Achieving Positive Protein Balance in the Immediate Post-Operative Period in Neonates with Amino Acid Administration Plus Narcotic Analgesia

Abstract 1625 Neonatology: Clinical Investigation Platform, Monday, 5/3

In neonates, the stress responses produced by the birth process and by surgery are both associated with metabolic events that produce a net catabolic effect. In adults, narcotic administration has been show to attenuate the surgical stress response. In order to determine if post-surgical neonates could achieve a positive protein balance without protein toxicity, ten newborns undergoing major surgery in the first 24 hours of life were prospectively randomized to immediate post-operative administration of 1.5 vs 2.5 g/kg/day amino acids (AA). All infants were maintained on fentanyl continuous infusion for 48 hours post-operatively. At 24-36 hours post-operatively, protein balance (pro bal) was determined by nitrogen balance (N bal) and leucine kinetic measurements were performed using stable isotope methodology to assess specific aspects of protein metabolism. Surgical diagnoses included gastroschisis in 8 neonates and diaphragmatic hernia in 2 infants. There were no differences in glucose and lipid intakes between groups. Results are shown below and expressed as mean ± sem by unpaired t-test (*p<0.05). (Table) Although many of these infants had a post-operative metabolic acidosis, there were no differences in arterial pH or volume/kg of sodium bicarbonate administration between the 2 groups. Clinical status of the 2 groups was comparable as determined by 2 different severity of illness scores (SNAP and NTISS). In a subset of 6 infants (2 receiving 1.5 g/kg/d AA intake and 4 receiving 2.5 g/kg/d AA intake), all AA concentrations were higher in the 2.5 g/kg/d AA intake group though these differences were not statistically significant. In conclusion, neonates undergoing simultaneous major metabolic stresses (birth and major surgery) in the first 24 hours of life were able to achieve a net positive protein balance without clinical evidence of protein toxicity when administered an AA intake of 2.5 g/kg/d with concurrent fentanyl analgesia.

Table 1 No caption available