High-Risk Period and Patient Characteristics

The American College of Cardiology recommends that patients with severe malnutrition (less than 70% ideal body weight) be closely monitored during the first week of refeeding, as this is a high-risk period for cardiac complications 1, 2
Patients with severe malnutrition are at increased risk of cardiac complications, including life-threatening ventricular arrhythmias and sudden cardiac death, during the first week of refeeding 1, 2, 3

Cardiac Complications

The American College of Cardiology states that up to one-third of deaths in anorexia nervosa patients are due to cardiac causes, including those occurring during refeeding 1, 2
Pre-existing cardiac muscle atrophy and QTc prolongation from starvation increase the risk of cardiac complications during refeeding 1, 2

The American College of Cardiology recommends starting with a conservative caloric intake of 5-10 kcal/kg/day in high-risk patients, with slow progression over several days, to avoid precipitating fatal complications 1, 2, 3
For patients at risk of refeeding syndrome, the Clinical Nutrition guidelines recommend limiting initial intake to 15-20 kcal/kg/day 4

The American College of Cardiology, American Heart Association, and European Society of Cardiology guidelines explicitly state that rapid, aggressive refeeding in severely malnourished patients can be fatal, and recommend avoiding overzealous refeeding 1, 2, 3

The American Society for Parenteral and Enteral Nutrition recommends screening all patients for refeeding syndrome risk before initiating nutritional support, with high-risk factors including BMI <16 kg/m², unintentional weight loss >15% in 3-6 months, and little or no nutritional intake for >10 days 5, 6
Electrolyte disturbances, such as hypophosphatemia, hypokalemia, and hypomagnesemia, are key diagnostic criteria for refeeding syndrome, according to the National Institute for Health and Care Excellence 7, 8

The European Society for Clinical Nutrition and Metabolism recommends starting feeding at low caloric levels (5-10 kcal/kg/day) with slow progression over several days, while aggressively supplementing electrolytes and thiamine, in high-risk patients 7, 8
The American College of Gastroenterology suggests providing prophylactic thiamine and multivitamin supplementation, and monitoring electrolytes daily for the first 3 days, then regularly until stable 7, 8

The American Geriatrics Society notes that older patients with malnutrition have significant overlap between malnutrition risk and refeeding syndrome risk, requiring careful monitoring during refeeding 9
The National Comprehensive Cancer Network recommends careful monitoring during refeeding for cancer patients with severe malnutrition 7, 8