Recent Advances in Pathophysiology and Management of Transient Tachypnea of Newborn

The Association Between Hypoxic-Ischemic Encephalopathy and Thyroid Hormones

We aimed to compare serum thyroid-stimulating hormone (TSH) and free thyroxine (fT4) levels in neonates with different hypoxic-ischemic encephalopathy (HIE) stages undergoing therapeutic hypothermia (TH), and to evaluate the TSH and fT4 levels in neonates with HIE/TH in comparison with a control group. This was a retrospective study conducted between January 2020 and December 2022. The neonates with HIE/TH constituted the study group and the neonates with transient tachypnea of the newborn (TTN) constituted the control group. The study group consisted of neonates with stage 2 and stage 3 HIE. Serum TSH and fT4 levels measured at postnatal fifth day were compared between the groups. Of the 202 (47.1%) neonates included in the study group, 144 (71.3%) had stage 2 HIE and 58 (28.7%) had stage 3 HIE. In the control group, there were 227 (52.9%) newborns. Serum TSH and fT4 levels were found to be lower in the newborns with stage 3 HIE compared with those with stage 2 HIE (p = 0.015, 0.002, respectively). Although the serum TSH level was higher in the newborns with HIE compared with the newborns with TTN, serum fT4 levels did not change between the groups (p = < 0.001, 0.14, respectively). When we made the analysis according to the reference intervals, HIE/TH was associated with higher rates of TSH elevation compared with TTN, and the difference was more pronounced in stage 2 HIE/TH (p < 0.001). Although stage 3 HIE/TH was significantly associated with higher rates of low fT4 compared with TTN (p = 0.006), this relationship was not significant between stage 2 HIE/TH and TTN. It would be reasonable to interpret thyroid function tests performed on the fifth day with caution in newborns with HIE/TH, because higher TSH and lower fT4 levels on the fifth day in this patient group may result in unnecessary repetition of tests.

Setting the Standards: Neonatal Lung Ultrasound in Clinical Practice

The use of lung ultrasonography in neonates is increasing at a very fast rate. Evidence-based guidelines on the use of lung ultrasound (LU) in neonates and children have been published and well received across the world. However, there remains a lack of standardized curriculum for lung ultrasound training and standards for its application at the bedside. This article focuses on providing a standardized approach to the application of lung ultrasonography in neonates for the common neonatal conditions and how it can be integrated into bedside clinical decision-making.

Left atrial strain assessment unveils left ventricular diastolic dysfunction in neonates with transient tachypnea of the newborn: A prospective observational study

INTRODUCTION

An inadequate clearance of lung fluid plays a key role in the pathogenesis of transient tachypnea of the newborn (TTN).

OBJECTIVES

To evaluate if left ventricular diastolic dysfunction contributes to reduced clearance of lung fluid in TTN.

MATERIALS AND METHODS

This was a prospective, observational study. Echocardiography and lung ultrasound were performed at 2, 24 and 48 h of life (HoL) to assess biventricular function and calculate lung ultrasound score (LUS). Left atrial strain reservoir (LASr) provided surrogate measurement of left ventricular diastolic function.

RESULTS

Twenty-seven neonates with TTN were compared with 27 controls with no difference in gestation (36.1 ± 2 vs. 36.9 ± 2 weeks) or birthweight (2508 ± 667 vs. 2718 ± 590 g). Biventricular systolic function was normal in both groups. LASr was significantly lower in cases at 2 (21.0 ± 2.7 vs. 38.1 ± 4.4; p < 0.01), 24 (25.2 ± 4.5 vs. 40.6 ± 4.0; p < 0.01) and 48 HoL (36.5 ± 5.8 and 41.6 ± 5.2; p < 0.01), resulting in a significant group by time interaction (p < 0.001), after adjusting for LUS and gestational diabetes. A logistic regression model including LUS, birth weight and gestational diabetes as covariates, showed that LASr at 2 HoL was a predictor of respiratory support at 24 HoL, with an adjusted odds ratio of 0.60 (CI 0.36-0.99).

CONCLUSIONS

LASr was reduced in neonates with TTN, suggesting diastolic dysfunction, that may contribute to the delay in lung fluid clearance.

Thoracic fluid content (TFC) using electrical cardiometry versus lung ultrasound in the diagnosis of transient tachypnea of newborn

This study aimed to evaluate TFC by EC versus lung ultrasound (LUS) findings for diagnosing and follow-up of TTN in late preterm and term neonates. This prospective observational study was conducted on 80 neonates with gestational age ≥ 34 weeks. TTN group included 40 neonates diagnosed with TTN, and no lung disease (NLD) group included 40 neonates without respiratory distress. LUS and EC were performed within the first 24 h of life and repeated after 72 h. There was a statistically significant increase in TFC in TTN group on D1 [48.48 ± 4.86 (1 KOhm-1)] compared to NLD group [32.95 ± 4.59 (1 KOhm-1)], and then significant decrease in TFC in D3 [34.90 ± 4.42 (1 KOhm-1)] compared to D1 in the TTN group. There was a significant positive correlation between both TFC and LUS with Downes' score, TTN score, and duration of oxygen therapy in the TTN group.   Conclusion: Both LUS and TFC by EC provide good bedside tools that could help to diagnose and monitor TTN. TFC showed a good correlation with LUS score and degree of respiratory distress. What is Known: • Transient tachypnea of the newborn (TTN) is the most common cause of respiratory distress in newborns. • TTN is a diagnosis of exclusion, there are no specific clinical parameters or biomarker has been identified for TTN. What is New: • Thoracic fluid content (TFC) by electrical cardiometry is a new parameter to evaluate lung fluid volume and could help to diagnose and monitor TTN and correlates with lung ultrasound score.

Lung-Gut Microbiota and Tryptophan Metabolites Changes in Neonatal Acute Respiratory Distress Syndrome

Purpose

Neonatal Acute Respiratory Distress Syndrome (NARDS) is a severe respiratory crisis threatening neonatal life. We aim to identify changes in the lung-gut microbiota and lung-plasma tryptophan metabolites in NARDS neonates to provide a differentiated tool and aid in finding potential therapeutic targets.

Patients and Methods

Lower respiratory secretions, faeces and plasma were collected from 50 neonates including 25 NARDS patients (10 patients with mild NARDS in the NARDS_M group and 15 patients with moderate-to-severe NARDS in the NARDS_S group) and 25 control patients screened based on gestational age, postnatal age and birth weight. Lower airway secretions and feces underwent 16S rRNA gene sequencing to understand the microbial communities in the lung and gut, while lower airway secretions and plasma underwent LC-MS analysis to understand tryptophan metabolites in the lung and blood. Correlation analyses were performed by comparing differences in microbiota and tryptophan metabolites between NARDS and control, NARDS_S and NARDS_M groups.

Results

Significant changes in lung and gut microbiota as well as lung and plasma tryptophan metabolites were observed in NARDS neonates compared to controls. Proteobacteria and Bacteroidota were increased in the lungs of NARDS neonates, whereas Firmicutes, Streptococcus, and Rothia were reduced. Lactobacillus in the lungs decreased in NARDS_S neonates. Indole-3-carboxaldehyde decreased in the lungs of NARDS neonates, whereas levels of 3-hydroxykynurenine, indoleacetic acid, indolelactic acid, 3-indole propionic acid, indoxyl sulfate, kynurenine, and tryptophan decreased in the lungs of the NARDS_S neonates. Altered microbiota was significantly related to tryptophan metabolites, with changes in lung microbiota and tryptophan metabolites having better differentiated ability for NARDS diagnosis and grading compared to gut and plasma.

Conclusion

Significant changes occurred in the lung-gut microbiota and lung-plasma tryptophan metabolites of NARDS neonates. Alterations in lung microbiota and tryptophan metabolites were better discriminatory for the diagnosis and grading of NARDS.

Does the use of antenatal corticosteroids reduce respiratory morbidity in babies born in late preterm period?

BACKGROUND

The aim of this study is to determine the effectiveness of antenatal corticosteroid in reducing respiratory morbidity in babies born in the late preterm period.

METHODS

Two hundred and eighty-six pregnant women at risk of having a late preterm delivery were studied. One hundred and forty-three (143) served as the cases and were given 2 doses of 12 mg intramuscular dexamethasone 12 h apart, while 143 served as the controls and were given a similar quantity of placebo. The women were followed up prospectively and data were collected on the pregnant women and their newborns on a standardized form. The neonates were assessed for acute respiratory distress syndrome and transient tachypnea of the newborn based on clinical signs, symptoms, and chest x-ray results (when indicated). The primary outcome was the occurrence of neonatal respiratory morbidity.

RESULTS

The primary outcome occurred in 5 out of 130 infants (3.8%) in the dexamethasone group and 31 out of 122 (25.4%) in the placebo group (P value = 0.000003). Birth asphyxia, neonatal intensive care admission and need for active resuscitation at birth also occurred significantly less frequently in the dexamethasone group (P value 0.004, 0.009, 0.014 respectively). There were no significant group differences in the incidence of neonatal sepsis, neonatal jaundice, hypoglycemia and feeding difficulties.

CONCLUSIONS

Administration of dexamethasone to women at risk for late preterm delivery significantly reduced the rate of neonatal respiratory complications, neonatal intensive care unit admission, and need for active resuscitation at birth.

TRIAL REGISTRATION

PACTR ( www.pactr.org ) Registration Number: PACTR202304579281358. The study was retrospectively registered on April 19, 2023.

Adverse respiratory patterns in near-term spontaneously breathing newborn lambs with elevated airway liquid volumes at birth

Introduction

Recent evidence indicates that respiratory distress (RD) in near-term infants is caused by elevated airway liquid (EL) volume at the beginning of air-breathing after birth. While the adverse effects EL volumes on newborn lung function are known, the effects on respiratory control and breathing patterns shortly after birth (<4 h) are unknown. We investigated the effects of EL volumes on cardiorespiratory function and breathing patterns in spontaneously breathing near-term newborn lambs in the first hours after birth.

Methods

At 137-8 days gestation (2-3 days prior to delivery; term ∼147 days), sterile surgery was performed on fetal sheep (n = 17) to implant catheters and blood flow probes. At 140 days, lambs were delivered via caesarean section under spinal anaesthesia. Airway liquid volumes were adjusted to mimic the level expected following vaginal delivery (∼10 ml/kg; Controls; n = 7), or elective caesarean section (∼30 ml/kg; elevated airway liquid group; EL; n = 10). Spontaneous breathing and cardiorespiratory parameters were recorded over four hours after birth. Non-invasive respiratory support with supplemental oxygen was provided if required.

Results

EL lambs required higher inspired oxygen levels (p = 0.0002), were less active (p = 0.026), fed less (p = 0.008) and had higher respiratory morbidity scores than Controls (p < 0.0001). EL lambs also displayed higher rates of breathing patterns associated with RD, such as expiratory braking and tachypnoea. These patterns were particularly evident in male EL lambs who displayed higher levels of severe respiratory morbidity (e.g., expiratory braking) than female EL lambs.

Conclusion

The study demonstrates that EL volumes at birth trigger respiratory behaviour and breathing patterns that resemble clinically recognised features of RD in term infants.

Pneumothorax in a term newborn

With the advent of surfactant and gentle ventilation, the incidence of neonatal pneumothorax has decreased over the last two decades. Pneumothorax associated with respiratory distress syndrome is more common in preterm infants, but term infants often present with isolated pneumothorax. The use of CPAP or non-invasive respiratory support in the delivery room for a term infant with respiratory distress increases transpulmonary pressures and increases the risk of pneumothorax. Prompt diagnosis with a high index of suspicion, quick evaluation by transillumination, chest X-ray or lung ultrasound is critical. Management includes observation, needle thoracocentesis and if necessary, chest tube placement. This manuscript reviews the incidence, pathogenesis, diagnosis and management of a term infant with isolated pneumothorax, summarizing the combination of established knowledge with new understanding, including data on diagnostic modes such as ultrasound, reviewing preventative measures, and therapeutic interventions such as needle thoracocentesis and a comparison of pigtail vs. straight chest tubes.

Neonatal point-of-care lung ultrasound: what should be known and done out of the NICU?

Lung ultrasound is rapidly becoming a useful tool in the care of neonates: its ease of use, reproducibility, low cost, and negligible side effects make it a very suitable tool for the respiratory care of all neonates. This technique has been extensively studied by different approaches in neonatal intensive care unit (NICU), both for diagnostic and prognostic aims and to guide respiratory treatments. However, many neonates are being born in level I/II hospitals without NICU facilities so all pediatricians, not just neonatal intensivists, should be aware of its potential. This is made possible by the increasing access to ultrasound machines in a modern hospital setting. In this review, we describe the ultrasonographic characteristics of the normal neonatal lung. We also discuss the ultrasound features of main neonatal respiratory diseases: transient tachypnea of the neonate (TTN), respiratory distress syndrome (RDS), meconium aspiration syndrome (MAS), pneumothorax (PNX), pleural effusion (PE), or pneumonia. Finally, we mention two functional approaches to lung ultrasound: 1. The use of lung ultrasound in level I delivery centers as a mean to assess the severity of neonatal respiratory distress and request a transport to a higher degree structure in a timely fashion. 2. The prognostic accuracy of lung ultrasound for early and targeted surfactant replacement.

CONCLUSION

 LU is still a useful tool in level I/II neonatal units, both for diagnostic and functional issues.

WHAT IS KNOWN

• Neonatal lung ultrasound has been recently introduced in the usual care in many Neonatal Intensive Care Units.

WHAT IS NEW

• It also has many advantages in level I/II neonatal units, both for neonatologist or even pediatricians that treat neonates in those sites.

Declining birth rates, increasing maternal age and neonatal intensive care unit admissions

OBJECTIVE

To describe the number of US births, maternal age at birth and NICU admissions by maternal age cohorts. Our study aims to measure NICU utilization by maternal age over time.

STUDY DESIGN

We queried the CDC WONDER Natality database for births, NICU admissions, and maternal age at delivery from 2016 to 2021. Births and NICU admissions were analyzed by maternal age.

RESULTS

Between 2016 and 2021, US births decreased by 7% (3,945,875 to 3,664,292/year). NICU admissions increased from 344,454 to 351,775 (+2%) and admit rate from 8.7% to 9.6%. The proportion of births by maternal age declined each year for ≤29 y but increased for ≥30 y. NICU admission rates were lowest at maternal age 20-29 y and increased with age ≥30 y.

CONCLUSIONS

US NICUs have demonstrated a 2% increase in admissions despite a 7% decrease in births. Higher rates of NICU admissions among infants born at maternal age ≥30 y warrants investigation.

Neonatal and Infant Lung Disorders: Glossary, Practical Approach, and Diagnoses

A multitude of lung disorders ranging from congenital and genetic anomalies to iatrogenic complications can affect the neonate or the infant within the first year of life. Neonatal and infant chest imaging, predominantly by plain radiography and computed tomography, is frequently employed to aid in diagnosis and management; however, these disorders can be challenging to differentiate due to their broad-ranging, and frequently overlapping radiographic features. A systematic and practical approach to imaging interpretation which includes recognition of radiologic patterns, utilization of commonly accepted nomenclature and classification, as well as interpretation of imaging findings in conjunction with clinical history can not only assist radiologists to suggest the diagnosis, but also aid clinicians in management planning. The contents of this article were endorsed by the leadership of both the World Federation of Pediatric Imaging (WFPI), and the International Society of Pediatric Thoracic Imaging (ISPTI).

Ultrasound diagnosis and grading criteria of neonatal respiratory distress syndrome

Background: Respiratory distress syndrome (RDS) is a common critical lung disease in newborn infants, especially those in premature infants with higher mortality rate. Early and correct diagnosis is the key to improve its prognosis. Previously, the diagnosis of RDS mainly relied on chest X-ray (CXR) findings, and it has been graded into four stages based on the progression and severity of CXR changes. This traditional diagnosing and grading method may lead to high misdiagnosis rate or delayed diagnosis. Recently, using ultrasound to diagnose neonatal lung diseases and RDS is becoming increasingly popular, and the technology is gaining higher sensitivity and higher specificity. The management of RDS under lung ultrasound (LUS) monitoring has achieved significant results, reducing the misdiagnosis rate of RDS, thereby reducing the probability of mechanical ventilation and the use of exogenous pulmonary surfactant, and making the success rate of treatment of RDS up to 100%.Objective: The purpose of the article was to introduce the ultrasound grading methods and criteria of RDS, in order to promote the application of LUS in the diagnosis and treatment of RDS.Methods: Literature (in English and Chinese) on the use of ultrasound in the diagnosis of neonatal RDS between 2008 and 2022 was selected for inclusion in this study.Results: From the collected literature, the use of ultrasound in the diagnosis of RDS is increasing, and people's understanding of the ultrasound imaging findings of RDS is also changing. Among them, the research on ultrasound grading of RDS is the latest progress.Conclusion: Ultrasound is accurate and reliable in the diagnosis and differential diagnosis of RDS. It is of great clinical value to master the ultrasound diagnosis and grading criteria of RDS.

Characteristics and outcomes of respiratory distress among term infants born in a regional setting

INTRODUCTION

Respiratory distress is the leading cause of admission to neonatal units and is a common indication for medical retrieval. Whilst approximately 25% of births in NSW occur in regional centres, there is a paucity of neonatal research in these settings.

OBJECTIVE

To describe the characteristics and outcomes of term neonates admitted with respiratory distress to two regional special care nurseries (SCNs) and identify variables associated with the need for medical retrieval.

DESIGN

We describe a cohort of 629 term infants admitted to the SCN in two regional hospitals, 2015-2019. We describe the admission characteristics, level of respiratory support, biochemical investigations, diagnosis and outcomes.

FINDINGS

During the study period, 629 eligible term infants were admitted, retrieval occurred in 29 (4.6%). Those admitted were more often male (66.5%), with a mean gestational age of 39 + 1 weeks (±9 days) and birth weight of 3470 g (±500 g). Infants requiring medical retrieval had higher PaCO2 on blood gas analysis (59.8 mmHg vs. 53.3 mmHg, OR 1.03, p = 0.02). There was no association between maternal GBS status, meconium-stained liquor, gestational age, or raised inflammatory markers and medical retrieval. Transient tachypnoea of the newborn was the most common diagnosis of neonates admitted to SCN with respiratory distress.

DISCUSSION

Among term infants admitted to a SCN for respiratory distress most were male, of a normal birthweight and born in good condition. Within our cohort there was no association between retrieval and maternal GBS colonisation, meconium-stained liquor or raised infectious biomarkers. Medical retrieval was infrequent and was associated with higher PaCO2 on initial blood gas analysis.

CONCLUSION

We present a large cohort of term newborn infants managed for respiratory distress in a regional setting over a five-year period. Retrieval was infrequent, and outcomes for the cohort were excellent with no deaths during the study period.

Association between maternal coronavirus disease 2019 and transient tachypnea of the newborn: a single-center study

BACKGROUND

Limited clinical reports have investigated the effects of maternal coronavirus disease 2019 (COVID-19) on fetuses and neonates.

PURPOSE

This retrospective study aimed to assess the impact of maternal COVID-19 on neonates during the perinatal period, including neonatal clinical outcomes, versus the outcomes of neonates of mothers without COVID-19.

METHODS

Neonates born to COVID-19-infected mothers at the National Health Insurance Service Ilsan Hospital between February 2021 and March 2022 were included. Those with gestational age (GA) ≥35+0 weeks who were born within 2 weeks of the maternal infection were matched 1:2 with a control group based on GA. The main outcomes were respiratory diseases, including transient tachypnea of the newborn (TTN), respiratory distress syndrome, meconium aspiration syndrome, the need for respiratory support, and length of hospital stay. Uni- and multivariate logistic regression analyses were performed and adjusted for relevant covariates, including maternal age, obstetric complications (hypertension and gestational diabetes), delivery mode, birth weight, sex, and small-for-gestational-age status.

RESULTS

The case group comprised 103 neonates (mean GA, 38.5±1.3 weeks; mean birth weight, 3,121±397 g), while the control group included 206 neonates (mean GA, 38.4±1.2 weeks; mean birth weight, 3088±428 g). In the case and control groups, the proportion of cesarean sections was 91% and 40%, respectively, while the proportion of male infants was 56% and 47%, respectively. After adjusting for covariates, the case group had a higher risk of TTN (adjusted odd ratio [AOR], 3.69; 95% confidence interval [CI], 1.69-8.07), noninvasive respiratory ventilator use (AOR, 2.28; 95% CI, 1.05-4.97), and oxygen support (AOR, 4.83; 95% CI, 1.46-15.95).

CONCLUSION

Newborns born to COVID-19-infected mothers are at increased risk of TTN and may require respiratory support. Close monitoring of respiratory symptoms is crucial in neonates.

The diagnostic value of pulmonary near-infrared spectroscopy in the early distinction of neonatal pneumonia from transient tachypnea of the newborn

AIM

Pulmonary near-infrared spectroscopy (NIRS) is a new and promising tool for diagnosis of neonatal respiratory diseases (RD). The study aimed to determine the role of pulmonary regional oxygen saturation (pRSO2 ) values obtained by NIRS in the early distinction of neonatal pneumonia (NP) from transient tachypnea of the newborn (TTN).

METHODS

This prospective, observational, double-blind study was conducted in neonatal intensive care unit (NICU) between 2020 and 2021. Late preterm and term newborns hospitalized in the NICU due to the diagnosis of TTN and NP were included. Cerebral RSO2 and pRSO2 values were measured during the 1st, 24th, 48th, and 72nd hours of hospitalization, using NIRS.

RESULTS

Of the eligible 40 infants, 65% (n: 26) were diagnosed as TTN and 35% (n: 16) as NP. The pRSO2 values were significantly higher in the TTN group than the NP group for both apexes (75.3 ± 8.7 vs. 69 ± 5.4, p: .018, respectively) and lateral lung (77.8 ± 6 vs. 72.7 ± 6.2, p: .016, respectively) in the 1st hour of hospitalization. There were significant differences in pRSO2 apex and pRSO2 lateral values between the 1st and 24th hours of hospitalization and the 24th and 48th hours in the NP group (p2 : .001 for both). The optimal pRSO2 apex cut-off value was >72% to predict the diagnosis of NP with a sensitivity of 78.6% and a specificity of 69.2%.

CONCLUSION

Pulmonary NIRS may be considered as a feasible and promising diagnostic tool in late preterm and term infants with RD. It may also be helpful for the early differentiation of NP from TTN and the courses of these diseases.

An Interpretable Neonatal Lung Ultrasound Feature Extraction and Lung Sliding Detection System Using Object Detectors

The objective of this study was to develop an interpretable system that could detect specific lung features in neonates. A challenging aspect of this work was that normal lungs showed the same visual features (as that of Pneumothorax (PTX)). M-mode is typically necessary to differentiate between the two cases, but its generation in clinics is time-consuming and requires expertise for interpretation, which remains limited. Therefore, our system automates M-mode generation by extracting Regions of Interest (ROIs) without human in the loop. Object detection models such as faster Region Based Convolutional Neural Network (fRCNN) and RetinaNet models were employed to detect seven common Lung Ultrasound (LUS) features. fRCNN predictions were then stored and further used to generate M-modes. Beyond static feature extraction, we used a Hough transform based statistical method to detect "lung sliding" in these M-modes. Results showed that fRCNN achieved a greater mean Average Precision (mAP) of 86.57% (Intersection-over-Union (IoU) = 0.2) than RetinaNet, which only displayed a mAP of 61.15%. The calculated accuracy for the generated RoIs was 97.59% for Normal videos and 96.37% for PTX videos. Using this system, we successfully classified 5 PTX and 6 Normal video cases with 100% accuracy. Automating the process of detecting seven prominent LUS features addresses the time-consuming manual evaluation of Lung ultrasound in a fast paced environment. Clinical impact: Our research work provides a significant clinical impact as it provides a more accurate and efficient method for diagnosing lung diseases in neonates.

Outcomes of neonates born through meconium-stained amniotic fluid pre and post 2015 NRP guideline implementation

A shift in the Neonatal Resuscitation Program (NRP) guidelines occurred in 2015 from routine intubation and endotracheal suctioning of all meconium-stained non-vigorous infants towards less aggressive interventions based on response to initial resuscitation. This study aims to examine the impact of this change on outcomes of non-vigorous infants born through meconium-stained amniotic fluid at a level III academic NICU encompassing years before and after the change in guideline. This single-center retrospective study compared NICU therapies and clinical outcomes of 117 non-vigorous newborns pre-guideline implementation to 106 non-vigorous newborns post-guideline implementation. Nearly two thirds of infants in the pre-guideline cohort received endotracheal suctioning with recovery of meconium compared to less than a third of infants in the post-guideline cohort (p<0.01). Though a higher proportion of the pre-guideline cohort were admitted to the NICU for respiratory issues compared to the post-guideline cohort, the two groups did not differ significantly with regard to morbidity and therapies. Despite a marked reduction in rates of intubation and endotracheal suctioning, there is no difference in outcomes between pre-guideline implementation vs post-guideline implementation in non-vigorous meconium-stained infants, supporting the recent NRP guideline change and highlighting the benefit of expectant management.

Persistent Tachypnoea in Early Infancy: A Clinical Perspective

Tachypnoea in the newborn is common. It may arise from the many causes of the respiratory distress syndrome such as hyaline membrane disease, transient tachypnoea of the newborn, meconium aspiration etc. Congenital heart disease rarely presents with early tachypnoea on day one or two, in contrast to the early presentation of cyanosis, unless there is "pump" (ventricular) failure such as may occur in a cardiomyopathy/myocarditis, or as a result of severe obstruction to either ventricle. Space-occupying lesions within the chest, for example from a diaphragmatic hernia or a congenital cystic adenomatoid malformation, may present with early tachypnoea, as can a metabolic cause resulting in acidosis. The aim of this paper, however, is to focus on infants where the tachypnoea persists or develops beyond the newborn period, at times with minimal signs but occasionally with serious underlying pathology. They include causes that may have originated in the newborn but then persist; for example, arising from pulmonary hypoplasia or polycythemia. Many congenital cardiac abnormalities, particularly those causing left sided obstructive lesions, or those due to an increasing left to right shunt from large communications between the systemic and pulmonary circulations, need be considered. Respiratory causes, for example arising from aspiration, primary ciliary dyskinesia, cystic fibrosis, or interstitial lung disease, may lead to ongoing tachypnoea. Infective causes such as bronchiolitis or infantile wheeze generally are readily recognisable. Finally, there are a few infants who present with persistent tachypnoea over the first few weeks/months of their life who remain well and have normal investigations with the tachypnoea gradually resolving. How should one approach infants with persistent tachypnoea?

The diagnostic value of n-terminal probrain natriuretic peptides to differentiate neonatal pneumoniae and transient tachypnea of the newborn

BACKGROUND

The primary objective of the study was to determine the diagnostic value of serum N-terminal probrain natriuretic peptide (NT-proBNP) levels to differentiate neonatal pneumonia (NP) and transient tachypnea of the newborn (TTN). The secondary objective was to investigate the prognostic role of NT-proBNP levels in neonates with severe respiratory distress (RD).

METHODS

A prospective, observational, single-blinded study involving 58 late preterm and term newborns who were diagnosed with TTN or NP was conducted between June 2020 and June 2021 at a level-3 neonatal intensive care unit in Kırıkkale University Faculty of Medicine. TTN and NP groups were compared for serum NT-proBNP levels measured at the 1st and 24th hours of life. Optimal cut-off NT-proBNP value was determined by Youden index to predict the diagnosis of NP. Lung ultrasound was used to support the diagnosis of TTN and NP. In addition, lung ultrasound score (LUS) was used to determine severe RD.

RESULTS

The median of NT-proBNP level was significantly higher at the 24th hour of life in the NP group than in the TTN group, respectively 7263.5 pg/mL (1643-35,000) and 3308 pg/mL (69-19,746), p = 0.004. At a cut-off value of 5515.5 pg/mL, NT-proBNP had a sensitivity of 75% and specificity of 73.8% to predict NP [AUC= 0.749 (95% CI: 0.602-0.895; p = 0.004)]. The study population was divided into two groups as high score group (n: 23, LUS ≥ 7) and low score group (n: 35, LUS < 7) according to the LUS at the 6th hour of life. NT-proBNP values at 24th hour of life were 6320 pg/mL (69-35,000) in high score group and 3500 pg/mL (570-15,948) in low score group, p = 0.044. Duration of oxygen support (p = 0.006), noninvasive ventilation (p = 0.008) and NICU stay (p = 0.004) were higher in high-score group.

DISCUSSION

NT-proBNP values at 24th hour of life can be used as a relatively early predictor in the differentiation between NP and TTN in late preterm and term neonates. In addition, elevated NT-proBNP values are related to the higher LUS which reflects the severity of RD regardless of diagnosis.

Association between thiol-disulfide hemostasis and transient tachypnea of the newborn in late-preterm and term infants

BACKGROUND

Transient tachypnea of the newborn (TTN), which is the most common respiratory disease in the neonatal period, increases respiratory workload in newborns. We purposed to evaluate the oxidative stress (OS) status and thiol disulfide hemostasis in late preterm and term newborns with TTN in this study.

METHODS

The study was carried out in a single-centre neonatal intensive care unit to investigate the effect of continuous airway positive pressure (CPAP) on the oxidative system in newborns with TTN. Thiol (native and total) and disulfide levels, total antioxidant and oxidant status (TAS/TOS) and Oxidative stress index (OSI) levels were measured.

RESULTS

Total thiol levels measured before treatment was 429.5 (369.5-487) µmol/L in the late preterm group and 425 (370-475) µmol/L in the term group (p = 0.741). We found significant changes in TOS, OSI and TAS levels after CPAP treatment in the late preterm group (p < 0.001, p < 0.001, p = 0.012 respectively). It was also found that the disulfide level, which was 26.2 (19.2-31.7) before the treatment, decreased to 19.5 (15.5-28.75) after the treatment (p = 0.001) in late preterms.

CONCLUSION

CPAP treatment reduced the OS status burden associated with TTN in neonates. The late preterm newborns with TTN are more affected by OS and increased OS levels decrease with CPAP treatment.

Use of Cardio-Pulmonary Ultrasound in the Neonatal Intensive Care Unit

Cardiopulmonary ultrasound (CPUS), the combination of lung ultrasound (LUS) and targeted neonatal echocardiography (TnECHO)AA, may offer a more appropriate approach to the challenging neonatal cardiovascular and respiratory disorders. This paper reviews the possible use of CPUS in the neonatal intensive care unit (NICU).

Salbutamol and Epinephrine Inhalation as a Conservative Treatment of Transient Tachypnea of Newborn: a Pilot Randomized Controlled Trial.. [DOI: 10.21203/rs.3.rs-2591668/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Objective: To evaluate the efficacy and the safety of inhaled salbutamol and epinephrine in the treatment of TTN. Design: Double-blinded randomized control pilot study was carried out on 135 near and full-term infants with TTN in the NICU of Mansoura University children's hospital. They were randomly assigned to receive either a single dose of epinephrine, salbutamol, or placebo inhalation. The primary outcome was the level of TTN Downe’s score and the required respiratory support. PaO2 and PaCO2, duration of oxygen therapy, hospital stay, and the adverse effects were considered secondary outcomes. registered at www.clinicaltrials.gov (NCT05006235). Results: Downe’s score, CPAP requirement, and PaCO2 were significantly less in the salbutamol and epinephrine groups, in addition to a shorter duration of oxygen support and hospital stay with tolerable adverse effects. Conclusion: Epinephrine or salbutamol inhalation in treatment of TTN is safe, well tolerated, and effective in reduction of the severity of respiratory distress.

Cardiopulmonary Ultrasound Patterns of Transient Acute Respiratory Distress of the Newborn: A Retrospective Pilot Study

Acute transient respiratory distress in the first hours of life is usually defined as transient tachypnea of the newborn (TTN). TTN is a respiratory self-limiting disorder consequent to delayed lung fluid clearance at birth. While TTN is the most common etiology of respiratory distress near term, its pathogenesis and diagnostic criteria are not well-defined. Lung ultrasound and targeted neonatal echocardiography are increasingly being used to assess critically ill infants, although their combined use to improve diagnostic precision in neonatal intensive care units has not yet been described. This retrospective pilot analysis aimed to identify possible cardiopulmonary ultrasound (CPUS) patterns in term and late preterm infants suffering from transient respiratory distress and requiring non-invasive respiratory support. After retrospectively revising CPUS images, we found seven potential sonographic phenotypes of acute neonatal respiratory distress. Up to 50% of the patients presented with signs of increased pulmonary vascular resistance, suggesting that those patients may be diagnosed with mild forms of persistent pulmonary hypertension of the newborn. Approximately 80% of the infants with a history of meconium-stained amniotic fluid displayed irregular atelectasis, indicating that they may have suffered from mild meconium aspiration syndrome. CPUS evaluation may improve accuracy in the approach to the infants presenting with transient acute respiratory distress, supporting communication with the parents and carrying important epidemiological consequences.

Recommended Guideline for Uniform Reporting of Neonatal Resuscitation: The Neonatal Utstein Style

Clinical research on neonatal resuscitation has accelerated over recent decades. However, an important methodologic limitation is that there are no standardized definitions or reporting guidelines for neonatal resuscitation clinical studies. To address this, the International Liaison Committee on Resuscitation Neonatal Life Support Task Force established a working group to develop the first Utstein-style reporting guideline for neonatal resuscitation. The working group modeled this approach on previous Utstein-style guidelines for other populations. This reporting guideline focuses on resuscitation of newborns immediately after birth for respiratory failure, bradycardia, severe bradycardia, or cardiac arrest. We identified 7 relevant domains: setting, patient, antepartum, birth/preresuscitation, resuscitation process, postresuscitation process, and outcomes. Within each domain, relevant data elements were identified as core versus supplemental. Core data elements should be collected and reported for all neonatal resuscitation studies, while supplemental data elements may be collected and reported using standard definitions when possible. The Neonatal Utstein template includes both core and supplemental elements across the 7 domains, and the associated Data Table provides detailed information and reporting standards for each data element. The Neonatal Utstein reporting guideline is anticipated to assist investigators engaged in neonatal resuscitation research by standardizing data definitions. The guideline will facilitate data pooling in meta-analyses, enhancing the strength of neonatal resuscitation treatment recommendations and subsequent guidelines.

Evolution of Ultrasound-Assessed Lung Aeration and Gas Exchange in Respiratory Distress Syndrome and Transient Tachypnea of the Neonate

OBJECTIVE

To use clinical, lung ultrasound, and gas exchange data to clarify the evolution of lung aeration and function in neonates with respiratory distress syndrome (RDS) and transient tachypnea of the neonate (TTN), the most common types of neonatal respiratory failure.

STUDY DESIGN

In this prospective observational cohort study, lung aeration and function were measured with a semiquantitative lung ultrasound score (LUS) and transcutaneous blood gas measurement performed at 1 hour (time point 0), 6 hours (time point 1), 12 hours (time point 2), 24 hours (time point 3) and 72 hours (time point 4) of life. Endogenous surfactant was estimated using lamellar body count (LBC). LUS, oxygenation index (OI), oxygen saturation index (OSI), and transcutaneous pressure of carbon dioxide (PtcCO₂) were the primary outcomes. All results were adjusted for gestational age.

RESULTS

Sixty-nine neonates were enrolled in the RDS cohort, and 58 neonates were enrolled in the TTN cohort. LUS improved over time (within-subjects, P < .001) but was worse for the RDS cohort than for the TTN cohort at all time points (between-subjects, P < .001). Oxygenation improved over time (within-subjects, P = .011 for OI, P < .001 for OSI) but was worse for the RDS cohort than for the TTN cohort at all time points (between-subjects, P < .001 for OI and OSI). PtcCO₂ improved over time (within-subjects, P < .001) and was similar in the RDS and TTN cohorts at all time points. Results were unchanged after adjustment for gestational age. LBC was associated with RDS (β = -0.2 [95% CI, -0.004 to -0.0001]; P = .037) and LUS (β = -3 [95% CI, -5.5 to -0.5]; P = .019).

CONCLUSIONS

For the first 72 hours of life, the RDS cohort had worse lung aeration and oxygenation compared with the TTN cohort at all time points. CO₂ clearance did not differ between the cohorts, whereas both lung aeration and function improved in the first 72 hours of life.

A case-control study on the effects of incomplete, one, and more than one dexamethasone course on acute respiratory problems in preterm neonates born between 280 and 366 weeks of gestation

OBJECTIVE

To compare the effects of an incomplete course and more than 1 course of dexamethasone, relative to a control of a single complete course, on foetal respiratory problems and other adverse outcomes of preterm birth.

METHODS

This was a retrospective chart review of 1800 women with preterm delivery. Data were collected on newborns whose mothers administered 1 full course of dexamethasone (916/1800; 50.9%), a partial course (716/1800; 39.8%) and more than 1 course (168/1800; 9.3%). Demographic data and adverse maternal and neonatal outcomes were recorded.

RESULTS

Preterm singleton newborns whose mothers received several steroid hormone courses were significantly more likely to have adverse outcomes than newborns of mothers given 1 course. The negative outcomes were the need for positive pressure ventilation ([aOR] 1.831; 95% CI, (1.185,2.829); P = 0.019), ventilator support ([aOR] 1.843; 95% CI, (1.187,2.861); P = 0.011), and phototherapy ([aOR] 1.997; 95% CI, (1.378,2.895); P <  0.001), transient tachypnoea of the newborn ([aOR] 1.801; 95% CI, (1.261,2.571); P = 0.002), intraventricular haemorrhage ([aOR] 2.215; 95% CI, (1.159, 4.233); P = 0.027), sepsis ([aOR] 1.737; 95% CI, (1.086, 2.777); P = 0.007), and admission to neonatal intensive care ([aOR] 1.822; 95% CI, (1.275,2.604); P = 0.001). In the group of very preterm infants, newborns of mothers administered an incomplete course had developed respiratory distress syndrome (RDS) ([aOR] 3.177; 95% CI, (1.485, 6.795); P = 0.006) and used ventilatory support ([aOR] 3.565; 95% CI, (1.912, 6.650); P <  0.001) more than those of mothers receiving a single course.

CONCLUSIONS

Preterm singleton newborns whose mothers were given multiple courses of dexamethasone had an increased incidence of RDS and other adverse outcomes than those of mothers receiving a full course. However, very preterm newborns whose mothers were administered 1 full dexamethasone course had a significantly lower incidence of RDS than those whose mothers were given partial courses.

The Outcome- or Cost-Effectiveness Analysis of LUS-Based Care or CXR-Based Care of Neonatal Lung Diseases: The Clinical Practice Evidence from a Level Ⅲ NICU in China

OBJECTIVE

To compare the effect of managing neonatal lung disease with lung ultrasound (LUS) or chest X-ray (CXR) monitoring on health outcomes and cost-effectiveness.

METHODS

The data obtained from the NICU of the Beijing Chaoyang District Maternal and Child Healthcare Hospital were used as the study group, as LUS has completely replaced CXR in managing newborn lung disease in the hospital for the past 5 years. The primary outcomes of this study were the misdiagnosis rate of respiratory distress syndrome (RDS), the using status of mechanical ventilation, the incidence rate of bronchopulmonary dysplasia (BPD) and the survival rate in hospitalized infants. The secondary outcomes included the use pulmonary surfactant (PS), and the mortality rate of severe diseases (such as pneumothorax, pulmonary hemorrhage and RDS, etc.).

RESULTS

Managing neonatal lung disease with LUS monitoring may enable the following effects: The frequency of ventilator use reducing by 40.2%; the duration of mechanical ventilation reducing by 67.5%; and the frequency of ventilator weaning failure being totally avoided. A misdiagnosis rate of 30% for RDS was also avoided. The dosage of PS was significantly reduced by 50% to 75%. No BPD occurred in the LUS-based care group for 5 years. The fatality rates of RDS, pneumothorax and pulmonary hemorrhage decreased by 100%. The poor prognosis rate of VLBW infants decreased by 85%, and the total mortality rate of hospitalized infants decreased by 90%. Therefore, the cost of LUS-based care was inevitably saved.

CONCLUSIONS

Diagnosing and managing neonatal lung diseases with LUS monitoring have significant benefits, and this technology should be widely promoted and applied around the world.

Evaluation of Morbidities and Complications of Neonatal İntensive Care Unit Patients with Respiratory Disorders at Different Gestational Ages

OBJECTIVE

Respiratory distress presented within the first few days of life is life-threatening and common problem in the neonatal period. The aim of this study is to estimate (1) the incidence of respiratory diseases in newborns and related mortality; (2) the relationship between acute neonatal respiratory disorders rates and gestational age, birth weight, and gender; and (3) the incidence of complications associated with respiratory disturbances.

STUDY DESIGN

Only inborn patients with gestational age between 23^0/7 and 41^6/7 weeks having respiratory distress were included in the study. The data were collected from the medical records and gestational age was based on the menstrual dating.

RESULTS

There were 8,474 live births between January 1, 2013, and June 30, 2013, in our hospital. A total of 1,367 newborns were hospitalized and oxygen therapy was applied in 903 of them because of respiratory distress. An acute respiratory disorder was found to be in 10.6% (903/8,474) among all live births. Mortality was 0.76% (66/8,474). The incidence of respiratory distress syndrome was 2.8% (n = 242). The occurrence of transient tachypnea of newborn was 3.1% (n = 270). Meconium aspiration syndrome, pneumonia, congenital diaphragmatic hernia, and pulmonary maladaptation and primary persistent pulmonary hypertension rates were 0.1, 0.7, 2.2, and 0%, respectively. Overall, 553 (61%) of the 903 newborns having respiratory diseases had complications. The occurrence of necrotizing enterocolitis, patent ductus arteriosus, bronchopulmonary dysplasia, intraventricular hemorrhage and air leak was 6.8, 19.8, 4.7, 24.9, and 5%, respectively.

CONCLUSION

This study offers an epidemiological perspective for respiratory disorders from a single-center level-III neonatal intensive care unit. Although number of births, premature newborns, extremely low birth weight/very low birth weight infants, and complicated pregnancies increase in years, decreasing rates of mortality and complications are very promising. As perinatal and neonatal cares are getting better in every day, we think that more promising results can be achieved over the coming years.

KEY POINTS

· Respiratory distress in the newborn is life-threatening.. · Pulmonary or extrapulmonary diseases may be underlying cause.. · More promising results can be achieved over the coming years with advanced care..

Value of Serum miR-34a and Ang-1 in Severity Evaluation and Prognosis of Neonatal Respiratory Distress Syndrome

Methods

A total of 96 neonates with RDS admitted to the hospital from February 2020 to April 2021 were selected as the research subjects. According to the neonatal critical illness score, the subjects were divided into non-critical group (n = 50), critical group (n = 27), and extremely critical group (n = 19). According to survival status, the subjects were divided into survival group (n = 76) and death group (n = 20). Serum miR-34a and Ang-1 levels and NCIS were compared between RDS neonates with different severity and prognosis. The predictive value of serum miR-34a, Ang-1, and NCIS for death was analyzed using the receiver operating characteristic (ROC) curve.

Results

Serum miR-34a and Ang-1 levels and NCIS were significantly different in the 3 groups (P < 0.05). Serum miR-34a level decreased in order, while serum Ang-1 level and NCIS increased in order from the extremely critical group, the critical group to the non-critical group (P < 0.05). The survival group had lower serum miR-34a level and higher Ang-1 level and NCIS than the death group (P < 0.05). ROC curve analysis showed that the area under the curve (AUC) values of serum miR-34a, Ang-1, and NCIS to predict death of RDS neonates were 0.745, 0.7667, and 0.736. The cutoff values were 1.175, 6.815 ng/mL, and 85 points. The AUC of joint prediction with the three was 0.924, significantly larger than that of each index. The sensitivity and specificity were 94.70% and 90.00%.

Conclusion

Serum miR-34a, Ang-1, and NCIS are closely related to the severity and prognosis of neonatal RDS. Combined detection of the three is helpful for prognosis of neonatal RDS.

Lowering of the Neonatal Lung Ultrasonography Score after nCPAP Positioning in Neonates over 32 Weeks of Gestational Age with Neonatal Respiratory Distress

Respiratory distress (RD) is one of the most common causes of admission to the neonatal intensive care unit. Correct diagnosis and timely intervention are crucial. Lung ultrasonography (LU) is a useful diagnostic tool for the neonatologist in the diagnosis of RD; the neonatal lung ultrasonography score (nLUS) can be used in the diagnostic process, but some authors hypothesise that it is also useful for the management of some neonatal RD. The aim of this study is to analyse the changes in nLUS score before (T0) and after (T1) the start of respiratory support with nasal CPAP in neonates over 32 weeks of age with RD. Thirty-three newborns were enrolled in this retrospective study. LU was performed before and after the start of CPAP. The median nLUS scores at T0 and T1 were 9 (IQR 7−12) and 7 (IQR 4−10), respectively, and showed a significant difference (p < 0.001). The magnitude of reduction in nLUS score, expressed as a percentage, was inversely related to the need for subsequent administration of exogenous surfactant. The study suggests the usefulness of the nLUS score in assessing the response to CPAP in neonates over 32 weeks gestational age.

Diagnostic accuracy of lung ultrasound for transient tachypnea: a meta-analysis

OBJECTIVE

The objective of this meta-analysis was to study the diagnostic value of lung ultrasound (LUS) for transient tachypnea of the newborn (TTN).

METHODS

Embase, Cochrane Library, PubMed, Web of Science, and Google Scholar were searched, and the last search date was October 31, 2020. Studies on the diagnostic accuracy of pulmonary ultrasound for transient tachypnea were included. The quality assessment of the included study was assessed using the Diagnostic Accuracy Studies-2 tool. A meta-analysis was performed using Meta-Disc 1.4. A random-effects model was used and subgroup analysis was carried out to identify possible sources of heterogeneity.

RESULTS

A total of 378 articles were retrieved and nine studies with 3239 patients were included in the present meta-analysis. The overall quality of the included studies was moderate to high. The result of threshold analysis shows that there was no threshold effect. However, there was a significant heterogeneity caused by non-threshold effects in the included studies. A random-effects model was used. The pooled sensitivity, specificity, PLR and NLR were 0.55 (95% CI: 0.51-0.58), 0.98 (95% CI: 0.98-0.99), 58.30 (95% CI: 14.05-241.88) and 0.28 (95% CI: 0.18-0.43). The pooled DOR and AUC were 689.12 (95% CI: 68.71 to 6911.79) and 0.994. The results of subgroup analysis showed that the LUS diagnostic criteria and gold standard might be responsible for heterogeneity. Choosing "DLP combined with B line" as the diagnostic standard of LUS and choosing CXR as the gold standard could significantly improve the diagnostic performance of LUS.

CONCLUSION

LUS is a promising method to diagnose TTN. Only DLP is not enough to diagnose TTN, while DLP combined with B-line has good diagnostic performance.

Lung ultrasonography decreases radiation exposure in newborns with respiratory distress: a retrospective cohort study

Chest X-ray (CXR) is commonly used as a first-line imaging method to determine the cause of respiratory distress in NICUs. The aim of the study was to retrospectively assess the decrease in the number of CXRs performed due to the use of lung ultrasonography on the first day of life for newborns with respiratory distress. Infants who were admitted to the NICU on the first day of life due to respiratory distress were enrolled in this study (ClinicalTrials.gov identifier NCT04722016) and divided into two groups: the study group (n = 104) included patients born between January 2019 and June 2020, and the historical control group (n = 73) included patients born between June 2017 and December 2018. As a first-line technique for lung imaging, only CXR had been used in the historical control group, whereas ultrasound had been preferred in the study group. The radiation dose to the newborns and the number of CXRs performed in the first day of life were compared between the two groups. Significant reductions in the number of CXRs performed and radiation exposure were observed in the study group. The radiation dose decreased from 5.54 to 4.47 µGy per baby when LUS was routinely used. The proportion of patients who underwent CXR decreased from 100 to 71.2%.Conclusion: We observed that using lung ultrasonography as a first-line evaluation method in neonates with respiratory distress decreased both the number of CXRs performed and radiation exposure. What is Known: • Chest X-ray is commonly used as a first line imaging method to diagnose the reason of respiratory distress in NICUs. • Lung ultrasound is a new diagnostic tool for lung imaging. What is New: • With the use of lung ultrasonography, radiation exposure of both newborns and healthcare workers can be reduced. • This retrospective study revealed that most of the babies with respiratory distress were treated without CXR.

Interventions for the management of transient tachypnoea of the newborn - an overview of systematic reviews

BACKGROUND

Transient tachypnoea of the newborn (TTN) is characterised by tachypnoea and signs of respiratory distress. It is caused by delayed clearance of lung fluid at birth. TTN typically appears within the first two hours of life in term and late preterm newborns. Although it is usually a self-limited condition, admission to a neonatal unit is frequently required for monitoring, the provision of respiratory support, and drugs administration. These interventions might reduce respiratory distress during TTN and enhance the clearance of lung liquid. The goals are reducing the effort required to breathe, improving respiratory distress, and potentially shortening the duration of tachypnoea. However, these interventions might be associated with harm in the infant.

OBJECTIVES

The aim of this overview was to evaluate the benefits and harms of different interventions used in the management of TTN.

METHODS

We searched the Cochrane Database of Systematic Reviews on 14 July 2021 for ongoing and published Cochrane Reviews on the management of TTN in term (> 37 weeks' gestation) or late preterm (34 to 36 weeks' gestation) infants. We included all published Cochrane Reviews assessing the following categories of interventions administered within the first 48 hours of life: beta-agonists (e.g. salbutamol and epinephrine), corticosteroids, diuretics, fluid restriction, and non-invasive respiratory support. The reviews compared the above-mentioned interventions to placebo, no treatment, or other interventions for the management of TTN. The primary outcomes of this overview were duration of tachypnoea and the need for mechanical ventilation. Two overview authors independently checked the eligibility of the reviews retrieved by the search and extracted data from the included reviews using a predefined data extraction form. Any disagreements were resolved by discussion with a third overview author. Two overview authors independently assessed the methodological quality of the included reviews using the AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews) tool. We used the GRADE approach to assess the certainty of evidence for effects of interventions for TTN management. As all of the included reviews reported summary of findings tables, we extracted the information already available and re-graded the certainty of evidence of the two primary outcomes to ensure a homogeneous assessment. We provided a narrative summary of the methods and results of each of the included reviews and summarised this information using tables and figures.

MAIN RESULTS

We included six Cochrane Reviews, corresponding to 1134 infants enrolled in 18 trials, on the management of TTN in term and late preterm infants, assessing salbutamol (seven trials), epinephrine (one trial), budesonide (one trial), diuretics (two trials), fluid restriction (four trials), and non-invasive respiratory support (three trials). The quality of the included reviews was high, with all of them fulfilling the critical domains of the AMSTAR 2. The certainty of the evidence was very low for the primary outcomes, due to the imprecision of the estimates (few, small included studies) and unclear or high risk of bias. Salbutamol may reduce the duration of tachypnoea compared to placebo (mean difference (MD) -16.83 hours, 95% confidence interval (CI) -22.42 to -11.23, 2 studies, 120 infants, low certainty evidence). We did not identify any review that compared epinephrine or corticosteroids to placebo and reported on the duration of tachypnoea. However, one review reported on "trend of normalisation of respiratory rate", a similar outcome, and found no differences between epinephrine and placebo (effect size not reported). The evidence is very uncertain regarding the effect of diuretics compared to placebo (MD -1.28 hours, 95% CI -13.0 to 10.45, 2 studies, 100 infants, very low certainty evidence). We did not identify any review that compared fluid restriction to standard fluid rates and reported on the duration of tachypnoea. The evidence is very uncertain regarding the effect of continuous positive airway pressure (CPAP) compared to free-flow oxygen therapy (MD -21.1 hours, 95% CI -22.9 to -19.3, 1 study, 64 infants, very low certainty evidence); the effect of nasal high-frequency (oscillation) ventilation (NHFV) compared to CPAP (MD -4.53 hours, 95% CI -5.64 to -3.42, 1 study, 40 infants, very low certainty evidence); and the effect of nasal intermittent positive pressure ventilation (NIPPV) compared to CPAP on duration of tachypnoea (MD 4.30 hours, 95% CI -19.14 to 27.74, 1 study, 40 infants, very low certainty evidence). Regarding the need for mechanical ventilation, the evidence is very uncertain for the effect of salbutamol compared to placebo (risk ratio (RR) 0.60, 95% CI 0.13 to 2.86, risk difference (RD) 10 fewer, 95% CI 50 fewer to 30 more per 1000, 3 studies, 254 infants, very low certainty evidence); the effect of epinephrine compared to placebo (RR 0.67, 95% CI 0.08 to 5.88, RD 70 fewer, 95% CI 460 fewer to 320 more per 1000, 1 study, 20 infants, very low certainty evidence); and the effect of corticosteroids compared to placebo (RR 0.52, 95% CI 0.05 to 5.38, RD 40 fewer, 95% CI 170 fewer to 90 more per 1000, 1 study, 49 infants, very low certainty evidence). We did not identify a review that compared diuretics to placebo and reported on the need for mechanical ventilation. The evidence is very uncertain regarding the effect of fluid restriction compared to standard fluid administration (RR 0.73, 95% CI 0.24 to 2.23, RD 20 fewer, 95% CI 70 fewer to 40 more per 1000, 3 studies, 242 infants, very low certainty evidence); the effect of CPAP compared to free-flow oxygen (RR 0.30, 95% CI 0.01 to 6.99, RD 30 fewer, 95% CI 120 fewer to 50 more per 1000, 1 study, 64 infants, very low certainty evidence); the effect of NIPPV compared to CPAP (RR 4.00, 95% CI 0.49 to 32.72, RD 150 more, 95% CI 50 fewer to 350 more per 1000, 1 study, 40 infants, very low certainty evidence); and the effect of NHFV versus CPAP (effect not estimable, 1 study, 40 infants, very low certainty evidence). Regarding our secondary outcomes, duration of hospital stay was the only outcome reported in all of the included reviews. One trial on fluid restriction reported a lower duration of hospitalisation in the restricted-fluids group, but with very low certainty of evidence. The evidence was very uncertain for the effects on secondary outcomes for the other five reviews. Data on potential harms were scarce, as all of the trials were underpowered to detect possible increases in adverse events such as pneumothorax, arrhythmias, and electrolyte imbalances. No adverse effects were reported for salbutamol; however, this medication is known to carry a risk of tachycardia, tremor, and hypokalaemia in other settings.

AUTHORS' CONCLUSIONS

This overview summarises the evidence from six Cochrane Reviews of randomised trials regarding the effects of postnatal interventions in the management of TTN. Salbutamol may reduce the duration of tachypnoea slightly. We are uncertain as to whether salbutamol reduces the need for mechanical ventilation. We are uncertain whether epinephrine, corticosteroids, diuretics, fluid restriction, or non-invasive respiratory support reduces the duration of tachypnoea and the need for mechanical ventilation, due to the extremely limited evidence available. Data on harms were lacking.

Protocol for a multicenter, double-blind, randomized, placebo-controlled phase III trial of the inhaled β2-adrenergic receptor agonist salbutamol for transient tachypnea of the newborn (the REFSAL trial)

BACKGROUND

Transient tachypnea of the newborn (TTN), which results from inadequate absorption of fetal lung fluid, is the most common cause of neonatal respiratory distress. Stimulation of β-adrenergic receptors enhances alveolar fluid absorption. Therefore, the β2-adrenergic receptor agonist salbutamol has been proposed as a treatment for TTN. This study aims to evaluate the efficacy and safety of salbutamol as supportive pharmacotherapy together with non-invasive nasal continuous positive airway pressure (NIV/nCPAP) for the prevention of persistent pulmonary hypertension of the newborn (PPHN) in infants with TTN.

METHODS AND ANALYSIS

This multicenter, double-blind, phase III trial will include infants with a gestational age between 32 and 42 weeks who are affected by respiratory disorders and treated in eight neonatal intensive care units in Poland. A total of 608 infants within 24 h after birth will be enrolled and randomly assigned (1:1) to receive nebulized salbutamol with NIV or placebo (nebulized 0.9% NaCl) with NIV. The primary outcome is the percentage of infants with TTN who develop PPHN. The secondary outcomes are the severity of respiratory distress (assessed with the modified TTN Silverman score), frequency of need for intubation, duration of NIV and hospitalization, acid-base balance (blood pH, partial pressure of O₂ and CO₂, and base excess), and blood serum ionogram for Na⁺, K⁺, and Ca²⁺.

DISCUSSION

The Respiratory Failure with Salbutamol (REFSAL) study will be the first clinical trial to evaluate the efficacy and safety of salbutamol in the prevention of persistent pulmonary hypertension in newborns with tachypnea, and will improve short term outcomes. If successful, the study will demonstrate the feasibility of early intervention with NIV/nCPAP together with nebulized salbutamol in the management of TTN.

ETHICS AND DISSEMINATION

The study protocol was approved by the Bioethics Committee of the Medical University of Warsaw, Warsaw, Poland on November 16, 2020 (decision number KB/190/2020). All procedures will follow the principles of the Declaration of Helsinki. The results of the study will be submitted for knowledge translation in peer-reviewed journals and presented at national and international pediatric society conferences.

CLINICAL TRIAL REGISTRATION

It is registered at ClinicalTrials.gov NCT05527704, EudraCT 2020-003913-36; Protocol version 5.0 from 04/01/2022.

Application of ultrasonography in neonatal lung disease: An updated review

Lung disease is often life-threatening for both preterm and term newborns. Therefore, an accurate and rapid diagnosis of lung diseases in newborns is crucial, as management strategies differ with different etiologies. To reduce the risk of radiation exposure derived from the conventionally used chest x-ray as well as computed tomography scans, lung ultrasonography (LUS) has been introduced in clinical practice to identify and differentiate neonatal lung diseases because of its radiation-free characteristic, convenience, high accuracy, and low cost. In recent years, it has been proved that LUS exhibits high sensitivity and specificity for identifying various neonatal lung diseases. Here, we offer an updated review of the applications of LUS in neonatal lung diseases based on the reports published in recent years (2017 to present).

Brief research report: Chest radiographic thoracic area in term ventilated infants without respiratory disease

OBJECTIVE

To report values of the chest radiographic thoracic area (CRTA) in ventilated, term-born infants without respiratory disease and to evaluate whether CRTA is related to demographic data at birth.

METHODS

Retrospective, observational cohort study in a tertiary neonatal unit at King's College Hospital NHS Foundation Trust, London, UK.Newborn infants born after 36 completed weeks of gestation, ventilated for poor perinatal adaptation or hypoxic ischaemic encephalopathy without respiratory disease and admitted in a recent eight-year period (2014-2022).The CRTA was assessed by free-hand tracing of the perimeter of the thoracic area as outlined by the diaphragm and the rib cage excluding the mediastinal structures and was calculated using the Sectra PACS software.

RESULTS

One hundred and twenty-one infants (75 male) were included with a median (IQR) gestation of 40 (38-41) weeks and birth weight of 3.41 (3.04-3.75) kg. The median (IQR) CRTA was 2,589 (2,167-2,943) mm² and was significantly related to birth weight (r = 0.316, p = 0.003), gestation at birth (r = 0.193, p = 0.032) and birth weight z-score (r = 0.187, p = 0.038).

CONCLUSIONS

We report values of the chest radiographic thoracic area in ventilated term-born infants which could be used as reference for determining respiratory disease severity.

Simple Hematological Markers in Predicting the Severity of Transient Tachypnea of Newborn: New Wine in Old Bottles

OBJECTIVES

To evaluate the validity of red cell distribution width (RDW), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and platelet mass index (PMI) of patients with transient tachypnea of the newborn (TTN), and to find out their roles in predicting severity of TTN.

PATIENTS AND METHODS

In this prospective study, hematological parameters (RDW, PMI) and ratios (NLR, PLR) of 147 patients with TTN and 147 full-term healthy controls were evaluated and compared at birth and at 72nd h of life.

PATIENT

s with TTN and 147 full-term healthy controls were evaluated and compared at birth and at 72nd hours of life.

RESULTS

RDW and NLR were not only significantly higher in patients with TTN at birth (p = 0.001) and at 72nd hours of life (p: 0.001), but also were correlated with days of nasal continuous positive airway pressure therapy, duration of O2 therapy, TTN clinical scores, hospitalization and TTN duration. At a cut-off value of 2.40, NLR had a sensitivity of 82.5% and specificity of 77.5% to predict TTN, the most striking parameter at 72nd hours of life. RDW of 17.75 was also determined as the predictive cutoff value of TTN (sensitivity 72.5%; specificity 67.5%; area under the receiver-operating characteristic curve 0.80; p = 0.001). Multivariate analysis model adjusted for delivery, gestational age, male gender revealed that RDW and NLR were significantly and independently associated with TTN.

CONCLUSION

RDW and NLR both at birth and at 72nd hours of life can be used as biomarkers to distinguish TTN patients from healthy newborns and to predict the severity of TTN.

An Interpretable Object Detection-Based Model For The Diagnosis Of Neonatal Lung Diseases Using Ultrasound Images

Over the last few decades, Lung Ultrasound (LUS) has been increasingly used to diagnose and monitor different lung diseases in neonates. It is a noninvasive tool that allows a fast bedside examination while minimally handling the neonate. Acquiring a LUS scan is easy, but understanding the artifacts concerned with each respiratory disease is challenging. Mixed artifact patterns found in different respiratory diseases may limit LUS readability by the operator. While machine learning (ML), especially deep learning can assist in automated analysis, simply feeding the ultrasound images to an ML model for diagnosis is not enough to earn the trust of medical professionals. The algorithm should output LUS features that are familiar to the operator instead. Therefore, in this paper we present a unique approach for extracting seven meaningful LUS features that can be easily associated with a specific pathological lung condition: Normal pleura, irregular pleura, thick pleura, A- lines, Coalescent B-lines, Separate B-lines and Consolidations. These artifacts can lead to early prediction of infants developing later respiratory distress symptoms. A single multi-class region proposal-based object detection model faster-RCNN (fRCNN) was trained on lower posterior lung ultrasound videos to detect these LUS features which are further linked to four common neonatal diseases. Our results show that fRCNN surpasses single stage models such as RetinaNet and can successfully detect the aforementioned LUS features with a mean average precision of 86.4%. Instead of a fully automatic diagnosis from images without any interpretability, detection of such LUS features leave the ultimate control of diagnosis to the clinician, which can result in a more trustworthy intelligent system.

Wet lung leading to RDS: the lung ultrasound findings and possible mechanisms - a pilot study from an animal mode

BACKGROUND

Clinically, the lung ultrasound (LUS) showed wet lung could cause respiratory distress syndrome (RDS) in newborns. This work aimed to investigate LUS changes over time and its potential mechanism as alveolar fluid increase in a rabbit model.

METHODS

A total of 35 New Zealand Rabbits were randomly assigned to seven groups. Models of various alveolar fluid levels were induced by infusion of different volumes of normal saline (NS) via the endotracheal tube. LUS was performed before NS infusion, immediately after NS infusion and 4 h after NS infusion. To appraise LUS changes and its potential mechanism as alveolar fluid increase, histopathological examination, the mRNA and protein expression of surfactant protein (SP), and immunohistochemistry (IHC) were performed. The expression levels of SP-B and SP-C proteins were detected using western blotting, and the relative expression levels of SP-B and SP-C mRNA were detected using qRT-PCR.

RESULTS

The results showed that LUS changed from B-line to lung consolidations accompanied by air-bronchograms in some locations of lungs at 4 h when the injection volume ≥ 6 ml/kg. Histopathological examination showed alveoli collapse, inflammatory cell infiltration and alveolar wall thickened. SP-B and SP-C mRNA and protein expression were statistically significantly reduced when the injection volume ≥6 ml/kg (p < .05). IHC staining displayed the same findings.

CONCLUSIONS

As alveolar fluid increase, LUS changed from wet lung to RDS after 4 h. The possible mechanism was that the SP protein expression was significantly reduced. LUS can be used to guide the administration of exogenous surfactant in this situation.