From a review:
RFS is a potentially life-threatening condition induced by initiation of feeding after a period of starvation. Although a uniform definition is lacking, most definitions comprise a complex constellation of laboratory markers (i.e. hypophosphatemia, hypokalemia, hypomagnesemia) or clinical symptoms, including cardiac and pulmonary failure. Recent studies show that low caloric intake results in lower mortality rates in critically ill RFS patients compared with RFS patients on full nutritional support. Therefore, standard monitoring of RFS-markers (especially serum phosphate) and caloric restriction when RFS is diagnosed should be considered. Furthermore, standard therapy with thiamin and electrolyte supplementation is essential.