Barbara Battistini

Near-infrared reflectance analysis to evaluate the nitrogen and fat content of human milk in neonatal intensive care units

Objective: To validate near-infrared reflectance analysis (NIRA) as a fast, reliable and suitable method for routine evaluation of human milk’s nitrogen and fat content. Setting: One neonatal intensive care unit. Patients: 124 samples of expressed human milk (55 from preterm mothers and 69 from term mothers). Intervention: Measurement of nitrogen and fat content by NIRA and traditional methods (Gerber method for fat and Kjeldahl method for nitrogen). Main outcome measures: Agreement between NIRA and traditional methods. Variability in fat and nitrogen content of human milk. Results: A strong agreement was found between the results of traditional methods and NIRA for both fat and nitrogen content (expressed as g/100 g of milk) in term (mean fat content: NIRA = 2.76; Gerber = 2.76; mean nitrogen content: NIRA = 1.88; Kjeldahl  = 1.92) and preterm (mean fat content: NIRA = 3.56; Gerber = 3.52; mean nitrogen content: NIRA = 1.91; Kjeldahl  = 1.89) mothers’ milk. Nitrogen content of the milk samples, measured by NIRA, ranged from 1.18 g/100 g to 2.71 g/100 g of milk in preterm milk and from 1.48 g/100 g to 2.47 g/100 g in term milk; fat content ranged from 1.27 g/100 g to 6.23 g/100 g of milk in preterm milk and from 1.01 g/100 g to 6.01 g/100 g of milk in term milk. Conclusion: NIRA can be used as a quick and reliable tool for routine monitoring of macronutrient content of human milk and for devising individualised human milk fortification regimens in the feeding of very premature infants.

A thickened formula does not reduce apneas related to gastroesophageal reflux in preterm infants.

Background: Apnea of prematurity (AOP) occurs frequently in preterm infants and a variable proportion of AOP can be induced by gastroesophageal reflux (GER). Conservative treatment, including dietary modifications, should be the first-line approach for both GER and GER-related apneas in this population. Objectives: To evaluate the efficacy of a starch-thickened preterm formula (PF) in reducing the frequency of apneas related to GER. Methods: Preterm infants with AOP were studied by combined impedance and pH monitoring and polysomnography. The 6-hour study period included two feeds, one of a commercially available PF and one of the same formula thickened with amylopectin (TPF). GER indexes, apneas and GER-related apneas detected after TPF and PF feeds were compared by Wilcoxon signed-rank test. Results: 24 infants were studied. During 140 h of registration, 289 apneas (147 after TPF and 142 after PF; p = 0.876), and 861 GER episodes (400 after TPF and 461 after PF; p = 0.465) were recorded. No difference in the number of AOP was found between TPF and PF. A significant reduction in acid exposure was found after TPF; there was no influence on non-acid GER indexes. The frequency of GER-related apneas did not differ between TPF and PF. Conclusions: A formula thickened with amylopectin did not reduce the number of AOP or GER-related apneas. It reduced acid GER features but had no effect on non-acid GER indexes. Future research should focus on exploring different conservative strategies to treat GER-related apneas in preterm infants.

Bolus vs. continuous feeding: effects on splanchnic and cerebral tissue oxygenation in healthy preterm infants

Background:Intermittent and continuous tube feeding modes are commonly used to feed preterm infants. However, there is no clear evidence regarding which method is better tolerated. We investigated the differences between bolus and continuous feeding in terms of cerebral and splanchnic oxygenation in healthy preterm infants.Methods:Thirty preterm infants underwent a simultaneous 6-h near-infrared-spectroscopy monitoring of cerebral and splanchnic oxygenation, during which they were fed twice through an orogastric tube: one meal was given as a 10-min bolus, and the other was given continuously over a period of 3 h. Oxygenation trends over time were evaluated and compared between bolus and continuous feeding modes.Results:Cerebral oxygenation did not change over time and did not differ between the two feeding techniques. Splanchnic oxygenation changed significantly over time and differed between the two feeding techniques, with a significant increase after bolus feeding and a remarkable reduction during continuous feeding.Conclusion:Bolus and continuous feeding modes influence splanchnic oxygenation in healthy preterm infants differently. Further studies are needed to investigate possible underlying mechanisms and potential effects on feeding tolerance.

Lack of correlation between fecal elastase-1 levels and fecal nitrogen excretion in preterm infants.

We measured fecal elastase-1 (FE1) levels in 34 preterm newborns (15 small-for-gestational-age and 19 appropriate-for-gestational-age) during the first 2 months of life and evaluated whether they were correlated with nitrogen loss in stools. FE1 increased over time, and values were similar in both groups of newborns. Fecal nitrogen was significantly higher in small-for-gestational-age infants. There was no correlation between FE1 levels and fecal nitrogen excretion. Pancreatic proteolytic function was efficient at an early stage in enterally fed preterm newborns. Despite the similar FE1 values, fecal nitrogen loss was significantly higher in small-for-gestational-age preterm infants than in appropriate-for-gestational-age preterm infants.

Splanchnic Oxygenation at First Enteral Feeding in Preterm Infants: Correlation with Feeding Intolerance.

ABSTRACT Preterm infants are at risk of developing gastrointestinal complications such as feeding intolerance and necrotizing enterocolitis. Near-infrared spectroscopy (NIRS) provides continuous monitoring of abdominal oxygenation (ArSO2) and could help to predict gastrointestinal complications in preterm neonates. In this prospective observational study, ArSO2 patterns at first enteral feed were evaluated by NIRS in 61 clinically stable preterm infants. Splanchnic-cerebral oxygenation ratio, which is a marker of gut hypoxia, was also calculated. ArSO2 and splanchnic-cerebral oxygenation ratio were significantly lower both at baseline and after feeding administration in infants who later developed feeding intolerance (n = 23). NIRS could help the early prediction of gastrointestinal complications in high-risk preterm infants.

346 Effects of Bolus and Continuous Enteral Feeding on Splanchnic and Cerebral Tissue Oxygenation Evaluated by Near Infrared Spectroscopy

Background and Aims Bolus and continuous tube feeding represent the most frequently used enteral feeding techniques in preterm infants, but the best strategy is not yet established. Near-Infrared-Spectroscopy (NIRS) provides a noninvasive monitoring of splanchnic oxygenation, which may play a role in the multifactorial pathophysiology of necrotizing enterocolitis (NEC). The aim of this study is to evaluate by NIRS the effects of bolus and continuous enteral feeding on splanchnic and cerebral oxygenation in preterm infants with normal feeding tolerance. Methods Eighteen healthy preterms (GA 27–32 weeks), tolerating at least 100 ml/kg-1/day-1 of fortified human milk or preterm formula, underwent a 6-hours simultaneous monitoring of cerebral and splanchnic oxygenation using NIRO-200 oximeter. Sensors were placed on frontal and sub-umbilical region. During the monitoring they randomly received a 10-minutes bolus meal and a 3 hours continuous meal. Recorded values of cerebral and splanchnic Tissue Oxygenation Index (TOI) were clustered in 5-minutes intervals and compared between different feeding techniques using Wilcoxon Signed Ranks Test. Statistical significance was set at p≤0.05. Results Splanchnic oxygenation significantly decreased (p<0.05) during continuous feeding, from 1.30’ hour after the beginning to almost the end of the feed. No differences were found on cerebral oxygenation. Conclusions To the best of our knowledge, this is the first study comparing the effect of different feeding techniques on splanchnic and cerebral oxygenation in preterms. A significant reduction in splanchnic oxygenation was observed during continuous enteral. A possible role of these findings on the multifactorial NEC pathogenesis remains to be investigated.