Background The standardised, concentrated with added macronutrients parenteral (SCAMP) nutrition regimen provides hyperalimentation to very preterm infants (VPI). Current neonatal parenteral nutrition (PN) amino acid (AA) formulations predate recent recommended protein intakes. AA were categorised as essential, conditionally essential (in VPI) and non-essential. We hypothesised hyperalimentation would prevent low plasma levels of conditionally essential AA (CEAA).

Methods Infants (<1200 g; <29 weeks) were randomised to start SCAMP or remain on control before day 5. Daily parenteral (AA) and enteral protein intakes were calculated from daily nutritional data. Plasma AA levels were measured weekly in PN-dependent infants by ion-exchange chromatography.

Results Infants were randomised to SCAMP (n = 74) and control (n = 76) groups. The mean difference (95% confidence interval) in total protein intake (g/kg) was 8.7 (6.0–11.5) d1–28. All essential AAs (phenylalanine, lysine, valine, leucine, isoleucine, methionine, threonine, histidine and tryptophan) were within or above the reference range (RR) in both groups. Plasma arginine/cysteine levels (week 2) were below RR in both SCAMP (n = 45) and control (n = 62) infants (Table 1). Plasma cysteine levels (week 3) were below RR in both SCAMP (n = 39) and control (n = 36) infants.

Conclusion Despite hyperalimentation and increased protein intake, PN-dependent VPI remain biochemically deficient in some conditionally essential AAs.