Managing Potassium During Eating Disorder Refeeding

Hypokalemia, or low potassium in the blood, is the most common electrolyte problem seen in eating disorders, and should be monitored along with phosphorus during nutritional rehabilitation.

The process of taking in vital nutrition following periods of caloric restriction can trigger dangerous electrolyte imbalances in the blood which if untreated can lead to multiple body system failures. 

Low potassium in the blood is the most common electrolyte problem observed in serious eating disorders, especially among patients who purge and/or abuse laxatives or diuretics as these purging behaviors waste fluid and key electrolytes from the body. Potassium is the major electrolyte inside nearly all of the cells in the body, and it is vital for nerve and muscle cellular functioning. Particularly critical for cardiac function, adequate potassium helps the heart muscle to beat strongly and in a normal rhythm. When calories are reintroduced to a starving body, potassium and other key electrolytes are absorbed into the new tissue cells, lowering the concentration of electrolytes in the blood. Cardiac complications of hypokalemia can include an irregular heartbeat, low blood pressure and cardiac arrest. Low potassium can also cause weakness, muscle cramps, seizures, paralysis, confusion, respiratory failure, constipation and impaired kidney function.

While managing potassium during eating disorder refeeding is essential, it is equally important to monitor phosphorus and other electrolyte levels in the body as calories are reintroduced. Phosphorus is the electrolyte used by all cells to make energy, and a low level of phosphorus in the blood can result in a life-threatening complication known as the refeeding syndrome. The nutritionally compromised body requires significant energy to heal, so nutrients in food are broken down and phosphorus is absorbed into starving cells to provide the energy to repair and rebuild. Absorption of this key electrolyte into the cells can cause levels in the blood stream to drop dangerously low. A drop in phosphorus in the blood, or hypophosphatemia, is a key precursor for refeeding syndrome and if not repleted can lead to seizures, confusion, muscle weakness and heart failure.

There is complex interplay among potassium, phosphorus and other key electrolytes in the refeeding process. Traditional medical settings, even many residential eating disorder treatment programs, are unlikely to have expertise in the medical complications that occur when refeeding extremely underweight patients. As a result, it may be necessary to initiate nutritional rehabilitation in a specialized inpatient medical facility trained in navigating the medical pitfalls of refeeding. There, experts across several disciplines carefully initiate nutritional replenishment tailored to each patient’s unique needs and risk factors, frequently monitoring blood chemistry and vitals, addressing complications immediately and aggressively replenishing these electrolytes orally or intravenously as the clinical situation dictates. 

For more information on managing potassium during eating disorder refeeding, contact us.