Summary
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.
Etiology
Risk factors
Underlying medical conditions [1][2]
- Protein-energy malnutrition
- Eating disorders causing severe malnutrition (see “Malnutrition severity for eating disorders”)
- Alcohol use disorder
- Dysphagia, esophageal motility disorders
- Malabsorption, maldigestion
- Cancer
- Postoperative complications, post bariatric surgery
- AIDS
- Electrolyte abnormalities prior to refeeding
- Failure to thrive
- Hyperemesis gravidarum
Other risk factors [1][2]
- Food insecurity
- Prolonged fasting
- Misuse of laxatives, diuretics, or insulin
Pathophysiology
Clinical features
- Neurological: seizures; , ataxia, encephalopathy
- Cardiovascular: arrhythmias (e.g., tachycardia, torsades de pointes, cardiac arrest; ), edema [4]
- Gastrointestinal: abdominal discomfort, bloating after meals [4]
- Musculoskeletal: : weakness, rhabdomyolysis
- See also:
Diagnostics
Routine studies
- CBC
- CMP
- Phosphorus levels
- Magnesium levels
- Workup of the underlying disorder, e.g., diagnostics for eating disorders
Diagnostic criteria [1]
Diagnosis is based on the occurrence of ≥ 1 of the following within 5 days of restarting or increasing caloric intake in malnourished patients :
- Hypophosphatemia
- Hypokalemia
- Hypomagnesemia
- Organ dysfunction due to the above electrolyte deficiencies and/or thiamine deficiency
Management
Tailor prevention and treatment measures to patients in collaboration with a dietician. Follow local protocols if available. [1][2][4]
Approach [1][2][4]
-
Before nutritional support (e.g., feeding, dextrose-containing IV solutions) [1]
- Consider hospital admission for stabilization, e.g., volume and electrolyte repletion.
- Consider starting IV thiamine to prevent Wernicke encephalopathy. [1]
-
During nutritional support
- Use the oral or enteral route for feeding and electrolyte repletion as much as possible.
- Calculate caloric intake for refeeding based on patient age, weight, and risk profile.
- Treat any features of refeeding syndrome that may occur, e.g., phosphate repletion, potassium repletion, magnesium repletion, thiamine deficiency.
- Identify and treat complications, e.g., volume overload, arrhythmias, rhabdomyolysis.
Avoid aggressive IV fluid resuscitation in patients at risk of refeeding syndrome to prevent volume overload and third spacing. [2][4]
Monitoring [1]
- Vital signs
- Input/output monitoring
- Volume status assessment
- Daily weights
- Changes in mental status
- For patients at high risk (e.g., with severe electrolyte abnormalities, severe malnutrition):
- Obtain ECG.
- Consider hemodynamic monitoring.
- Measure serum glucose and electrolytes every 12 hours for the first 72 hours. [2]
Caloric intake calculation for refeeding [1]
Adjust existing daily caloric goals (e.g., nutritional goals for anorexia nervosa) according to individual patient needs and risk.
-
Adults
- 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 [1]
- Replete serum electrolytes as needed.
- Delay increasing calories until electrolytes are corrected.
- If electrolytes are not easily corrected or levels fall significantly:
- Reduce calories by 50%.
- Consider stopping nutritional support if an electrolyte disturbance becomes life-threatening.
- If electrolytes remain stable with dextrose infusion over several days, consider gradually increasing calories again. [1]
Hypophosphatemia is the primary biochemical indicator of refeeding syndrome. [4][5]
Other nutritional support [1]
- Continue IV thiamine for at least 5–7 days in patients with clinical features of or risk factors for thiamine deficiency in consultation with a nutritionist.
- Provide daily multivitamins for 10 days.
Acute management checklist
- Consider admission prior to initiating nutritional support.
- Administer fluid resuscitation if necessary.
- Obtain CBC, CMP, and phosphate and magnesium levels.
- Monitoring
- High-risk patients
- Obtain ECG.
- Measure serum glucose and electrolytes every 12 hours for 72 hours.
- Consider hemodynamic monitoring.
- Replete electrolytes as needed.
- Obtain additional diagnostics as needed, e.g., diagnostics for eating disorders.
- Consider administering IV thiamine prior to starting nutrition or dextrose-containing IV fluids.
- Prioritize electrolyte repletion and oral or enteral nutrition.
- Calculate caloric intake for refeeding.
- Treat any arising electrolyte disturbances and adjust caloric intake accordingly.
- Identify and treat complications, e.g., cardiac arrhythmias, volume overload, rhabdomyolysis.
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