Health care-associated infections in neonatology

Health care-associated infections are common in neonatology, but there is no consensus on their definitions. This makes it difficult to compare their incidence or assess the effectiveness of prevention bundles. This is why we think it is very important to achieve a consensus on the definitions and diagnostic criteria for one of the most frequent causes of morbidity in hospitalised neonates. This document aims to standardise the definitions for the most frequent health care-associated infections, such as catheter-associated bloodstream infection, ventilator-associated pneumonia and surgical wound infection, as well as the approach to their diagnosis and treatment.

Clinical Utility of the FilmArray® Blood Culture Identification (BCID) Panel for the Diagnosis of Neonatal Sepsis

This prospective single-center study was designed to assess the clinical utility of the FilmArray® blood culture identification (BCID) panel for improving the diagnostic accuracy in neonatal sepsis. Results obtained using the FilmArray® BCID panel were correlated with results of blood culture in all consecutive neonates with suspicion of early-onset (EOS) and late-onset sepsis (LOS) attended in our service over a two-year period. A total of 102 blood cultures from 92 neonates were included, 69 (67.5%) in cases of EOS and 33 (32.3%) in LOS. The FilmArray® BCID panel was performed in negative culture bottles at a median of 10 h of blood culture incubation (IQR 8–20), without differences by the type of sepsis. The FilmArray® BCID panel showed a 66.7% sensitivity, 100% specificity, 100% positive predictive value, and 95.7% negative predictive value. There were four false-negative cases, three of which were Streptococcus epidermidis in neonates with LOS, and there was one case of Granulicatella adiacens in one neonate with EOS. We conclude that the use of the FilmArray® BCID panel in negative blood cultures from neonates with clinical suspicion of sepsis is useful in decision-making of starting or early withdrawal of empirical antimicrobials because of the high specificity and negative predictive values of this assay.

Postnatal Growth Faltering: Growth and Height Improvement at Two Years in Children with Very Low Birth Weight between 2002-2017

The prevalence of postnatal growth faltering (PGF) in preterm infants with very low birth weight (VLBW) (<1500 g) is a universal problem. Growth improvement is expected as neonatal care is optimized. Objectives: To determine if there has been a decrease in the prevalence of PGF and an improvement in height at 2 years in appropriate for gestational age VLBW children in the last two decades. Methods: Clinical descriptive retrospective analysis of neonatal somatometry at birth and at two-year corrected age in VLBW preterm infants. Small for gestational age were excluded. Two cohorts (2002−2006, n = 112; and 2013−2017, n = 92) were compared. Results. In the second five-year period, a decrease in prevalence of PGF was observed (36.6% vs. 22.8%, p = 0.033), an increase in growth rate in the first 28 days (5.22 (4.35−6.09) g/kg/day vs. 11.38 (10.61−12.15) g/kg/day, p < 0.0001) and an increase in height standard deviation (SD) at 2 years (−1.12 (−1.35−−0.91) vs. −0.74 (−0.99−−0.49) p = 0.023). Probability of short stature at 2 years was directly related to daily weight gain in the first 28 days. Conclusions: when comparing two five-year periods in the last two decades, growth in VLBW preterm infants has improved, both during neonatal period and at two years of age.

Near-Infrared Sensors for Onsite and Noninvasive Quantification of Macronutrients in Breast Milk

Breast milk is an optimal food that covers all the nutritional needs of the newborn. It is a dynamic fluid whose composition varies with lactation period. The neonatal units of hospitals have human milk banks, a service that analyzes, stores, and distributes donated human milk. This milk is used to feed premature infants (born before 32 weeks of gestation or weighing less than 1500 g) whose mothers, for some reason, cannot feed them with their own milk. Here, we aimed to develop near-infrared spectroscopy (NIRS) measures for the analysis of breast milk. For this purpose, we used a portable NIRS instrument scanning in the range of 1396-2396 nm to collect the spectra of milk samples. Then, different chemometrics were calculated to develop 18 calibration models with and without using derivatives and the standard normal variate. Once the calibration models were developed, the best treatments were selected according to the correlation coefficients (r²) and prediction errors (SECVs). The best results for the assayed macronutrients were obtained when no pre-treatment was applied to the NIR spectra of fat (r² = 0.841, SECV = 0.51), raw protein (r² = 0.512, SECV = 0.21), and carbohydrates (r² = 0.741, SECV = 1.35). SNV plus the first derivative was applied to obtain satisfactory results for energy (r² = 0.830, SECV = 9.60) quantification. The interpretation of the obtained results showed the richness of the NIRS spectra; moreover, the presence of specific bands for fat provided excellent statistics in quantitative models. These results demonstrated the ability of portable NIRS sensors in a methodology developed for the quality control of macronutrients in breast milk.

Extrauterine Growth Restriction in Very Low Birth Weight Infants: Concordance Between Fenton 2013 and INTERGROWTH-21st Growth Charts

Postnatal growth restriction has high prevalence in very low birth weight (VLBW) preterm neonates, and this could affect their long-term prognosis. Nowadays, there is no consensus on how to monitor growth in these neonates. Objective: This study aimed to compare prevalence of intra- and extrauterine growth restriction (IUGR and EUGR) in a sample of VLBW infants according to the Fenton 2013 charts and INTERGROWTH-21st (IW-21) standards and to analyze concordance between both in the different EUGR definitions criteria (cross-sectional, dynamic, and true). Patients and Methods: An observational retrospective study of 635 VLBW preterm was performed. The study was carried out in Central University Hospital of Asturias. Body measurements (weight, length, and head circumference) were collected at birth and at hospital discharge and expressed in z-scores for the two references (Fenton 2010 and IW-21). Kappa concordance was calculated. Results: Kappa concordance between Fenton and IW-21 was 0.887 for IUGR and 0.580 for static EUGR. Prevalence was higher according to Fenton in IUGR (36.5 vs. 35.1%), in static EUGR (73.8 vs. 59.3%), and in dynamic EUGR (44.3 vs. 29.3%). Despite observing low prevalence of EUGR when IW-21 was used to define EUGR, a statistical association between neonatal morbidity and diagnosis of EUGR was observed. Conclusion: The Fenton and IW-21 concordance for IUGR is good. IW-21 is more restrictive than Fenton in EUGR. Patients diagnosed by IW-21 as EUGR are more likely to have neonatal morbidity, especially if we use EUGR dynamic definition. In our study, we cannot conclude that one graph is better than the other.

Topiramate plus Cooling for Hypoxic-Ischemic Encephalopathy: A Randomized, Controlled, Multicenter, Double-Blinded Trial

BACKGROUND AND OBJECTIVES

Therapeutic interventions to improve the efficacy of whole-body cooling for hypoxic-ischemic encephalopathy (HIE) are desirable. Topiramate has been effective in reducing brain damage in experimental studies. However, in the clinical setting information is limited to a small number of feasibility trials. We launched a randomized controlled double-blinded topiramate/placebo multicenter trial with the primary objective being to reduce the antiepileptic activity in cooled neonates with HIE and assess if brain damage would be reduced as a consequence.

STUDY DESIGN

Neonates were randomly assigned to topiramate or placebo at the initiation of hypothermia. Topiramate was administered via a nasogastric tube. Brain electric activity was continuously monitored. Topiramate pharmacokinetics, energy-related and Krebs' cycle intermediates, and lipid peroxidation biomarkers were determined using liquid chromatography-mass spectrometry and MRI for assessing brain damage.

RESULTS

Out of 180 eligible patients 110 were randomized, 57 (51.8%) to topiramate and 53 (48.2%) to placebo. No differences in the perinatal or postnatal variables were found. The topiramate group exhibited less seizure burden in the first 24 h of hypothermia (topiramate, n = 14 [25.9%] vs. placebo, n = 22 [42%]); needed less additional medication, and had lower mortality (topiramate, n = 5 [9.2%] vs. placebo, n = 10 [19.2%]); however, these results did not achieve statistical significance. Topiramate achieved a therapeutic range in 37.5 and 75.5% of the patients at 24 and 48 h, respectively. A significant association between serum topiramate levels and seizure activity (p < 0.016) was established. No differences for oxidative stress, energy-related metabolites, or MRI were found.

CONCLUSIONS

Topiramate reduced seizures in patients achieving therapeutic levels in the first hours after treatment initiation; however, they represented only a part of the study population. Our results warrant further studies with higher loading and maintenance dosing of topiramate.

Evolution of Energy Related Metabolites in Plasma from Newborns with Hypoxic-Ischemic Encephalopathy during Hypothermia Treatment

Therapeutic hypothermia (TH) initiated within 6 h from birth is the most effective therapeutic approach for moderate to severe hypoxic-ischemic encephalopathy (HIE). However, underlying mechanisms and effects on the human metabolism are not yet fully understood. This work aims at studying the evolution of several energy related key metabolites in newborns with HIE undergoing TH employing gas chromatography - mass spectrometry. The method was validated following stringent FDA requirements and applied to 194 samples from a subgroup of newborns with HIE (N = 61) enrolled in a multicenter clinical trial (HYPOTOP) for the determination of lactate, pyruvate, ketone bodies and several Krebs cycle metabolites at different sampling time points. The analysis of plasma samples from newborns with HIE revealed a decrease of lactate, pyruvate and β-hydroxybutyrate concentrations, whereas rising malate concentrations were observed. In healthy control newborns (N = 19) significantly lower levels of pyruvate and lactate were found in comparison to age-matched newborns with HIE undergoing TH, whereas acetoacetate and β-hydroxybutyrate levels were clearly increased. Access to a validated analytical method and a controlled cohort of newborns with HIE undergoing hypothermia treatment for the first time allowed the in-depth study of the evolution of key metabolites of metabolic junctions in this special population.

In vivo study of the effect of lactoferrin on iron metabolism and bioavailability from different iron chemical species for formula milk fortification

Iron fortification in infant formulas is a common practice for providing iron to newborns in order to avoid its deficiency (anemia). Depending on the physicochemical species used, its bioavailability might be insufficient to meet iron requirements. In this vein, the influence of Lactoferrin (Lf) presence on iron bioavailability in 2-week-old wistar rats fed with formula milk fortified with ⁵⁷ Fe(III)₂ -Lf or ⁵⁷ Fe(II)SO₄ (in presence of Lf) using quantitative speciation (by HPLC-ICP-MS) and Isotope Pattern Deconvolution (IPD) is studied here. Results obtained were compared among fortifiers and also with the maternal group. In RBCs, iron was mainly bound to hemoglobin in all the assayed groups in the same extent. Regarding serum samples, several iron-proteins were observed (such as transferrin and albumin). In both samples, iron content in the fractions studied was similar in all groups compared and exogenous ⁵⁷ Fe incorporation of intaked iron was always above 50%, showing no significative differences between physicochemical forms but related to the dose administered. Regarding iron stores (liver) the group fed with formula milk fortified with the higher dose of ⁵⁷ FeSO₄ in presence of Lf presented the highest values of total iron even superior than those found in the maternal group, and also the highest exogenous (⁵⁷ Fe) incorporation. In conclusion, it was proved that iron fortification is required to ensure proper iron levels in all body compartments. No significative differences were observed between different physicochemical species when iron is administered at low doses. However, higher iron doses lead to a greater incorporation in all the iron-proteins studied.

[Oxidative stress in perinatal asphyxia and hypoxic-ischaemic encephalopathy]

Birth asphyxia is one of the principal causes of early neonatal death. In survivors it may evolve to hypoxic-ischaemic encephalopathy and major long-term neurological morbidity. Prolonged and intense asphyxia will lead to energy exhaustion in tissues exclusively dependent on aerobic metabolism, such as the central nervous system. Energy deficit leads to ATP-dependent pumps blockage, with the subsequent loss of neuronal transmembrane potential. The most sensitive areas of the brain will die due to necrosis. In more resistant areas, neuronal hyper-excitability, massive entrance of ionic calcium, activation of NO-synthase, free radical generation, and alteration in mitochondrial metabolism will lead to a secondary energy failure and programmed neuronal death by means of the activation of the caspase pathways. A third phase has recently been described that includes persistent inflammation and epigenetic changes that would lead to a blockage of oligodendrocyte maturation, alteration of neurogenesis, axonal maturation, and synaptogenesis. In this scenario, oxidative stress plays a critical role causing direct damage to the central nervous system and activating metabolic cascades leading to apoptosis and inflammation. Moderate whole body hypothermia to preserve energy stores and to reduce the formation of oxygen reactive species attenuates the mechanisms that lead to the amplification of cerebral damage upon resuscitation. The combination of hypothermia with coadjuvant therapies may contribute to improve the prognosis.

Assessment of the global intelligence and selective cognitive capacities in preterm 8-year-old children

The aim of this study was to assess various cognitive abilities such as attention, IQ, reasoning, and memory related to academic achievement in 8- and 9-year-old preterm children. A total of 141 children were assessed. The preterm group (=37 weeks) comprised 63 children and was compared to 78 full-term children. Attention was evaluated using the d2 Selective Attention test, and the IQ by the L-M form of the Stanford-Binet Intelligence Scale, establishing a profile of abilities: perception, memory, comprehension, reasoning, and verbal fluency. Significant differences in IQ were found between the preterm and full-term children. Of the cognitive abilities assessed, the only significant differences were found in verbal fluency, with preterm boys showing lower verbal fluency scores than full-term children. In conclusion, all preterm groups have attention ability similar to that of full-term children. However, preterm children obtain lower scores in intelligence measures. In addition, preterm boys have verbal fluency difficulties. Taking into account the increase in preterm births, suitable intervention programs must be planned to attend the difficulties found.

[Usefulness of different risk factor associations in predicting admissions due to respiratory syncytial virus in premature newborns of 32 to 35 weeks gestation in Spain]

AIM

The aim of the study was to evaluate the risk factor associations for respiratory syncytial virus (RSV) hospitalization in preterm infants from 32 to 35 weeks gestation, treated during two consecutive RSV seasons in Spain.

PATIENTS AND METHODS

A database (FLIP-2) was used after excluding the infants who received prophylactic palivizumab. A total of 193 RSV+ admissions and 4568 non-hospitalized children were studied. The risk factors analyzed were: chronological age <=10 weeks at start of RSV season or to be born during the first 10 weeks of the season; school-age siblings or daycare attendance; mother smoking during pregnancy; male gender; breastfeeding <=2 months; >=4 adults at home; history of wheezing; small for gestational age; >=2 smokers at home.

RESULTS

Logistic regression model included the first four previously mentioned risk factors as independently significant variables, with R(2) of 0.062 and area under curve of 0.687 (P<0.001). Predictive values for a child with the four risk factors were: sensitivity 6.2%, specificity 98.6%, predictive positive value 16.2%, negative predictive value 96.1%, accuracy 94.9%, positive likelihood ratio 4.581, and negative likelihood ratio 0.951. Positive likelihood ratio for a child with the two major risk factors is 2.657.

CONCLUSIONS

Usefulness of different risk factor associations to predict hospitalization for respiratory syncytial virus infection in preterm infants 32 to 35 weeks gestation in Spain is low, although similar to other models.