Hypophosphatemia before endoscopic gastrostomy predicts higher mortality during the first week and first month post-gastrostomy: a risk marker of refeeding syndrome in gastrostomy-fed patients.

Introduction: starvation is usual in patients referred for endoscopic gastrostomy (PEG). A high risk of refeeding syndrome (RS) may contribute to poor prognosis. Objectives: this study aims to: a) evaluate serum phosphorus and magnesium when patients underwent PEG; b) determine the mortality rate during the first week and first month of enteral nutrition; and c) assess if hypophosphatemia or hypomagnesemia are associated with early mortality. Material and methods: retrospective study with patients followed in the Artificial Nutrition Clinic and died under PEG feeding. General nutritional assessment included NRS 2002, anthropometry and serum proteins. Serum phosphorus and magnesium were measured immediately before gastrostomy. Survival was recorded and compared to electrolyte and nutritional status. Results: one hundred and ninety-seven patients (137 men/60 women) aged 26-100 years. Most underwent PEG due to neurologic disorders (60.9%) and were malnourished according to body mass index (BMI) and serum proteins. Low phosphorus and magnesium were found in 6.6% and 4.6%, respectively. Hypophosphatemia was associated with malnutrition (p < 0.05). Mean survival was 13.7 ± 15.4 months. Mortality was 4.6% in the first week and 13.2% in the first month post-gastrostomy. Overall survival was shorter in malnourished patients but malnutrition did not directly influence early mortality (p > 0.05). Hypophosphatemia was associated with mortality during the first week (p = 0.02) and the first month of PEG feeding (p = 0.02). Conclusions: hypophosphatemia was uncommon but predicted early mortality after PEG. Although RS may be less frequent than expected, hypophosphatemia may be used as a RS marker and RS is the probable cause of increase early mortality in hypophosphatemic PEG-fed patients.