II. Definitions

  1. Refeeding Syndrome
    1. Metabolic imbalance complicating initial refeeding of a severely malnourished patient
    2. Occurs in first 7 days (typically first 3 days) if refeeding is too aggressive
    3. Results in severe Electrolyte abnormalities with risk of Cardiac Dysrhythmias and death

III. Pathophysiology

  1. Severely malnourished patients are starting with depleted energy and Electrolyte stores
    1. Energy stores including glycogen, adipose tissue and Muscle are depleted
    2. Electrolytes including Potassium, Magnesium and Phosphorus are depleted
    3. Thiamine deficiency
  2. High Caloric Intake reintroduced in a severely malnourished patient (e.g. Anorexia Nervosa)
    1. Triggers Insulin release
    2. Insulin promotes intracellular shifts of Potassium, Magnesium and Phosphorus
    3. Insulin stimulates glycogen, fat, and protein synthesis and further depletes Electrolytes
  3. Abrupt Electrolyte shifts result in potentially life-threatening complications
    1. Hypophosphatemia results in diminished ATP and Muscle Weakness
    2. Hypokalemia may result in Arrhythmias, Muscle Weakness and ileus
    3. Hypomagnesemia risks Arrhythmias and Seizures
  4. Fluid balance also shifts with refeeding
    1. Risk of Fluid Overload (Congestive Heart Failure, Pulmonary Edema)

IV. Risk Factors

  1. Rapid weight loss prior to refeeding
  2. Rapid refeeding
  3. Severe malnourishment
    1. Body Mass Index <16 kg/m2
    2. Unintentional Weight Loss >15% in the past three to six months
    3. Minimal nutritional intake for >10 days
  4. Preexisting Electrolyte deficiency prior to starting refeeding
    1. Hypokalemia
    2. Hypomagnesemia
    3. Hypophosphatemia
  5. Comorbidity
    1. Anorexia Nervosa
    2. Alcoholism
    3. Elderly
    4. Postoperative patients
    5. Diabetes Mellitus
    6. Cancer
    7. Morbidly obese patients with profound weight loss
    8. Malabsorption (e.g. Inflammatory Bowel Disease, Cystic Fibrosis, Chronic Pancreatitis, short bowel syndome)
    9. Long-term Diuretic use
    10. Long-term Antacids (Magnesium or aluminum salts)

V. Labs

  1. Monitor Electrolytes closely in first 7 days of refeeding (esp. first 3 days)
    1. Serum Phosphorus
      1. Severe Hypophosphatemia is the hallmark finding in Refeeding Syndrome
    2. Serum Potassium
    3. Serum Magnesium
    4. Serum Sodium
    5. Thiamine deficiency

VI. Diagnostics

  1. Monitor inpatients on telemetry
  2. Electrocardiogram findings with risk of cardiovascular collapse
    1. Prolonged QT interval (Risk of sudden death)
    2. Bradycardia with Heart Rate <40 beats per minute

VII. Complications

  1. Fluid Overload (e.g. Congestive Heart Failure, Pulmonary Edema)
  2. Arrhythmia
  3. Cardiovascular collapse
  4. Death

VIII. Prevention

  1. Obtain baseline labs prior to refeeding and monitor during refeeding
  2. Avoid excessive Intravenous Fluids
  3. Before starting refeeding
    1. Normalize Electrolytes
    2. Thiamine 300-400 mg daily orally
    3. Vitamin B supplementation
  4. Initiate weight gain slowly
    1. See Anorexia Nervosa for management
    2. Limit initial Energy Intake to 20 to 25 kcal/kg/day
    3. Early Consultation to nutrition specialist

IX. References

  1. Renbarger and Pearson (2021) Crit Dec Emerg Med 35(8): 17-23
  2. Mehanna (2008) BMJ 336(7659):1495-8 +PMID: 18583681 [PubMed]

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Ontology: Refeeding Syndrome (C0860549)

Definition (MSH) A condition of metabolic imbalance that is caused by complications of initially feeding a severely malnourished patient too aggressively. Usually occurring within the first 5 days of refeeding, this syndrome is characterized by WATER-ELECTROLYTE IMBALANCE; GLUCOSE INTOLERANCE; CARDIAC ARRHYTHMIAS; and DIARRHEA.
Concepts Disease or Syndrome (T047)
MSH D055677
SnomedCT 427698009
Dutch refeeding syndrome
German Refeeding-Syndrom, Refeeding Syndrom
Italian Sindrome da rialimentazione, Sindrome da refeeding
Portuguese Síndrome de realimentação, Síndrome da Realimentação, Síndrome de Realimentação
Spanish Síndrome de realimentación, síndrome de realimentación (trastorno), síndrome de realimentación, Síndrome de Realimentación
Japanese リフィーディング症候群, リフィーディングショウコウグン
English Refeeding syndrome, Refeeding syndrome (disorder), refeeding syndrome (diagnosis), refeeding syndrome, Refeeding Syndrome, Syndrome, Refeeding, Refeeding Syndrome [Disease/Finding], refeed syndrome
Czech Reperfúzní syndrom, realimentační syndrom, refeeding syndrom
French SRI (Syndrome de Renutrition Inappropriée), Syndrome de renutrition, Syndrome de réalimentation, Syndrome de renutrition inappropriée
Russian SINDROM VOZOBNOVLENNOGO PITANIIA, REFEEDING СИНДРОМ, REFEEDING SINDROM, СИНДРОМ ВОЗОБНОВЛЕННОГО ПИТАНИЯ
Swedish Återuppfödningssyndrom
Polish Zespół ponownego odżywienia
Hungarian Refeeding syndroma
Norwegian Refeeding syndrom, Reernæringssyndrom