Refeeding syndrome or refeeding hypophosphatemia: a systematic review of cases

Nutrition support clinicians refer to the abnormalities in laboratory data and changes in clinical signs and symptoms that follow refeeding of starved or malnourished patients as refeeding syndrome. Theoretical descriptions of refeeding syndrome include a complex and extensive list of changes, such as hypophosphatemia, hypomagnesemia, hypokalemia, hyponatremia, hypocalcemia, hyperglycemia, and vitamin deficiency--all of which are accompanied by clinical signs and symptoms. In practice, clinicians see asymptomatic refeeding hypophosphatemia more often than a full-blown syndrome with multiple laboratory and clinical abnormalities. Confusion results because there is no widely accepted or uniformly applied set of defining characteristics for diagnosing refeeding syndrome. To gain insight into the clinical characteristics of refeeding syndrome described in the literature, a systematic review of reported cases and case series was conducted. Since 2000, 20 authors described 27 cases that contained sufficient data for review. Hypophosphatemia occurred in 26 patients (96%). While 19 patients (71%) experienced at least 1 other laboratory abnormality, only 14 (51%) exhibited a consistent pattern of abnormally low phosphorus and magnesium levels. Seven patients had hypocalcemia (26%), and hyponatremia was reported in 3 patients (11%). There were no reports of hyperglycemia. Mean data reported in case series containing data from 63 patients showed that hypophosphatemia was a consistent finding but that other abnormalities were not consistently identified. Findings suggest that refeeding hypophosphatemia is not accompanied by a consistent pattern of biochemical or clinical abnormalities among case reports or case series of patients reported to have refeeding syndrome.