High-dose parenteral amino acid intake in very low birthweight infants: what is the current evidence?

PURPOSE OF REVIEW: There is uncertainty regarding optimal dosing for parenteral amino acids in preterm infants and wide variability exists in clinical practice. There is new data from clinical trials trying to address these concerns. We review the recent evidence on parenteral high-dose amino acid intake in very low birth weight (VLBW) neonates with a focus on relevant clinical outcomes. RECENT FINDINGS: Preterm infants often receive less protein than intended in the first week of life. Parenteral amino acid administration in doses that exceed requirements, however, leads to increased oxidation and higher blood urea concentrations. Amino acid doses greater than 3.5 g/kg/day have not shown to improve mortality, neonatal morbidities including sepsis, necrotizing enterocolitis, chronic lung disease, growth parameters or neurodevelopmental outcomes at 2 years of age. SUMMARY: Parenteral amino acid administration in VLBW infants should be initiated soon after birth at a dose of at least 1.5 g/kg/day to maintain anabolism. The maximum dose for parenteral amino acid should be between 2.5 and 3.5 g/kg/day, with adequate nonprotein calories and micronutrients to ensure efficient protein utilization and growth.

Human milk fortifier: an occult cause of bowel obstruction in extremely premature neonates.

BACKGROUND: Human milk fortifier (HMF) is used in neonatal units throughout North America to facilitate growth of preterm infants. Little data is available on the gastrointestinal side effects and potential adverse events. The purpose of this paper was to present a series of infants presenting with bowel obstruction associated with HMF. METHODS: Cases of HMF obstruction were collected between January 2010 and December 2012. Charts were reviewed and relevant data was collected. RESULTS: During the study period, 7 premature infants presented with bowel obstruction secondary to intestinal concretions of HMF. All babies were premature with gestational ages from 25 to 27 weeks. Birth weight was less than 1000 grams in all patients. Patients presented with feeding intolerance, bilious aspirates, abdominal distension, and obstipation. Four of the patients presented with acute deterioration and required urgent surgical intervention. CONCLUSIONS: HMF is an important source of nutritional support in infants, which is felt to be safe. We present a series of infants where its use has resulted in significant complications. HMF should be used with caution in infants, especially those with a history of necrotizing enterocolitis. Further research should examine the calcium, protein, and fatty acid concentration tolerable in the gastrointestinal tract of infants.

Elevated triglycerides levels in two infants with hypoxic-ischemic encephalopathy undergoing therapeutic hypothermia and receiving parenteral nutrition.

Therapeutic hypothermia has been widely applied to improve the survival/neurodevelopmental outcomes among infants with moderate-to-severe hypoxic ischemic encephalopathy (HIE). Due to their critical condition and concerns over feeding tolerance, it is not uncommon to withhold enteral feeds and provide parenteral nutrition (PN) during hypothermia and early rewarming. Here we report 2 infants with HIE undergoing therapeutic hypothermia, and receiving PN, who exhibited early elevated triglyceride levels. Hypertriglyceridemia can be associated with neurologic complications, ranging from altered mental status, or irritability to seizures. Given the possible altered lipid metabolism under hypothermic conditions, we advocate close monitoring of lipid tolerance and conducting further prospective trials to elucidate lipid metabolism in these infants.