Risk Factors for the Development of Refeeding Syndrome-Like Hypophosphatemia in Very Low Birth Weight Infants

BACKGROUND: Refeeding syndrome is characterized by metabolic disturbance including hypophosphatemia and hypokalemia upon reinstitution of nutrition in severely malnourished patients. OBJECTIVE: The present study sought to identify the risk factors for the development of refeeding syndrome-like metabolic disturbance in very low birth weight infants. METHODS: The correlations of severe hypophosphatemia with the serum levels of potassium and ionized calcium, daily calorie and phosphate intake, and umbilical cord blood flow on ultrasonography were analyzed in 49 very low birth weight infants. RESULTS: Fifteen infants (36%) presented with hypophosphatemia during the first postnatal week. Hypophosphatemia was significantly associated with birth weight z score (odds ratio, 1.60; 95% confidence interval, 1.04–2.47; p = 0.034) and umbilical artery resistance index (odds ratio, 7.72E−04; 95% confidence interval, 1.14E−06–0.523; p = 0.031). Multiple regression analysis revealed that umbilical artery resistance index was independently associated with hypophosphatemia. CONCLUSIONS: Umbilical artery resistance index may serve as a useful marker for future development of refeeding syndrome-like hypophosphatemia in very low birth weight infants. Close monitoring of serum phosphorus and potassium levels and early intervention are important for the management of very low birth weight infants with intrauterine growth restriction due to placental dysfunction.