Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 27 Aug 2026Clinical review pending
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Metabolic instability, unsafe swallowing or refeeding syndrome
Shock, severe dehydration, hypoglycaemia, aspiration, complete obstruction, uncontrolled vomiting or a new fall in phosphate, potassium or magnesium with oedema, arrhythmia, weakness, delirium or respiratory failure after feeding requires immediate treatment.
Action: Use ABCDE care, stop or reduce the precipitating feed, monitor ECG and fluid balance and replace phosphate, potassium, magnesium and thiamine through the refeeding protocol. Assess swallowing and obstruction before further oral or enteral intake and involve acute medicine, dietetics, pharmacy and the responsible oncology or palliative team urgently.
Synopsis
Detect involuntary weight and muscle loss early, distinguish cachexia from simple starvation and reversible barriers, prevent refeeding injury and align counselling, oral, enteral, parenteral, exercise and appetite treatment with cancer trajectory and patient goals.
Cancer cachexia is a multifactorial syndrome of ongoing muscle loss, with or without fat loss, that cannot be fully reversed by conventional nutrition alone.
A practical diagnostic threshold is weight loss above 5% over six months, or above 2% with BMI below 20 kg/m² or established sarcopenia, after clinical context is checked.
First-line assessment records current and usual weight, percentage and rate of loss, intake, symptoms, muscle function, inflammation, cancer trajectory and treatment intent.
Key red flags
Rapid unintentional weight loss, inability to eat for more than five days or a body mass index below 18.5 requires prompt nutrition-risk and refeeding assessment.
Unsafe swallow
Coughing, voice change, choking, prolonged meals or recurrent chest infection needs urgent speech-and-language assessment before unrestricted oral intake.
Investigation priorities
01
First-line serial weight and intake historyFirst stepFirst line
Calculate percentage and speed of unintentional loss and document actual calories, protein, fluids and barriers over time.
Management branches
Early weight lossScreen, diagnose and remove barriers
Weight, muscle, intake or function declines during cancer assessment or treatment.
Calculate loss from usual dry weight, complete validated screening and assess intake, symptoms, swallow, muscle function, inflammation, cancer stage and psychosocial access.
Treat pain, nausea, mouth disease, constipation, obstruction, infection, endocrine and pancreatic insufficiency and refer dysphagia or high-risk nutrition promptly.
Key medicines
Thiamine for high refeeding riskGive oral thiamine 200 to 300 mg daily immediately before and during the first 10 days of feeding, with a balanced multivitamin and intravenous vitamin preparation when the oral route is unavailable.
Short-course dexamethasone for appetiteFor selected patients with a short prognosis and a clear appetite or wellbeing goal, use dexamethasone 2 to 4 mg orally each morning for a brief trial and stop within one to two weeks if benefit is absent or wanes.
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.