Laryngeal Mask Airway for Surfactant Administration in Neonates: A Randomized, Controlled Trial.

OBJECTIVE: To determine if preterm infants with moderate respiratory distress syndrome on continuous positive airway pressure (CPAP) who received surfactant via a laryngeal mask airway (LMA) would have a decreased rate of intubation and mechanical ventilation compared with those on CPAP who did not receive surfactant. STUDY DESIGN: In this prospective, multicenter, randomized controlled trial, 103 premature infants 280/7-356/7 weeks gestation, ≥1250 g and ≤36 hours old on CPAP requiring fraction of inspired oxygen 0.30-0.40 were assigned to receive surfactant administered through an LMA then placed back on CPAP (LMA group) or maintained on CPAP with no surfactant administered (control group). The primary outcome was treatment failure necessitating intubation and mechanical ventilation in the first 7 days of life. RESULTS: Surfactant administration through an LMA (n = 50) significantly decreased the rate of intubation and mechanical ventilation compared with controls (n = 53): 38% vs 64%, respectively, OR 0.30 (95% CI 0.13, 0.70), P = .006, number needed to treat: 4). There were no serious adverse events associated with placement of the LMA or surfactant administration. CONCLUSIONS: In premature neonates with moderate respiratory distress syndrome, surfactant administered through an LMA decreased the rate of intubation and mechanical ventilation. This intervention may have significant impact on clinical care in both high and low resource settings. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01116921.

Tobacco smoking and breastfeeding: Effect on the lactation process, breast milk composition and infant development. A critical review.

Approximately 10% of women report smoking during pregnancy. The number of breastfeeding women who relapse back to smoking is even greater. Smoking may cause adverse changes to the milk's composition by not only reducing its protective properties, but also by affecting the infant's health. The pathophysiological mechanisms underlying these adverse effects are not entirely known. This article is a review of previous reports about the effects of smoking on the lactation process, breast milk composition and infant development. A systematic search for English language articles published until 2015 was made, using a MEDLINE data. The key search terms were "smoking and breastfeeding", "smoking and lactation", "smoking and milk composition", "nicotine and breast milk". Studies have shown that nicotine levels in breast milk of women who smoke are three times higher than those in the plasma levels. Breast milk volume is reduced and the duration of lactation period is shorter. Smoking causes adverse changes to the milk's composition by not only reducing its protective properties, but also affecting infants' response to breastfeeding and to breast milk.

Peripartum and neonatal outcomes of small-for-gestational-age infants with gastroschisis.

OBJECTIVES: Neonates with gastroschisis are often small for gestational age (SGA) based on population nomograms. Our objective was to evaluate the effect of SGA on perinatal and neonatal outcomes in cases of gastroschisis. METHODS: This is a retrospective study of neonates with prenatally diagnosed gastroschisis from two academic centers between 2008 and 13. Perinatal and neonatal outcomes of neonates with SGA at birth were compared with appropriate-for-gestational-age (AGA) neonates. The primary composite outcome was defined as any of the following: neonatal sepsis, short bowel syndrome at discharge, prolonged mechanical ventilation (upper quartile for the cohort), bowel atresia or death. RESULTS: We identified 112 cases of gastroschisis, 25 of whom (22%) were SGA at birth. There were no differences in adverse peripartum outcomes between SGA and AGA infants. No difference was found in the primary composite neonatal outcome (52% vs 36%, p = 0.21), but SGA infants were more likely to have prolonged mechanical ventilation (44% vs 22%, p = 0.04) and prolonged length of stay (LOS) (52% vs 22%, p = 0.007). After adjusting for GA at delivery, SGA remained associated with prolonged LOS (OR = 4.3, CI: 1.6-11.8). CONCLUSION: Among infants with gastroschisis, SGA at birth is associated with a fourfold increase in odds for prolonged LOS, independent of GA.

Hypotension following patent ductus arteriosus ligation: the role of adrenal hormones.

OBJECTIVE: To test the hypothesis that an impaired adrenal response to stress might play a role in the hypotension that follows patent ductus arteriosus (PDA) ligation. STUDY DESIGN: We performed a multicenter study of infants born at <32 weeks' gestation who were about to undergo PDA ligation. Serum adrenal steroids were measured 3 times: before and after a cosyntropin (1.0 µg/kg) stimulation test (performed before the ligation), and at 10-12 hours after the ligation. A standardized approach for diagnosis and treatment of postoperative hypotension was followed at each site. A modified inotrope score (1 × dopamine [µg/kg/min] + 1 × dobutamine) was used to monitor the catecholamine support an infant received. Infants were considered to have catecholamine-resistant hypotension if their greatest inotrope score was >15. RESULTS: Of 95 infants enrolled, 43 (45%) developed hypotension and 14 (15%) developed catecholamine-resistant hypotension. Low postoperative cortisol levels were not associated with the overall incidence of hypotension after ligation. However, low cortisol levels were associated with the refractoriness of the hypotension to catecholamine treatment. In a multivariate analysis: the OR for developing catecholamine-resistant hypotension was OR 36.6, 95% CI 2.8-476, P = .006. Low cortisol levels (in infants with catecholamine-resistant hypotension) were not attributable to adrenal immaturity or impairment; their cortisol precursor concentrations were either low or unchanged, and their response to cosyntropin was similar to infants without catecholamine-resistant hypotension. CONCLUSION: Infants with low cortisol concentrations after PDA ligation are likely to develop postoperative catecholamine-resistant hypotension. We speculate that decreased adrenal stimulation, rather than an impaired adrenal response to stimulation, may account for the decreased production.

Late-onset bloodstream infections of Very-Low-Birth-Weight infants: data from the Polish Neonatology Surveillance Network in 2009-2011.

BACKGROUND: Late-Onset Bloodstream Infections (LO-BSI) continue to be one of the most important complications associated with hospitalization of infants born with very low birth weight (VLBW). The aims of this study were to assess the epidemiology of LO-BSI together with the risk factors and the distribution of causative pathogens at six Polish neonatal intensive care units that participated in the Polish Neonatology Surveillance Network from January 1, 2009 to December 31, 2011. METHODS: The surveillance covered 1,695 infants whose birth weights were <1501 grams (VLBW) in whom LO-BSI was diagnosed >72 hours after delivery. Case LO-BSI patients were defined according to NeoKISS. RESULTS: Four hundred twenty seven episodes of LO-BSI were diagnosed with a frequency of 25.3% and an incidence density of 6.7/1000 patient-days (pds). Results of our multivariate analysis demonstrated that surgical procedures and lower gestational age were significantly associated with the risk of LO-BSI. Intravascular catheters were used in infants with LO-BSI significantly more frequently and/or for longer duration: Central venous cathters (CVC) (OR 1.29) and Peripheral venous catheters (PVC) (OR 2.8), as well as, the total duration of total parenteral nutrition (13 vs. 29 days; OR 1.81). Occurrence of LO-BSI was significantly associated with increased the length of mechanical ventilation (MV) (OR 2.65) or the continuous positive airway pressure (CPAP) (OR 2.51), as well as, the duration of antibiotic use (OR 2.98). The occurrence of more than one infection was observed frequently (OR 9.2) with VLBW with LO-BSI. Microorganisms isolated in infants with LO-BSI were dominated by Gram-positive cocci, and predominantly by coagulase-negative staphylococci (62.5%). CONCLUSIONS: Independent risk factor for LO-BSI in VLBV infants are: low gestational age and requirement for surgery. The incidence rates of LO-BSI especially CVC-BSI were higher in the Polish NICUs surveillance than those of other national networks, similar to the central- and peripheral utilization ratio.

School-age spirometry in survivors of chronic lung disease of prematurity in the surfactant era.

OBJECTIVE: To assess whether school-age spirometry and lung volume outcomes of preterm infants with history of moderate to severe respiratory distress syndrome (RDS), born in the surfactant era and treated with conventional mechanical ventilation (IMV) and discharged home with or without the diagnosis of BPD (chronic lung disease of prematurity), differ from those of term neonates (controls). PARTICIPANTS: The study included 148 Caucasian school-aged children (38 preterm infants without BPD, 20 preterm infants with BPD and 90 term infants). All infants were born at the Department of Pathology of Pregnancy and Labor, Pomeranian Medical University Szczecin, Poland. METHODS: Respiratory outcome in school-aged children was assessed using spirometry with the evaluation of flow and volume parameters, adjusted for age, weight and gender. The differences in spirometry were tested by the Wilcoxon or Mann-Whitney tests. Linear correlation and regression were also used. RESULTS: No statistically significant differences between the spirometric parameters in preterm infants with and without BPD were found. All investigated parameters were significantly lower in both ventilated groups compared to term controls, with the exception of ERV%, which was significantly higher CONCLUSIONS: The necessity to use assisted ventilation in preterm infants without neurological disorders most probably had an adverse effect on the lung function, assessed by spirometry at the age of 9-10 years, in the groups of children discharged home with or without BPD. Regardless of BPD, lung function parameters in prematurely born children with respiratory distress syndrome are always worse than in term controls.

The effect of whole-body cooling on brain metabolism following perinatal hypoxic-ischemic injury.

INTRODUCTION: Magnetic resonance imaging (MRI) and spectroscopy (MRS) have proven valuable in evaluating neonatal hypoxic-ischemic injury (HII). RESULTS: MRI scores in the basal ganglia of HII/HT(+) neonates were significantly lower than HII/HT(-) neonates, indicating less severe injury and were associated with lower discharge encephalopathy severity scores in the HII/HT(+) group (P = 0.01). Lactate (Lac) was detected in the occipital gray matter (OGM) and thalamus (TH) of significantly more HII/HT(-) neonates (31.6 and 35.3%) as compared to the HII/HT(+) group (10.5 and 15.8%). In contrast, the -N-acetylaspartate (NAA)-based ratios in the OGM and TH did not differ between the HII groups. DISCUSSION: Our data show that the HT was associated with a decrease in the number of HII neonates with detectable cortical and subcortical Lac as well as a decrease in the number of MRI-detectable subcortical lesions. METHODS: We retrospectively compared the medical and neuroimaging data of 19 HII neonates who received 72 h of whole-body cooling (HII/HT(+)) with those of 19 noncooled HII neonates (HII/HT(-)) to determine whether hypothermia was associated with improved recovery from the injury as measured by MRI and MRS within the first 14 days of life. MRI scores and metabolite ratios of HII/HT(+) and HII/HT(-) neonates were also compared with nine healthy, nonasphyxiated "control" neonates.

The impact of second-hand tobacco smoke exposure on pregnancy outcomes, infant health, and the threat of third-hand smoke exposure to our environment and to our children.

Smoking during pregnancy is associated with various adverse effects on pregnancy and fetal development, carries a lot of serious complications such as spontaneous abortion, placental abruption, and reduced birth weight of the newborn. Children of smoking mothers have an increased risk of premature birth, low birth weight, sudden infant death syndrome and respiratory diseases during infancy. Smoking also causes long-term risk of maternal health problems such as: heart disease, cancer, emphysema, chronic obstructive pulmonary disease and higher mortality rate. Because women are more likely to quit smoking during pregnancy than at any other time, there are attempts to increase motivation and help them to stop smoking at the procreative phase of their life. The article describes interventions that are carried out in Loma Linda, where the educational program "When You Smoke Your Baby Smokes" reminds parents about the health effects of smoking during pregnancy and harmful impact on child's health caused by second-hand smoke. Another threat to health and environment of our children, is the nicotine coming from indirect exposure to tobacco smoke. Residual nicotine that persists in high concentrations on the interior surfaces, including clothing, is forming in the reaction of nitric acid carcinogenic compounds of specific nitrosamines. In addition, ozone and related atmospheric oxidants react with nicotine smoke or smoke coming from the second-hand smoke, giving the smallest particles with high risk of asthma. Efforts towards reducing exposure to tobacco smoke coming from the passive and indirect smoking should be placed at a high priority throughout the European Union.

Neonatal Applications of Heliox: A Practical Review.

Heliox is a mixture of helium and oxygen that may be utilized as an alternative to air-oxygen during the ventilatory support in the neonate. Special physical properties of Heliox, particularly low density, allow for improved gas flow and diffusion. First reports of Heliox use in the pediatric population were published in 1930s; however, this therapy has never gained widespread popularity despite its described beneficial effects. Historically, this was largely due to technical challenges associated with Heliox ventilation that significantly limited its use and realization of large-scale clinical trials. However, nowadays several commercially available ventilators allow easy and safe ventilation with both conventional and non-invasive modes. In the era of minimally invasive respiratory interventions in the newborn Heliox could be seen as a therapy that may potentially decrease the risk of non-invasive ventilation failure. This review presents pathophysiologic rationale for the use of Heliox in the newborn, and summarizes available data regarding applications of Heliox in the setting of neonatal intensive care unit based on clinical studies and findings from animal models. Mechanisms of action and practical aspects of Heliox delivery are thoroughly discussed. Finally, future research directions for neonatal use of Heliox are proposed.

Effects of heliox and non-invasive neurally adjusted ventilatory assist (NIV-NAVA) in preterm infants.

Due to its unique properties, helium-oxygen (heliox) mixtures may provide benefits during non-invasive ventilation, however, knowledge regarding the effects of such therapy in premature infants is limited. This is the first report of heliox non-invasive neurally adjusted ventilatory assist (NIV-NAVA) ventilation applied in neonates born ≤ 32 weeks gestational age. After baseline NIV-NAVA ventilation with a standard mixture of air and oxygen, heliox was introduced for 3 h, followed by 3 h of air-oxygen. Heart rate, peripheral capillary oxygen saturation, cerebral oxygenation, electrical activity of the diaphragm (Edi) and selected ventilatory parameters (e.g., respiratory rate, peak inspiratory pressure) were continuously monitored. We found that application of heliox NIV-NAVA in preterm infants was feasible and associated with a prompt and significant decrease of Edi suggesting reduced respiratory effort, while all other parameters were stable throughout the study, and had similar values during heliox and air-oxygen ventilation. This therapy may potentially enhance the efficacy of non-invasive respiratory support in preterm neonates and reduce the number of infants progressing to ventilatory failure.

When you smoke your baby smokes: advancing maternal and child health through an academic alliance to improve health of mothers and their infants.

The detrimental effect of tobacco exposure prior to conception and during pregnancy has been receiving much worldwide attention. Maternal smoking during pregnancy is associated with early-onset wheezing, increased respiratory illnesses, and a 2-fold increased risk for Sudden Infant Death Syndrome (SIDS). Adverse effects on the infant include altered infant behaviors such as an increased occurrence of infant colic or Attention Deficit Disorders (ADD). Studies have shown that a significant number of smoking woman "quit" smoking during pregnancy. However, a majority of women, 67% by 3 months and up to 90% by 6 month, resume smoking following delivery. An infant's birth related hospitalization is a "teachable moment" to address parental smoking, and to advocate for reducing fetal exposure to tobacco smoke. Academic alliance focused on well designed educative program can further increase rate of smoking free pregnant women and decrease smoking relapse rates significantly.

An overview of pulmonary surfactant in the neonate: genetics, metabolism, and the role of surfactant in health and disease.

Pulmonary surfactant is a complex mixture of phospholipids (PL) and proteins (SP) that reduce surface tension at the air-liquid interface of the alveolus. It is made up of about 70-80% PL, mainly dipalmitoylphosphatidylcholine (DPPC), 10% SP-A, B, C and D, and 10% neutral lipids, mainly cholesterol. Surfactant is synthesized, assembled, transported and secreted into the alveolus where it is degraded and then recycled. Metabolism of surfactant is slower in newborns, especially preterm, than in adults. Defective pulmonary surfactant metabolism results in respiratory distress with attendant morbidity and mortality. This occurs due to accelerated breakdown by oxidation, proteolytic degradation, inhibition or inherited defects of surfactant metabolism. Prenatal corticosteroids, surfactant replacement, whole lung lavage and lung transplantation have yielded results in managing some of these defects. Gene therapy could prove valuable in treating inherited defects of surfactant metabolism.

Using Patient-Centered Care After a Prenatal Diagnosis of Trisomy 18 or Trisomy 13: A Review.

Importance: Patient-centered care (PCC) has been advocated by the Institute of Medicine to improve health care in the United States. Four concepts of PCC align with clinical ethics principles and are associated with enhanced patient/parent satisfaction. These concepts are dignity and respect, information sharing, participation, and collaboration. The objective of this article is to use the PCC approach as a framework for an extensive literature review evaluating the current status of counseling regarding prenatal diagnosis of trisomy 18 (T18) or trisomy 13 (T13) and to advocate PCC in the care of these infants. Observations: Extensive availability of prenatal screening and diagnostic testing has led to increased detection of chromosomal anomalies early in pregnancy. After diagnosis of T18 or T13, counseling and care have traditionally been based on assumptions that these aneuploidies are lethal or associated with poor quality of life, a view that is now being challenged. Recent evidence suggests that there is variability in outcomes that may be improved by postnatal interventions, and that quality-of-life assumptions are subjective. Parental advocacy for their infant's best interest mimics this variability as requests for resuscitation, neonatal intensive care, and surgical intervention are becoming more frequent. Conclusions and Relevance: With new knowledge and increased parental advocacy, physicians face ethical decisions in formulating recommendations including interruption vs continuation of pregnancy, interventions to prolong life, and choices to offer medical or surgical procedures. We advocate a PCC approach, which has the potential to reduce harm when inadequate care and counseling strategies create conflicting values and uncertain outcomes between parents and caregivers in the treatment of infants with T18 and T13.

Device-associated pneumonia of very low birth weight infants in Polish Neonatal Intensive Care Units.

PURPOSE: Late-Onset Pneumonia (LO-PNEU) is still the most important complication associated with the hospitalization of infants with very low birth weight (<1501g). The purpose of this paper is to summarize the results of an ongoing surveillance program defining LO-PNEU as associated or not associated with respiratory support in the NICU and distribution of causative pathogens from the Polish Neonatology Surveillance Network (PNSN). MATERIALS AND METHODS: Surveillance of infections was conducted in the years 2009-2011 at six Polish NICUs. RESULTS: The incidence was 3.1/1000 NICU patient days (pds). The mean gestational age and birth weight among infants with LO-PNEU were significantly lower. The VAP incidence was of 18.2/1000 NICU pds for mechanically ventilated (MV) infants, while the rates for those receiving only CPAP were as low as 7.7/1000 NICU pds. MV significantly increased the risk of PNEU, but MV or CPAP for <10 days did not increase the risk of LO-PNEU. Significantly associated with LO-PNEU was the use of central or peripheral venous catheters and total parenteral nutrition for longer periods. Microorganisms isolated in cases of LO-PNEU were Gram-positive cocci (53.5%) and Gram-negative rods, with predominating E. coli. Non fermentative bacilli were significantly more frequent in cases of VAP than in other cases. CONCLUSIONS: Observed incidence rates associated with VAP and CPAP-PNEU, were higher than in other national surveillance systems and expressing the feasibility of lowering the risk of LO-PNEU and increasing patient safety. The incidence of pneumonia was found to be lower when using CPAP as compared to using MV.

Effect of antepartum meconium staining on perinatal and neonatal outcomes among pregnancies with gastroschisis.

OBJECTIVE: To investigate the association between meconium staining and perinatal and neonatal outcomes in pregnancies with gastroschisis. METHODS: Retrospective analysis of infants with prenatally diagnosed gastroschisis born in two academic medical centers between 2008 and 2013. Neonatal outcomes of deliveries with and without meconium staining were compared. Primary outcome was defined as any of the following: neonatal sepsis, prolonged mechanical ventilation, bowel atresia or death. Secondary outcomes were preterm delivery, preterm-premature rupture of membranes (PPROM) and prolonged hospital length of stay. RESULTS: One hundred and eight infants with gastroschisis were included of which 56 (52%) had meconium staining at delivery. Infants with meconium staining had a lower gestational age at delivery (36.3 (±1.4) versus 37.0 (±1.2) weeks, p = 0.007), and a higher rate of PPROM (25% versus 8%, p = 0.03) than infants without meconium. Meconium staining was not significantly associated with the primary composite outcome or with any of its components. After adjustments, meconium staining remained significantly associated with preterm delivery at <36 weeks [odds ratio OR = 4.0, 95% confidence intervals (CI): 1.5-11.4] and PPROM (OR = 3.8, 95%CI: 1.2-14.5). CONCLUSIONS: Among infants with gastroschisis, meconium staining was associated with prematurity and PPROM. No significant increase in other adverse neonatal outcomes was seen among infants with meconium staining, suggesting a limited prognostic value of this finding.

Disordered eating attitudes during pregnancy in mothers of newborns requiring Neonatal Intensive Care Unit admission: a case control study.

OBJECTIVE: The aim of the study was to assess disordered eating attitudes and other related factors in mothers of newborns requiring Neonatal Intensive Care Unit (NICU) admission compared to those of mothers who delivered healthy infants. METHODS: An anonymous self-report study conducted among 199 mothers of newborns hospitalized in NICU, and a control group of 127 mothers of healthy newborns. Eating Attitudes Test-26 (EAT-26) and a survey regarding other perinatal health issues were used. RESULTS: Women in the study group (SG) gained significantly less weight during pregnancy when compared to control group (CG; p = 0.001). There were fewer women with appropriate pre-gestational BMI in the SG (p = 0.052). Women who feared weight-gain during pregnancy were younger (p < 0.001) and had higher EAT-26 scores (p < 0.001). Women with EAT-26 scores >20 smoked significantly more often during their last pregnancy in the SG (p = 0.010). Cesarean section was more frequent in the SG (p = 0.017). CONCLUSIONS: Disordered eating attitudes in gestation may significantly influence the pregnancy outcomes and newborns' health. Hence, it is vital for perinatal counseling and obstetrical care to focus on these issues to facilitate early diagnosis and intervention.

Effects of variable concentrations of inhaled nitric oxide and oxygen on the lungs of newborn piglets.

We previously demonstrated that inhalation of high concentrations of nitric oxide (iNO) and oxygen for 48 hr causes significant lung injury in newborn piglets. To determine if these effects persist at lower concentrations, groups of newborn piglets were mechanically ventilated for 48 hr with (study 1) constant O(2) (90-100%) and decreasing iNO (100-2 ppm) or (study 2) constant iNO (50 ppm) and decreasing O(2) (95-30%). Bronchoalveolar lavage (BAL) fluid was assayed for surfactant function, and markers of lung inflammation and physiologic parameters were monitored. Neutrophil chemotactic activity (NCA), % neutrophils, and total protein (TP) concentrations decreased significantly in BAL fluid of study 1 piglets as iNO was reduced and inhaled oxygen fraction remained constant, indicating less pulmonary injury at low iNO levels. Low-dose iNO (2 ppm) did not have antiinflammatory effects. However, surfactant function was minimally affected by lowering iNO, and was abnormal in all groups. In contrast, in study 2, pulmonary inflammation and injury were lower when O(2) was decreased to 70% or less, with iNO constant at 50 ppm. Surfactant function normalized and oxygenation improved in study 2 piglets when the inhaled oxygen fraction was decreased and iNO remained constant. These data suggest that iNO- and O(2)-induced lung injury may be minimized by weaning O(2) or iNO, although better physiologic function may be obtained when iNO concentrations are constant and O(2) is reduced. This has important implications in the clinical management of critically ill newborns treated with O(2) and iNO for pulmonary disorders.

Heliox for mechanically ventilated newborns with bronchopulmonary dysplasia.

OBJECTIVE: We assessed the safety and studied the influence of short-term helium-oxygen (heliox) mechanical ventilation (MV) on respiratory function, gas exchange and oxygenation in infants with bronchopulmonary dysplasia (BPD) or at high risk for BPD. DESIGN: A pilot, time-series study. SETTING: Neonatal intensive care unit. PATIENTS: Infants with severe BPD who required MV. INTERVENTIONS: MV with helium-oxygen and air-oxygen mixtures. MAIN OUTCOME MEASURES: Respiratory parameters, acid-base balance, oxygenation and vital signs were recorded at five time points: initially during MV with air-oxygen, after 15 and 60 min of helium-oxygen MV, and 15 and 60 min after return to air-oxygen MV. RESULTS: 15 infants with BPD were enrolled. Helium-oxygen MV was well tolerated and was associated with a statistically significant increase in tidal volume, dynamic compliance and peak expiratory flow rate. An improvement in oxygenation and a decrease in fraction of inspired oxygen was also observed. During helium-oxygen MV there was a significant decrease in the oxygenation index and alveolar-arterial oxygen tension difference. The PaO2/fraction of inspired oxygen (FiO2) ratio increased significantly during helium-oxygen ventilation. A decrease in PaCO2 and an increase in pH were also observed during helium-oxygen administration, however this was not statistically significant. After ventilation with helium-oxygen was discontinued, the infants' respiratory function and oxygenation deteriorated and supplemental oxygen requirements increased accordingly. CONCLUSIONS: Helium-oxygen MV is safe and resulted in improvement of respiratory function and oxygenation in infants with severe BPD requiring MV.

Nitrite and nitrate concentrations and metabolism in breast milk, infant formula, and parenteral nutrition.

Dietary nitrate and nitrite are sources of gastric NO, which modulates blood flow, mucus production, and microbial flora. However, the intake and importance of these anions in infants is largely unknown. Nitrate and nitrite levels were measured in breast milk of mothers of preterm and term infants, infant formulas, and parenteral nutrition. Nitrite metabolism in breast milk was measured after freeze-thawing, at different temperatures, varying oxygen tensions, and after inhibition of potential nitrite-metabolizing enzymes. Nitrite concentrations averaged 0.07 ± 0.01 µM in milk of mothers of preterm infants, less than that of term infants (0.13 ± 0.02 µM) (P < .01). Nitrate concentrations averaged 13.6 ± 3.7 µM and 12.7 ± 4.9 µM, respectively. Nitrite and nitrate concentrations in infant formulas varied from undetectable to many-fold more than breast milk. Concentrations in parenteral nutrition were equivalent to or lower than those of breast milk. Freeze-thawing decreased nitrite concentration ~64%, falling with a half-life of 32 minutes at 37°C. The disappearance of nitrite was oxygen-dependent and prevented by ferricyanide and 3 inhibitors of lactoperoxidase. Nitrite concentrations in breast milk decrease with storage and freeze-thawing, a decline likely mediated by lactoperoxidase. Compared to adults, infants ingest relatively little nitrite and nitrate, which may be of importance in the modulation of blood flow and the bacterial flora of the infant GI tract, especially given the protective effects of swallowed nitrite.