#3060 Assessment of differences in management and outcomes of severe hypophosphatemia secondary to refeeding syndrome
Authors: Guillén María Soriano , Shabaka Amir , Raso Irene Vázquez , De Pedro Maria Patricia Sanz , Juarez Gema Maria Fernandez 
Published: May 2024

Abstract

Background and Aims
Refeeding syndrome is a severe, potentially life-threatening condition characterized by fatal shifts in fluids and electrolytes that may occur in malnourished patients receiving parenteral or enteral artificial refeeding. This condition may present with hypokalemia, hypomagnesemia, thiamine deficiency and changes in glucose and fat metabolism, but the hallmark of the syndrome is hypophosphatemia. The rise in insulin during refeeding may lead to a significant uptake and utilization of phosphorus into the cells, leading to a deficit in intracellular and extracellular phosphorus. The best method for phosphate repletion has not yet been determined. In this study we describe the different management strategies and outcomes of severe hypophosphatemia secondary to refeeding syndrome observed at our centre.

Method
We performed a retrospective observational study of patients admitted at out tertiary hospital from December 2022 and May 2023 who presented severe hypophosphatemia (defined as serum phosphate level &lt;1.2 mg/dl) secondary to refeeding syndrome. We collected demographic data, comorbidities, changes in electrolytes and kidney function and treatments received during in-hospital admission. Our outcomes were development of complications associated with severe hypophosphatemia (convulsions, myopathy, fractures, haemolytic anemia, and major cardiovascular events) and death.

Results
We identified 16 cases of severe hypophosphatemia secondary to refeeding syndrome during the study period, with a mean phosphate level of 0.81 ± 0.26 mg/dl. Mean age was 54.7 ± 16.4 years, and females were predominant (62.5%), and all were associated with parenteral nutrition. 18.8% of patients had had previous episodes of severe hypophosphatemia, 25% presented diarrhoea as well and 18.8% had also received intravenous iron previous to the episode. At presentation, mean serum creatinine was 0.64 ± 0.3 mg/dl, mean potassium levels were 3.5 ± 0.9 mmol/l, mean sodium 141.7 ± 6.3 mmol/l, mean calcium was 8.62 ± 0.37 mg/dl and mean magnesium was 2.05 ± 0.45 mg/dl. Most patients (75%) were treated by discontinuation of parenteral nutrition and intravenous phosphate, while 18.8% of patients were only treated by temporary discontinuation of parenteral nutrition and only 1 patient (6.3%) was treated with oral phosphate supplementation. Regarding complications, 18.8% of patients presented myopathy, 12.5% presented convulsions, 25% presented major cardiovascular events, and 18.8% of patients died during hospitalization.

Conclusion
Refeeding syndrome is a potential fatal condition that frequently presents with severe hypophosphatemia, however it frequently passes unrecognized. Prompt detection and management is essential, especially in patients receiving parenteral nutrition, to prevent complications and death. Further research is needed to determine the best management strategy in refeeding syndrome to improve outcomes.