Biomarkers of neonatal stress assessment: A prospective study

Fetal cardiac troponin I levels decline toward birth in sheep

Elevated cardiac troponin I (cTnI), a myocardial damage biomarker, has been reported in cord blood of neonates delivered vaginally or by cesarean section. Although the neonatal peak likely reflects the physiological adjustment to extrauterine life, a better understanding of serial prepartum changes is required to determine physiological causes of fetal cTnI release. We longitudinally sampled eight healthy lambs (20 days before spontaneous birth to 5 days postnatal), and from three fetuses receiving intravenous IGF-1. Samples were collected into heparin, and the plasma was stored at -80°C for later determination of high-sensitivity (hs) cTnI levels (BeckmanCoulter UniCel DxI Access IA; log transformed detection limit = 0.30, quantification limit = 0.78, 99th percentile = 1.78). Positive and negative control samples were drawn from an adult ewe during a terminal experiment (myocardial ischemia) and similarly assessed. hs-cTnI data were log transformed from ng/L. Log(hs-cTnI) was 1.47 ± 0.30 (means ± SD) at 20 days before birth and declined to 1.02 ± 0.65 in fetuses 12 ± 4 h before birth (P < 0.0001, R2 = 0.7869). Birth stimulated a delayed, transient peak in hs-cTnI (P = 0.0058). Newborn (43 ± 19 min postnatal) levels were 1.39 ± 0.40 (P = 0.0650 vs. fetus on day of birth) and 2.14 ± 0.63 the day after birth (P = 0.0331 vs. newborn). The second day after birth, levels declined to 1.65 ± 0.48 (P = 0.0238 vs. day 1). IGF-1 infusion increased hs-cTnI levels 25-50% over baseline (P = 0.0252, R2 = 0.9938). Baseline adult ewe log(hs-cTnI) was below the limit of detection; 3 h following coronary artery ligation, levels were 3.21. In conclusion, we newly report that fetal hs-cTnI levels decline concomitantly with reduced proliferation of cardiomyocytes toward term.NEW & NOTEWORTHY Serial blood samples were collected from catheterized, normally developing fetal and newborn lambs and high-sensitivity cardiac troponin I (hs-cTnI) levels were assessed, providing unprecedented insight into the physiological processes leading to high levels in the perinatal period. Moderately high levels of hs-cTnI found in the normally developing fetus declined toward term. An elevation to high levels peaked the day after birth, after which hs-cTnI declined again. Stimulation of fetal cardiomyocyte proliferation with IGF-1 also elevated hs-cTnI.

Copeptin levels in hospitalized infants and children with suspected vasopressin-dependent disorders: a case series

OBJECTIVES

There have been recent advances assessing copeptin levels in adults with suspected disorders of vasopressin release. Very limited data exits on copeptin levels in children and infants, especially in a critically-ill hospitalized population where hyper- and hypo-natremia are very common. Our objective is to describe the institutional experience assessing copeptin levels in hospitalized infants and children with hyper- or hypo-natremia.

METHODS

We performed a single-center retrospective case series of all infants, children, and adolescents who had an ultrasensitive plasma copeptin level obtained between 2019-2021.

RESULTS

A total of 29 critically ill patients (6 infants) were identified with 38 % of patients having copeptin levels after neurosurgical procedures for tumors or trauma. Approximately 13/17 children with hypernatremia had CDI to diagnose CDI, A copeptin level ≤ 4.9 pmol/L resulted in an 88 % sensitivity (95 % CI 47-99 %), and 66 % specificity (95 % CI 30-93 %). Amongst those with hyponatremia levels were more variable, 8/12 children had SIAD with copeptin levels ranging 4.7-72.6 pmol/L.

CONCLUSIONS

While difficult to conclude due to multiple limitations, this case series highlights that typical copeptin cutoffs used to diagnose DI in adults in an ambulatory setting may also translate to a critically-ill pediatric population. Large prospective studies are needed to confirm this observation. In addition, postoperative copeptin levels could potentially be utilized as an additional marker to predict permanent from transient DI, but much larger studies are needed. Further work is needed to establish normative copeptin levels in infants and patients with SIAD.

Neonatal heavy metals levels are associated with the severity of neonatal respiratory distress syndrome: a case–control study

Background

This case–control study aimed to compare lead (Pb), cadmium (Cd), and arsenic (As) levels in neonates with respiratory distress syndrome (NRDS) with those levels in normal neonates and tested their associations with the severity of NRDS indicated by the levels of serum surfactant protein D (SP-D) and cord blood cardiac troponin I (CTnI), and high-sensitive C-reactive protein (hs-CRP).

Methods

The study included two groups: G1 (60 healthy neonates) and G2 (100 cases with NRDS). Cord blood Pb, erythrocytic Cd (E-Cd), neonatal scalp hair As (N-As), maternal urinary Cd (U-Cd), and arsenic (U-As) were measured by a Thermo Scientific iCAP 6200, while CTnI, hs-CRP, and SP-D by their corresponding ELISA kits.

Results

The levels of cord blood Pb, E-Cd, N-As, U-Cd, U-As, SP-D, CTnI, and hs-CRP were significantly higher in G2 than G1 (p = 0.019, 0.040, 0.003, 0.010, 0.011, < 0.001, 0.004, < 0.001, respectively). While the birth weight, and APGAR score at 1, 5 and 10 min were significantly lower in G2 than G1 (p = 0.002, < 0.001, < 0.001, < 0.001, respectively). The levels of the studied heavy metals correlated positively with the levels of SP-D, CTnI, and hs-CRP.

Conclusion

Heavy metals toxicity may be accused to be one of the causes of NRDS especially if other apparent causes are not there. Measuring and follow-up of heavy metal levels should be considered during pregnancy.

Does the delivery mode affect post-birth neonatal serum C-reactive protein levels? A causal effect analysis

AIM

To determine if the delivery mode has a causal effect on neonatal serum C-reactive protein (CRP) levels. If such a causal effect exists, we aim to quantify its magnitude.

METHODS

We investigated the causal effect of the delivery mode on serum CRP levels 6-8 h after delivery, with appropriate statistical tools for retrospective studies, combining classical and machine-learning methods. The statistical inference is followed by sensitivity analysis to quantify the magnitude of unobserved bias required in order to alter the study's conclusion.

RESULTS

This retrospective study reviewed laboratory records of neonates after birth who underwent blood tests due to suspected sepsis. A total of 440 newborns were included, 324 of which underwent a vaginal delivery, 59 an urgent caesarean delivery, and 57 an elective caesarean delivery. Our results revealed that serum CRP values following elective caesarean deliveries were 50% less than those following a vaginal delivery (P = 0.030; -0.907; 95% CI [-1.545, -0.268] in log-CRP units). No significant effect was found for urgent caesarean deliveries compared to vaginal deliveries (P = 0.887). Those results were strengthened by (1) a sensitivity magnitude of 1.6 to unobserved bias and (2) non-significant effects when analysis is repeated on blood collected 12-24 h after birth.

CONCLUSION

CRP concentrations in neonatal blood during the first 6-8 h of life are higher following vaginal deliveries compared to elective caesarean deliveries. Further studies with the intent of improving EONS detection should include information on the delivery mode.

NT-proBNP Concentrations in the Umbilical Cord and Serum of Term Neonates: A Systematic Review and Meta-Analysis

The detection of NT-proBNP levels both in umbilical cord blood (UCB) samples and in serum samples collected from healthy term neonates during the neonatal period. A systematic review of relevant literature in accordance with PRISMA guidelines was conducted. For quality appraisal, the potential risk of bias was assessed using the BIOCROSS evaluation tool. The random-effects and fixed-effects models were used to calculate weighted mean differences with a corresponding 95% confidence interval. A total of forty (40) studies met the inclusion criteria for the systematic review. After further examination, eighteen (18) studies (1738 participants) from the UCB sample group and fourteen (14) studies (393 participants) from the serum sample group were selected to perform a meta-analysis. Using the fixed-effects model, the mean intervals of NT-proBNP in UCB and serum samples were 492 pg/mL (95% CI: 480−503 pg/mL) and 1341 pg/mL (95% CI: 1286−1397 pg/mL), respectively. A higher concentration of ΝΤ-proBNP was observed in the serum sample group compared to the UCB samples (p < 0.001). We present the intervals of NT-proBNP in UCB and in the serum of healthy term neonates. The determination of the potential effect of perinatal factors on the biomarker’s reference range was also aimed.

Hemodynamic changes and evaluation during hypoxic-ischemic encephalopathy and therapeutic hypothermia

Multiorgan damage is a hallmark of hypoxic-ischemic encephalopathy and cardiovascular and hemodynamic changes during asphyxia contribute significantly to the brain damage. The main insult to the heart is myocardial damage and associated ventricular dysfunction, which is manifested by reduced preload and afterload. The immature myocardium reacts to asphyxia by bradycardia and reduced contractile capacity. Pulmonary hypertension aggrevates cardiac dysfunction. Hypothermia is the only effective treatment for HIE but it may also affect the heart and peripheral vascular system leading to bradycardia and peripheral vasoconstriction. In fact, these effects might be cardioprotective also. Rewarming after hypothermia may increase the heart rate and cardiac metabolism, augmenting the cardiac output. Monitoring of patient with HIE during and after hypothermia is possible by using near-infrared spectroscopy, echocardiography and electrocardiography. Cerebral effects may be monitored by magnetic resonance imaging also. Management should include the physiological status of the patient and appropriate treatments, including inotropes, vasopressors or rarely fluid boluses. Dopamine should not be used unless absolutely necessary. Drugs like melatonin and magnesium are under investigation. All treatments should be evidence-based and targeted echocardiography should be used more often in these vulnerable infants.

Copeptin Concentrations in Plasma of Healthy Neonates in Relation to Water–Electrolyte Homeostasis in the Early Adaptation Period

Copeptin (CTproAVP) is a stable by-product of arginine–vasopressin synthesis and reflects its secretion by the pituitary gland, considered as a potential new marker of dehydration. The objective of the study was to investigate CTproAVP measured after the first 48 h of postnatal life in relation to serum effective osmolality, urine osmolality, and vessels filling according to the following variables: delivery mode, postnatal weight loss, fluids administered intravenously to the mother, and fluids given orally to the neonate. A prospective observational study was conducted with 200 healthy term infants (53% male) enrolled. Serum CTproAVP concentrations were measured using the ELISA kit; haematocrit, urine osmolality, serum effective osmolality were assessed after 48 h of life. Sonographic measurements of inferior vena cava (IVC) and aorta (Ao) were performed and IVC/Ao ratios were calculated. No correlations were found between CTproAVP concentrations and both serum effective osmolality and urine osmolality. There was also no association between CTproAVP concentrations and vessel filling represented by IVC/Ao index at 48 h of life.

Copeptin and Stress

Vasopressin (AVP) and copeptin are released in equimolar amounts from the same precursor. Due to its molecular stability and countless advantages as compared with AVP, copeptin perfectly mirrors AVP presence and has progressively emerged as a reliable marker of vasopressinergic activation in response to osmotic and hemodynamic stimuli in clinical practice. Moreover, evidence highlighting the prognostic potential of copeptin in several acute diseases, where the activation of the AVP system is primarily linked to stress, as well as in psychologically stressful conditions, has progressively emerged. Furthermore, organic stressors induce a rise in copeptin levels which, although non-specific, is unrelated to plasma osmolality but proportional to their magnitude: suggesting disease severity, copeptin proved to be a reliable prognostic biomarker in acute conditions, such as sepsis, early post-surgical period, cardiovascular, cerebrovascular or pulmonary diseases, and even in critical settings. Evidence on this topic will be briefly discussed in this article.

Use of Copeptin Levels to Predict the Resolution of Transient Postoperative SIADH

BACKGROUND

Copeptin levels reflect vasopressin activity and help classify osmoregulatory disorders. There is limited pediatric experience using copeptin to diagnose and manage diabetes insipidus, syndrome of inappropriate antidiuretic hormone secretion (SIADH), and bi- or tri-phasic postsurgical osmoregulatory disorders. In this report, we describe serial copeptin levels in an infant who developed transient SIADH after neurosurgery.

CASE DESCRIPTION

A 4-month-old infant with no prior pituitary dysfunction underwent endoscopic fenestration of a large arachnoid cyst (3.5 × 4.7 × 3.8 cm). He developed SIADH on postoperative day 4 with seizures, hyponatremia (sodium 121 mmol/L), and concentrated urine (535 mOsm/kg). His initial copeptin level was inappropriately high in the context of his hyponatremia. Copeptin levels decreased as his SIADH resolved. Serial copeptin levels correlated to the infant's increased ability to dilute urine.

CONCLUSION

Copeptin levels in this infant are consistent with levels described in adults and older children. Obtaining copeptin levels may improve providers' ability to quickly diagnose and manage SIADH amongst other heterogeneous causes of hyponatremia. Lastly, trending copeptin levels improved providers' ability to monitor SIADH progression, and may allow preemptive fluid titration for children with bi- or tri-phasic shifts in osmoregulation after neurological procedures.

Prenatal Particulate Matter (PM) Exposure and Natriuretic Peptides in Newborns from Mexico City

(1) Background: The aim of this study was to assess associations between particulate matter (PM) exposure and natriuretic peptide concentrations in cord blood from newborns. (2) Methods: we conducted a cross-sectional study in Mexico City with 101 pregnant women from CIMIGEN Hospital. Atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) were measured in plasma from cord blood in 51 newborns by ELISA. We estimated PM exposure (PM2.5 and PM10) at first, second and third trimester of pregnancy. (3) Results: The median and interquartile range for ANP, BNP and CNP plasma concentrations were 66.71 (46.92-80.23), 98.23 (73.64-112.30) and 1129.11 (944.10-1452.02) pg/mL, respectively. PM2.5 and PM10 levels for the whole pregnancy period were 22.2 µg/m³ and 41.63 µg/m³, respectively. Employing multivariable linear regression models adjusted for maternal age, newborn sex, smoking before pregnancy, maternal occupation and newborns' length and height, we observed a 2.47 pg/mL (95%CI: -4.67, -0.27) decrease in BNP associated with PM2.5 exposure during second trimester. Adjusted for the same set of confounders, third trimester PM10 exposure was inversely associated with ANP concentrations (beta estimate: -0.90; 95% CI: -1.80, -0.03). Neither PM10 nor PM2.5 were associated with CNP at any trimester of pregnancy. (4) Conclusions: Prenatal exposure to particulate matter was associated with ANP and BNP decrease in newborns.

Vasopressin-Dependent Disorders: What Is New in Children?

Arginine vasopressin (AVP)-mediated osmoregulatory disorders, such as diabetes insipidus (DI) and syndrome of inappropriate secretion of antidiuretic hormone (SIADH) are common in the differential diagnosis for children with hypo- and hypernatremia and require timely recognition and treatment. DI is caused by a failure to concentrate urine secondary to impaired production of or response to AVP, resulting in hypernatremia. Newer methods of diagnosing DI include measuring copeptin levels; copeptin is AVP's chaperone protein and serves as a surrogate biomarker of AVP secretion. Intraoperative copeptin levels may also help predict the risk for developing DI after neurosurgical procedures. Copeptin levels hold diagnostic promise in other pediatric conditions, too. Recently, expanded genotype and phenotype correlations in inherited DI disorders have been described and may better predict the clinical course in affected children and infants. Similarly, newer formulations of synthetic AVP may improve pediatric DI treatment. In contrast to DI, SIADH, characterized by inappropriate AVP secretion, commonly leads to severe hyponatremia. Contemporary methods aid clinicians in distinguishing SIADH from other hyponatremic conditions, particularly cerebral salt wasting. Further research on the efficacy of therapies for pediatric SIADH is needed, although some adult treatments hold promise for pediatrics. Lastly, expansion of home point-of-care sodium testing may transform management of SIADH and DI in children. In this article, we review recent developments in the understanding of pathophysiology, diagnostic workup, and treatment of better outcomes and quality of life for children with these challenging disorders.

Early postnatal changes of circulating N-terminal-pro-B-type natriuretic peptide in neonates with congenital diaphragmatic hernia

BACKGROUND

Severity of lung hypoplasia, pulmonary hypertension (PH) and cardiac dysfunction are major contributors to mortality in congenital diaphragmatic hernia (CDH). Therefore, early assessment and management is important to improve outcome. NT-proBNP is an established cardiac biomarker with only limited data for early postnatal risk assessment in CDH newborns.

AIMS

To investigate the correlation of NT-proBNP at birth, 6 h, 12 h, 24 h, and 48 h with PH and cardiac dysfunction and the prognostic information of NT-proBNP for the use of ECMO support or mortality.

SUBJECTS

44 CDH newborns treated at our institution (December 2014-October 2017) were prospectively enrolled.

OUTCOME MEASURES

Primary clinical endpoint was either need for ECMO or death within the first 48 h (group A). Infants not receiving ECMO support were allocated to group B. Mortality was tested as secondary endpoint.

RESULTS

NT-proBNP levels measured at 6 h, 12 h, 24 h and 48 h postpartum correlated significantly with PH severity following NICU admission and at 24 h, and with severity of cardiac dysfunction at birth, 24 h, 48 h and after 7 days of life. There was no difference in NT-proBNP levels between survivors and non-survivors. NT-proBNP levels were significantly higher in group A at 6 h (p = 0.007), 12 h (p = 0.036), and 24 h (p = 0.007), but not at birth (p = 0.785) or 48 h (p = 0.15) compared to group B.

CONCLUSION

NT-proBNP analysis in the first 48 h of life may be useful to assess PH and cardiac dysfunction in CDH newborns and to predict the need for ECMO support.

Getting an Early Start in Understanding Perinatal Asphyxia Impact on the Cardiovascular System

Perinatal asphyxia (PA) is a burdening pathology with high short-term mortality and severe long-term consequences. Its incidence, reaching as high as 10 cases per 1000 live births in the less developed countries, prompts the need for better awareness and prevention of cases at risk, together with management by easily applicable protocols. PA acts first and foremost on the nervous tissue, but also on the heart, by hypoxia and subsequent ischemia-reperfusion injury. Myocardial development at birth is still incomplete and cannot adequately respond to this aggression. Cardiac dysfunction, including low ventricular output, bradycardia, and pulmonary hypertension, complicates the already compromised circulatory status of the newborn with PA. Multiorgan and especially cardiovascular failure seem to play a crucial role in the secondary phase of hypoxic-ischemic encephalopathy (HIE) and its high mortality rate. Hypothermia is an acceptable solution for HIE, but there is a fragile equilibrium between therapeutic gain and cardiovascular instability. A profound understanding of the underlying mechanisms of the nervous and cardiovascular systems and a close collaboration between the bench and bedside specialists in these domains is compulsory. More resources need to be directed toward the prevention of PA and the consecutive decrease of cardiovascular dysfunction. Not much can be done in case of an unexpected acute event that produces PA, where recognition and prompt delivery are the key factors for a positive clinical result. However, the situation is different for high-risk pregnancies or circumstances that make the fetus more vulnerable to asphyxia. Improving the outcome in these cases is possible through careful monitoring, identifying the high-risk pregnancies, and the implementation of novel prenatal strategies. Also, apart from adequately supporting the heart through the acute episode, there is a need for protocols for long-term cardiovascular follow-up. This will increase our recognition of any lasting myocardial damage and will enhance our perspective on the real impact of PA. The goal of this article is to review data on the cardiovascular consequences of PA, in the context of an immature cardiovascular system, discuss the potential contribution of cardiovascular impairment on short and long-term outcomes, and propose further directions of research in this field.