Background

Intestinal citrulline and arginine synthesis is limited in preterm infants. Arginine deficiency can contribute to the high rate of morbidity and mortality in premature births.

Objectives

Describe citrulline and arginine kinetics.

Methods

prospective observational study in patients born <1500 g. Citrulline and arginine (dried blood on paper, analysis by tandem mass spectrometry), and other analytical-clinical data collected at 3 and 15 days.

Results

58 patients: 29.6±2.5 weeks, 1210±346 grams. Only two cases developed necrotizing enterocolitis, two died and 46.6%developed sepsis. Initial citrulline (18.5±6.6 mcmol/L) falls significantly (p<0.05) at 15 days of age (14.2±4.5). Initial arginine (21.1±14.2 mcmol/L) falls significantly (p<0.05) at 15 days of life (14.0±6.5). Decrease in citrulline in first 15 days correlates with arginine (R 0.63, p>0.001). Greater basal citrulline correlates with lower gestational age (p 0.044), higher frequency of sepsis (p 0.037), more delay in initiating (p<0.001) and achieving complete enteral nutrition (p 0.026) and longer duration of parenteral nutrition (p 0,02). The highest arginine decrease at 15 days of age correlates with a higher frequency of necrotizing enterocolitis (p<0.001), sensitivity 98.1% and specificity 100% for cut-off point of 6.71 mcmol/L.

Conclusion

Arginine and citrulline decrease in first days of life in preterm infants, with a relationship between greater basal citrulline and worse digestive tolerance and between the greater decrease with more nosocomial sepsis. Citrulline levels are related to age and can serve as reference values, which facilitates the evaluation of compromised intestinal function in preterm infants with severe gastrointestinal problems. The greatest decreases in arginine are indicative of digestive complications.

Background

Carnitine availability is especially important during the immediate postnatal period.

Objectives

to characterize carnitine status in preterm infants <1500 g and to determine if not orally-fed low birth weight babies are at risk of carnitine deficiency.

Methods

Prospective observational study in patients born <1500 g. Free carnitine levels, and analytical-clinical data collected at 3 and 15 days.

Results

58 patients included, gestational age 29.6±2.5 weeks, 1210±346 grams. Two cases developed necrotizing enterocolitis and two died. Sepsis in 46.6%. Basal carnitine is 25.6±12.3 mcmol/L and falls significantly (p 0.011) at 15 days of age (21.0±8.9). This fall is 32.4% in cases that develop nosocomial sepsis compared to 5.4% in those who do not (p 0.022). Basal carnitine inversely correlates with the days of mechanical ventilation. Carnitine at 15 days of age rises more in patients of older gestational age and is inversely proportional to the days of invasive mechanical ventilation, the days of enteral initiation (p 0.016), the days with complete enteral nutrition (p 0.023) and duration of parenteral nutrition (p 0.014). Carnitine at 15 days of life is significantly lower in those who develop nosocomial sepsis (18.75±9.6 vs 22.9±8.0, p 0.016).

Conclusion

premature babies are born with a limited amount of carnitine and are not able to synthesize enough to maintain blood levels. Carnitine deficiency can occur despite parenteral nutrition, during the first two weeks of life. More research is needed into the metabolic consequences secondary to poor carnitine intake in premature infants before considering the administration of carnitine supplements.

Background

High fecal calprotectin (FC) levels have been documented in term and preterm infants (PI).

Objectives

To determine FC levels in PI and to correlate them with clinical- biochemical sepsis and inflammatory intestinal disorders (necrotising enterocolitis or not).

Methods

prospective longitudinal observational study of PI ≤35s EG, from which stool samples were collected at 4, 8, 15, 30 days of life for FC determination (μg/g). Predominant breastfeeding was considered if more than 80% of the daily intake is breastfeeding.

Results

369 stool samples collected from 114 PI. Mean gestational age 30.26 (±2.38) weeks, birth weight 1376.90±429.16 grams. 76 pathological processes in 42 neonates (36.8% of PI). No differences according to feeding or gestational age.

Mean calprotectin in healthy PI is significantly lower than in the ones with diseases, being statistically significant differences between 4 and 30 days, between 4 and 15 and 8 and 15.

Conclusion

A high calprotectin mean was observed in all cases, being greater in the first 4 days of life significantly, with slight posterior decrease and stabilization during the first months. During intercurrent diseases, both systemic infections and intestinal distress, the FC rises before the onset of symptoms or the elevation of acute phase reactants and after the improvement remains elevated for 8-10 days. Its use as a predictor of digestive pathology in preterm infants is possible.