What causes refeeding syndrome in patients who have been malnourished?

Refeeding syndrome is a potentially dangerous condition that can occur when feeding is resumed in individuals who have been malnourished, particularly after a period of starvation or significant caloric restriction. The critical factor in refeeding syndrome is the body’s metabolic response to newly reintroduced nutrients, especially carbohydrates.

When carbohydrates are reintroduced into the diet, they stimulate insulin secretion. Insulin facilitates the uptake of glucose into cells, but it also promotes the shift of electrolytes, particularly phosphate, into the cells. In malnourished patients, the reserves of phosphate are often depleted, and the rapid shift from extracellular to intracellular compartments can lead to severely low serum phosphate levels, which is a hallmark of refeeding syndrome. Hypophosphatemia can lead to various complications, including respiratory failure, hemolysis, muscle weakness, and cardiac issues.

Maintaining awareness about this shift and monitoring electrolyte levels is vital when refeeding malnourished individuals to prevent the successional health issues associated with refeeding syndrome. This physiological response underscores the importance of careful dietary management and appropriate monitoring during the refeeding process.