"Calcium-Phosphorus-Magnesium " and the Metabolic Issue of Newborns Undergoing Parenteral Nutrition: Is It Time to Change Our Perspectives?

In recent years, progress in the field of care has made prematurity an increasingly frequent phenomenon. The premature newborn, due to incompetence, is often subjected to parenteral nutrition (PN) for prolonged periods, and there may be several complications associated with it, first and foremost metabolic complications. In particular, the aim of this study was to evaluate how specific risk factors and/or auxological parameters influenced plasma variations in calcium, phosphorus, and magnesium levels. This is because, although little analyzed in the past, these electrolytes are essential for limiting the onset of unfavorable outcomes in neonatal age. This retrospective observational study was conducted by accessing the site intranet of the University Hospital "P. Giaccone" of Palermo, recruiting all newborns with PN necessities (106 in a total of 191), admitted to NICU in the period between 1 January 2020 and 1 January 2023. Infants undergoing PN through a central venous catheter (CVC), who remained in situ for a period ≥ 72 h, admitted to the NICU for the first time, were included. Infants with congenital malformations and/or deceased and/or transferred and/or without CVC or with CVC who remained in situ for a period < 72 h were excluded. We thus obtained 35 newborns in 2020, 33 newborns in 2021, and 38 newborns in 2022. Hypophosphatemia was associated with a lower weight percentile (average 34.8 °C vs. 50.8 °C; = 0.02) and a longer duration of PN (average 34.6 days vs. 17.3 days; = 0.002). Newborns with hypercalcemia had, on average, lower gestational age (average 31.6 weeks vs. 35.7 weeks; = 0.049) and weight at birth (average 1586 g vs. 2520 g; = 0.038). Newborns with hypermagnesemia had, on average, higher weight and length (average weight percentile 62.1 °C vs. 42.7 °C; = 0.038; average length percentile 66.7 °C vs. 44.4 °C; = 0.003). Among the risk factors, cesarean section and undergoing surgery most influence the serum trend of the analyzed electrolytes. Although our results are partial and preliminary and have not always reached statistical significance, it is clear that dyselectrolytemias, in the context of metabolic complications PN-related, must be re-evaluated and carefully examined by the clinician. Prospective and controlled trials are needed to confirm our data, i.e., that the "calcium-phosphorus-magnesium axis" no longer plays only the niche role that was previously believed.