Immature control of breathing and apnea of prematurity: the known and unknown

Roflumilast, a phosphodiesterase-4 (PDE4) inhibitor, induces respiratory frequency plasticity that is resistant to inflammation in neonatal rat in vitro preparations

Premature and newborn infants often have prolonged apneas and are susceptible to bacterial infections that further disrupt breathing. Phoshodiesterase-4 (PDE4) inhibitor drugs increase inspiratory motor activity and appear to induce a long-lasting increase in inspiratory frequency ("frequency plasticity"). To test whether a PDE4 inhibitor drug induces frequency plasticity, neonatal rat brainstem-spinal cords were isolated and exposed to bath-applied roflumilast (10 min, 0.02-1.0 µM). Roflumilast acutely increased burst frequency and induced frequency plasticity in a concentration-dependent manner. Blockade of protein kinase A (PKA) or exchange protein activated by cAMP (EPAC) signaling pathways abolished the induction, but not the maintenance, of roflumilast-induced frequency plasticity. Brainstem-spinal cords isolated from neonatal rats injected with lipopolysaccharide (LPS, 0.1 mg/kg, 3 h prior) expressed frequency plasticity following bath-applied roflumilast at 0.05-0.5 µM, but not at lower concentrations. This shows that roflumilast-induced frequency plasticity is largely resistant to LPS-induced inflammation. Thus, roflumilast increases inspiratory burst frequency acutely and induces frequency plasticity even during ongoing inflammation, which could have important clinical implications.

A family-centric, comprehensive nurse-led home oxygen programme for neonatal chronic lung disease: home oxygen policy evaluation (HOPE) study

OBJECTIVES

Considerable variation and little objective evidence exists to guide the use of supplemental oxygen therapy in infants with neonatal chronic lung disease (nCLD) after hospital discharge. We developed a new policy utilizing regular oximetry downloads to help determine commencement and titration of low flow oxygen. The aim of this policy is to improve safety and uniformity in practice and potentially lead to improvements in outcomes including the number of infants being discharged on home oxygen therapy (HOT) and length of stay (LOS).

METHODS

This single-centre pre- and post-implementation study included 86 and 94 infants <32 weeks' gestation (pre- vs. post-implementation) meeting definition of nCLD. The primary outcomes were (1) successful implementation of the new policy, (2) changes in number of patients discharged on HOT and (3) in LOS. Secondary outcomes were changes in feeding mode at discharge, total length of HOT, readmission to hospital within the first year of life and neurodevelopmental outcomes at 8 months post menstrual age amongst infants treated with HOT.

RESULTS

The policy was successfully implemented with 100 % of infants with nCLD receiving downloads in the post-implementation epoch. Pre-implementation 36 % (31 of 85) of infants with nCLD were treated with HOT vs. 17 % (16 of 94) post-implementation (p=0.03). There was no significant difference in LOS or any of the secondary outcomes.

CONCLUSIONS

A protocolised approach to decision making using predetermined parameters regarding the need for supplemental oxygen in neonates with nCLD is practical and achievable and may result in fewer neonates requiring HOT.

Electrical impedance tomography in neonates: a review

Appropriate interventions informed by real-time assessment of pulmonary function in mechanically ventilated critically ill neonates can reduce the incidence of bronchopulmonary dysplasia, pneumothorax, intraventricular hemorrhage and other complications of newborn life. The respiratory system in neonates is uniquely different from older children, and its physiological and anatomic attributes increase neonatal vulnerability to respiratory distress and eventual failure. While significant advancements have been made in developing respiratory support for neonates, such support is accompanied by inherent risks to their delicate lungs. Ventilator-associated lung injury poses a critical concern that can be potentially decreased with more precise, non-invasive, non-radiating, bedside methods for assessing neonatal pulmonary function in real time. Electrical impedance tomography (EIT) is one such tool, with immense potential for real-time pulmonary function monitoring in neonates. Still relatively new and in the earliest stages of clinical adoption, EIT use in neonatal critical care has been reported in several studies. This review discusses the basic features of EIT, its distinct advantages over traditional pulmonary function monitoring tools, the scope of its adoption in neonatal clinical practice, challenges associated with clinical adoption, and prospects for future applications. IMPACT: 1. Individualized care assisted by bedside pulmonary function monitoring can positively impact neonatal critical care and outcomes. 2. Electrical impedance tomography (EIT) has the potential to improve neonatal pulmonary function monitoring and treatment outcomes. 3. Electrical impedance tomography can be adopted as a part of routine neonatal respiratory critical care, especially in the population of patients most at risk for bronchopulmonary dysplasia and acute respiratory complications.

Prenatal Risk Factors for Brief Resolved Unexplained Events in Infants

BACKGROUND

Prenatal factors have been implicated in the likelihood of reporting sleep disorders in infants. The influence of prenatal and pregnancy-related factors on the incidence of brief resolved unexplained events (BRUEs) in infants has not been established.

OBJECTIVES

This study aims to evaluate the prenatal and pregnancy-related factors that may contribute to the development of BRUEs in infants.

METHODS

A single-center, observational, and cross-sectional cohort study was conducted on mothers of children presenting to the Pediatric Clinic of the University of Insubria's Center for the Study of Respiratory Sleep Disorders with BRUEs as infants. The mothers of typically developing children were enrolled as a control group consecutively at their respective outpatient clinics. All mothers were administered comprehensive questionnaires including demographics, past medical histories, and pregnancy-related issues (weight gain, Berlin sleep-disordered breathing score, and insomnia severity index), psychological symptoms, medical history, illnesses, and medications.

RESULTS

Infants with BRUEs were delivered at an earlier gestational age. Mothers of infants with BRUEs were more likely to snore during pregnancy and have lower extremity edema during the first trimester, uterine contractions and restless legs syndrome symptoms during the second trimester, and muscle aches and aspirin usage during the third trimester. The insomnia severity index composite score was not different between the control and BRUE groups. Mothers of infants with BRUEs were less likely to report leg cramps, pregnancy-related diarrhea, fatigue, and gastroesophageal reflux.

CONCLUSIONS

Mothers of infants presenting with BRUEs had more symptoms during pregnancy of snoring and uterine contractions but not insomnia and were less likely to report leg cramps, pregnancy-related diarrhea, fatigue, and gastroesophageal reflux. The reporting of this study conforms with the STROBE statement.

Clinical efficacy of different maintenance doses of caffeine citrate in the treatment of apnea of prematurity

Objective

To investigate the efficacy and adverse reactions of caffeine citrate in the treatment of primary apnea of prematurity(AOP) and its effect on the long-term development of preterm infants.

Methods

This was a retrospective study. One hundred and forty six infants with AOP treated in the Neonatal Department of Second People's Hospital of Changzhou Affiliated to Nanjing Medical University between December 2019 and December 2023 were divided into the low-dose group (5mg/kg) and the high-dose group (10 mg/kg) according to the maintenance doses of caffeine, with 73 patients each group. Efficacy, complications, adverse reactions, total hospitalization cost and long-term development of the two groups of patients were retrospectively compared.

Results

Short-term efficacy: No statistically significant differences in the number of apnea events, assisted ventilation duration, oxygen inhalation duration, and weaning success rate were observed between the two groups (P<0.05). The incidences of bronchopulmonary dysplasia (BPD) (P=0.012) and periventricular leukomalacia (PVL) (P=0.005) in the high-dose group were decreased compared with those in the low-dose group, with statistically significant differences. Long-term efficacy: the motor and mental development scores at 12 months of age in the high-dose group were increased compared with those in the low-dose group (P<0.05); and cost-effect analysis: there was no significant difference in the total hospitalization cost between the two group (P>0.05).

Conclusion

High maintenance dose of citrate caffeine in the treatment of AOP significantly reduces the number of apnea events, oxygen inhalation duration, the incidence of BPD and PVL, and positively affects the long-term neurological and motor development, without a significant increase in the hospitalization cost.

The effect of an additional pre-extubational loading dose of caffeine citrate on mechanically ventilated preterm infants (NEOKOFF trial): Study protocol for a multicenter randomized clinical trial

BACKGROUND

Minimizing the duration of mechanical ventilation is one of the most important therapeutic goals during the care of preterm infants at neonatal intensive care units (NICUs). The rate of extubation failure among preterm infants is between 16% and 40% worldwide. Numerous studies have been conducted on the assessment of extubation suitability, the optimal choice of respiratory support around extubation, and the effectiveness of medical interventions. Since the Caffeine Therapy for Apnea of Prematurity (CAP) trial, caffeine has become one of the essential drugs at NICUs. However, the optimal dosage and timing for adequate effectiveness still need to be more conclusive. Previous studies suggest that higher doses of caffeine treatment increase the success rate of extubation. Therefore, we aim to determine whether using a single additional loading dose of caffeine citrate one hour prior to extubation impacts the success rate of extubation.

METHODS

The study is an open-label, multicenter randomized clinical trial testing the effectiveness and safety of pre-extubational loading dose of caffeine citrate. Inclusion criteria will be infants born before the 32nd gestational week, before the first extubation attempt after at least 48 hours of mechanical ventilation, and a signed parental informed consent. A total of 226 patients will be randomly allocated to either the experimental or control group. The randomization will be stratified by gestational age and antenatal steroid prophylaxis. Preterm infants in the experimental group will receive an additional intravenous (IV) loading dose (20 mg/kg) of caffeine citrate one hour before the first planned extubation, in addition to the standard dosing regimen (20 mg/kg caffeine citrate IV on the first day of life and 5 to 10 mg/kg IV or orally caffeine citrate each consecutive day). Preterm infants in the control group will receive the standard dosing regimen. The primary outcome will be reintubation within 48 hours.

DISCUSSION

A pre-extubational loading dose of caffeine citrate can reduce extubation failure. Obtaining evidence on this feature has the potential to contribute to finding the optimal dosing regimen.

TRIAL REGISTRATION NUMBER

The study protocol was approved by the Hungarian Ethics Committee for Clinical Pharmacology of the Medical Research Council and National Institute of Pharmacy and Nutrition (OGYÉI/6838-11/2023). ClinicalTrials.gov identifier NCT06401083 Registered 06. May 2024.; EudraCT number: 2022-003202-77.

Preoperative Challenges for Pediatric Ambulatory Surgery

The demand for ambulatory anesthesia in pediatric surgery has been increasing, reflecting a significant shift over recent decades toward performing a growing number of procedures in an outpatient setting.1 The growing shortage of pediatric anesthesiologists, coupled with an increase in pediatric ambulatory surgery volumes, will require general anesthesiologists to deliver anesthesia care to children. Children with prematurity, hypotonia, upper respiratory tract infections (URTI), obesity, and congenital heart disease (CHD) are frequently encountered in the ambulatory setting and present significant challenges for ambulatory anesthesiologists. In addition, the management of preoperative fasting, pregnancy testing, and perioperative anxiety further complicates the care of a pediatric patient. This review will examine the existing evidence and provide guidance for ambulatory anesthesiologists on preoperative considerations for pediatric patients undergoing ambulatory surgical procedures.

Physiological basis of non-invasive ventilation in the newborn

Non-invasive ventilation (NIV) is a form of respiratory support provided primarily to preterm born infants in an effort to avoid any endotracheal intubation or as a weaning step following invasive ventilation. In the context of the respiratory distress syndrome of the newborn, NIV could target and partially reverse specific pathophysiological phenomena, by improving alveolar recruitment and establishing adequate functional residual capacity. It can also assist in minimizing lung injury by avoiding excessive pressure delivery, which can be harmful for the developing lung. Non-invasive ventilation can unload the respiratory muscles and decrease the work of breathing as reported by studies that compare the measured work of breathing at increasing levels of non-invasive support. NIV can also be beneficial in moderating the frequency and intensity of apnea of prematurity. Unintended physiological effects of NIV include gaseous distension of the gastrointestinal tract and increased incidence of air-leak complications. During NIV there is also a lack of direct access to the trachea for suctioning and pulmonary toiletry. Insufficient non-invasive respiratory support could be associated with inadequate oxygenation and ventilation, insufficient gas exchange and atelectotrauma. Excessive provision of non-invasive support could be inefficient or harmful, as overdistention can be associated with decreased compliance of the respiratory system, impaired gas exchange and abnormal diaphragmatic function. An individualized physiological approach could, thus, aim to optimize the beneficial effects of non-invasive ventilation while avoiding inadequate or excessive levels of support.

AMPK Phosphorylates LMX1b to Regulate a Brainstem Neurogenic Network Important for Control of Breathing in Neonatal Mice

Ventilatory drive is modulated by a variety of neurochemical inputs that converge on spatially oriented clusters of cells within the brainstem. This regulation is required to maintain energy homeostasis and is essential to sustain life across all mammalian organisms. Therefore, the anatomical orientation of these cellular clusters during development must have a defined mechanistic basis with redundant genomic variants. Failure to completely develop these features causes several conditions including apnea of prematurity (AOP) and sudden infant death syndrome (SIDS). AOP is associated with many adverse outcomes including increased risk of interventricular hemorrhage. However, there are no pharmacological interventions that reduce SIDS and AOP prevalence by promoting brainstem development. AMP-activated protein kinase (AMPK) is a kinase that regulates ventilatory control to maintain homeostasis. This study identifies a signaling axis in which the pharmacological activation of AMPK in vivo via metformin in brainstem ventilatory control centers results in the phosphorylation of LIM homeobox transcription factor 1-beta (Lmx1b), a key player in dorsal-ventral patterning during fetal development. The phosphorylation of Lmx1b transactivates a neurogenic interactome important for the development and regulation of ventilatory control centers. These findings highlight the potential for metformin in the treatment and prevention of AOP.

Congenital extraventricular neurocytoma with atypical features in a 3-day-old neonate

Extraventricular neurocytoma (EVN) is a rare neuronal tumor with a marked tendency towards ganglionic or glial differentiation. Although EVN commonly occurs in young adults, congenital cases are extremely rare, and standardized therapeutic strategies remain undetermined. The presence of atypical features such as increased mitotic activity on histological analysis is correlated with a higher rate of recurrence and poor prognosis. A 3-d-old infant with no abnormalities at birth presented with recurrent apnea and paroxysmal eye deviation on the upper right side. Magnetic resonance imaging revealed a large intracranial tumor located anterior to the brainstem. The patient underwent biopsy via craniotomy, leading to a histological diagnosis of EVN with atypical features. Despite the absence of adjuvant radiation therapy or chemotherapy, the lesion remained stable over 18 months, and the patient's growth was within normal limits. EVN is an important differential diagnosis of congenital brain tumors. Therapeutic strategies for congenital cases should be distinguished from those used for older children, and treatment decisions should be based on individual patient risks.

Deep sedation in lateral position for preterm infants during cerebral magnetic resonance imaging: a pilot study

INTRODUCTION

Respiratory adverse events are common during the sedation of preterm babies, often needing active airway support. During magnetic resonance imaging, this occurrence could extend the acquisition time, with a negative impact on the thermic and metabolic homeostasis. The aim of the study is to verify if lying in a lateral position instead of supine could improve the safe quality of sedation, without worsening the quality of imaging.

METHODS

This study was performed as a single-center, prospective study at a university-affiliated tertiary care center. A consultant provided deep sedation with sevoflurane 3-4% delivered by an external mask, in the lateral decubitus position. All patients were evaluated for the incidence of apnea and desaturation, quality of imaging obtained, the timing of imaging acquisition, and thermic and metabolic homeostasis.

RESULTS

We enrolled 23 consecutive preterm babies born < 37 weeks gestational age, candidates for sedation for elective brain magnetic resonance imaging. All patients completed the radiological procedure in 30 min (SD ± 6.39 min) without complications requiring exam interruption. Only one patient (4%) experienced a transient desaturation, while 2 neonates (9%) showed apnea lasting > 20 s. On average, there was a 1 °C decrease in body temperature and full enteral feeding was resumed within 1.5 h. Neuroradiologists rated the quality of the images obtained as high.

CONCLUSIONS

Lateral lying seems to be a viable option for sedated preterm babies during magnetic resonance imaging with a low risk of intervention for apnea and a reduced impact on thermic and metabolic homeostasis. Quality of imaging would be preserved maintaining correct scheduling of standard care.

TRIAL REGISTRATION

The study was registered at www.

CLINICALTRIALS

gov before enrollment (NCT05776238 on December, 21th 2023).

Acute respiratory compromise in the NICU

Acute respiratory compromise (ARC) is a significant and frequent emergency in the Neonatal Intensive Care Unit (NICU), characterized by absent, agonal, or inadequate respiration that necessitates an immediate response. The primary etiologies of ARC in neonates can be categorized into upper and lower airway issues, disordered control of breathing, and lung tissue disease. ARC events are particularly dangerous as they compromise oxygen delivery and carbon dioxide removal, potentially leading to cardiopulmonary arrest. Approximately 1 % of NICU admissions experience cardiopulmonary arrest, and ARC is the primary cause of most events. This article provides a comprehensive review of the etiologies of ARC, including anatomical abnormalities, syndromic disorders, airway obstruction, and pulmonary diseases such as bronchopulmonary dysplasia and pneumonia. Management strategies include the use of continuous positive airway pressure, positive pressure ventilation, and advanced interventions like extracorporeal membrane oxygenation (ECMO) in cases of severe respiratory distress. Additionally, quality improvement initiatives aimed at reducing incidents such as unplanned extubations (UE) are discussed, along with emergency responses to ARC, which often require multidisciplinary collaboration and advanced airway management. The article emphasizes the importance of preparedness, training, and structured emergency protocols to ARC in the NICU to optimize patient care.

Physiology during sleep in preterm infants: Implications for increased risk for the sudden infant death syndrome

Approximately 15 million babies are born preterm (<37 weeks of completed gestation) worldwide annually. Although neonatal and perinatal medicine have contributed to the increased survival rate of preterm newborn infants, premature infants are at increased risk of mortality in the first years of life. Infants born preterm are at four times the risk of Sudden Infant Death Syndrome (SIDS) compared to infants born at term. SIDS is believed to be multifactorial in origin. The Triple Risk hypothesis has been proposed to explain this. The model suggests that when a vulnerable infant, such as one born preterm, is at a critical but unstable developmental period in homeostatic control, death may occur if exposed to an exogenous stressor, such as being placed prone for sleep. The highest risk period is at ages 2-4 months, with 90 % of deaths occurring before 6 months. The final pathway to SIDS is widely believed to involve some combination of immature cardiorespiratory control and a failure of arousal from sleep. This review will focus on the physiological factors which increase the risk for SIDS in preterm infants and how these factors may be identified and potentially lead to effective preventative strategies.

Impaired cerebrovascular CO2 reactivity at high altitude in prematurely born adults

Premature birth impairs cardiac and ventilatory responses to both hypoxia and hypercapnia, but little is known about cerebrovascular responses. Both at sea level and after 2 days at high altitude (3375 m), 16 young preterm-born (gestational age, 29 ± 1 weeks) and 15 age-matched term-born (40 ± 0 weeks) adults were exposed to two consecutive 4 min bouts of hyperoxic hypercapnic conditions (3% CO2-97% O2; 6% CO2-94% O2), followed by two periods of voluntary hyperventilation-induced hypocapnia. We measured middle cerebral artery blood velocity, end-tidal CO2, pulmonary ventilation, beat-by-beat mean arterial pressure and arterialized capillary blood gases. Baseline middle cerebral artery blood velocity increased at high altitude compared with sea level in term-born (+24 ± 39%, P = 0.036), but not in preterm-born (-4 ± 27%, P = 0.278) adults. The end-tidal CO2, pulmonary ventilation and mean arterial pressure were similar between groups at sea level and high altitude. Hypocapnic cerebrovascular reactivity was higher at high altitude compared with sea level in term-born adults (+173 ± 326%, P = 0.026) but not in preterm-born adults (-21 ± 107%, P = 0.572). Hypercapnic reactivity was altered at altitude only in preterm-born adults (+125 ± 144%, P < 0.001). Collectively, at high altitude, term-born participants showed higher hypocapnic (P = 0.012) and lower hypercapnic (P = 0.020) CO2 reactivity compared with their preterm-born peers. In conclusion, exposure to high altitude revealed different cerebrovascular responses in preterm- compared with term-born adults, despite similar ventilatory responses. These findings suggest a blunted cerebrovascular response at high altitude in preterm-born adults, which might predispose these individuals to an increased risk of high-altitude illnesses. KEY POINTS: Cerebral haemodynamics and cerebrovascular reactivity in normoxia are known to be similar between term-born and prematurely born adults. In contrast, acute exposure to high altitude unveiled different cerebrovascular responses to hypoxia, hypercapnia and hypocapnia. In particular, cerebral vasodilatation was impaired in prematurely born adults, leading to an exaggerated cerebral vasoconstriction. Cardiovascular and ventilatory responses to both hypo- and hypercapnia at sea level and at high altitude were similar between control subjects and prematurely born adults. Other mechanisms might therefore underlie the observed blunted cerebral vasodilatory responses in preterm-born adults at high altitude.

Apnea of Prematurity and Oxidative Stress: Potential Implications

Apnea of prematurity (AOP) occurs in 85% of neonates ≤34 weeks of gestational age. AOP is frequently associated with intermittent hypoxia (IH). This narrative review reports on the putative relationship of AOP with IH and the resulting oxidative stress (OS). Preterm infants are susceptible to OS due to an imbalance between oxidant and antioxidant systems with the excessive free radical load leading to serious morbidities that may include retinopathy of prematurity, bronchopulmonary dysplasia, and neurodevelopmental delay. Current therapeutic approaches to minimize the adverse effects of AOP and optimize oxygen delivery include noninvasive ventilation and xanthine inhibitor therapy, but these approaches have only been partially successful in decreasing the incidence of AOP and associated morbidities.

Red Blood Cell Transfusion for Incidence of Retinopathy of Prematurity: Prospective Multicenter Cohort Study

Background

Retinopathy of prematurity (ROP) is a leading cause of visual impairment and blindness in preterm infants.

Objective

This study sought to investigate the association between red blood cell (RBC) transfusion and ROP in very preterm infants (VPIs) to inform clinical strategies for ROP prevention and treatment.

Methods

We designed a prospective multicenter cohort study that included VPIs and follow-up data from January 2017 to December 2022 at 3 neonatal clinical medicine centers. They were categorized into a transfusion group (infants who received an RBC transfusion within 4 wk) and a nontransfusion group. The relationship between RBC transfusion and ROP incidence was assessed using binary logistic regression, with subgroup analyses based on gestational age, birth weight, sex, and sepsis status. Inverse probability of treatment weighting and propensity score matching were applied to account for all potential confounding factors that could affect ROP development, followed by sensitivity analysis.

Results

The study included 832 VPIs, including 327 in the nontransfusion group and 505 in the transfusion group. The transfusion group had a lower average birth weight and gestational age and a greater incidence of ROP, ≥stage 2 ROP, and severe ROP. Logistic regression analysis revealed that the transfusion group had a significantly greater risk of ROP (adjusted odds ratio [aOR] 1.70, 95% CI 1.14-2.53, P=.009) and ≥stage 2 ROP (aOR 1.68, 95% CI 1.02-2.78, P=.04) but not severe ROP (aOR 1.75, 95% CI 0.61-5.02, P=.30). The trend analysis also revealed an increased risk of ROP with an increasing number of transfusions and a larger volume of blood transfused (P for trend<.001). Subgroup analyses confirmed a consistent trend, with the transfusion group at a higher risk for ROP across all subgroups. Inverse probability of treatment weighting and propensity score matching analyses supported the initial findings.

Conclusions

For VPIs, RBC transfusion significantly increases the risk of ROP, and the risk increases with an increasing number of transfusions and volume of blood transfused.

Caffeine: The Story beyond Oxygen-Induced Lung and Brain Injury in Neonatal Animal Models-A Narrative Review

Caffeine is one of the most commonly used drugs in intensive care to stimulate the respiratory control mechanisms of very preterm infants. Respiratory instability, due to the degree of immaturity at birth, results in apnea of prematurity (AOP), hyperoxic, hypoxic, and intermittent hypoxic episodes. Oxidative stress cannot be avoided as a direct reaction and leads to neurological developmental deficits and even a higher prevalence of respiratory diseases in the further development of premature infants. Due to the proven antioxidant effect of caffeine in early use, largely protective effects on clinical outcomes can be observed. This is also impressively observed in experimental studies of caffeine application in oxidative stress-adapted rodent models of damage to the developing brain and lungs. However, caffeine shows undesirable effects outside these oxygen toxicity injury models. This review shows the effects of caffeine in hyperoxic, hypoxic/hypoxic-ischemic, and intermittent hypoxic rodent injury models, but also the negative effects on the rodent organism when caffeine is administered without exogenous oxidative stress. The narrative analysis of caffeine benefits in cerebral and pulmonary preterm infant models supports protective caffeine use but should be given critical consideration when considering caffeine treatment beyond the recommended corrected gestational age.

Oxygen-induced stress reveals context-specific gene regulatory effects in human brain organoids

The interaction between genetic variants and environmental stressors is key to understanding the mechanisms underlying neurological diseases. In this study, we used human brain organoids to explore how varying oxygen levels expose context-dependent gene regulatory effects. By subjecting a genetically diverse panel of 21 brain organoids to hypoxic and hyperoxic conditions, we identified thousands of gene regulatory changes that are undetectable under baseline conditions, with 1,745 trait-associated genes showing regulatory effects only in response to oxygen stress. To capture more nuanced transcriptional patterns, we employed topic modeling, which revealed context-specific gene regulation linked to dynamic cellular processes and environmental responses, offering a deeper understanding of how gene regulation is modulated in the brain. These findings underscore the importance of genotype-environment interactions in genetic studies of neurological disorders and provide new insights into the hidden regulatory mechanisms influenced by environmental factors in the brain.

Development and application of a population pharmacokinetic model repository for caffeine dose tailoring in preterm infants

BACKGROUND

Considerable interindividual variability for the pharmacokinetics of caffeine in preterm infants has been demonstrated, emphasizing the importance of personalized dosing. This study aimed to develop and apply a repository of currently published population pharmacokinetic (PopPK) models of caffeine in preterm infants to facilitate model-informed precision dosing (MIPD).

RESEARCH DESIGN AND METHODS

Literature search was conducted using PubMed, Embase, Scopus, and Web of Science databases. Relevant publications were screened, and their quality was assessed. PopPK models were reestablished to develop the model repository. Covariate effects were evaluated and the concentration-time profiles were simulated. An online simulation and calculation tool was developed as an instance.

RESULTS

Twelve PopPK models were finally included in the repository. Preterm infants' age and body size, especially the postnatal age and current weight, were identified as the most clinically critical covariates. Simulated blood concentration-time profiles across these models were comparable. Caffeine citrate-dose regimen should be adjusted according to the age and body size of preterm infants. The developed online tool can be used to facilitate clinical decision-making.

CONCLUSIONS

The first developed repository of PopPK models for caffeine in preterm infants has a wide range of potential applications in the MIPD of caffeine.

Sedation and anesthesia for imaging of the infant and neonate-a brief review

Sedation and anesthesia are often required in order to facilitate collection of high-quality imaging studies free of significant motion artifact for infants and neonates. Provision of safe sedation and anesthesia requires good communication between the ordering provider, radiologist, and anesthesiologist, careful pre-procedural evaluation of the patient, and availability of appropriate and sufficient equipment, drugs, personnel, and facilities. There are many additional factors to be considered for provision of safe sedation or anesthesia for infants and neonates-it is ideal to involve a fellowship-trained pediatric anesthesiologist in the planning and carry-out of these plans. In this review, we discuss some of the basic definitions of sedation and anesthesia, requirements for safe sedation and anesthesia, and many of the germane risks and additional considerations that factor into the delivery of a safe sedation or anesthesia plan for the imaging of an infant or neonate.

Respiratory Arrest in a Late Preterm Infant Presenting for a 2-Week Well-Visit

A 13-day-old, late preterm male, born appropriate for gestational age, presented to the pediatric clinic for his routine 2-week well visit with less than 1-day history of decreased oral intake and lethargy. During the baby's well exam, he acutely decompensated and required resuscitation and transfer to the emergency department, where he was intubated for frequent apneic events. He was admitted to the NICU for management and further workup. Physical examination and initial laboratory tests were unremarkable. An EEG demonstrated electrographic and clinical seizures. His initial MRI was unremarkable, and infection studies revealed the diagnosis. We review the patient's initial presentation, evaluation, hospital course, and the long-term implications of his diagnosis.

Gas exchange parameters for the prediction of obstructive sleep apnea in infants

STUDY OBJECTIVES

Sleep laboratory polysomnography is the gold standard for obstructive sleep apnea (OSA) diagnosis in infants, but its access remains limited. Oximetry-capnography is another simple and widely used tool that can provide information on the presence of desaturations and alveolar hypoventilation. However, its reliability is debated. This study aimed at examining its use in determining OSA severity in infants.

METHODS

This retrospective study was conducted in a sleep unit in a tertiary hospital in infants < 4 months old with clinical signs of OSA or Pierre Robin sequence who underwent a 1-night polysomnography coupled with oximetry-capnography.

RESULTS

Among the 78 infants included (median [interquartile range] age: 61 [45-89] days at polysomnography), 44 presented with Pierre Robin sequence and 34 presented with isolated airway obstruction. The clinical, sleep, and respiratory characteristics were not significantly different between the 2 subgroups. In the entire cohort, 63.5% had severe OSA. The median obstructive apnea-hypopnea index was 14.5 (7.4-5.9) events/h, peripheral oxygen saturation (SpO2) was 97.4% (96.5-98.1%), and transcutaneous carbon dioxide pressure (PtcCO2) was 41.1 mmHg (38.3-44.9). The optimal threshold to predict an obstructive apnea-hypopnea index > 10 events/h was 6 events/h for an oxygen desaturation index ≥ 3% (sensitivity, 95.7%; specificity, 51.9%) and 2 events/h for an oxygen desaturation index ≥ 4% (sensitivity, 95.7%; specificity, 48.1%).

CONCLUSIONS

Whereas transcutaneous capnography does not appear to be sufficient in predicting severe OSA in infants < 4 months old with Pierre Robin sequence or clinical signs of OSA, oximetry may be a useful alternative for the screening of severe OSA in infants in the absence of polysomnography.

CITATION

Gyapay R, Ioan I, Thieux M, et al. Gas exchange parameters for the prediction of obstructive sleep apnea in infants. J Clin Sleep Med. 2024;20(7):1059-1067.

Longitudinal effects of early exposure to intermittent hypoxia on autonomic cardiovascular control in very preterm infants

INTRODUCTION

Cardiorespiratory control is immature in infants born preterm compared to those born at term. Animal studies have shown that repetitive hypoxia associated with periodic breathing can alter autonomic control. We aimed to elucidate if the amount of time spent with apnoea and periodic breathing in the neonatal unit was associated with longitudinal changes in autonomic control assessed using heart rate variability.

METHODS

Twenty-nine very preterm infants (10 M 19F) were studied during supine daytime sleep on 4 occasions. Study 1: 32-36 weeks post menstrual age (PMA) (n = 29), Study 2: 36-40 weeks PMA (n = 27), Study 3: 3-months corrected age (CA) (n = 20) and Study 4: 6-months CA (n = 26). The percentage total sleep time (%TST) spent having apnoeas in active (AS) and quiet sleep (QS) at each study was calculated. Total power, low frequency (LF, sympathetic + parasympathetic activity) high frequency (HF, parasympathetic activity), and LF/HF (sympathovagal balance) were calculated. Infants were divided into two groups based on the %TST spent with apnoeas above and below the median in AS and QS at Study 1. Data were normalised and compared with two-way ANOVA with Bonferroni post-hoc tests.

RESULTS

When apnoeas were included in the analysis, in QS Total power and HF power were higher, and when apnoeas were excluded HF power was higher in QS but lower in AS in the above median group at Study 4.

CONCLUSION

This study provides new evidence that short apnoeas, particularly periodic breathing, which is currently not detected or treated in the neonatal unit can affect autonomic cardiovascular control.

A multicentre neonatal manikin study showed a large heterogeneity in tactile stimulation for apnoea of prematurity

AIM

Apnoea of prematurity requires prompt intervention to prevent long-term adverse outcomes, but specific recommendations about the stimulation approach are lacking. Our study investigated the modalities of tactile stimulation for apnoea of prematurity in different settings.

METHODS

In this multi-country observational prospective study, nurses and physicians of the neonatal intensive care units were asked to perform a tactile stimulation on a preterm neonatal manikin simulating an apnoea. Features of the stimulation (body location and hand movements) and source of learning (training course or clinical practice) were collected.

RESULTS

Overall, 112 healthcare providers from five hospitals participated in the study. During the stimulation, the most frequent location were feet (72%) and back (61%), while the most frequent techniques were rubbing (64%) and massaging (43%). Stimulation modalities different among participants according to their hospitals and their source of learning of the stimulation procedures.

CONCLUSION

There was a large heterogeneity in stimulation approaches adopted by healthcare providers to counteract apnoea in a simulated preterm infant. This finding may be partially explained by the lack of specific guidelines and was influenced by the source of learning for tactile stimulation.

Complications of Preterm Birth-The Importance of Care for the Outcome: A Narrative Review

Preterm-born children are susceptible to problems of adaptation in the early neonatal period, as well as the emergence of consequences due to the immaturity of the respiratory, cardiovascular, and especially cerebrovascular systems. The authors searched PubMed, Scopus, the Cochrane Library, and Web of Science for articles that were available in their entirety and published in English between 1990 and 2024 in peer-reviewed journals using keywords relevant to the manuscript topic. Analyzing the requested studies and manuscripts, adequate articles describing the stated problem were used. The last trimester of pregnancy is the most important period in brain development. Brain growth is at its most intense, and nerve cells are created, multiply, and migrate, creating numerous connections between them and receptors. During this period, the baby is protected from the influence of external environmental factors. When a baby is born, it leaves its protected environment and very often requires intensive treatment to survive. In these circumstances, the immature nervous system, which is in a sensitive stage of development, is overloaded with numerous external stimuli, continuous light, noise, inappropriate positioning, and repeated painful reactions due to necessary diagnostic and therapeutic procedures and the unavoidable absence of the mother and the family, which cause stress that threatens proper programmed development. Minimally invasive therapeutic procedures and the presence of parents during hospitalization play a significant role in reducing the consequences for a premature child.

Caffeine for apnea and prevention of neurodevelopmental impairment in preterm infants: systematic review and meta-analysis

This systematic review and meta-analysis evaluated the evidence for dose and effectiveness of caffeine in preterm infants. MEDLINE, EMBASE, CINHAL Plus, CENTRAL, and trial databases were searched to July 2022 for trials randomizing preterm infants to caffeine vs. placebo/no treatment, or low (≤10 mg·kg-1) vs. high dose (>10 mg·kg-1 caffeine citrate equivalent). Two researchers extracted data and assessed risk of bias using RoB; GRADE evaluation was completed by all authors. Meta-analysis of 15 studies (3530 infants) was performed in REVMAN across four epochs: neonatal/infant (birth-1 year), early childhood (1-5 years), middle childhood (6-11 years) and adolescence (12-19 years). Caffeine reduced apnea (RR 0.59; 95%CI 0.46,0.75; very low certainty) and bronchopulmonary dysplasia (0.77; 0.69,0.86; moderate certainty), with higher doses more effective. Caffeine had no effect on neurocognitive impairment in early childhood but possible benefit on motor function in middle childhood (0.72; 0.57,0.91; moderate certainty). The optimal dose remains unknown; further long-term studies, are needed.

ATS core curriculum 2023. Pediatric pulmonary medicine: Respiratory disorders in infants

The American Thoracic Society Core Curriculum updates clinicians annually in pediatric pulmonary disease. This is a summary of the Pediatric Pulmonary Medicine Core Curriculum presented at the 2023 American Thoracic Society International Conference. The respiratory disorders of infancy discussed in this year's review include: the care of the patient with bronchopulmonary dysplasia in the neonatal intensive care unit, clinical phenotypes and comorbidities; diffuse lung disease; pulmonary hypertension; central and obstructive sleep apnea. The care of infants with respiratory disorders often poses significant challenges to the general pediatric pulmonologist, sleep clinician, and neonatologist. This review aims to highlight the most clinically relevant aspects of the evaluation, management, and outcomes of infants with these key respiratory disorders, while emphasizing the importance of multidisciplinary care. Furthermore, this document summarizes essential aspects of genetic testing, novel imaging and treatment modalities, and includes multiple resources for clinical practice.

Effects of Nasal Respiratory Support on Laryngeal and Esophageal Reflexes in Preterm Lambs

BACKGROUND

Significant cardiorespiratory events can be triggered in preterm infants as part of laryngeal chemoreflexes (LCRs) and esophageal reflexes (ERs). We previously showed that nasal continuous positive airway pressure (nCPAP) blunted the cardiorespiratory inhibition induced with LCRs. Therefore, we aimed to compare the effects of nCPAP and high-flow nasal cannulas (HFNC) on the cardiorespiratory events induced during LCRs and ERs. The hypothesis is that nCPAP but not HFNC decreases the cardiorespiratory inhibition observed during LCRs and ERs.

METHODS

Eleven preterm lambs were instrumented to record respiration, ECG, oxygenation, and states of alertness. LCRs and ERs were induced during non-rapid eye movement sleep in a random order under these conditions: nCPAP 6 cmH2O, HFNC 7 L/min, high-flow nasal cannulas 7 L/min at a tracheal pressure of 6 cmH2O, and no respiratory support.

RESULTS

nCPAP 6 cmH2O decreased the cardiorespiratory inhibition induced with LCRs, but not with ERs in preterm lambs. This blunting effect was less marked with HFNC 7 L/min, even when the tracheal pressure was maintained at 6 cmH2O.

CONCLUSIONS

nCPAP might be a treatment for cardiorespiratory events related to LCRs in newborns, either in the context of laryngopharyngeal refluxes or swallowing immaturity. Our preclinical results merit to be confirmed through clinical studies.

IMPACT

Laryngeal chemoreflexes can be responsible for significant cardiorespiratory inhibition in newborns, especially preterm. Nasal continuous positive airway pressure at 6 cmH2O significantly decreased this cardiorespiratory inhibition. High-flow nasal cannulas at 7 L/min had a lesser effect than nasal continuous positive airway pressure. Esophageal stimulation was responsible for a smaller cardiorespiratory inhibition, which was not significantly modified by nasal continuous positive airway pressure or high-flow nasal cannulas. Nasal continuous positive airway pressure should be tested for its beneficial effect on cardiorespiratory events related to laryngeal chemoreflexes in preterm newborns.

Hypoxia sensing in the body: An update on the peripheral and central mechanisms

An adequate supply of O2 is essential for the maintenance of cellular activity. Systemic or local hypoxia can be experienced during decreased O2 availability or associated with diseases, or a combination of both. Exposure to hypoxia triggers adjustments in multiple physiological systems in the body to generate appropriate homeostatic responses. However, with significant reductions in the arterial partial pressure of O2, hypoxia can be life-threatening and cause maladaptive changes or cell damage and death. To mitigate the impact of limited O2 availability on cellular activity, O2 chemoreceptors rapidly detect and respond to reductions in the arterial partial pressure of O2, triggering orchestrated responses of increased ventilation and cardiac output, blood flow redistribution and metabolic adjustments. In mammals, the peripheral chemoreceptors of the carotid body are considered to be the main hypoxic sensors and the primary source of excitatory feedback driving respiratory, cardiovascular and autonomic responses. However, current evidence indicates that the CNS contains specialized brainstem and spinal cord regions that can also sense hypoxia and stimulate brain networks independently of the carotid body inputs. In this manuscript, we review the discoveries about the functioning of the O2 chemoreceptors and their contribution to the monitoring of O2 levels in the blood and brain parenchyma and mounting cardiorespiratory responses to maintain O2 homeostasis. We also discuss the implications of the chemoreflex-related mechanisms in paediatric and adult pathologies.

Maturation of cardioventilatory physiological trajectories in extremely preterm infants

BACKGROUND

In extremely preterm infants, persistence of cardioventilatory events is associated with long-term morbidity. Therefore, the objective was to characterize physiologic growth curves of apnea, periodic breathing, intermittent hypoxemia, and bradycardia in extremely preterm infants during the first few months of life.

METHODS

The Prematurity-Related Ventilatory Control study included 717 preterm infants <29 weeks gestation. Waveforms were downloaded from bedside monitors with a novel sharing analytics strategy utilized to run software locally, with summary data sent to the Data Coordinating Center for compilation.

RESULTS

Apnea, periodic breathing, and intermittent hypoxemia events rose from day 3 of life then fell to near-resolution by 8-12 weeks of age. Apnea/intermittent hypoxemia were inversely correlated with gestational age, peaking at 3-4 weeks of age. Periodic breathing was positively correlated with gestational age peaking at 31-33 weeks postmenstrual age. Females had more periodic breathing but less intermittent hypoxemia/bradycardia. White infants had more apnea/periodic breathing/intermittent hypoxemia. Infants never receiving mechanical ventilation followed similar postnatal trajectories but with less apnea and intermittent hypoxemia, and more periodic breathing.

CONCLUSIONS

Cardioventilatory events peak during the first month of life but the actual postnatal trajectory is dependent on the type of event, race, sex and use of mechanical ventilation.

IMPACT

Physiologic curves of cardiorespiratory events in extremely preterm-born infants offer (1) objective measures to assess individual patient courses and (2) guides for research into control of ventilation, biomarkers and outcomes. Presented are updated maturational trajectories of apnea, periodic breathing, intermittent hypoxemia, and bradycardia in 717 infants born <29 weeks gestation from the multi-site NHLBI-funded Pre-Vent study. Cardioventilatory events peak during the first month of life but the actual postnatal trajectory is dependent on the type of event, race, sex and use of mechanical ventilation. Different time courses for apnea and periodic breathing suggest different maturational mechanisms.

Heart rate variability in school-age children born moderate-to-late preterm

BACKGROUND

Prematurity is associated with reduced cardiac autonomic function. This study aimed to investigate the heart rate variability (HRV) in school-age children born moderately to late preterm (MLPT).

METHODS

This cross-sectional study investigated school-age children, aged 5 to 10 years, born moderate-to-late preterm. Electrocardiograms recordings were performed during fifteen-minutes. Time and frequency domain parameters were calculated, corrected for heart rate and compared between the groups.

RESULTS

A total of 123 children were evaluated and 119 were included in this study. HRV measures, studied in the time and frequency domains, were similar in both groups. Corrected values of root mean square of successive differences between normal cycles (RMSSD), percentage of successive cycles with a duration difference >50 ms (pNN50%), and high frequency (HF), indices that predominantly represent the parasympathetic activity of the autonomic nervous system, were 1.6E-7 and 1.8E-7 (p=0.226); 1.6E-13 and 1.6E-13 (p=0.506); 6.9E-12 and 7.4E-12 (p=0.968) in the preterm and control groups, respectively.

CONCLUSION

This study did not find differences in heart rate variability between school-age children born MLPT and those born at term, suggesting that plasticity of cardiac autonomic modulation continues to occur in children up to school age or there is less impairment of the autonomic system in MLPT.

Association between intermittent hypoxemia and neurodevelopmental outcomes in extremely premature infants: A single-center experience

OBJECTIVE

To describe the association between intermittent hypoxemic events (IHEs) and severe neurodevelopmental impairment (SNDI) or death in extremely premature infants.

STUDY DESIGN

Retrospective study of extremely premature infants 230/7-276/7 weeks gestational age (GA) and birthweight (BW) ≤1250 grams (g) admitted to a level IV neonatal intensive care unit (NICU) from 2013 to 2017. IHEs, defined as events with SpO2 ≤ 80 % lasting 10 s to 5 min, were algorithmically identified using data extracted from bedside monitors at 2 s intervals (0.5 Hz). The primary outcome was SNDI at 18-24 months corrected age (CA), defined as a Bayley-III motor, language or cognitive composite score ≤69, or death before discharge while the secondary outcome was SNDI alone. We used mixed-effects regression models to evaluate the relationship between mean daily IHE rate per postnatal week of life for the first 12 weeks and the outcomes, and logistic regression models to assess the association between outcomes and summary measures of hypoxic burden for the entire NICU hospitalization.

RESULTS

The mortality rate was 7 % (18/249) during NICU hospitalization. Of 249 infants born during this time period, IHE and neurodevelopmental outcome data were fully available for 65 infants (mean GA 26 ± 1.4 weeks, mean birth weight (BW) 738 ± 199 g. The outcome of SNDI alone occurred in 34 % (22/65) with a majority demonstrating motor or language delay on the Bayley-III. Although mean daily IHE rate/week was not associated with SNDI or death, total IHE duration was associated with increased odds of SNDI (OR (95 % CI) 1.03 (1.01, 1.05), p = 0.008) in models adjusted for GA.

CONCLUSIONS

In a cohort of extremely premature infants 23-27 weeks GA, each hour of total IHE duration (SpO2 ≤ 80 %) was associated with a 2.7 % (0.7 %, 4.8 %) increase in the odds of SNDI at 18-24 months CA.

The effect of acute respiratory events and respiratory stimulants on EEG-recorded brain activity in neonates: A systematic review

Objective

We conducted a systematic review to investigate electroencephalography (EEG) changes during periods of acute respiratory events such as apnoea and the effect of respiratory stimulants on EEG features in infants.

Methods

Studies examining respiration and EEG-recorded brain activity in human neonates between 28 and 42 weeks postmenstrual age were included. Two reviewers independently screened all records and included studies were assessed using the Joanna Briggs Institute Critical Appraisal Tool. The protocol was registered in PROSPERO (CRD42022339873).

Results

We identified 14 studies with a total of 534 infants. Nine articles assessed EEG changes in relation to apnoea, one assessed hiccups, and four investigated the effect of respiratory stimulants. The relationship between neonatal apnoea and EEG changes was inconsistent; EEG suppression and decreased amplitude and frequency were observed during some, but not all, apnoeas. Respiratory stimulants increased EEG continuity compared with before use.

Conclusions

Current studies in this area are constrained by small sample sizes. Diverse exposure definitions and outcome measures impact inference.

Significance

This review highlights the need for further work; understanding the relationship between respiration and the developing brain is key to mitigating the long-term effects of apnoea.

Intermittent hypoxia in neonatal rodents affects facial bone growth

Preterm human infants often show periodic breathing (PB) or apnea of prematurity (AOP), breathing patterns which are accompanied by intermittent hypoxia (IH). We examined cause-effect relationships between transient IH and reduced facial bone growth using a rat model. Neonatal pups from 14 timed pregnant Sprague-Dawley rats were randomly assigned to an IH condition, with oxygen altering between 10% and 21% every 4 min for 1 h immediately after birth, or to a litter-matched control group. The IH pups were compared with their age- and sex-matched control groups in body weight (WT), size of facial bones and nor-epinephrine (NE) levels in blood at 3, 4, and 5-weeks. Markedly increased activity of osteoclasts in sub-condylar regions of 3-week-old IH-treated animals appeared, as well as increased numbers of sympathetic nerve endings in the same region of tissue sections. Male IH-pups showed significantly higher levels of NE levels in sera at 3, 4 as well as 5-week-old time points. NE levels in 4- and-5-week-old female pups did not differ significantly. Intercondylar Width, Mandible Length and Intermolar Width measures consistently declined after IH insults in 3- and 4-week-old male as well as female animals. Three-week-old male IH-pups only showed a significantly reduced (p < 0.05) body weight compared to those of 3-week controls. However, female IH-pups were heavier than age-matched controls at all 3 time-points. Trabecular bone configuration, size of facial bones, and metabolism are disturbed after an IH challenge 1 h immediately after birth. The findings raise the possibility that IH, introduced by breathing patterns such as PB or AOP, induce significantly impaired bone development and metabolic changes in human newborns. The enhanced NE outflow from IH exposure may serve a major role in deficient bone growth, and may affect bone and other tissue influenced by that elevation.

The associations between caffeine treatment and common preterm morbidities: a retrospective cohort analysis

Introduction

Caffeine is one of the most used drugs in the neonatal intensive care units (NICUs). It is widely regarded as beneficial in preventing many morbidities by reducing apnea of prematurity and improving respiratory functions.

Methods

Premature infants with gestational ages >25 and <32 weeks who were hospitalized in the NICU between 2008 and 2013 and survived up to discharge were retrospectively analyzed. Infants treated with prophylactic caffeine were compared with historical controls born in 2008 and did not receive caffeine treatment. Maternal and neonatal characteristics and common neonatal morbidities were recorded.

Results

A total of 475 patients were analyzed. The patients receiving caffeine were classified as Group 1 (n = 355), and the patients not receiving caffeine were classified as Group 2 (n = 120). Despite the higher incidence of respiratory distress syndrome requiring surfactant therapy and a longer duration of respiratory support in Group 2, the rates of bronchopulmonary dysplasia (BPD) and most other common morbidities were quite comparable. The frequency of apnea was statistically lower in the group that received caffeine prophylaxis (p < 0.01).

Conclusion

In this retrospective cohort analysis, we found that caffeine prophylaxis significantly decreased apnea attacks however does not prevent respiratory morbidity such as BPD.

Oxygen and mechanical stretch in the developing lung: risk factors for neonatal and pediatric lung disease

Chronic airway diseases, such as wheezing and asthma, remain significant sources of morbidity and mortality in the pediatric population. This is especially true for preterm infants who are impacted both by immature pulmonary development as well as disproportionate exposure to perinatal insults that may increase the risk of developing airway disease. Chronic pediatric airway disease is characterized by alterations in airway structure (remodeling) and function (increased airway hyperresponsiveness), similar to adult asthma. One of the most common perinatal risk factors for development of airway disease is respiratory support in the form of supplemental oxygen, mechanical ventilation, and/or CPAP. While clinical practice currently seeks to minimize oxygen exposure to decrease the risk of bronchopulmonary dysplasia (BPD), there is mounting evidence that lower levels of oxygen may carry risk for development of chronic airway, rather than alveolar disease. In addition, stretch exposure due to mechanical ventilation or CPAP may also play a role in development of chronic airway disease. Here, we summarize the current knowledge of the impact of perinatal oxygen and mechanical respiratory support on the development of chronic pediatric lung disease, with particular focus on pediatric airway disease. We further highlight mechanisms that could be explored as potential targets for novel therapies in the pediatric population.

Why, when and how to assess autonomic nervous system maturation in neonatal care units: A practical overview

The evaluation of the autonomic reactivity of newborns by heart rate variability (HRV) analysis is a simple and essential aid to identifying pathological situations of dysautonomia. Thanks to this relatively simple and reproducible analytic tool, the pediatrician can identify and target children at high risk of life-threatening events, i.e., those with insufficient intrinsic capacity for cardiorespiratory self-regulation, who should benefit from close cardiorespiratory monitoring. Different mathematical algorithms integrate delayed or real-time variations in the length of the RR interval to better understand the state of autonomic maturation of the newborn. HRV analysis, as a non-invasive tool for assessing autonomic balance, is essential to assess the functioning of the autonomic nervous system and, more specifically, parasympathetic/sympathetic balance. Despite many recognized diagnostic and therapeutic implications, its application to neonatal medicine is not yet well understood.

The influence of late prematurity on the encephalopathy exam of infants with neonatal encephalopathy

BACKGROUND

Late preterm (LPT) infants are increasingly treated for hypoxic-ischemic encephalopathy (HIE). However, neurodevelopmental differences of LPT infants may independently influence the neurologic exam and confound care.

METHODS

Perinatal and outcome characteristics were extracted along with the worst autonomic and state/neuromuscular/reflex Sarnat components in a cross-section of infants with moderate/severe HIE. Infants were classified as late preterm (LPT, 34-36 weeks) or term (>36 weeks).

RESULTS

250 infants were identified, 55 were late preterm. LPT infants had lower mean gestational age and birthweight and greater length of stay (LOS). LPT infants had higher median scores for the Moro and respiratory autonomic components, but no difference in total score.

CONCLUSIONS

LPT infants had increased LOS, worse Moro reflex, and respiratory status, but no clinically or statistically significant differences in total Sarnat scores. Although it is important to note the impact of immaturity on the exam, it is unlikely to independently alter management.

Determination of caffeine, paraxanthine, theophylline and theobromine in premature infants by HILIC-MS/MS

Aim: Caffeine is a central nervous system stimulant, used to treat apnea of prematurity. A hydrophilic interaction chromatography-tandem mass spectrometry (HILIC-MS/MS) approach was developed to detect caffeine, paraxanthine, theophylline and theobromine in premature infants. Method: Protein precipitation of plasma samples (10 μl) was carried out by treating with acetonitrile containing caffeine-¹³C₃. The separation was carried out on an ACQUITY HPLC^® BEH HILIC column. Caffeine and its metabolites were quantified by multiple reaction monitoring modes with positive electrospray ionization. Results: The established method had a good linear relationship in the range of 0.0600-60.0 μg/ml for caffeine, 0.0250-7.50 μg/ml for theobromine and 0.0150-4.50 μg/ml for paraxanthine and theophylline. Conclusion: A HILIC-MS/MS method was developed and validated to determine caffeine and its major metabolites in plasma of premature infants.

Effects of early aminophylline therapy on clinical outcomes in premature infants

BACKGROUND

Aminophylline use and the association between clinical outcomes and therapy timing have been less investigated. The objective of this study was to determine the efficacy of early aminophylline use (within the first two days of life) in premature infants.

METHOD

A retrospective observational cohort of infants weighing <1500 g and <30 weeks of gestational age at Kaohsiung Veterans General Hospital received aminophylline either within the first two days of life (EA, early aminophylline group), after the third day of life (LA, late aminophylline group), or without aminophylline during the first month of life (WA, without aminophylline group). Demographic data and neonatal clinical outcomes were compared among the three groups.

RESULTS

This study included 89 preterm infants (EA = 33, LA = 38, WA = 18). The EA group had a lower incidence of bronchopulmonary dysplasia (BPD) than the WA group (adjusted odds ratio [aOR] = 8.86(1.56-59.32); P = 0.024). Although there was no significant difference in BPD incidence between the EA and LA groups (aOR = 2.66(0.51-13.81), P = 0.244), a trend remained. Birth body weight less than 1000 g was also a significant risk factor for BPD (aOR = 8.86(1.32-47.41), P = 0.014). The duration of mechanical ventilation was shorter in the infants in the EA group compared to the WA group (estimated beta = -11.344(-19.57-3.12); P = 0.008).

CONCLUSION

Early aminophylline administration may be associated with a decreased incidence of BPD in preterm infants. However, the clinical benefits of aminophylline treatment require further investigation. In addition, a birth body weight of less than 1000 g was a crucial risk factor for BPD.

A survey of barriers and facilitators to caffeine use for apnoea of prematurity in low- and middle-income countries

BACKGROUND

Despite its associated benefits which include better long-term pulmonary and neurodevelopmental outcome, the use of caffeine for apnoea of prematurity (AoP) has been limited in low- and middle-income countries (LMIC).

AIM

To better understand current caffeine use, the barriers and facilitators to its use and perceptions and practices in LMIC which have a disproportionately high burden of prematurity.

METHODS

An anonymous online global survey was conducted, targeting healthcare providers working and training in paediatrics and/or neonatology in LMIC.

RESULTS

A total of 181 respondents in 16 LMIC were included in the analysis; most were physicians working in publicly-funded urban tertiary hospitals. Most had received training in the use of caffeine for AoP (77%), reported expertise (70%) and confidence (96%) in its use, and had access to caffeine (65%). Caffeine availability was reported to be the greatest barrier (48%) and the greatest facilitator (37%). Other common barriers included cost (31%), access (7%) and policies or guidelines on caffeine use (7%); other common facilitators included policies or guidelines on caffeine use (11%), access (10%), staff/other providers' acceptance of caffeine as an appropriate treatment (9%) and the availability of staff to administer caffeine (8%). Most (79%) noted that access to caffeine was important, 92% agreed that caffeine improves quality of care, and 95% agreed that caffeine improves patient outcome.

CONCLUSION

Improving availability and access to low-cost caffeine will be key to increasing caffeine use in LMIC.

ABBREVIATIONS

AoP: Apnoea of Prematurity; LMIC: low- and middle-Income countries; REDCap: Research Electronic Data Capture.

[Recent research on gene polymorphisms related to caffeine therapy in preterm infants with apnea of prematurity]

Apnea of prematurity (AOP) is one of the common diseases in preterm infants. The main cause of AOP is immature development of the respiratory control center. If AOP is not treated timely and effectively, it will lead to respiratory failure, hypoxic brain injury, and even death in severe cases. Caffeine is the first choice for the treatment of AOP, but its effectiveness varies in preterm infants. With the deepening of AOP research, more and more genetic factors have been confirmed to play important roles in the pathogenesis and treatment of AOP; in particular, the influence of single nucleotide polymorphism on the efficacy of caffeine has become a research hotspot in recent years. This article reviews the gene polymorphisms that affect the efficacy of caffeine, in order to provide a reference for individualized caffeine therapy. Citation.

HIDEA syndrome: A rare cause of congenital hypoventilation in a premature infant

BACKGROUND

HIDEA (hypotonia, hypoventilation, intellectual disability, dysautonomia, epilepsy and eye abnormalities) syndrome is a rare and novel disease. We describe a premature patient who required extensive work up for his hypoventilation with a diagnosis of HIDEA syndrome.

CASE DESCRIPTION

The patient was born to a pair of consanguineous parents at 32-week gestation. His intermittent bradypnoea requiring significant respiratory support during his postnatal clinical course was atypical for bronchopulmonary dysplasia and this required further extensive work up to look for a cause for his hypoventilation. A trio whole exon sequencing was done which identified homozygous variants in P4HTM, in keeping with the diagnosis of autosomal recessive HIDEA syndrome. He is currently doing well on BiPAP 18 cm H2O / 8 cm H2O, Rate 30 breaths per minute in room air and full nasogastric feeding. He also has cortical blindess and severe global developmental delay.

CONCLUSION

Early diagnosis is crucial to optimise adequate ventilatory management including early tracheostomy as many require lifelong continuous or intermittent ventilation. This minimises the complications of chronic hypoxia and reduces mortality risk.

Impact of Kangaroo Mother Care Intervention on Immunological and Pulmonary Functions of Preterm Infants during Breastfeeding

Objective

Preterm infants (PTIs) are prone to respiratory failure or other diseases due to immature organ development and poor immunological function. Herein, the effects of Kangaroo Mother Care (KMC) on the immunological and pulmonary functions of PTIs during breastfeeding were investigated in this study.

Methods

The study recruited 86 delivery women and their PTIs with preterm pregnancy outcomes, consisting of 46 cases receiving breastfeeding plus KMC intervention (KMC group) and 40 cases receiving breastfeeding plus routine care (control group). The time of first lactation, time of first breastfeeding, and duration of first breastfeeding were observed in both cohorts. The breastfeeding status was assessed using the LATCH system. Maternal psychological status was evaluated by the breastfeeding self-efficacy scale (BSES) and self-rating anxiety/depression scale (SAS/SDS). The growth and development of PTIs were recorded, and the levels of postalbumin (PA), transferrin (TRF), plasma albumin (ALB), immunoglobulin (Ig) A, IgG, IgM, and complement C3 and C4 were measured. The tidal volume (VT), tidal volume per kilogram (VT/kg), minute volume (MV), and minute volume per kilogram (MV/kg) were detected using a pulmonary function tester.

Results

The KMC group presented shorter time of first lactation and first breastfeeding than the control group, with longer duration of first breastfeeding (P < 0.05). After intervention, the BSES scores of delivery women were increased, while the SAS and SDS scores were decreased, with more notable improvements in the KMC group (P < 0.05). The levels of PA, TRF, ALB, IgA, IgG, VT, and MV were elevated in PTIs in both groups, with more evident increase in the KMC group than in the control group (P < 0.05). A better growth of PTIs was found in the KMC group than the control group (P < 0.05).

Conclusions

The study demonstrated that KMC intervention during breastfeeding could benefit PTIs specifically regarding their immunological and pulmonary functions.

Diagnosis and management of cardiopulmonary events in very low birth weight infants close to discharge: a quality improvement initiative

BACKGROUND

Cardiopulmonary events (CPE) have a central, obstructive, or mixed etiology. Lack of standardized diagnosis and management of CPE may prolong the length of stay (LOS).

OBJECTIVE

To increase the accuracy of CPE diagnosis and decrease LOS by 10% for preterm infants over a 12-month period.

METHODS

Develop an evidence-based algorithm to identify type of CPE, determine management approach, and evaluate cardio-respiratory monitors output. Apply model for improvement and statistical process control charts to determine special cause variation.

RESULTS

Identification of central apnea increased from 15 to 39% (p < 0.01). LOS decreased 26% from 52.6 days to 39.2 days, with an estimated cost savings of $13,119 per each of the 225 infants in the initiative.

CONCLUSION

After implementing an evidence-based algorithm for management of neonatal CPE, a significant increase in the accuracy of the diagnosis of central apnea and cost savings associated with a decrease in LOS were observed.

Heart Rate Variability Analysis to Evaluate Autonomic Nervous System Maturation in Neonates: An Expert Opinion

While heart rate variability (HRV) is a relevant non-invasive tool to assess the autonomic nervous system (ANS) functioning with recognized diagnostic and therapeutic implications, the lack of knowledge on its interest in neonatal medicine is certain. This review aims to briefly describe the algorithms used to decompose variations in the length of the RR interval and better understand the physiological autonomic maturation data of the newborn. Assessing newborns' autonomous reactivity can identify dysautonomia situations and discriminate children with a high risk of life-threatening events, which should benefit from cardiorespiratory monitoring at home. Targeted monitoring of HRV should provide an objective reflection of the newborn's intrinsic capacity for cardiorespiratory self-regulation.