Carbohydrate intake and refeeding syndrome in children and adolescents with anorexia nervosa

A standard carbohydrate (CHO) mealplan was used which provides 50-60% of total energy from carbohydrate as per the Australian Guide to Healthy Eating recommendations. The starting calorie intake of this mealplan is matched to the control group with increments to calories over the first 7 days as per usual care. The starting caloric prescription of the meal plan was assessed by the dietitian following a comprehensive nutrition assessment including anthropometric measures, malnutrition diagnosis and recent food and fluid intake. Participants were commenced on a meal plan of oral food and fluid providing a minimum of 2000kcal (8400kJ). Participants deemed at high risk of refeeding syndrome were those who were less than 70% of their expected body weight on admission, or who had minimal carbohydrate intake for 7-10 days. These participants were commenced on a meal plan of 1500kcal/day (6300kJ). The meal plan includes 3 main meals (breakfast, lunch and dinner) and 3 snacks (morning tea, afternoon tea and supper). The meal plans were increased incrementally by approximately 400kcal twice weekly, until the participant reached a meal plan of 3000kcal (12600kJ). This was usually achieved by day 7 of admission (and by day 10 for those starting on 1500kcal/day). Following this, increases to meal plans were dependent on adequacy of weight gain with the expectation of 1-1.5kg weight gain per week as per local hospital guidelines. Once the participants reached the 3000kcal meal plan there was no further difference in the carbohydrate content of the meal plans, with carbohydrates providing 50-60% total energy in each meal plan. The dietitian was responsible for choosing the appropriate starting mealplan (as stated above) and ordering the prescribed meals and snacks from the hospital food service department. The nursing staff were responsible for setting the participants up at meal times with the prescribed mealplan. All meals and snacks were supervised and supported by nursing staff. If participants were unable to consume the entirety of their prescribed meal or snack they were required to have a nutritionally equivalent supplement drink or “bolus”. This was initially offered orally, however if the participant was unable to consume it orally it was administered via a nasogastric tube. As per local hospital guidelines, nursing staff recorded oral intake after each meal/snack on Cerner under fluid balance tab. The dietitian would review this information twice weekly. Participants were on supervised bed rest following meal and snack times and bathroom visits were supervised. Locker searches were performed by nursing staff if there was suspicion of food hiding. Patients were recruited within 24hrs of admission. The intervention was commenced immediately following recruitment (i.e at the next meal or snack). Participants were reviewed by the dietitian twice weekly until discharge. Participants were medically reviewed daily to monitor for clinical features of refeeding syndrome (RFS) including signs of congestive cardiac failure, confusion, and seizures. Participants were monitored closely for biochemical markers of RFS, with analysis of electrolytes, calcium, magnesium, phosphate, glucose daily for 7 days and then twice weekly thereafter. In those patients deemed at high risk for RFS, biochemical markers were evaluated daily for 10 days and twice weekly thereafter during the admission. Prophylactic phosphate was not routinely administered. Phosphate was prescribed in the form of Sandoz Phosphate 500mg twice per day with titration as indicated if refeeding hypophosphatemia (RH) occurred (<0.95mmol/L in patients under 16 years and <0.87mmol/L in patients >16 years as per local hospital guideline). A general multivitamin was not provided to participants.