Prophylactic Phosphate Supplementation for the Inpatient Treatment of Restrictive Eating Disorders

Abstract

Purpose: The medical stabilization of adolescent patients with restrictive eating disorders can be associated with refeeding syndrome, a potentially fatal complication preceded by refeeding hypophosphatemia (RH). Whether RH can be prevented by routine prophylactic phosphate supplementation has not been previously examined. This study sought to determine the safety and efficacy of a refeeding strategy that incorporates prophylactic phosphate supplementation to prevent RH.

Methods: Retrospective chart data were collected for patients aged younger than 18 years with restrictive eating disorders admitted to a tertiary pediatric inpatient ward between January 2011 and December 2014. All patients were refed with a standardized protocol that included prophylactic oral phosphate supplementation (1.0 ± .2 mmol/kg/day).

Results: During the 4-year study period, 75 admissions (70 patients) were included for analysis. The mean age and percent median body mass index of included patients were 15.3 years and 83.5%, respectively. Seven out of 75 (9%) had percent median body mass index of <70% and 26 out of 75 (35%) had percent body weight loss >20%. All patients were normophosphatemic at the time of admission (mean serum phosphate 1.24 ± .2 mmol/L). Serial laboratory evaluation revealed that all supplemented patients maintained serum phosphate levels >1.0 mmol/L during the initial 7 days of refeeding. Eleven patients became mildly hyperphosphatemic (range 1.81-2.17 mmol/L) with no associated clinical consequences. Additional analysis of 11 patients presenting with hypophosphatemia before refeeding revealed that with supplementation, phosphate values normalized by Day 1, and this group experienced no further RH episodes during initial refeeding.

Conclusions: Prophylactic oral phosphate supplementation appears safe, and no episodes of RH occurred in patients with restrictive eating disorders undergoing inpatient refeeding.

Keywords: Anorexia nervosa; Eating disorder; Hypophosphatemia; Refeeding syndrome.