A post-operative patient on total parenteral nutrition (TPN) develops muscle weakness, paraesthesias, and respiratory failure. Serum phosphate is 0.4 mmol/L. This is characteristic of:
- A Wernicke's encephalopathy from thiamine deficiency
- B Essential fatty acid deficiency from TPN without lipid emulsion
- C Refeeding syndrome causing hypophosphataemia ✓
- D Hypomagnesaemia from inadequate TPN supplementation
Explanation
Refeeding syndrome occurs when malnourished patients are given high-glucose TPN or enteral nutrition rapidly; insulin secretion drives phosphate, potassium, and magnesium into cells, causing severe hypophosphataemia. The hallmark is severe hypophosphataemia (<0.5 mmol/L) manifesting as muscle weakness, haemolytic anaemia, cardiac arrhythmias, and respiratory failure. Prevention involves starting nutritional support slowly and monitoring electrolytes closely. NICE guidelines recommend not exceeding 50% of estimated energy requirements for the first 2 days in at-risk patients.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.