Refeeding syndrome: an important aspect of supportive oncology

Refeeding syndrome (RFS) is an underappreciated, yet common and potentially dangerous, constellation of metabolic derangements that can occur upon reinstitution of any type of nutritional intervention. The typical patient who experiences RFS has been malnourished for days to weeks and develops hypophosphatemia and, occasionally, hypokalemia and hypomagnesemia when administered a carbohydrate load in the form of glucose-containing fluids, total parenteral nutrition (TPN), tube feedings, or an oral diet. The pathophysiology of RFS is complex but mainly results from an acute intracellular shift in electrolytes, increased phosphate demand during tissue anabolism, and formation of high-energy phosphate bonds. Potential complications of RFS include fatal cardiac arrhythmia, systolic heart failure, respiratory insufficiency, and hematologic derangements. Because supportive care of the cancer patient often involves nutritional and metabolic support, any clinician involved with providing acute or palliative oncologic care should be familiar with the risks, manifestations, and treatment of RFS.