G69(P) Hyperalimentation using current UK parenteral amino acid formulations does not prevent low plasma arginine levels in very preterm infants

Background Arginine deficiency is well recognised in very preterm infants (VPI) receiving parenteral nutrition (PN) and is associated with major morbidity. Current UK PN amino acid (AA) formulations are AA-P (arginine 8.4 g/100 gAA) and AA-V (arginine 6.2 g/100 gAA). Human milk contains 4 g/100 gAA arginine. We hypothesised that hyperalimentation in PN-dependent VPI would prevent arginine deficiency irrespective of AA formulation. Aim To compare the plasma arginine levels in VPI (reference range; RR:54–78 micromol/l) randomised to receive control PN (CPN) or hyperalimentation PN (HPN) regimens in two randomised controlled trials (RCT). Methods Both studies were single centre RCT with HPN containing 30% more protein/energy than CPN. RCT1 (AA-P) and RCT2 (AA-V) recruited infants 35% nutrients from PN. Results Plasma AA levels were obtained at median (IQR) postnatal age 9 (8–10) days in both RCT1 and RCT2. Both studies achieved significantly higher actual daily protein and arginine intakes (Table 1) in HPN compared to CPN infants (p Conclusion These study data demonstrate hyperalimentation does not prevent low plasma arginine levels in VPI. The proportion of arginine in current UK neonatal PN AA formulations is too low.