Adverse Fetal and Neonatal Outcomes Associated with a Life-Long High Fat Diet: Role of Altered Development of the Placental Vasculature

Maternal obesity results in a number of obstetrical and fetal complications with both immediate and long-term consequences. The increased prevalence of obesity has resulted in increasing numbers of women of reproductive age in this high-risk group. Since many of these obese women have been subjected to hypercaloric diets from early childhood we have developed a rodent model of life-long maternal obesity to more clearly understand the mechanisms that contribute to adverse pregnancy outcomes in obese women. Female Sprague Dawley rats were fed a control diet (CON - 16% of calories from fat) or high fat diet (HF - 45% of calories from fat) from 3 to 19 weeks of age. Prior to pregnancy HF-fed dams exhibited significant increases in body fat, serum leptin and triglycerides. A subset of dams was sacrificed at gestational day 15 to evaluate fetal and placental development. The remaining animals were allowed to deliver normally. HF-fed dams exhibited a more than 3-fold increase in fetal death and decreased neonatal survival. These outcomes were associated with altered vascular development in the placenta, as well as increased hypoxia in the labyrinth. We propose that the altered placental vasculature may result in reduced oxygenation of the fetal tissues contributing to premature demise and poor neonatal survival

Could Near Infrared Spectroscopy (NIRS) be the new weapon in our fight against Necrotising Enterocolitis?

There is no ideal single gut tissue or inflammatory biomarker available to help to try and identify Necrotising Enterocolitis (NEC) before its clinical onset. Neonatologists are all too familiar with the devastating consequences of NEC, and despite many advances in neonatal care the mortality and morbidity associated with NEC remains significant. In this article we review Near Infrared Spectroscopy (NIRS) as a method of measuring regional gut tissue oxygenation. We discuss its current and potential future applications, including considering its effectiveness as a possible new weapon in the early identification of NEC

Respiratory Management of Newborns

In this book, you'll learn multiple new aspects of respiratory management of the newborn. For example, ventilator management of infants with unusually severe bronchopulmonary dysplasia and infants with omphalocele is discussed, as well as positioning of endotracheal tube in extremely low birth weight infants, noninvasive respiratory support, utilization of a protocol-driven respiratory management, and more. This book includes a chapter on noninvasive respiratory function monitoring during chest compression, analyzing the efficacy and quality of chest compression and exhaled carbon dioxide. It also provides an overview on new trends in the management of fetal and transitioning lungs in infants delivered prematurely. Lastly, the book includes a chapter on neonatal encephalopathy treated with hypothermia along with mechanical ventilation. The interaction of cooling with respiration and the strategies to optimize oxygenation and ventilation in asphyxiated newborns are discussed

The Association of Kangaroo Mother Care, Energy Conservation, and Bonding in Preterm Neonates

Purpose:To examine the association of kangaroo mother care (KMC) on energy utilization and bonding as evidenced by reduced biochemical markers of adenosine triphosphate (ATP) degradation, hypoxanthine (Hx), xanthine (Xa), and uric acid (UA), and (allantoin), a measure of oxidative stress in preterm infants 24-36 weeks gestation. A secondary objective was to compare specific physiological parameters using bedside monitoring and perfusion and oxygenation of the gut using near-infrared spectroscopy (NIRS) during 1 hour of KMC compared to incubator care. Study design: A randomized controlled trial (RCT) examining the effects of 1-hour of KMC or 1-hour incubator care on urinary markers from samples collected 3-6 hrs before, and 3-6 hours after KMC. Preterm infants (n = 51) were assigned to intervention/control groups using stratified randomization based on weight. Urine concentrations of Hx, Xa, and UA were measured using high performance liquid chromatography (HPLC) and allantoin was quantified using gas chromatography-mass spectrometry (GC-MS) methods. Bonding was measured using the Mother-to-infant Bonding Scale, a reliable 8-item self-assessment scale linking early maternal moods to difficulties in bonding. Psychometric properties have demonstrated a two-factor model, good predictive validity, a sensitivity of 0.90 and specificity of 0.80 for a threshold score ≥ 2, and acceptable internal consistency (a= 0.71). Physiologic measures were captured using bedside monitoring and abdominal NIRS to capture gut perfusion and oxygenation. Results: There was a decrease in oxidative stress (p= 0.026) in the KMC group compared to incubator group.In both groups there were trending improvement in uric acid (p = 0.025) and xanthine (p= 0.042) over time, and in abdominal temperatures (p = 0.004) and perfusion index (p = 0.031) over time. No other physiologic or urinary measures showed statistically significant changes either between the groups or over time. A mixed model analysis of variance (ANOVA) was conducted with the use of unstructured covariance matrix adjusted using the Bonferroni method to assess the changes in the outcome measures of urinary purines and physiological measures. Mother-Infant Bonding scores were calculated using relative risk. The number and percentage of subjects who changed their MIBS scores from baseline to time 3 were measured, and the comparison of these changes between the KMC on DOL 3 and DOL 4 as measured by the Mother-Infant-Bonding-Scale (MIBS) in intervention and control groups were calculated. We found that scores showed that KMC mothers showed a higher risk of bonding problems than those in the control group. Nineteen percent more mothers in KMC group demonstrated an increase in MIBS score or a 26 percent increase relative risk for an increase of score (RR=1.26; 95% CI 0.97,1.63). However, the results were not statistically significant as the null value was included in the 95% confidence interval. Significance was set at an alpha of 0.05. Conclusions: This is the first study of its kind to evaluate the association of KMC on biochemical markers of stress and physiological parameters of abdominal near-infrared spectroscopy (NIRS) and abdominal temperatures in preterm infants 24-36 weeks gestation. The results of this study suggest that stress and inflammatory processes are decreased in the presence of KMC. Further research is needed to understand the role of biochemical markers and KMC and its implications in nursing research in preterm neonates and improved outcomes. This study has the potential to provide the physiological data to further support the benefits of energy conservation for recovery and growth in neonates

Measurement and Assessment of Work of Breathing in Neonates During Nasal Continuous Positive Airway Pressure Therapy

Introduction: Nasal continuous positive airway pressure (nCPAP) is a widely used form of non-invasive respiratory support in neonates. The general aim of nCPAP therapy is to improve lung volume, oxygenation and decrease work of breathing. There is little data to guide clinicians on how to adjust the pressure and what parameter nCPAP should be titrated against. This is due to the lack of commercially available equipment to measure lung mechanics in patients receiving non-invasive respiratory support. In mechanically ventilated patients, measurements of work of breathing have been found to be useful in optimising ventilation strategies. An indicator of work of breathing or estimate of the metabolic and oxygen cost of breathing is the pressure time product (PTP). Objectives: To develop a monitoring system for the measurement of work of breathing in neonates on nCPAP, to investigate the effects of different nCPAP levels on PTP and to identify non-invasively determined predictors of PTP. Methods: PTP’s (PTPoe=oesophageal, PTPga=gastric and PTPdi=diaphragmatic pressure time product) derived by oesophageal gastric pressure transducer was compared with parameters derived by respiratory inductance plethysmography. Subjects were randomised to receive nCPAP level sequences of 2, 4, 6 and 8 cmH2O. Main results 37 of 57 subjects were analysed. Median gestational age 30 ± 4.9 weeks, median birth weight 1234 ± 443 g, chronological age ≤ 24 hours 24 subjects (64.9%) and baseline FiO2 ≤ 0.35. PTP’s decreased with increasing nCPAP level (p < 0.05). “Optimal” nCPAP as determined by the lowest PTPoe and PTPdi occurred between 6-8 cmH2O for 56% of the subjects. “Optimal” nCPAP as defined by the lowest PTPga occurred between 6-8 cmH2O for 39% of the subjects. Respiratory rate, abdominal excursion decreased, Te increased and heart rate remained unchanged with increased nCPAP level. PTPoe correlated best out of all three PTP’s with selected variables derived by non-invasive techniques. Respiratory rate explained 36.7% of the variance of PTPoe and abdominal excursion explained 45.5% of the variance of PTPoe. Best fitted prediction model for PTPoe included respiratory rate, phase angle, abdominal excursion, birth weight, gestational age and applied nCPAP level and explained 65.8% of the variance of PTPoe. One suspected pneumothorax was reported (1.7%). Conclusion: Respiratory muscle work load is affected by changes in nCPAP levels and can be predicted more accurately by a model consisting of respiratory rate, phase angle, abdominal excursion, gestational age and birth weight than by clinical parameters alone

Objective Assessment of Physiologic Alterations Associated with Hemodynamically Significant Patent Ductus Arteriosus in Extremely Premature Neonates

Delay in closure of ductus arteriosus in postnatal life may lead to serious consequences and complications in an extremely premature neonate secondary to hemodynamic alterations in regional blood flow pattern in various organs. Despite the widespread recognition amongst neonatologists to identify a hemodynamically significant patent ductus arteriosus (hsPDA) early in the postnatal course, there is lack of consensus in its definition and thus the threshold to initiate treatment. Echocardiographic assessment of PDA shunt size and volume combined with neonatologists\u27 impression of clinical significance is most frequently used to determine the need for treatment of PDA. Common clinical signs of hsPDA utilized as surrogate for decreased tissue perfusion may lag behind early echocardiographic signs. Although echocardiogram allows direct assessment of PDA shunt and hemodynamic alterations in the heart, it is limited by dependence on pediatric cardiologist availability, interobserver variation and isolated time point assessment. Electrical cardiometry (EC) is a non-invasive continuous real time measurement of cardiac output by applying changes in thoracic electrical impedance. EC has been validated in preterm newborns by concomitant transthoracic echocardiogram assessments and may be beneficial in studying changes in cardiac output in premature newborns with hsPDA. Alterations in perfusion index derived from continuous pulse oximetry monitoring has been used to study changes in cardiac performance and tissue perfusion in infants with PDA. Near infrared spectroscopy (NIRS) has been used to objectively and continuously assess variations in renal, mesenteric, and cerebral oxygen saturation and thus perfusion changes due to diastolic vascular steal from hsPDA in preterm neonates. Doppler ultrasound studies measuring resistive indices in cerebral circulation indicate disturbance in cerebral perfusion secondary to ductal steal. With recent trends of change in practice toward less intervention in care of preterm newborn, treatment strategy needs to be targeted for select preterm population most vulnerable to adverse hemodynamic effects of PDA. Integration of these novel ways of hemodynamic and tissue perfusion assessment in routine clinical care may help mitigate the challenges in defining and targeting treatment of hsPDA thereby improving outcomes in extremely premature neonates

Necrotizing enterocolitis : imaging and risk assessment

Despite decades of research on necrotizing enterocolitis (NEC), no major finding has improved the mortality and morbidity of the disease or changed the clinical management. The exact pathogenesis remains unclear, but several factors such as immature intestinal immunity, impaired bowel microcirculation, enteral nutrition and abnormal microbiota may play important roles. In the post-surfactant era, the NEC patient population has changed, with an increasing proportion of extremely preterm infants. Plain abdominal radiography is still considered the gold standard imaging technique for NEC. Unfortunately, abdominal radiography has low sensitivity and specificity, making the decision to intervene surgically very challenging. Recent studies have shown the increasing role of abdominal ultrasound and near-infrared spectroscopy in the diagnosis and monitoring of NEC. The overall aim of this project was to describe the preterm infants at risk of NEC and how those who develop severe NEC and need surgical treatment could be identified early, using new imaging techniques and monitoring. The aim of Paper I was to describe the difference in the clinical and radiological presentation of NEC in extremely preterm infants compared with more mature ones. Extremely preterm infants show less typical signs of NEC, such as bloody stool or pneumatosis intestinalis, compared with more mature neonates. The aim of Paper II was to assess if splanchnic oxygenation, as measured by near infrared spectroscopy (NIRS), in the first week of life is associated with the risk of developing necrotizing enterocolitis. Extremely preterm infants underwent NIRS monitoring during enteral nutrition. Low mean splanchnic oxygenation, below 30%, was associated with an increased risk of developing necrotizing enterocolitis during enteral nutrition in the first days of life. The aim of Paper III was to determine whether a correlation exists between the sonographic findings and the clinical outcomes, defined as surgery or death in infants with NEC. Infants with a confirmed diagnosis of NEC, who underwent an abdominal ultrasound, were included in the study. The sonographic sign of complex fluid collections appeared to be strongly correlated with the need for surgery in infants with severe NEC. The aim of Paper IV was to assess if hyponatremia, or worsening of already present hyponatremia, at the onset of necrotizing enterocolitis is associated with intestinal inflammation and ischaemia requiring surgery or death. In this cohort study, neonates with a confirmed diagnosis of NEC were included. Hyponatremia and a sudden decrease in plasma sodium concentration at the onset of NEC can be useful markers for severe intestinal inflammation/ischemia where an imminent need for surgery can be expected

Ventilatory Support, Extubation and Cerebral Perfusion Changes in Preterm: a NIRS study

Objective: to investigate any change in cerebral oxygenation (rScO2) and fractional tissue oxygen extraction (cFTOE) after extubation in preterm infant. Study design: single-centre observational study with retrospective analysis of near infrared spectroscopy (NIRS) data of all consecutive preterm patient born at our institution in 1 year. Correlation analysis and comparison between subgroups was made. Result: 19 patients were included; average gestational age (GA): 29,4 weeks.No significant change was noted in rScO2 and cFTOE after extubation in whole population. A correlation between GA, GMH-IVH and DrScO2, DcFTOE were noted. A significant increase of cFTOE was noted in patient with previous GMH-IVH (+0.040; p=0.036). Conclusion: extubation per se is not linked with significant change in cerebral oxygenation and perfusion. Patient with GMH-IVH shows an increase in cFTOE suggesting a perturbation in cerebral perfusion.Further observations on larger populations should corroborate this data highlighting cautious extubation in preterm babies with GMH-IVHpe