MRCPI GM Part I cheat sheet

STEMI reperfusion: primary PCI is preferred if symptoms are within 12 hours and PCI can be delivered within 120 minutes of first medical contact; fibrinolysis is used when timely PCI is unavailable and there is no contraindication.

Atrial fibrillation anticoagulation: CHA2DS2-VASc ≥2 in men or ≥3 in women supports oral anticoagulation; score components are congestive heart failure, hypertension, age ≥75 (2 points), diabetes, stroke/TIA (2 points), vascular disease, age 65–74, and female sex.

Heart failure with reduced ejection fraction foundational therapy: ARNI or ACE inhibitor plus beta-blocker plus mineralocorticoid receptor antagonist plus SGLT2 inhibitor.

Severe aortic stenosis: peak jet velocity ≥4 m/s, mean gradient ≥40 mmHg, or aortic valve area <1.0 cm²; symptomatic severe stenosis warrants aortic valve replacement.

Acute pericarditis diagnosis requires at least 2 of 4 features: pericarditic chest pain, friction rub, widespread ST elevation or PR depression, and new or worsening pericardial effusion.

Hypertrophic cardiomyopathy murmur: systolic murmur increases with Valsalva manoeuvre and standing and decreases with squatting and handgrip.

Infective endocarditis: modified Duke criteria are used; obtain three sets of blood cultures before antibiotics and perform transoesophageal echocardiography when transthoracic imaging is non-diagnostic or suspicion is high.

Long QT syndrome: QTc >500 ms indicates high risk; avoid QT-prolonging drugs and correct hypokalaemia, hypomagnesaemia, and hypocalcaemia.

Asthma reversibility: post-bronchodilator FEV1 increase ≥12% and ≥200 mL supports the diagnosis in the appropriate clinical setting.

COPD: post-bronchodilator FEV1/FVC <0.70 confirms persistent airflow obstruction; severity is graded by FEV1 percent predicted.

CURB-65: confusion, urea >7 mmol/L, respiratory rate ≥30/min, systolic BP <90 mmHg or diastolic ≤60 mmHg, and age ≥65; score ≥2 suggests hospital admission.

Pulmonary embolism: Wells score guides pretest probability; age-adjusted D-dimer threshold is age × 10 µg/L for patients over 50; high-risk PE with shock is treated with thrombolysis.

Light criteria for exudative pleural fluid: protein ratio >0.5, LDH ratio >0.6, or pleural LDH > two-thirds the serum upper limit of normal.

Winter's formula for metabolic acidosis: expected PaCO2 = 1.5 × bicarbonate + 8 ± 2.

Obstructive sleep apnoea: apnoea-hypopnoea index ≥5 with symptoms or ≥15 without symptoms defines clinically significant disease.

Sarcoidosis: bilateral hilar lymphadenopathy and non-caseating granulomas are characteristic; serum ACE is supportive but not diagnostic.

Ascites: serum-ascites albumin gradient ≥11 g/L indicates portal hypertension; <11 g/L suggests non-portal causes such as peritoneal carcinomatosis, tuberculosis, or pancreatitis.

Spontaneous bacterial peritonitis: ascitic polymorphonuclear cell count ≥250/mm³ establishes the diagnosis; treat with a third-generation cephalosporin and add albumin when renal impairment is present.

Upper gastrointestinal bleeding: Glasgow-Blatchford score predicts need for clinical intervention; Rockall score predicts mortality.

Coeliac disease: check anti-tissue transglutaminase IgA together with total IgA, then confirm with duodenal biopsies while on a gluten-containing diet.

Wilson disease: low ceruloplasmin, Kayser-Fleischer rings, and high urinary copper support the diagnosis.

Primary biliary cholangitis: cholestatic liver enzymes with positive antimitochondrial antibodies; ursodeoxycholic acid is first-line therapy.

Acute pancreatitis: lipase >3 times the upper limit of normal supports diagnosis; Atlanta criteria classify severity and guide fluid resuscitation.

Hepatorenal syndrome: functional renal failure in cirrhosis is treated with terlipressin plus albumin.

Diabetic ketoacidosis: glucose >11 mmol/L, ketonaemia or ketonuria, pH <7.3 or bicarbonate <15 mmol/L; treat with fluids, insulin infusion, and potassium replacement.

Hyperosmolar hyperglycaemic state: glucose >30 mmol/L, osmolality >320 mOsm/kg, minimal ketosis, and profound dehydration.

Primary thyroid dysfunction: low TSH with high free T4 indicates primary hyperthyroidism; high TSH with low free T4 indicates primary hypothyroidism.

Thyroid storm: Burch-Wartofsky score supports diagnosis; give beta-blocker, thionamide, glucocorticoid, and iodine at least one hour after the thionamide.

Adrenal crisis: hypotension, hyponatraemia, and hyperkalaemia require immediate intravenous hydrocortisone and fluid resuscitation without waiting for confirmatory tests.

Primary hyperaldosteronism: elevated aldosterone-to-renin ratio with hypokalaemia; confirm with saline suppression or captopril challenge.

Acromegaly: screen with IGF-1; confirm with failure of GH suppression during an oral glucose tolerance test.

Corrected calcium (mmol/L) = measured calcium + 0.02 × (40 − albumin g/L).

KDIGO acute kidney injury: creatinine rise ≥26.5 µmol/L within 48 hours, ≥1.5 times baseline within 7 days, or urine output <0.5 mL/kg/h for 6 hours.

Hyperkalaemia with ECG changes: give intravenous calcium gluconate first to stabilise the myocardium, then insulin-dextrose, salbutamol, and definitive potassium removal.

SIADH: euvolemic hyponatraemia with urine osmolality >100 mOsm/kg and urine sodium >30 mmol/L in the absence of diuretics or renal disease.

Nephrotic syndrome: proteinuria >3.5 g/day, albumin <30 g/L, and oedema; hyperlipidaemia is common and thrombosis is a major complication.

Nephritic syndrome: haematuria with red cell casts, hypertension, oliguria, and variable proteinuria.

CKD eGFR stages: G1 ≥90, G2 60–89, G3a 45–59, G3b 30–44, G4 15–29, G5 <15 mL/min/1.73 m².

Serum anion gap = sodium − (chloride + bicarbonate); normal is 8–12 mmol/L, and a raised gap suggests ketoacidosis, lactic acidosis, renal failure, or toxins.

Dialysis indications: refractory acidosis, electrolyte disturbance such as hyperkalaemia, intoxication, fluid overload, and uraemic complications (AEIOU).

Ischaemic stroke: intravenous thrombolysis is indicated within 4.5 hours of onset after excluding haemorrhage; selected patients may undergo thrombectomy up to 24 hours.

Bacterial meningitis CSF: neutrophil-predominant pleocytosis, low glucose with CSF/serum ratio <0.4, and high protein; give empiric antibiotics and dexamethasone promptly.

Status epilepticus: a benzodiazepine is first-line, followed by levetiracetam, valproate, or phenytoin if seizures persist.

Myasthenia gravis: fatigable weakness, anti-acetylcholine receptor antibodies, and decrement on repetitive nerve stimulation; crisis requires respiratory monitoring.

Guillain-Barré syndrome: ascending symmetrical weakness with areflexia and albuminocytologic dissociation; treat with intravenous immunoglobulin or plasma exchange.

Parkinson disease: resting tremor, bradykinesia, and rigidity; levodopa is the most effective symptomatic treatment.

Multiple sclerosis: dissemination in space and time on MRI; CSF oligoclonal bands support diagnosis.

Subarachnoid haemorrhage: thunderclap headache; CT is highly sensitive within 6 hours, and lumbar puncture may show xanthochromia if CT is negative.

Gout: needle-shaped monosodium urate crystals with negative birefringence; acute attacks are treated with NSAIDs, colchicine, or intra-articular glucocorticoid.

Pseudogout: rhomboid calcium pyrophosphate crystals with positive birefringence.

Rheumatoid arthritis: symmetrical small-joint synovitis with anti-CCP and rheumatoid factor; methotrexate is the anchor disease-modifying drug.

Systemic lupus erythematosus: ANA is sensitive; anti-dsDNA and anti-Sm are specific, and complement levels are often low in active disease.

Giant cell arteritis: age >50 years with new headache, jaw claudication, visual symptoms, and raised ESR/CRP; start high-dose glucocorticoid immediately.

Polymyalgia rheumatica: shoulder and hip girdle pain with raised ESR/CRP and rapid response to low-dose glucocorticoid.

Ankylosing spondylitis: HLA-B27 association, sacroiliitis, inflammatory back pain, and morning stiffness.

Osteoporosis: dual-energy X-ray absorptiometry T-score ≤ −2.5 defines osteoporosis; FRAX estimates fracture risk.

Iron deficiency: low serum ferritin with microcytic hypochromic anaemia; ferritin is an acute-phase reactant, so a normal value does not exclude deficiency in inflammation.

Vitamin B12 deficiency: macrocytic anaemia with raised methylmalonic acid and homocysteine; neurological features may occur without anaemia.

Chronic myeloid leukaemia: Philadelphia chromosome t(9;22) produces BCR-ABL1; tyrosine kinase inhibitors such as imatinib are highly effective.

Acute myeloid leukaemia: myeloblasts with Auer rods; urgent haematology referral and induction chemotherapy are required.

Hodgkin lymphoma: Reed-Sternberg cells with B symptoms of fever, night sweats, and weight loss.

Disseminated intravascular coagulation: prolonged PT/APTT, thrombocytopenia, low fibrinogen, and raised D-dimer.

Thrombotic thrombocytopenic purpura: ADAMTS13 deficiency causes microangiopathic haemolytic anaemia and thrombocytopenia; urgent plasma exchange is life-saving.

Heparin-induced thrombocytopenia: platelet fall >50% at 5–10 days with thrombosis; stop heparin and start a non-heparin anticoagulant.

Sepsis: measure lactate, obtain blood cultures before antibiotics, give broad-spectrum antibiotics within 1 hour for septic shock, and give 30 mL/kg crystalloid for hypotension or lactate ≥4 mmol/L.

Drug-sensitive tuberculosis: rifampicin, isoniazid, pyrazinamide, and ethambutol for 2 months, followed by rifampicin and isoniazid for 4 months.

HIV with CD4 <200 cells/µL: co-trimoxazole prophylaxis against Pneumocystis jirovecii pneumonia.

Severe falciparum malaria: intravenous artesunate is first-line treatment.

Clostridioides difficile infection: stop precipitating antibiotics and treat with oral vancomycin or fidaxomicin.

Meningococcal disease: close contacts receive prophylaxis with rifampicin or ciprofloxacin.

Needlestick HIV exposure: start post-exposure prophylaxis as soon as possible and within 72 hours.

Hepatitis B exposure: post-exposure management includes hepatitis B vaccination and hepatitis B immunoglobulin when indicated.

CYP enzyme inducers include rifampicin, carbamazepine, phenytoin, and St John's wort; they reduce concentrations of many co-administered drugs such as warfarin and oral contraceptives.

CYP enzyme inhibitors include macrolides, azole antifungals, ritonavir, and grapefruit; they increase concentrations of CYP-metabolised drugs.

Warfarin major bleeding: give intravenous vitamin K plus prothrombin complex concentrate for rapid reversal.

Digoxin toxicity: nausea, visual disturbance, and bradyarrhythmia; digoxin-specific antibody fragments are used for severe toxicity.

Lithium: narrow therapeutic range around 0.6–0.8 mmol/L; toxicity causes tremor, ataxia, and confusion and is precipitated by NSAIDs, thiazides, and dehydration.

ACE inhibitors: cough, angioedema, hyperkalaemia, and acute kidney injury are key adverse effects.

Aminoglycosides: nephrotoxicity and ototoxicity require dose adjustment and therapeutic drug monitoring.

Paracetamol overdose: N-acetylcysteine replenishes glutathione and is most effective within 8 hours; the Rumack-Matthew nomogram guides treatment after acute single overdose.

Delirium: acute fluctuating attention and cognition; the 4AT is a rapid screening tool, and precipitants such as infection, drugs, pain, constipation, and urinary retention must be identified.

Falls in older adults: multifactorial assessment includes medication review, vision, gait and balance, postural blood pressure, and home hazards.

Dementia: Alzheimer disease is the most common cause; MMSE and MoCA are cognitive screening tools and do not themselves establish aetiology.

Beers criteria: identify potentially inappropriate medications in older adults, including long-acting benzodiazepines, anticholinergics, and NSAIDs.

Frailty phenotype: unintentional weight loss, exhaustion, low physical activity, slow gait speed, and weakness.

Older adult hypertension: target <150/90 mmHg for many patients aged ≥80 years and <140/90 mmHg if tolerated, with individualisation in frailty.

Urinary incontinence types: stress, urge, overflow, and functional incontinence have different mechanisms and management.

Polypharmacy: anticholinergic burden and drug–drug interactions increase falls, confusion, and hospital admission risk.

Sensitivity is the proportion of diseased people correctly identified; specificity is the proportion of non-diseased people correctly identified; both are independent of disease prevalence.

Positive likelihood ratio = sensitivity/(1 − specificity); negative likelihood ratio = (1 − sensitivity)/specificity.

Number needed to treat = 1/absolute risk reduction; number needed to harm = 1/absolute risk increase.

Hardy-Weinberg equilibrium: p² + 2pq + q² = 1 in large random-mating populations without selection, mutation, or migration.

Autosomal dominant inheritance is typically vertical across generations; autosomal recessive is often horizontal among siblings; mitochondrial inheritance is maternal.

Hypersensitivity types: I IgE-mediated, II antibody-mediated, III immune-complex-mediated, and IV T-cell-mediated delayed hypersensitivity.

A p-value is the probability of observing data at least as extreme as those obtained if the null hypothesis is true; it is not the probability that the null hypothesis is true.

Odds ratio is used in case-control studies; it approximates relative risk when the outcome is rare.