Neutropenic Sepsis

•    Definition: Fever ≥38°C and neutrophils <0.5 × 10⁹/L (or expected to fall)

•    Common pathogens: Gram-negative bacilli (e.g., Pseudomonas), 

                                        Gram-positive cocci (e.g., coagulase-negative staph), Candida

•    Initial management:

o    Immediate empirical broad-spectrum IV antibiotics (do not wait for cultures)

o    Example: piperacillin-tazobactam ± gentamicin

•    Avoid:

o    Rectal exams → mucosal injury → bacteraemia

o    NSAIDs → mask fever, increase renal injury risk

Spinal Cord Compression

•    Causes: vertebral metastases (breast, prostate, lung, myeloma)

•    Key features:

o    Severe back pain, worse when lying flat or with Valsalva

o    Motor weakness, sensory level

o    Urinary retention or incontinence, faecal incontinence

•    Urgent management:

o    High-dose IV dexamethasone (e.g., 16 mg/day) → reduce oedema

o    MRI entire spine urgently

o    Definitive treatment: surgical decompression or radiotherapy depending on prognosis and tumour type

Superior Vena Cava (SVC) Obstruction

•    Causes:

o    Lung cancer (especially small cell)

o    Non-Hodgkin lymphoma

o    Thrombosis (e.g., catheter-related)

•    Clinical features:

o    Facial, periorbital and upper limb swelling

o    Dyspnoea, cough, orthopnoea

o    Distended neck and chest wall veins ("collaterals")

o    Headache, dizziness (cerebral congestion)

•    Investigations:

o    CXR: widened mediastinum

o    CT thorax with contrast: assess cause, extent

•    Management:

o    Elevate head, oxygen

o    Dexamethasone to reduce tumour oedema

o    Endovascular stenting if severe symptoms

o    Definitive treatment: chemotherapy (SCLC) or radiotherapy

Tumour Lysis Syndrome (TLS)

•    At risk: high tumour burden, rapidly proliferating malignancies

o    High-grade lymphomas (e.g., Burkitt)

o    Acute leukaemias (especially ALL)

•    Biochemical features:

o    ↑ Potassium, ↑ phosphate, ↑ uric acid, ↓ calcium

•    Complications:

o    AKI (uric acid and calcium phosphate precipitation)

o    Arrhythmias, seizures

•    Prevention:

o    Vigorous IV hydration

o    Allopurinol (xanthine oxidase inhibitor) or rasburicase (urate oxidase; rapidly lowers uric acid)

•    Treatment:

o    Continue hydration

o    Correct electrolytes

o    Rasburicase if hyperuricaemia established

Hypercalcaemia of Malignancy

•    Mechanisms:

o    PTHrP secretion (squamous cell carcinoma)

o    Bone metastases (breast, myeloma)

o    Vitamin D production (lymphoma)

•    Clinical features:

o    Polyuria, polydipsia

o    Dehydration, nausea

o    Confusion, reduced consciousness

o    Arrhythmias (short QT)

•    Diagnosis: serum calcium >3.0 mmol/L often symptomatic

•    Management:

o    IV saline rehydration (restore volume, promote calciuresis)

o    IV bisphosphonates (zoledronic acid or pamidronate)

o    Consider calcitonin for rapid but temporary reduction

Key Extra Revision Points

Hyperviscosity syndrome

•    Causes:

o    Waldenström macroglobulinaemia (IgM)

o    Multiple myeloma (high IgG or IgA)

•    Clinical features:

o    Visual disturbance ("sausage link" retinal veins)

o    Headache, dizziness

o    Bleeding diathesis (impaired platelet function)

•    Treatment: plasmapheresis

SIADH (syndrome of inappropriate ADH)

•    Causes:

o    Small cell lung cancer (ectopic ADH)

o    CNS disease (e.g., stroke, trauma, infection)

o    Drugs: SSRIs, carbamazepine, cyclophosphamide

•    Features:

o    Euvolaemic hyponatraemia

o    Confusion, seizures if severe

Multiple endocrine neoplasia (MEN)

•    MEN 1 ("3 Ps"): pituitary, parathyroid, pancreatic tumours

•    MEN 2A: medullary thyroid carcinoma, phaeochromocytoma, hyperparathyroidism

•    MEN 2B: medullary thyroid carcinoma, phaeochromocytoma, mucosal neuromas, marfanoid habitus

•    Screening and prophylactic thyroidectomy often required in RET mutations

Extra Pearls

•    TLS → always check baseline uric acid and renal function before induction chemotherapy

•    Bone metastases (breast, prostate) → bisphosphonates also help reduce skeletal events

•    Hypercalcaemia → "stones, bones, groans, thrones, psychiatric overtones"