II. Definitions
- Refeeding Syndrome
- Metabolic imbalance complicating initial refeeding of a severely malnourished patient
- Occurs in first 7 days (typically first 3 days) if refeeding is too aggressive
- Results in severe Electrolyte abnormalities with risk of Cardiac Dysrhythmias and death
III. Pathophysiology
- Severely malnourished patients are starting with depleted energy and Electrolyte stores
- Energy stores including glycogen, adipose tissue and Muscle are depleted
- Electrolytes including Potassium, Magnesium and Phosphorus are depleted
- Thiamine deficiency
- High Caloric Intake reintroduced in a severely malnourished patient (e.g. Anorexia Nervosa)
- Metabolism shifted to anabolic from catabolic
- Triggers Insulin release
- Insulin promotes intracellular shifts of Potassium, Magnesium, Phosphorus and water
- Insulin stimulates glycogen, fat, and Protein synthesis and further depletes Electrolytes
- Abrupt Electrolyte shifts result in potentially life-threatening complications
- Hypophosphatemia results in diminished ATP and Muscle Weakness
- Hypokalemia may result in Arrhythmias, Muscle Weakness and ileus
- Hypomagnesemia risks Arrhythmias and Seizures
- Fluid balance also shifts with refeeding
IV. Risk Factors
- Rapid weight loss prior to refeeding
- Rapid refeeding
- Severe malnourishment
- Body Mass Index <16 kg/m2
- Unintentional Weight Loss >15% in the past three to six months
- Minimal nutritional intake for >10 days
- Preexisting Electrolyte deficiency prior to starting refeeding
- Comorbidity
- Chronic Malnutrition
- Anorexia Nervosa
- Alcoholism
- Elderly
- Postoperative patients
- Diabetes Mellitus
- Cancer
- Morbidly obese patients with profound weight loss
- Malabsorption (e.g. Inflammatory Bowel Disease, Cystic Fibrosis, Chronic Pancreatitis, short bowel syndome)
- Long-term Diuretic use
- Long-term Antacids (Magnesium or aluminum salts)
V. Labs
- Complete Blood Count
- Creatine Phosphokinase (CPK)
- Monitor Electrolytes closely in first 7 days of refeeding (esp. first 3 days)
- Serum Phosphorus
- Severe Hypophosphatemia is the hallmark finding in Refeeding Syndrome
- Serum Potassium
- Serum Magnesium
- Serum Sodium
- Thiamine deficiency
- Serum Phosphorus
VI. Diagnostics
- Monitor inpatients on telemetry
-
Electrocardiogram findings with risk of cardiovascular collapse
- Prolonged QT interval (Risk of sudden death)
- Bradycardia with Heart Rate <40 beats per minute
VII. Complications
- Fluid Overload (e.g. Congestive Heart Failure, Pulmonary Edema)
- Hemolytic Anemia
- Rhabdomyolysis
- Seizures
- Arrhythmia
- Cardiovascular collapse
- Death
VIII. Prevention
- Obtain baseline labs prior to refeeding and monitor during refeeding
- Avoid excessive Intravenous Fluids
- Before starting refeeding
- Normalize Electrolytes
- Thiamine 300-400 mg daily orally
- Vitamin B supplementation
- Initiate weight gain slowly
- See Anorexia Nervosa for management
- See Specialized Nutritional Support
- Start refeeding at one third or less of nutritional needs and gradually increase every 5-7 days
- Limit initial Energy Intake to 20 to 25 kcal/kg/day
- Early Consultation to nutrition specialist
IX. Prognosis
- Life threatening complication if not recognized
X. References
- Renbarger and Pearson (2021) Crit Dec Emerg Med 35(8): 17-23
- Mehanna (2008) BMJ 336(7659):1495-8 +PMID: 18583681 [PubMed]