Are current guidelines overcautious regarding refeeding of patients with severe anorexia nervosa: a retrospective cohort study

Abstract

Weight restoration is an integral part of managing anorexia nervosa patients and has been found to be associated with electrolyte and fluid abnormalities gathered under the umbrella term refeeding syndrome, which has led to cautious initiation of caloric regimes. This study looks at how a sample of severe anorexia nervosa patients were managed using higher rates of refeeding than the ones currently recommended.

Design retrospective cohort study of consecutive patients with severe eating disorders admitted to an UK specialist tertiary centre. The treatment programme uses a weight restoration regime starting at 1000 kcal/day, increased to 1500 kcal/day after two days and to 2000 kcal/day after seven days. The main outcome was the rate of hypophosphatemia, hypokalemia and hypomagnesemia within the first two weeks of weight restoration. The secondary outcomes included rate of weight gain and tendency of electrolyte shift.

Results 83% of the patient sample were categorised as extreme anorexia nervosa (BMI <15). 11.3% of patients developed hypophosphatemia, 11.3% had hypomagnesemia, 42% had hypokalaemia. The lowest levels were found between the 5-6 days after starting refeeding. The vast majority of electrolyte abnormalities fell into the mild category. Electrolyte abnormalities were easily corrected by oral supplementation, and only 5% required iv replacement. The only significant predictor for hypophosphatemia was a BMI below 13.

Conclusions The majority of extremely ill patients with anorexia nervosa tolerate refeeding starting at 25-30kcal/kg. Oral supplementation is effective, so overcautious refeeding is unnecessary, provided that the patient is carefully monitored.