Early hypophosphatemia in preterm infants receiving aggressive parenteral nutrition

OBJECTIVE: To report the prevalence of hypophosphatemia during the first week of life in preterm infants receiving aggressive parenteral nutrition and to analyze population variables associated with severe hypophosphatemia. STUDY DESIGN: A retrospective cohort of 61 neonates below 1250 g birth weight consecutively born at Hospital Italiano de Buenos Aires exposed to high caloric and protein intake from the first day of birth. Primary outcome was hypophosphatemia (phosphate <4mg dl(-1)). A one-sample mean comparison test was used to compare our sample with a hypothesized population mean. RESULTS: The prevalence of hypophosphatemia was 91% (95% confidence interval (CI) 82 to 97%). The mean phosphatemia value was 2.52 mg dl(-1) (95% CI 2.18 to 2.86), significantly different from the hypothesized population mean (P<0.001). Patients with severe hypophosphatemia (<2mg dl(-1)) were smaller. They presented with sepsis more frequently and received more vasoactive drugs and mechanical ventilation. CONCLUSION: The prevalence of hypophosphatemia in this group of preterm infants is high. The potential association with adverse clinical outcomes deserves further research.