Refeeding Syndrome

Epidemiology

History
- Refeeding was First Observed Following the Refeeding of WWII Prisoners

Carbohydrate Load Administered Orally (Oral Intake or Enteral Nutrition)/Intravenously (TPN) Following a Period of Starvation
- During Starvation, Phosphate Stores are Depleted
- With Refeeding
  - Insulin Secretion with Intracellular Shift of Phosphate, Magnesium, and Potassium
  - Insulin Secretion Leads to Renal Sodium Reabsorption and Retention, Followed by Fluid Retention
  - Enhanced Metabolism of Ketoacids Back to Bicarbonate

Arrhythmias
- Epidemiology: most common cause of death in refeeding syndrome
- Clinical
  - Torsade (see Torsade, [[Torsade]]): may occur (due to hypomagnesemia)
Congestive Heart Failure (CHF) (see Congestive Heart Failure, [[Congestive Heart Failure]])
- Physiologic Mechanisms
  - Impaired Myocardial Contractility: due to starvation-associated myocardial atrophy, hypophosphatemia, and thiamine deficiency
  - Sodium and Fluid Retention
Hypertension (see Hypertension, [[Hypertension]])
- Epidemiology: may occur
Hypotension (see Hypotension, [[Hypotension]])
- Epidemiology: may occur

Diarrhea (see Diarrhea, [[Diarrhea]])
- Physiology: due to atrophy of intestinal mucosa and pancreatic impairment which occur during starvation
- Treatment
  - May Require Decreasing the Rate of Nutritional Supplementation, Less Complex Carbohydrates, or Elemental Diet
  - Generally Resolves within Weeks
Elevated Liver Function Tests (LFT’s) (see xxxx, [[xxxx]])
- Epidemiology: may occur during the first few weeks of refeeding
- Physiology: due to excessive calories, fat deposition, or cell death-apoptosis from malnutrition
- Clinical: mildly elevated
Hepatic Steatosis (Fatty Liver) (see Hepatic Steatosis, [[Hepatic Steatosis]])
Nausea/Vomiting (see Nausea and Vomiting, [[Nausea and Vomiting]])
- Treatment: may require decreasing the rate of nutritional supplementation

Central Pontine Myelinolysis (see Central Pontine Myelinolysis, [[Central Pontine Myelinolysis]])
- Epidemiology: has been reported in refeeding syndrome associated with anorexia nervosa
Coma (see Obtundation-Coma, [[Obtundation-Coma]])
Delirium (see Delirium, [[Delirium]])
- Physiology: due to electrolyte abnormalities
Exacerbation of Thiamine Deficiency (see Thiamine, [[Thiamine]])
- Physiology: thiamine deficiency occurs during starvation, refeeding may exacerbate this deficiency
- Clinical
  - Wernicke’s Encephalopathy (Encephalopathy, Oculomotor Dysfunction, and Ataxia): may occur
Parasthesias (see Parasthesias, [[Parasthesias]])
- Physiology: due to electrolyte abnormalities
Seizures (see Seizures, [[Seizures]])
- Physiology: due to electrolyte abnormalities
Weakness
- Physiology: impaired muscular contractility (due to hypophosphatemia)
Tetany (see Tetany, [[Tetany]])
- Physiology: due to hypophosphatemia

Respiratory Failure (see Respiratory Failure, [[Respiratory Failure]])
- Epidemiology: rare
- Physiology: impaired diaphragmatic contractility (due to atrophy and/or hypophosphatemia)

Hypokalemia (see Hypokalemia, [[Hypokalemia]])
- Physiology: glucose induces insulin release, resulting in intracellular shift of magnesium, phosphate, and potassium
Hypomagnesemia (see Hypomagnesemia, [[Hypomagnesemia]])
- Physiology: glucose induces insulin release, resulting in intracellular shift of magnesium, phosphate, and potassium
Hypophosphatemia (see Hypophosphatemia, [[Hypophosphatemia]])
- Physiology: hallmark and predominant cause of many of the clinical manifestations of the refeeding syndrome
  - Glucose induces insulin release, resulting in intracellular shift of magnesium, phosphate, and potassium
Metabolic Alkalosis (see Metabolic Alkalosis, [[Metabolic Alkalosis]])
- Physiology: due to enhanced metabolism of ketoacids back to bicarbonate

Myalgias (see Myalgias, [[Myalgias]])
- Physiology: due to hypophosphatemia
Peripheral Edema (see Peripheral Edema, [[Peripheral Edema]])
Rhabdomyolysis (see Rhabdomyolysis, [[Rhabdomyolysis]])
- Epidemiology: may occur
- Physiology: due to hypophosphatemia

Decrease in the Rate of Initial Nutritional Support: as required
Correction of Electrolyte Abnormalities: in general, any pre-existing electrolyte abnormalities should be corrected prior to starting feeding
- Hypokalemia (see Hypokalemia, [[Hypokalemia]])
- Hypomagnesemia (see Hypomagnesemia, [[Hypomagnesemia]])
- Hypophosphatemia (see Hypophosphatemia, [[Hypophosphatemia]])

Refeeding syndrome: what it is, and how to prevent and treat it. BMJ. 2008;336(7659):1495 [MEDLINE]
Refeeding syndrome. Pediatr Clin North Am. 2009;56(5):1201 [MEDLINE]
Refeeding syndrome: treatment considerations based on collective analysis of literature case reports. Nutrition. 2010;26(2):156 [MEDLINE]
Refeeding hypophosphatemia in adolescents with anorexia nervosa: a systematic review. Nutr Clin Pract. 2013 Jun;28(3):358-64. Epub 2013 Mar 4 [MEDLINE]