkalaemia in AKI?

ECG: tall tented T waves, then flattened/absent P waves, broad QRS, and eventually a sine-wave pattern. Emergency treatment: IV calcium gluconate (cardiac membrane stabilisation), then insulin with dextrose and nebulised salbutamol to shift potassium into cells; treat the underlying cause.

How is chronic kidney disease staged using eGFR and albuminuria (the G and A categories)?

G stages by eGFR (mL/min/1.73m²): G1 $\geq 90$, G2 60-89, G3a 45-59, G3b 30-44, G4 15-29, G5 $< 15$. A stages by albumin:creatinine ratio (mg/mmol): A1 $< 3$, A2 3-30, A3 $> 30$. CKD requires abnormalities present for $> 3$ months.

What are the diagnostic glucose thresholds for diabetes mellitus and the role of HbA1c?

Diabetes: fasting glucose $\geq 7.0$ mmol/L, random/2-hour OGTT glucose $\geq 11.1$ mmol/L, or $\text{HbA1c} \geq 48$ mmol/mol (6.5%). In asymptomatic patients two abnormal results are required. HbA1c reflects average glycaemia over $\approx$ 2-3 months.

What biochemical features define diabetic ketoacidosis (DKA) and its key management steps?

Diagnostic triad: blood glucose $> 11$ mmol/L (or known diabetes), ketonaemia $\geq 3$ mmol/L (or ketonuria $\geq 2+$), and acidosis with $\text{pH} < 7.3$ or bicarbonate $< 15$ mmol/L. Management: IV 0.9% saline fluid resuscitation first, then fixed-rate insulin infusion, careful potassium replacement, and treat the precipitant.

Contrast the typical thyroid function test results in primary hypothyroidism and primary hyperthyroidism.

Primary hypothyroidism: high TSH with low free T4 (e.g. Hashimoto's, anti-TPO antibodies). Primary hyperthyroidism: low/suppressed TSH with high free T4 and/or T3 (e.g. Graves' disease, TSH-receptor antibodies). In secondary (pituitary) disease TSH is inappropriately normal/low with low T4.

What is the classic biochemistry of Addison's disease (primary adrenal insufficiency), and what test confirms it?

Hyponatraemia, hyperkalaemia, hypoglycaemia, and metabolic acidosis, often with raised ACTH and skin hyperpigmentation. The short Synacthen (ACTH stimulation) test confirms it: cortisol fails to rise adequately after synthetic ACTH. An Addisonian crisis is treated with IV hydrocortisone and fluids.

How are the causes of hyponatraemia classified by volume status?

Hypovolaemic: D&V, diuretics, Addison's (renal/extra-renal sodium loss). Euvolaemic: SIADH (urine osmolality high, urine sodium $> 20$), hypothyroidism, glucocorticoid deficiency. Hypervolaemic: heart failure, cirrhosis, nephrotic syndrome, renal failure. Urine osmolality and urine sodium help localise the cause.

How do you classify a metabolic acidosis using the anion gap, and what is the formula?

Anion gap $= [\text{Na}^+] - ([\text{Cl}^-] + [\text{HCO}_3^-])$ (normal $\approx 8-12$ mmol/L). Raised anion gap acidosis (MUDPILES: methanol, uraemia, DKA, lactate etc.) reflects added acid; normal anion gap (hyperchloraemic) acidosis reflects bicarbonate loss (diarrhoea, renal tubular acidosis).

What time-critical assessment tool is used in suspected acute stroke, and what is the thrombolysis window?

FAST (Face, Arm, Speech, Time) in the community and ROSIER in hospital. After excluding haemorrhage with a non-contrast CT head, IV thrombolysis (alteplase/tenecteplase) is given within 4.5 hours of symptom onset; mechanical thrombectomy is considered for large-vessel occlusion up to 24 hours in selected patients.

What features differentiate the most common primary headache disorders: migraine, tension-type and cluster headache?

Migraine: unilateral, throbbing, 4-72 hours, with nausea, photophobia/phonophobia $\pm$ aura. Tension-type: bilateral, pressing/tight, non-pulsatile, no significant nausea. Cluster: severe unilateral periorbital pain in clusters, 15-180 minutes, with ipsilateral autonomic features (lacrimation, rhinorrhoea, ptosis) and restlessness.

What is the definition of status epilepticus and its first-line emergency management?

A seizure lasting $\geq 5$ minutes, or repeated seizures without recovery of consciousness in between. Management: ABCDE, oxygen, check glucose; first-line is IV lorazepam (or buccal midazolam/PR diazepam in the community), repeated once; second-line IV levetiracetam, phenytoin or valproate; then general anaesthesia/ICU if refractory.

What are the key clinical and CSF findings that distinguish bacterial from viral meningitis?

Bacterial: cloudy/turbid CSF, high neutrophils (polymorphs), high protein, low glucose (CSF:serum ratio $< 0.4$ to $0.6$), high opening pressure. Viral: clear CSF, lymphocytosis, normal/mildly raised protein, and normal glucose. Give empirical IV ceftriaxone immediately for suspected bacterial meningitis (plus dexamethasone).

What are the components of the Glasgow Coma Scale and the score that defines the need for airway protection?

Eye opening (max 4), Verbal response (max 5), Motor response (max 6); total range 3-15. A GCS $\leq 8$ indicates a significantly reduced conscious level and usually warrants definitive airway protection (intubation).

What is the qSOFA score, and what threshold indicates a high risk of poor outcome in suspected sepsis?

qSOFA (quick SOFA) uses: respiratory rate $\geq 22$/min, altered mentation (GCS $< 15$), and systolic BP $\leq 100$ mmHg. A score $\geq 2$ identifies patients at higher risk of mortality and prompts escalation. Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection.

What are the elements of the 'Sepsis Six' bundle to be delivered within the first hour?

Three IN: high-flow oxygen, IV broad-spectrum antibiotics, IV fluid resuscitation. Three OUT (measure): blood cultures (before antibiotics), serum lactate, and urine output (monitor hourly). The bundle aims to be completed within 1 hour of recognising sepsis.

What movement disorder features define Parkinson's disease, and what is the underlying pathology?

The classic triad: bradykinesia, resting (pill-rolling) tremor at $\approx 4-6$ Hz, and rigidity (cogwheel/lead-pipe), often with postural instability and asymmetric onset. Pathology: loss of dopaminergic neurones in the substantia nigra pars compacta with Lewy bodies; treated with levodopa/carbidopa.

What distinguishes a transient ischaemic attack (TIA) from a stroke, and how is early stroke risk managed?

A TIA is a transient neurological deficit of vascular origin without acute infarction (clinically resolves, typically within minutes-hours, fully within 24 hours); a stroke causes infarction/permanent injury. Give aspirin 300 mg immediately and refer for specialist assessment within 24 hours; the ABCD2 score historically estimated short-term stroke risk.

What antibody and electrophysiological features characterise myasthenia gravis (a neuromuscular disorder)?

Anti-acetylcholine receptor antibodies (anti-AChR), or anti-MuSK antibodies in seronegative cases. It causes fatigable weakness worsening with activity (ptosis, diplopia, bulbar/limb weakness). Repetitive nerve stimulation shows a decremental response; treated with pyridostigmine and immunosuppression. Associated with thymoma/thymic hyperplasia.

How is the severity and reversibility of asthma versus COPD distinguished on spirometry and clinical features?

Asthma: variable, reversible obstruction — $\text{FEV}_1$ improves $\geq 12\%$ (and $\geq 200$ mL) after bronchodilator, with diurnal PEF variability and atopy; often younger, non-smokers. COPD: largely fixed/irreversible obstruction ($\text{FEV}_1/\text{FVC} < 0.7$ post-bronchodilator), in older smokers with progressive dyspnoea and minimal reversibility.

What ECG features and management define ventricular fibrillation in a peri-arrest arrhythmia setting?

VF: chaotic, irregular waveform with no identifiable QRS complexes and no cardiac output — a shockable rhythm. Management per ALS: immediate unsynchronised defibrillation, high-quality CPR (30:2 or continuous with advanced airway), adrenaline 1 mg every 3-5 minutes, and amiodarone 300 mg after the third shock.

What is the cardiac biomarker of choice in ACS, and how should serial troponin be interpreted?

High-sensitivity cardiac troponin (T or I). A rise and/or fall on serial sampling (e.g. at 0 and 3 hours) above the 99th percentile, in an appropriate clinical context, supports myocardial infarction. Troponin can be chronically elevated in CKD, sepsis, PE and heart failure, so the dynamic change is key.

What clinical and biochemical features characterise a thyroid storm (thyrotoxic crisis), and its initial management?

Severe hyperthyroidism with fever, tachyarrhythmia/AF, agitation/delirium, heart failure and GI upset. Management: beta-blocker (propranolol) for symptoms, a thionamide (propylthiouracil/carbimazole) to block synthesis, Lugol's iodine $\geq 1$ hour later to block release, and hydrocortisone (blocks T4$\to$T3 conversion); treat the precipitant.

What is the difference between type 1 and type 2 respiratory failure on arterial blood gas?

Type 1: hypoxaemia ($\text{PaO}_2 < 8$ kPa) with normal or low $\text{PaCO}_2$ — a V/Q mismatch problem (e.g. pneumonia, PE, pulmonary oedema). Type 2: hypoxaemia with hypercapnia ($\text{PaCO}_2 > 6$ kPa) — alveolar hypoventilation (e.g. COPD, neuromuscular disease, opioid toxicity).

What features suggest a subarachnoid haemorrhage as a cause of headache, and how is it investigated?

Sudden-onset 'thunderclap' headache peaking within seconds ('worst headache of life'), $\pm$ neck stiffness, photophobia, vomiting and reduced consciousness. Investigate with urgent non-contrast CT head; if negative and done $> 6$ hours after onset, perform a lumbar puncture looking for xanthochromia (bilirubin from RBC breakdown).

How is the cause of jaundice classified, and what bilirubin/urine findings localise it?

Pre-hepatic (haemolysis): unconjugated hyperbilirubinaemia, normal urine, raised LDH/reticulocytes. Hepatic: mixed picture with raised transaminases. Post-hepatic (obstructive/cholestatic): conjugated hyperbilirubinaemia, dark urine, pale stools, raised ALP and GGT, and pruritus.

What is the corrected calcium formula, and what symptoms and ECG change accompany hypercalcaemia?

Corrected calcium $= \text{measured Ca}^{2+} + 0.02 \times (40 - \text{albumin in g/L})$. Symptoms: 'stones, bones, groans, and psychic moans' — renal stones, bone pain, abdominal pain/constipation, polyuria, confusion. ECG shows a shortened QT interval; managed with IV fluids $\pm$ bisphosphonates.