Hypophosphatemia and risk of refeeding syndrome in critically ill patients before and after nutritional therapy.

Abstract

To investigate the prevalence of hypophosphatemia as a marker of refeeding syndrome (RFS) before and after the start of nutritional therapy (NT) in critically ill patients. Retrospective cohort study including 917 adult patients admitted at the intensive care unit (ICU) of a tertiary hospital in Cuiabá-MT/Brasil. We assessed the frequency of hypophosphatemia (phosphorus <2.5mg/dl) as a risk marker for RFS. Serum phosphorus levels were measured and compared at admission (P1) and after the start of NT (P2). We observed a significant increase (36.3%) of hypophosphatemia and, consequently, a greater risk of RFS from P1 to P2 (25.6 vs 34.9%; p<0.001). After the start of NT, malnourished patients had a greater fall of serum phosphorus. Patients receiving NT had an approximately 1.5 times greater risk of developing RFS (OR= 1.44 95%CI 1.10-1,89; p= 0.01) when compared to those who received an oral diet. Parenteral nutrition was more associated with hypophosphatemia than either enteral nutrition (p=0,001) or parenteral nutrition supplemented with enteral nutrition (p=0,002). The frequency of critically ill patients with hypophosphatemia and at risk for RFS on admission is high and this risk increases after the start of NT, especially in malnourished patients and those receiving parenteral nutrition.