Categories: Endocrinology

Refeeding Syndrome: Mechanism

Refeeding Syndrome is a set of clinical complications that typically occur in severely malnourished patients as a result of aggressive fluid and electrolyte shifts during oral, enteral, or parenteral nourishment.

What conditions put you at risk for Refeeding Syndrome?

Anorexia Nervosa
Alcoholism
Cancer
Anything that can cause ongoing electrolyte losses (Diarrhea, vomiting, fistulas)
Any condition that places patients in the ICU

What are the clinical manifestations of Refeeding Syndrome?

Prolonged malnourishment leads to decreased carbohydrate intake which reduces serum glucose and ultimately a decreased insulin secretion. As a result, energy supply to the tissues and organs of the body is maintained through lipolysis and protein catabolism which causes intracellular losses of electrolytes, particularly phosphate.

When glucose is re-introduced into the malnourished patient, insulin secretion goes up, and rapidly drives phosphate into cells (including potassium) causing a decrease in the serum concentration of these electrolytes.

Hypophosphatemia: See mechanism above. Insulin also causes several molecules to utilize phosphate (i.e. ATP and 2-3 DPG) which further exacerbates the hypophastatemia. The decrease in phosphorylated intermediates contributes to tissue hypoxia and subsequent myocardial dysfunction, but also causes an inability of the diaphragm to contract which can cause respiratory failure. Hypophosphatemia can also induce: rhabdomyolysis, seizures, and delirium)

Hypokalemia: See mechanism above.

Vitamin and trace mineral deficiencies: due to decreased nutritional intake

Volume overload: insulin secretion can stimulate renal sodium absorption and retention and ultimately, fluid retention which can push a patient into congestive heart failure.

REFERENCES:

Fuentebella, J., & Kerner, J. A. (2009). Refeeding Syndrome. Pediatric Clinics of North America, 56(5), 1201-1210. doi:10.1016/j.pcl.2009.06.006
Hearing, S. D. (2004). Refeeding syndrome. Bmj, 328(7445), 908-909. doi:10.1136/bmj.328.7445.908