Master CPS - Infectious Disease/Haematology
for MSRA

What the MSRA Tests in CPS - Infectious Disease/Haematology

This exam tests the ability to manage common infectious disease and haematology presentations in primary care and emergency settings, with emphasis on recognition of serious pathology (e.g., sepsis, meningitis, neutropenic sepsis, sickle cell crisis) and appropriate use of investigations (FBC, blood film, coagulation screen, CRP, procalcitonin, blood cultures, lumbar puncture). Candidates must know UK guidelines for antibiotic prescribing (e.g., NICE for pneumonia, UTIs, cellulitis), vaccination schedules, and management of HIV, TB, and hepatitis. In haematology, focus is on anaemia (iron, B12, folate, haemolytic), clotting disorders (DVT/PE, ITP, DIC, haemophilia), and haematological malignancies (leukaemia, lymphoma, myeloma) including red flag symptoms and first-line treatments. Decision-making about when to refer, start anticoagulation, or give blood products is critical.

High-Yield Concepts

• Sepsis recognition and management: Use NEWS2 score ≥5 triggers sepsis screening. For sepsis with suspected source, give IV broad-spectrum antibiotics within 1 hour (e.g., piperacillin-tazobactam if hospital-acquired; ceftriaxone if community-acquired). Lactate >2 mmol/L indicates tissue hypoperfusion; give 30 mL/kg crystalloid bolus if lactate >4 or hypotensive.
• Meningitis and meningococcal disease: Classic triad: fever, neck stiffness, altered consciousness. Petechial/purpuric rash suggests meningococcal sepsis. Give IV ceftriaxone 2 g (or cefotaxime) immediately before CT if no delay. Dexamethasone 10 mg IV before or with first antibiotic dose if suspected bacterial meningitis. Do not perform lumbar puncture if signs of raised ICP (papilloedema, focal neurology, GCS <13).
• Community-acquired pneumonia (CAP) severity assessment: Use CURB-65: Confusion (AMTS ≤8), Urea >7 mmol/L, RR ≥30, BP <90/60, age ≥65. Score 0-1: home oral amoxicillin 500 mg TDS (or doxycycline if penicillin-allergic). Score 2: consider hospital admission, oral or IV antibiotics. Score ≥3: severe CAP, admit, IV co-amoxiclav + clarithromycin (or levofloxacin if penicillin-allergic).
• Neutropenic sepsis: Temperature ≥38°C in patient with neutrophil count <0.5 x10^9/L. Immediate IV piperacillin-tazobactam (or meropenem if severe penicillin allergy) within 1 hour. Take blood cultures, start empirical antifungal if persistent fever >96 hours. G-CSF not routinely recommended unless predicted prolonged neutropenia.
• Deep vein thrombosis (DVT) and pulmonary embolism (PE): Use Wells score for DVT (≥2 points likely) and PE (≥4 points likely). If likely, request D-dimer (age-adjusted: age x 0.1 mg/L if >50 years) and proximal leg ultrasound or CTPA. First-line treatment: DOAC (apixaban 10 mg BD for 7 days then 5 mg BD, or rivaroxaban 15 mg BD for 21 days then 20 mg OD) unless cancer-associated (then LMWH).
• Iron deficiency anaemia (IDA): Microcytic hypochromic anaemia with low ferritin (<30 ng/mL). Check for GI source: coeliac serology, upper and lower GI endoscopy if no obvious cause (especially men and postmenopausal women). Treatment: oral ferrous sulfate 200 mg OD (or ferrous fumarate) for 3 months; recheck FBC and ferritin. IV iron (ferric carboxymaltose) if intolerance, non-adherence, or severe anaemia.
• Immune thrombocytopenia (ITP): Isolated thrombocytopenia (<100 x10^9/L) with normal WBC and Hb. Exclude drug-induced, HIV, HCV, SLE. First-line: prednisolone 1 mg/kg OD for 2-4 weeks then taper. If bleeding or platelet <10-20 x10^9/L, consider IVIG 1 g/kg. Second-line: thrombopoietin receptor agonists (eltrombopag, romiplostim) or rituximab.
• Multiple myeloma – CRAB criteria and first-line treatment: CRAB: hyperCalcaemia (corrected Ca >2.75 mmol/L), Renal impairment (creatinine >177 μmol/L), Anaemia (Hb <100 g/L), Bone lesions (lytic on XR/MRI). Diagnosis: serum/urine protein electrophoresis, free light chains, bone marrow biopsy with >10% plasma cells. First-line for transplant-eligible: bortezomib + cyclophosphamide + dexamethasone (VCD). For non-eligible: lenalidomide + low-dose dexamethasone (Rd).

Common Traps in CPS - Infectious Disease/Haematology Questions

• Starting antibiotics before blood cultures in sepsis without delaying care – cultures should be taken before antibiotics but antibiotics must not be delayed beyond 1 hour.
• Using D-dimer without pre-test probability scoring – D-dimer is only useful if Wells score is 'likely' or 'unlikely' (low specificity in hospitalised patients).
• Forgetting to check ferritin in microcytic anaemia – low ferritin is diagnostic for IDA; normal/high ferritin suggests anaemia of chronic disease or thalassaemia trait.
• Not giving dexamethasone with first dose of antibiotics in suspected bacterial meningitis – this reduces neurological sequelae and must be given before or with the first antibiotic.
• Assuming a normal INR excludes DIC – DIC can present with normal INR early; look for thrombocytopenia, prolonged APTT, elevated D-dimer, and low fibrinogen.
• Treating suspected neutropenic sepsis with oral antibiotics – all febrile neutropenic patients require IV broad-spectrum antibiotics within 1 hour.

How to Revise CPS - Infectious Disease/Haematology for the MSRA

Prioritise memorising CURB-65, Wells criteria, NEWS2 thresholds, and first-line antibiotic choices for common infections (CAP, UTI, cellulitis, meningitis). Practice applying these scores to clinical vignettes, especially deciding admission vs. home management. For haematology, focus on differentiating microcytic anaemias (IDA vs. thalassaemia trait vs. ACD) using ferritin and HbA2, and knowing when to start anticoagulation for VTE (including DOAC dosing). Questions often present as 'best next step' or 'most appropriate management' – avoid over-investigating. Review NICE guidelines for suspected cancer (NG12) regarding myeloma and lymphoma red flags. Practise interpreting FBC and coagulation results quickly.

Practise it: MedLumen has 50 CPS - Infectious Disease/Haematology questions for the MSRA, each with a full explanation and references.