Refeeding syndrome is a life-threatening condition that can occur when severely malnourished individuals resume eating. This includes individuals with protein-energy malnutrition, eating disorders, chronic alcohol use, prolonged fasting, major surgeries, or critical illnesses. Refeeding in individuals who have physiologically adapted to malnutrition can cause severe hypophosphatemia, hypokalemia, and hypomagnesemia, and trigger thiamine deficiency syndrome. Clinical features include weakness, cardiac arrhythmias, respiratory distress, confusion, seizures, and edema. Diagnosis is based on electrolyte levels and signs of organ dysfunction caused by metabolic derangements. Management is aimed at both treatment and prevention. Measures include gradual reintroduction of nutrition, electrolyte monitoring and repletion, and treatment of complications.
- Neurological: seizures; , ataxia, encephalopathy
- Cardiovascular: arrhythmias (e.g., tachycardia, torsades de pointes, cardiac arrest; ), edema 
- Gastrointestinal: abdominal discomfort, bloating after meals 
- Musculoskeletal: : weakness, rhabdomyolysis
- See also:
Diagnostic criteria 
Diagnosis is based on the occurrence of ≥ 1 of the following within 5 days of restarting or increasing caloric intake in malnourished patients :
Tailor prevention and treatment measures to patients in collaboration with a dietician. Follow local protocols if available. 
- Before nutritional support (e.g., feeding, dextrose-containing IV solutions) 
- During nutritional support
Hypophosphatemia is the primary biochemical indicator of refeeding syndrome. 
- Vital signs
- Daily weights
- For patients at high risk (e.g., with severe electrolyte abnormalities, severe malnutrition):
Caloric intake calculation for refeeding 
Adjust existing daily caloric goals (e.g.,) according to individual patient needs and risk.
- Start with 100–150 g of dextrose OR 10–20 kcal/kg for the first 24 hours.
- Increase by 33% of the daily goal every 1–2 days.
Children and infants (ages 28 days to 18 years)
- Aim to start caloric intake at 40–50% of the daily calorie goal.
- Start dextrose at a rate of 4–6 mg/kg/minute.
- Advance by 1–2 mg/kg/minute daily as guided by blood glucose levels to a maximum of 14–18 mg/kg/minute.
Remember to include calories from maintenance IV dextrose and medications infused in dextrose solutions in daily caloric intake calculations.
Management of electrolyte disturbances 
- as needed.
- Delay increasing calories until electrolytes are corrected.
- If electrolytes are not easily corrected or levels fall significantly:
- If electrolytes remain stable with dextrose infusion over several days, consider gradually increasing calories again. 
Other nutritional support 
- Consider admission prior to initiating nutritional support.
- Administer fluid resuscitation if necessary.
- Obtain CBC, CMP, and phosphate and magnesium levels.
- Vital signs
- Daily weights
- High-risk patients
- Obtain additional diagnostics as needed, e.g., .
- Consider administering IV thiamine prior to starting nutrition or dextrose-containing IV fluids.
- Prioritize electrolyte repletion and oral or enteral nutrition.
- Treat any arising electrolyte disturbances and adjust caloric intake accordingly.
- Identify and treat complications, e.g., cardiac arrhythmias, volume overload, rhabdomyolysis.