Early hypophosphatemia in preterm infants receiving aggressive parenteral nutrition

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.

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 <4 mg dl(-1)). A one-sample mean comparison test was used to compare our sample with a hypothesized population mean.

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 (<2 mg dl(-1)) were smaller. They presented with sepsis more frequently and received more vasoactive drugs and mechanical ventilation.

The prevalence of hypophosphatemia in this group of preterm infants is high. The potential association with adverse clinical outcomes deserves further research.