What can sodium/fluid retention in refeeding syndrome lead to?

Sodium and fluid retention in refeeding syndrome can lead to cardiac decompensation due to several interconnected physiological processes that occur when feeding is restarted after a period of malnutrition or starvation. During refeeding, especially in individuals who have been significantly malnourished, there is a shift in electrolytes, particularly phosphorus, potassium, and magnesium, as the body begins to utilize carbohydrates for energy.

As carbohydrates are introduced, insulin secretion increases, which facilitates the uptake of glucose as well as electrolytes into cells. This shift can lead to increased sodium retention and fluid overload, due to the body’s attempts to maintain electrolyte balance and support cellular metabolism. The resultant fluid overload can cause an increase in blood volume that the heart may struggle to manage, especially if pre-existing cardiac function is compromised.

This can lead to signs of heart failure or cardiac decompensation, where the heart is unable to pump effectively, resulting in symptoms such as shortness of breath, edema, and even arrhythmias. Thus, understanding the implications of fluid and sodium retention during refeeding syndrome highlights the importance of careful monitoring and gradual reintroduction of nutrition in at-risk patients.