A Multicenter Lung Ultrasound Study on Transient Tachypnea of the Neonate

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.

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.

Combining lung ultrasound and oscillatory mechanics for assessing lung disease in very preterm infants

BACKGROUND

We investigated whether combining lung ultrasound scores (LUSs) and respiratory system reactance (Xrs) measured by respiratory oscillometry explains the severity of lung disease better than individual parameters alone.

METHODS

We performed a prospective observational study in very preterm infants. Forced oscillations (10 Hz) were applied using a neonatal mechanical ventilator (Fabian HFOi, Vyaire). We used the simultaneous respiratory severity score (RSS = mean airway pressure × FIO2) as a primary outcome. We built linear mixed-effect models to assess the relationship between Xrs z-score, LUS and RSS and compared nested models using the likelihood ratio test (LRT).

RESULTS

We enrolled 61 infants (median (Q1, Q3) gestational age = 30.00 (26.86, 31.00) weeks) and performed 243 measurements at a postnatal age of 26 (13, 41) days and postmenstrual age of 33.14 (30.46, 35.86) weeks. Xrs z-score and LUS were independently associated with simultaneous RSS (p < 0.001 for both). The model including Xrs and LUS explained the RSS significantly better than Xrs (p value LRT < 0.001) or LUS alone (p value LRT < 0.001).

CONCLUSIONS

Combining LUS and Xrs z-score explains the severity of lung disease better than each parameter alone and has the potential to improve the understanding of the underlying pathophysiology.

IMPACT

Combining respiratory system reactance by oscillometry and lung ultrasound score explains the respiratory support requirement (e.g., proxy of the severity of lung disease) significantly better than each parameter alone. We assessed the relationship between lung ultrasound and respiratory system reactance in very preterm infants for the first time. Combining respiratory oscillometry and lung ultrasound has the potential to improve the understanding of respiratory pathophysiology.

Use of Lung Ultrasound in Reducing Radiation Exposure in Neonates with Respiratory Distress: A Quality Management Project

Background and Objectives: Our quality management project aims to decrease by 20% the number of neonates with respiratory distress undergoing chest radiographs as part of their diagnosis and monitoring. Materials and Methods: This quality management project was developed at Life Memorial Hospital, Bucharest, between 2021 and 2023. Overall, 125 patients were included in the study. The project consisted of a training phase, then an implementation phase, and the final results were measured one year after the end of the implementation phase. The imaging protocol consisted of the performance of lung ultrasounds in all the patients on CPAP (continuous positive airway pressure) or mechanical ventilation (first ultrasound at about 90 min after delivery) and the performance of chest radiographs after endotracheal intubation in any case of deterioration of the status of the patient or if such a decision was taken by the clinician. The baseline characteristics of the population were noted and compared between years 2021, 2022, and 2023. The primary outcome measures were represented by the number of X-rays performed in ventilated patients per year (including the patients on CPAP, SIMV (synchronized intermittent mandatory ventilation), IPPV (intermittent positive pressure ventilation), HFOV (high-frequency oscillatory ventilation), the number of X-rays performed per patient on CPAP/year, the number of chest X-rays performed per mechanically ventilated patient/year and the mean radiation dose/patient/year. There was no randomization of the patients for the intervention. The results were compared between the year before the project was introduced and the 2 years across which the project was implemented. Results: The frequency of cases in which no chest X-ray was performed was significantly higher in 2023 compared to 2022 (58.1% vs. 35.8%; p = 0.03) or 2021 (58.1% vs. 34.5%; p = 0.05) (a decrease of 22.3% in 2023 compared with 2022 and of 23.6% in 2023 compared with 2021). The frequency of cases with one chest X-ray was significantly lower in 2023 compared to 2022 (16.3% vs. 35.8%; p = 0.032) or 2021 (16.3% vs. 44.8%; p = 0.008). The mean radiation dose decreased from 5.89 Gy × cm2 in 2021 to 3.76 Gy × cm2 in 2023 (36% reduction). However, there was an increase in the number of ventilated patients with more than one X-ray (11 in 2023 versus 6 in 2021). We also noted a slight annual increase in the mean number of X-rays per patient receiving CPAP followed by mechanical ventilation (from 1.80 in 2021 to 2.33 in 2022 and then 2.50 in 2023), and there was a similar trend in the patients that received only mechanical ventilation without a statistically significant difference in these cases. Conclusions: The quality management project accomplished its goal by obtaining a statistically significant increase in the number of ventilated patients in which chest radiographs were not performed and also resulted in a more than 30% decrease in the radiation dose per ventilated patient. This task was accomplished mainly by increasing the number of patients on CPAP and the use only of lung ultrasound in the patients on CPAP and simple cases.

Assessing the diagnostic accuracy of lung ultrasound in determining invasive ventilation needs in neonates on non-invasive ventilation: An observational study from a tertiary NICU in India

Effective management of neonatal respiratory distress requires timely recognition of when to transition from non-invasive to invasive ventilation. Although the lung ultrasound score (LUS) is useful in evaluating disease severity and predicting the need for surfactants, its efficacy in identifying neonates requiring invasive ventilation has only been explored in a few studies. This study aims to assess the accuracy of LUS in determining the need for invasive ventilation in neonates on non-invasive ventilation (NIV) support. From July 2021 to June 2023, we conducted a prospective study on 192 consecutively admitted neonates with respiratory distress needing NIV within 24 h of birth at our NICU in Hyderabad, India. The primary objective was the diagnostic accuracy of LUS in determining the need for invasive ventilation within 72 h of initiating NIV. We calculated LUS using the scoring system of Brat et al. (JAMA Pediatr 169:e151797, [10]). Treating physicians' assessments of the need for invasive ventilation served as the reference standard for evaluating LUS effectiveness. Out of 192 studied neonates, 31 (16.1%) required invasive ventilation. The median LUS was 5 (IQR: 2-8) for those on NIV and 10 (IQR: 7-12) for those needing invasive ventilation. The LUS had a strong discriminative ability for invasive ventilation with an AUC (area under the curve) of 0.825 (CI: 0.75-0.86, p = 0.0001). An LUS > 7 had 77.4% sensitivity (95% CI: 58.9-90.8%), 75.1% specificity (95% CI: 67.8-81.7%), 37.5% positive predictive value (PPV) (95% CI: 30.15-45.5%), 94.5% negative predictive value (NPV) (95% CI: 89.9-97.1%), 3.1 positive likelihood ratio (PLR) (95% CI: 2.2-4.3), 0.3 negative likelihood ratio (NLR) (95% CI: 0.15-0.58), and 75.5% overall accuracy (95% CI: 68.8-81.4%) for identifying invasive ventilation needs. In contrast, SAS, with a cutoff point greater than 5, has an AUC of 0.67. It demonstrates 62.5% sensitivity, 61.9% specificity, 24.7% PPV, 89.2% NPV, and an overall diagnostic accuracy of 61.9%. The DeLong test confirms the significance of this difference (AUC difference: 0.142, p = 0.04), underscoring LUS's greater reliability for NIV failure.  Conclusion: This study underscores the diagnostic accuracy of the LUS cutoff of > 7 in determining invasive ventilation needs during the initial 72 h of NIV. Importantly, while lower LUS values typically rule out the need for ventilation, higher values, though indicative, are not definitive. What is known? • The effectiveness of lung ultrasound in evaluating disease severity and the need for surfactants in neonates with respiratory distress is well established. However, traditional indicators for transitioning from non-invasive to invasive ventilation, like respiratory distress and oxygen levels, have limitations, underscoring the need for reliable, non-invasive assessment tools. What is new? • This study reveals that a LUS over 7 accurately discriminates between neonates requiring invasive ventilation and those who do not. Furthermore, the lung ultrasound score outperformed the Silverman Andersen score for NIV failure in our population.

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.

External Validation of a Multivariate Model for Targeted Surfactant Replacement

INTRODUCTION

Early targeted surfactant therapy for preterm infants is recommended but the best criteria to personalize treatment are unclear. We validate a previously published multivariate prognostic model based on gestational age (GA), lung ultrasound score (LUS), and oxygen saturation to inspire oxygen fraction ratio (SatO2/FiO2) using an independent data set.

METHODS

Pragmatic, observational study in 10 Italian and Spanish NICUs, including preterm babies (250 and 336 weeks divided into 3 GA intervals) with clinical signs of respiratory distress syndrome and stabilized on CPAP. LUS and SatO2/FiO2 were collected soon after stabilization. Their prognostic accuracy was evaluated on the subsequent surfactant administration by a rigorously masked physician.

RESULTS

One hundred seventy-five infants were included in the study. Surfactant was given to 74% infants born at 25-27 weeks, 38.5% at 28-30 weeks, and 26.5% at 31-33 weeks. The calibration curve comparing the validation and the development populations showed significant overlap with an intercept = 0.08, 95% CI (-0.34; 0.5) and a slope = 1.53, 95% CI (1.07-1.98). The validation cohort had a high predictive accuracy. Its ROC curve showed an AUC = 0.95, 95% CI (0.91-0.99) with sensitivity = 0.93, 95% CI (0.83-0.98), specificity = 0.81, 95% CI (0.73-0.88), PPV = 0.76, 95% CI (0.65-0.84), NPV = 0.95, 95% CI (0.88-0.98). LUS ≥9 demonstrated the highest sensitivity (0.91, 95% CI [0.82-0.97]) and specificity = 0.81, 95% CI (0.72-0.88) as individual predictor. LUS and SatO2/FiO2 prognostic performances varied with GA.

CONCLUSION

We validated a prognostic model based on LUS and Sat/FiO2 to facilitate early, customized surfactant administration that may improve respiratory management of preterm neonates.

Ultrasound-assessed lung aeration, oxygenation and respiratory care in neonatal bile acid pneumonia: A nested case-control study

AIM

Neonatal bile acid pneumonia (NBAP) occurs in neonates following obstetric cholestasis. We aimed to study the lung aeration and respiratory support of NBAP.

METHODS

Nested, case/control study enrolling age-matched neonates with NBAP, respiratory distress syndrome (RDS) or transient tachypnoea (TTN). Lung aeration and oxygenation were assessed with lung ultrasound score, oxygenation index and SpO2 /FiO2 .

RESULTS

Nineteen, 22 and 25 neonates with NBAP, RDS and TTN, respectively were studied (mean gestational age = 33 (2.2) weeks, 30 (45.5%) males). Upon admission, RDS patients had the worst lung ultrasound score (p = 0.022) and oxygenation index (p = 0.001), while NBAP and TTN neonates had similar values. At the worst time-point, NBAP and RDS patients showed similar oxygenation index (NBAP: 4.6 [2], RDS: 5.7 [3]) and SpO2 /FiO2 (NBAP: 3.1 [1.1], RDS: 2.7 [1]) which were worse than those of TTN patients (oxygenation index: p = 0.015, SpO2 /FiO2 : p = 0.001). RDS neonates needed the longest continuous positive airway pressure and highest mean airway pressure, but NBAP neonates needed invasive ventilation (26.3%, p = 0.01) and surfactant (31.6%, p = 0.003) more often than TTN patients who never needed these.

CONCLUSION

NBAP was a mild disorder in the first hours of life but subsequently worsened and became similar to RDS.

Monitoring of the Healthy Neonatal Transition Period with Serial Lung Ultrasound

Ultrasound has been used to observe lung aeration and fluid clearance during the neonatal transition period, but there is no consensus regarding the optimal timing of lung ultrasound. We aimed to monitor the trend of the serial lung ultrasound score (LUS) and extended LUS (eLUS) throughout the neonatal transition period (≤1, 2, 4, 8, 24, and 48 h after birth), assess any correlation to the clinical presentation (using the Silverman Andersen Respiratory Severity Score (RSS)), and determine the optimal time of the ultrasound. We found both LUS and eLUS decreased significantly after 2 h of life and had similar statistical differences among the serial time points. Although both scores had a positive, moderate correlation to the RSS overall (Pearson correlation 0.499 [p < 0.001] between LUS and RSS, 0.504 [p < 0.001] between eLUS and RSS), the correlation was poor within 1 h of life (Pearson correlation 0.15 [p = 0.389] between LUS and RSS, 0.099 [p = 0.573] between eLUS and RSS). For better clinical correlation, the first lung ultrasound for the neonate may be performed at 2 h of life. Further research is warranted to explore the clinical value and limitations of earlier (≤1 h of life) lung ultrasound examinations.

Optimal timing and cutoff range of lung ultrasound in predicting surfactant administration in neonates: A meta-analysis and systematic review

OBJECTIVE

Timely application of surfactant replacement therapy is critical for neonates with respiratory distress syndrome (RDS). Presently, early clinical decision on surfactant use relies solely on ventilator parameters. However, ventilator parameters are unable to truly recapitulate the extent of surfactant deficiency. Lung ultrasound has been increasingly used in the early prediction of surfactant use in recent years, but its predictive value remains unclear. Therefore, we conducted this study to examine its predictive value in surfactant use and determine the optimal timing and cutoff value.

METHODS

Studies on neonates with respiratory distress or diagnosed with RDS were collected from PubMed, Embase, Cochrane Library, and Web of Science. Primary outcomes included sensitivity, specificity, and positive and negative predictive values of lung ultrasound.

RESULTS

Ten eligible studies with 1162 participants were included. The sensitivity and specificity of lung ultrasound in predicting surfactant use were 0.86 (95% CI: 0.81-0.90) and 0.82 (95% CI: 0.71-0.90), respectively. Lung ultrasound performed within 1-3 h after birth had a sensitivity of 0.89 (95% CI: 0.79-0.95) and a Youden's index of 0.67. Compared with a lung ultrasound score (LUS) cutoff of ≤6/7, ≤8, >5, >6/7, and >8, a LUS cutoff of ≤5 had higher Youden's index (0.73) and sensitivity (0.94, 95% CI: 0.85-0.97) in predicting surfactant use.

CONCLUSIONS

Lung ultrasound is effective for predicting surfactant use in neonates. Lung ultrasound within 1-3 h after birth and a LUS cutoff of 5 are recommended. However, the symptoms and oxygenation of the neonatal patients must also be considered.

Prospective Evaluation of the Correlation of Lung Ultrasonography Score and Blood Gas Parameters in Neonates With Respiratory Distress

Introduction Lung ultrasonography (LUS) has become frequently used in neonatal intensive care units (NICU) because it is diagnostic, useful, harmless, radiation-free, and practical for bedside use due to its portability. Objective This study aimed to evaluate the association between lung ultrasound (LUS) scores and diagnoses of neonates hospitalized for respiratory distress and determine the value of the combined use of laboratory and imaging methods in patient evaluation by looking at the correlation between blood gas parameters and LUS score. Materials and methods Between March and July 2022, a total of 55 patients who were born term or premature and admitted due to respiratory distress in the NICU of Malatya Training and Research Hospital were included in the study. In this observational, prospective study, demographic information such as birth weights, gestational weeks, mode of delivery, Apgar scores, blood gas sample results, LUS results and scores, ventilation types, and discharge time were recorded during hospitalization in our unit. According to the newborns' clinical, laboratory, and radiologic evaluations, the diagnoses of respiratory distress syndrome (RDS), transient tachypnea of the newborn (TTN), or congenital pneumonia were made, and the relationship between the diagnoses and LUS scores was evaluated. The pH value and PCO2 value in the venous blood gas obtained on the day of LUS were recorded. Correlation analysis was performed between the LUS score and pH value, LUS score and PCO2 value. Results Twenty-seven newborns were diagnosed with TTN, 18 with RDS, and 10 with congenital pneumonia. There was a statistical difference between LUS scores and diagnoses (p<0.001). According to Spearman correlation analysis, a significant negative moderate correlation was found between LUS scores and venous blood gas pH value (p<0.001, r:-0.49). There was also a significant positive low, moderate correlation with venous blood gas PCO2 value (p<0.001, r:0.36). Conclusion This study demonstrates that LUS scoring has a role in determining the severity of disease and making diagnoses in patients hospitalized for respiratory distress. When LUS is widely used, it will be informative about the severity and prognosis of the disease, together with laboratory evaluation.

Pulmonary Sonography - Neonatal Diagnosis Part 2

A healthy, air-filled lung can only be visualized by its artifacts, and pathologies of the lung are revealed by changes in these artifacts. Because ultrasound artifacts are predominantly used in pulmonary sonography to assess pathologic processes, the variability of sonographically imageable phenomena is limited. For this reason, different pulmonary diseases may present very similarly in ultrasound. Therefore, a correct interpretation of the findings is only possible in the clinical context, taking into account the age-dependent differential diagnoses.The particular relevance of lung ultrasound in the treatment of neonatal patients results from a close correlation between the extent of sonographically-depictable pathologies and parameters of respiratory insufficiency. This suggests a direct correlation between ultrasound findings and the severity of lung injury. Lung ultrasound thus represents a unique, ubiquitously available, bedside, serial method for monitoring the pulmonary status.

Can lung ultrasound score accurately predict surfactant replacement? A systematic review and meta-analysis of diagnostic test studies

BACKGROUND

Clinical and radiographic criteria are traditionally used to determine the need for surfactant therapy in preterm infants. Lung ultrasound is a bedside test that offers a rapid, radiation-free, alternative to this approach.

OBJECTIVE

To conduct a systematic review and meta-analysis to determine the accuracy of a lung ultrasound score (LUS) in identifying infants who would receive at least one surfactant dose. Secondary aims were to evaluate the predictive accuracy for ≥2 doses and the accuracy of a different image classification system based on three lung ultrasound profiles.

METHODS

PubMed, SCOPUS, Biomed Central, and the Cochrane library between January 2011 and December 2021 were searched. Full articles enrolling preterm neonates who underwent lung ultrasound to predict surfactant administration were assessed and analyzed following Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) and QUADAS-2 guidelines.

RESULTS

Seven prospective studies recruiting 697 infants met the inclusion criteria. Risk of bias was generally low. Oxygen requirement, clinical and radiographic signs of respiratory distress syndrome were used as reference standards for surfactant replacement. The summary receiver operator characteristic (sROC) curve for LUS predicting first surfactant dose showed an area under the curve (AUC) = 0.88 (95% confidence interval [CI]: 0.82-0.91); optimal specificity and sensitivity (Youden index) were 0.83 and 0.81 respectively. Pooled estimates of sensitivity, specificity, diagnostic odds ratio, negative predictive value, and positive predictive value for LUS predicting the first surfactant dose were 0.89 (0.82-0.95), 0.86 (0.78-0.95), 3.78 (3.05-4.50), 0.92 (0.87-0.97), 0.79 (0.65-0.92). The sROC curve for the accuracy of Type 1 lung profile in predicting first surfactant dose showed an AUC of 0.88; optimal specificity and sensitivity were both 0.86. Two studies addressing the predictive accuracy of LUS for ≥2 surfactant doses had high heterogeneity and were unsuitable to combine in a meta-analysis.

DISCUSSION

Despite current significant variation in LUS thresholds, lung ultrasound is highly predictive of the need for early surfactant replacement. This evidence was derived from studies with homogeneous patient characteristics and low risk of bias.

Translating Guidelines into Practical Practice: Point-of-Care Ultrasound for Pediatric Critical Care Clinicians

Point-of-care ultrasound (POCUS) is now transitioning from an emerging technology to a standard of care for critically ill children. POCUS can provide immediate answers to clinical questions impacting management and outcomes within this fragile population. Recently published international guidelines specific to POCUS use in neonatal and pediatric critical care populations now complement previous Society of Critical Care Medicine guidelines. The authors review consensus statements within guidelines, identify important limitations to statements, and provide considerations for the successful implementation of POCUS in the pediatric critical care setting.

Comparison of lung ultrasound scores with clinical models for predicting bronchopulmonary dysplasia

Lung ultrasound scores (LUSs) have been demonstrated to accurately predict moderate-to-severe bronchopulmonary dysplasia (msBPD). This study attempted to explore the additional value of LUSs for predicting msBPD compared to clinical multivariate models in different gestational age (GA) groups. The study prospectively recruited preterm infants with GA < 32 weeks. Lung ultrasound was performed on days 3, 7, 14, and 21 after birth. A linear mixed-effects regression model was used to evaluate LUS evolution in infants born before and after 28 weeks. The receiver operating characteristic (ROC) procedure was used to analyze the reliability of LUS and clinical multivariable models for predicting msBPD. The optimal time to predict msBPD in all infants was 7 days with a cut-off point of 5 (area under the ROC (AUROC) curve: 0.78, 95% confidence interval (CI): 0.71-0.84). In infants with GA ≥ 28 weeks, LUSs provided a moderate diagnostic accuracy for all four time points (AUROC curve: 0.74-0.78), and the AUROC curve for the clinical multivariable model on day 14 was 0.91 (95% CI: 0.84-0.96), which was significantly higher than that of LUSs (AUROC curve: 0.77, 95% CI: 0.68-0.85, P < 0.05). In infants born at 23-27 weeks, LUSs showed a low diagnostic accuracy with higher cut-off points to predict msBPD, and the AUROC curve for GA to predict msBPD was 0.75 (95% CI: 0.59-0.85), providing diagnostic accuracy similar to that of LUSs.  Conclusion: The contribution of LUSs to predict msBPD in infants with different GAs remains controversial and requires further investigation. What is Known: • Lung ultrasound scores (LUSs) have been demonstrated to accurately predict moderate-to-severe bronchopulmonary dysplasia in infants with gestational age (GA)＜32 weeks. What is New: • The LUSs evolution differed between extremely preterm infants born before 28 weeks and preterm infants born at 28-32 weeks of gestation. • LUSs provided similar moderate predictive performance as GA-adjusted LUS and clinical multivariate models in infants born after 28 weeks, while LUSs seem to be less helpful in infants born before 28 weeks.

Lung ultrasound protocol decreases radiation in newborn population without side effects: A quality improvement project

OBJECTIVE

To reduce radiation exposure in newborns admitted due respiratory distress based on the implementation of lung ultrasound (LUS).

DESIGN

Quality improvement (QI), prospective, before-after, pilot study.

SETTING

Third level neonatal intensive care unit (NICU) level with 25-bed and 1800 deliveries/year.

PATIENTS

Inclusion criteria were neonates admitted with respiratory distress.

INTERVENTIONS

After a theoretical and practical LUS training a new protocol was approved and introduced to the unit were LUS was the first-line image. To study the effect of the intervention we compare two 6-month periods: group 1, with the previous chest X-ray (CXR)-protocol (CXR as the first diagnostic technique) vs. group 2, once LUS-protocol had been implemented.

MAIN VARIABLES OF INTEREST

The main QI measures were the total exposure to radiation. Secondary QI were to evaluate if the LUS protocol modified the clinical evolution as well as the frequency of complications.

RESULTS

122 patients were included. The number of CXR was inferior in group 2 (group 1: 2 CXR (IQR 1-3) vs. Group 2: 0 (IQR 0-1), p<0.001), as well as had lower median radiation per baby which received at least one CXR: 56 iGy (IQR 32-90) vs. 30 iGy (IQR 30-32), p<0.001. Respiratory support was similar in both groups, with lower duration of non-invasive mechanical ventilation and oxygen duration the second group (p<0.05). No differences regarding respiratory development complications, length of stay and mortality were found.

CONCLUSIONS

The introduction of LUS protocol in unit decreases the exposure radiation in infants without side effects.

To B or not to B. The rationale for quantifying B-lines in pediatric lung diseases

Lung ultrasound (LUS) is emerging as adjunct tool to be used during clinical assessment. Among the different hallmarks of LUS, B-lines are well known artifacts, which are not correlated with identifiable structures, but which can be used for pathological classification. The presence of multiple B-lines is a sonographic sign of lung interstitial syndrome. It has been demonstrated in adults that there is a direct correlation between the number of B-lines and the severity of the interstitial involvement of lung disease. Counting B-lines is an attempt to enrich the clinical assessment and clinical information, beyond obtaining a simple dichotomous answer. Semiquantitative or quantitative B-line assessment has been shown to correlate with fluid overload and demonstrated prognostic implications in specific neonatal and pediatric conditions. LUS with quantitative B-lines assessment is promising. Current evidence allows for quantification of B-lines in a limited number of neonatal and pediatric diseases.

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.

Lung ultrasound findings in asymptomatic healthy children with asthma

BACKGROUND

Lung ultrasound (LUS) has been shown to be an effective tool to rapidly diagnose certain causes of pediatric respiratory distress. However, very little is known about LUS findings in pediatric asthma.

OBJECTIVES

The primary objective of this study was to characterize LUS findings in a cohort of pediatric patients with a definitive diagnosis of asthma, outside of an asthma exacerbation.

METHODS

Eligible patients, aged 6-17 years old and diagnosed with asthma, underwent LUS during an outpatient visit. LUS was conducted using a six-zone scanning protocol. Presence of a LUS artifact was defined by one or more of the following: ≥3 B-lines per intercostal space, pulmonary consolidation, and/or pleural abnormality. Images were interpreted by an expert sonographer blinded to patient clinical characteristics.

RESULTS

Fifty-two patients were included. 10/52 (19.2%) patients demonstrated the presence of LUS artifacts: 8 with ≥3 B-lines, 1 with consolidation >1 cm, and 7 with subpleural consolidations <1 cm, 1 with a pleural line abnormality. Artifacts were seen in the right anterior and lateral zones in 60% of participants and were limited to 1-2 intercostal space(s) within one lung zone in all participants. No association was found between presence of LUS artifacts and asthma control or severity.

CONCLUSION

To our knowledge, this is the first report of LUS findings in outpatient pediatric asthma. LUS artifacts in asthmatic children can be seen outside of acute exacerbations. Such baseline findings need to be taken into consideration when using LUS for the acute evaluation of a pediatric patient with asthma.

Quantitative lung ultrasound detects dynamic changes in lung recruitment in the preterm lamb

BACKGROUND

Lung ultrasound (LUS) may not detect small, dynamic changes in lung volume. Mean greyscale measurement using computer-assisted image analysis (Q-LUS_MGV) may improve the precision of these measurements.

METHODS

Preterm lambs (n = 40) underwent LUS of the dependent or non-dependent lung during static pressure-volume curve mapping. Total and regional lung volumes were determined using the super-syringe technique and electrical impedance tomography. Q-LUS_MGV and gold standard measurements of lung volume were compared in 520 images.

RESULTS

Dependent Q-LUS_MGV moderately correlated with total lung volume (rho = 0.60, 95% CI 0.51-0.67) and fairly with right whole (rho = 0.39, 0.27-0.49), central (rho = 0.38, 0.27-0.48), ventral (rho = 0.41, 0.31-0.51) and dorsal regional lung volumes (rho = 0.32, 0.21-0.43). Non-dependent Q-LUS_MGV moderately correlated with total lung volume (rho = 0.57, 0.48-0.65) and fairly with right whole (rho = 0.43, 0.32-0.52), central (rho = 0.46, 0.35-0.55), ventral (rho = 0.36, 0.25-0.47) and dorsal lung volumes (rho = 0.36, 0.25-0.47). All correlation coefficients were statistically significant. Distinct inflation and deflation limbs, and sonographic pulmonary hysteresis occurred in 95% of lambs. The greatest changes in Q-LUS_MGV occurred at the opening and closing pressures.

CONCLUSION

Q-LUS_MGV detected changes in total and regional lung volume and offers objective quantification of LUS images, and may improve bedside discrimination of real-time changes in lung volume.

IMPACT

Lung ultrasound (LUS) offers continuous, radiation-free imaging that may play a role in assessing lung recruitment but may not detect small changes in lung volume. Mean greyscale image analysis using computer-assisted quantitative LUS (Q-LUS_MGV) moderately correlated with changes in total and regional lung volume. Q-LUS_MGV identified opening and closing pressure and pulmonary hysteresis in 95% of lambs. Computer-assisted image analysis may enhance LUS estimation of lung recruitment at the bedside. Future research should focus on improving precision prior to clinical translation.

Lung ultrasound in Italian neonatal intensive care units: A national survey

INTRODUCTION

Lung ultrasound (LU) is a noninvasive, bedside imaging technique that is attracting growing interest in the evaluation of neonatal respiratory diseases. We conducted a nationwide survey of LU usage in Italian neonatal intensive care units (NICUs).

METHODS

A structured questionnaire was developed and sent online to 114 Italian NICUs from June to September 2021.

RESULTS

The response rate was 79%. In the past 4 years (range: 2-6), LU has been adopted in 82% of Italian NICUs. It is the first-choice diagnostic test in 23% of the centers surveyed. The main LU diagnostic applications reported were: pneumothorax (95%), respiratory distress syndrome (89%), transient tachypnea of the newborn (89%), plural effusion (88%), atelectasis (66%), pneumonia (64%), bronchopulmonary dysplasia (43%), congenital pulmonary airway malformation (41%), and congenital diaphragmatic hernia (34%). Thirty percent of participating centers calculated LU score routinely, but only seven units used it to predict the need for surfactant replacement. Sixty-six percent of respondents learned the LU technique via a self-training process, while 34% of them visited an expert in the field for one-to-one tuition.

CONCLUSIONS

LU has a widespread use in Italian NICUs. However, the use of LU is extremely heterogeneous among centers. There is an urgent need to ensure standardization of clinical practice guidelines and to design and implement a formalized and accredited training program.

Semi-quantitative lung ultrasound score during ground transportation of outborn neonates with respiratory failure

Lung ultrasound score (LUS) is increasingly diffused in neonatal critical care but scanty data are available about its use during transfer of severely ill neonates. We aimed to clarify the effect of ground transportation on LUS evolution, conformity of interpretation, and relationships with oxygenation and clinical severity. This is a single-center, blinded, observational, cross-sectional study. Neonates of any gestational age with respiratory distress appearing within 24 h from birth were transferred by a mobile unit towards neonatal intensive care unit (NICU) of a tertiary referral center. Calculation of LUS prior to the transportation (T1), in the mobile unit (T2), at the end of transportation (T3), and finally upon NICU admission. LUS in the mobile unit and in the NICU was performed by different physicians blinded to each other's results. LUS did not change overtime (T1: 6.3 (3.5), T2: 6.1 (3.5), T3: 5.8 (3.4); p = 0.479; adjusted for gestational or postnatal age or transport duration: p = 0.951, p = 0.424, and 0.266, respectively) but reliably predicted surfactant need (AUC at T1: 0.833 (95%CI: 0.72-0.92); AUC at T2: 0.82 (95%CI: 0.70-0.91); AUC at T3: 0.82 (95%CI: 0.70-0.90); p always < 0.0001). There were significant agreement (ICC = 0.912 (95%CI: 0.83-0.95); p < 0.001) and correlation (r = 0.905, p < 0.001) between LUS calculated during transportation and in the NICU. LUS during transportation was also significantly correlated with oxygenation index (r = 0.321, p = 0.026; standardized B = 0.397 (95%CI: 0.03-0.76), p = 0.048) and TRIPS-II score (r = 0.302, p = 0.008; standardized B = 0.568 (95%CI: 0.04-1.1), p = 0.037).

CONCLUSION

LUS during ground transportation of neonates with respiratory failure is suitable and not influenced by the transportation itself. It has a high agreement with that calculated in the NICU and correlates with patients' oxygenation and severity.

WHAT IS KNOWN

• Lung ultrasound is a part of the point-of-care ultrasound, which is becoming an essential tool, to manage critically ill neonates and children in an accurate, non-invasive and quick way.

WHAT IS NEW

• Lung ultrasound score (LUS) is suitable during transportation of critically ill neonates with respiratory failure and is not influenced by the transportation itself. • LUS has a high agreement with that calculated in the NICU and correlates with patients' oxygenation and severity of respiratory failure.

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.

Accuracy and Reliability of Lung Ultrasound to Diagnose Transient Tachypnoea of the Newborn: Evidence from a Meta-analysis and Systematic Review

OBJECTIVE

Transient tachypnoea of the newborn (TTN) is one of the most common causes of neonatal respiratory distress (RD) during the newborn period. Chest radiography (CXR) is commonly used to rule out the diagnosis, but TTN is often misdiagnosed as neonatal respiratory distress syndrome (NRDS) on the basis of CXR alone. Increasing evidence suggests that lung ultrasound (LUS) may be a reliable diagnostic tool for transient tachypnoea of the newborn. However, studies of the diagnostic efficiency of LUS are still lacking. This study was aimed to evaluate the accuracy and reliability of LUS for diagnosing TTN by conducting a systematic review and meta-analysis.

STUDY DESIGN

We searched for articles in the Embase, PubMed, and Cochrane Library databases from inception until May 31, 2020. The selected studies were diagnostic accuracy studies that reported the utility of LUS in the diagnosis of TTN. Two researchers independently extracted data and assessed quality using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Then, we created a bivariate model of mixed effects to calculate the sensitivity and specificity of LUS in diagnosing TTN. A summary receiver operator characteristic (SROC) curve was constructed to summarize the performance characteristics of LUS.

RESULTS

Six studies involving 617 newborns were included in the review. LUS had a pooled sensitivity of 0.98 (confidence interval [CI]: 0.92-1.00) and a specificity of 0.99 (CI: 0.91-1.00). The area under the curve for LUS was 1.00 (0.98-1.0). Meta-regression revealed that LUS had a significant diagnostic accuracy for TTN.

CONCLUSION

The performance of ultrasound for the detection of TTN was excellent. Considering the various advantages of LUS compared with chest radiographs in diagnosing TTN, this study supports the routine use of LUS for the detection of TTN.

KEY POINTS

· Lung ultrasound is a highly accurate diagnostic tool, which may be a viable and superior alternative to CXR, in diagnosing TTN.. · Lung ultrasound can help differentiate TTN from other etiologies of respiratory distress in neonates.. · There are still some controversies on the ultrasound diagnostic criteria of TTN..

Pharmaceutical Expenditure Is Unchanged with Ultrasound-Guided Surfactant Administration

OBJECTIVE

Semiquantitative lung ultrasound improves the timeliness of surfactant replacement, but its financial consequences are unknown. We aim to investigate if the ultrasound-guided surfactant administration influences the general costs of surfactant therapy for preterm neonates affected by respiratory distress syndrome.

STUDY DESIGN

This is a pharmacoeconomic, retrospective, and before-and-after study investigating the impact of ultrasound-guided surfactant replacement (echography-guided Surfactant THERapy [ESTHER]) on pharmaceutical expenditure within the ESTHER initiative. Data extracted from the institutional official database hosted by the hospital administration for financial management were used for the analysis. We analyzed the number of surfactant administrations in neonates of gestational age ≤32^6/7 weeks, and the number of surfactant vials used from January 1_, 2014 to June 30, 2014 (i.e., during the period of standard surfactant administration policy) and from July 1, 2016 to December 31, 2018 (that is during ESTHER policy).

RESULTS

ESTHER did not modify surfactant use, as proportion of treated neonates with RDS receiving at least one surfactant dose (Standard: 21.3% vs. ESTHER: 20.9%; p = 0.876) or as proportion of used vials over the total number of vials opened for neonates of any gestational age (Standard: 37% vs. ESTHER: 35%; p = 0.509).

CONCLUSION

Ultrasound-guided surfactant replacement using a semiquantitative lung ultrasound score in preterm infants with RDS does not change the global use of surfactant and the related expenditure.

KEY POINTS

· ESTHER is able to increase the timeliness of surfactant replacement.. · The ultrasound-guided surfactant administration does not increase the cost of surfactant therapy.. · The ultrasound-guided surfactant administration does not change the global surfactant utilization..

Specification and guideline for technical aspects and scanning parameter settings of neonatal lung ultrasound examination

Lung ultrasound (LUS) is now widely used in the diagnosis and monitor of neonatal lung diseases. Nevertheless, in the published literatures, the LUS images may display a significant variation in technical execution, while scanning parameters may influence diagnostic accuracy. The inter- and intra-observer reliabilities of ultrasound exam have been extensively studied in general and in LUS. As expected, the reliability declines in the hands of novices when they perform the point-of-care ultrasound (POC US). Consequently, having appropriate guidelines regarding to technical aspects of neonatal LUS exam is very important especially because diagnosis is mainly based on interpretation of artifacts produced by the pleural line and the lungs. The present work aimed to create an instrument operation specification and parameter setting guidelines for neonatal LUS. Technical aspects and scanning parameter settings that allow for standardization in obtaining LUS images include (1) select a high-end equipment with high-frequency linear array transducer (12-14 MHz). (2) Choose preset suitable for lung examination or small organs. (3) Keep the probe perpendicular to the ribs or parallel to the intercostal space. (4) Set the scanning depth at 4-5 cm. (5) Set 1-2 focal zones and adjust them close to the pleural line. (6) Use fundamental frequency with speckle reduction 2-3 or similar techniques. (7) Turn off spatial compounding imaging. (8) Adjust the time-gain compensation to get uniform image from the near-to far-field.

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.

Chest ultrasound in neonates: What neonatologists should know

For many years, ultrasound was thought to have no indications in pulmonary imaging because lungs are filled with air, creating no acoustic mismatch, as encountered by ultrasound wave beam. Lung ultrasound (LUS) was started in adult critical care settings to detect pleural effusion and acquired more indications over time. In the neonatal intensive care unit (NICU), the use of chest ultrasound has gained more attention during the last two decades. Being a radiation-free, bedside, rapid, and handy tool, LUS started to replace chest X-rays in NICU. Using LUS depends upon understanding the nature of normal lungs and the changes induced by different diseases. With the help of LUS, an experienced neonatologist can detect many of the respiratory problems so fast that interventional therapy can be introduced as early as possible. LUS can diagnose pleural effusion, pneumothorax, pneumonia, transient tachypnoea of the newborn, respiratory distress syndrome, pulmonary atelectasis, meconium aspiration syndrome, bronchopulmonary dysplasia, and some other disorders with very high accuracy. LUS will be helpful in initial diagnosis, follow-up, and predicting the need for further procedures such as mechanical ventilation, diuretic therapy, surfactant therapy, etc. There are some limitations to using LUS in some respiratory disorders such as bullae, interstitial emphysema, and other conditions. This review will highlight the importance of LUS, its uses, and limitations.

Lung ultrasound to guide the administration of exogenous pulmonary surfactant in respiratory distress syndrome of newborn infants: A retrospective investigation study

BACKGROUND

Respiratory distress syndrome (RDS) is a common disease that seriously endangers the life and safety of newborns, especially premature infants. Exogenous pulmonary surfactant (PS) is the specific agent for the treatment of neonatal RDS. Lung ultrasound (LUS) has been successfully used in the diagnosis of RDS, but its value in guiding the application of PS is still unclear. This paper explored whether the application of PS under LUS monitoring has some advantages, including (1) decreasing the misdiagnosis rate of RDS and decreasing probability of using PS, and (2) reducing the dose of PS without reducing the therapeutic effect.

METHODS

This study included two parts. Part 1: To decide whether the LUS is good to differentiate RDS from other lung diseases in the premature infants. All patients who were diagnosed with RDS and required PS treatment based on conventional criteria were routinely examined by LUS. Then, according to LUS findings, we decided whether they needed to receive PS treatment. Part 2: To see the dose reduction of surfactant is applicable. In RDS patients diagnosed based on LUS presentation and treated with Curosurf (Chiesi Pharmaceutical, Parma, Italy), the dose of Curosurf was compared with that recommended by the European RDS management guidelines.

RESULTS

(1) Since March 2017, 385 newborn infants admitted to our neonatal intensive care unit met the traditional diagnostic criteria of RDS. Of these, only 269 cases were diagnosed with RDS and needed PS treatment according to LUS manifestations. The other 116 infants who did not meet the criteria for ultrasound diagnosis of RDS did not receive PS supplementation but obtained good outcomes, that is LUS findings decreased a misdiagnosis rate of RDS by 30.1% and subsequently resulted in a 30.1% reduction in PS use. (2) Among the 269 RDS patients diagnosed based on LUS findings, 148 were treated with Curosurf (another 121 RDS infants who received domestic PS treatment were not included in the study group), and the average dose was 105.4 ± 24.3 mg/kg per time, which is significantly lower than the dose of 200 mg/kg per time recommended by the European RDS guidelines. (3) The mortality rate of RDS patients was 0%, and no patients had ventilator-associated pneumonia or bronchopulmonary dysplasia in this study.

CONCLUSION

LUS can decrease the misdiagnosis rate of RDS, thereby decreasing the probability of using PS and decreasing the dose of PS, and can help RDS infants to achieve better outcomes.

Lung Ultrasound Characteristics in Neonates With Positive Real Time Polymerase Chain Reaction for SARS-CoV-2 on a Tertiary Level Referral Hospital in Mexico City

INTRODUCTION

Acute respiratory syndrome secondary to SARS-CoV-2 virus infection has been declared a pandemic since December 2019. On neonates, severe presentations are infrequent but possible. Lung ultrasound (LUS) has been shown to be useful in diagnosing lung involvement and following up patients, giving more information, and reducing exposure compared to traditional examination.

METHODS

LUS was performed after the diagnosis of SARS-CoV-2 infection with respiratory Real Time Polymerase Chain Reaction RT-PCR with portable equipment protected with a silicone sleeve. If hemodynamic or cardiology consultation was necessary, a prepared complete ultrasound machine was used. Ten regions were explored (anterior superior and inferior, lateral, and posterior superior and inferior, right and left), and a semiquantitative score (LUSS) was calculated. Disease severity was determined with a pediatric modified score.

RESULTS

Thirty-eight patients with positive RT-PCR were admitted, 32 (81%) of which underwent LUS. Included patients had heterogenous diagnosis and gestational ages as expected on a referral neonatal intensive care unit (NICU) (median, ICR: 36, 30-38). LUS abnormalities found were B-line interstitial pattern 90%, irregular/interrupted/thick pleural line 88%, compact B-lines 65%, small consolidations (≤5 mm) 34%, and extensive consolidations (≥5 mm) 37%. Consolidations showed posterior predominance (70%). LUSS showed a median difference between levels of disease severity and ventilatory support (Kruskal-Wallis, p = 0.001) and decreased with patient improvement (Wilcoxon signed-rank test p = 0.005). There was a positive correlation between LUSS and FiO₂ needed (Spearman r = 0.72, p = 0.01). The most common recommendation to the attending team was pronation (41%) and increase in positive end expiratory pressure (34%). Five patients with comorbidities died. A significant rank difference of LUSS and FiO₂ needed between survivors and non-survivors was found (Mann-Whitney U-test, p = 0.005).

CONCLUSION

LUS patterns found were like the ones described in other series (neonatal and pediatrics). Eighty-eight percent of the studies were performed with handheld affordable equipment. While there is no specific pattern, it varies according to gestational age and baseline diagnosis LUS, which were shown to be useful in assessing lung involvement that correlated with the degree of disease severity and respiratory support.

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).

Limitations of Bedside Lung Ultrasound in Neonatal Lung Diseases

Lung ultrasound is a technique that has rapidly developed in recent years. It is a low-cost, radiation-free, and easy-to-operate tool that can be repeatedly performed at the bedside. Compared to chest X-ray, lung ultrasound has high sensitivity and specificity in the diagnosis of neonatal respiratory distress syndrome, transient tachypnoea of newborns and pneumothorax. Lung ultrasound has been widely used in neonatal intensive care units. However, due to the physical barriers of air, where ultrasonic waves cannot pass and therefore reflection artifacts occur, it has limitations in some other lung diseases and cannot fully substitute for chest X-rays or CT/MRI scanning. This review describes these limitations in detail and highlights that if clinical symptoms are not effectively alleviated after medical treatment or the clinical presentation is not compatible with the ultrasound appearances, then chest X-rays or CT/MRI scanning should be performed to avoid misdiagnosis and mistreatment.

Lung Ultrasound in the Neonatal Intensive Care Unit: Does It Impact Clinical Care?

A neonatal point-of-care ultrasound has multiple applications, but its use has been limited in neonatal intensive care units in the Unites States. An increasing body of evidence suggests that lung ultrasound performed by the neonatologist, at the bedside, is reliable and accurate in differentiating neonatal respiratory conditions, predicting morbidity, and guiding invasive interventions. Recent research has shown that a lung ultrasound can assist the clinician in accurately identifying and managing conditions such as respiratory distress syndrome, transient tachypnea of the newborn, and bronchopulmonary dysplasia. In this review, we discuss basic lung ultrasound terminology, evidence for applications of neonatal lung ultrasound, and its use as a diagnostic and predictive tool for common neonatal respiratory pathologies.

Lung Ultrasound to Monitor Extremely Preterm Infants and Predict Bronchopulmonary Dysplasia. A Multicenter Longitudinal Cohort Study

Rationale: Lung ultrasound is useful in critically ill patients with acute respiratory failure. Given its characteristics, it could also be useful in extremely preterm infants with evolving chronic respiratory failure, as we lack accurate imaging tools to monitor them. Objectives: To verify if lung ultrasound can monitor lung aeration and function and has good reliability to predict bronchopulmonary dysplasia in extremely preterm neonates. Methods: A multicenter, international, prospective, longitudinal, cohort, diagnostic accuracy study consecutively enrolling inborn neonates with gestational age 30⁺⁶ weeks or younger. Lung ultrasound was performed on the 1, 7, 14, and 28 days of life, and lung ultrasound scores were calculated and correlated with simultaneous blood gases and work of breathing score. Gestational age-adjusted lung ultrasound scores were created, verified in multivariate models, and subjected to receiver operator characteristics (ROC) analyses to predict bronchopulmonary dysplasia at 36 weeks postmenstrual age. Measurements and Main Results: Mean lung ultrasound scores are different between infants developing (n = 72) or not developing (n = 75) bronchopulmonary dysplasia (P < 0.001 at any time point). Lung ultrasound scores significantly correlate with oxygenation metrics and work of breathing at any time point (P always < 0.0001). Gestational age-adjusted lung ultrasound scores significantly predict bronchopulmonary dysplasia at 7 (area under ROC curve, 0.826-0.833; P < 0.0001) and 14 (area under ROC curve, 0.834-0.858; P < 0.0001) days of life. Bronchopulmonary dysplasia severity and gestational age-adjusted lung ultrasound scores are significantly correlated at 7 and 14 days (P always < 0.0001). Conclusions: Lung ultrasound scores allow monitoring of lung aeration and function in extremely preterm infants. Gestational age-adjusted scores significantly predict the occurrence of bronchopulmonary dysplasia, starting from the seventh day of life.

Can lung ultrasound score accurately predict the need for surfactant replacement in preterm neonates? A systematic review and meta-analysis protocol

Respiratory distress syndrome (RDS) is a leading cause of morbidity and mortality in preterm infants due to primary surfactant deficiency. Surfactant replacement has greatly improved the short and long term prognosis of RDS but its administration criteria remain uncertain. Lung ultrasound has been recently shown as a non-invasive, repeatable, bedside tool to estimate parenchymal aeration using a semiquantitative score (LUS). The objective of this systematic review and meta-analysis is to evaluate the accuracy of LUS, assessed on the first day of life, to predict surfactant replacement. Methods will follow the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines and the protocol has been registered in PROSPERO database (registration number: CRD42021247888). Primary outcome: in a population of preterm infants, LUS will be compared in neonates who received surfactant replacement versus those who did not. Secondary outcome will be the accuracy of lung ultrasound score to predict the need for ≥ 2 doses of surfactant.

The Role of Lung Ultrasound in the Management of the Critically Ill Neonate-A Narrative Review and Practical Guide

Lung ultrasound makes use of artifacts generated by the ratio of air and fluid in the lung. Recently, an enormous increase of research regarding lung ultrasound emerged, especially in intensive care units. The use of lung ultrasound on the neonatal intensive care unit enables the clinician to gain knowledge about the respiratory condition of the patients, make quick decisions, and reduces exposure to ionizing radiation. In this narrative review, the possibilities of lung ultrasound for the stabilization and resuscitation of the neonate using the ABCDE algorithm will be discussed.

Quantitative Lung Ultrasound: Technical Aspects and Clinical Applications

Lung ultrasound is increasingly used in emergency departments, medical wards, and critical care units-adult, pediatric, and neonatal. In vitro and in vivo studies show that the number and type of artifacts visualized change with lung density. This has led to the idea of a quantitative lung ultrasound approach, opening up new prospects for use not only as a diagnostic but also as a monitoring tool. Consequently, the multiple scoring systems proposed in the last few years have different technical approaches and specific clinical indications, adaptable for more or less time-dependent patients. However, multiple scoring systems may generate confusion among physicians aiming at introducing lung ultrasound in their clinical practice. This review describes the various lung ultrasound scoring systems and aims to clarify their use in different settings, focusing on technical aspects, validation with reference techniques, and clinical applications.

Neonatal Lung Ultrasound and Surfactant Administration: A Pragmatic, Multicenter Study

BACKGROUND

Previous research shows that a lung ultrasound score (LUS) can anticipate CPAP failure in neonatal respiratory distress syndrome.

RESEARCH QUESTION

Can LUS also predict the need for surfactant replacement?

STUDY DESIGN AND METHODS

Multicenter, pragmatic study of preterm neonates who underwent lung ultrasound at birth and those given surfactant by masked physicians, who also were scanned within 24 h from administration. Clinical data and respiratory support variables were recorded. Accuracy of LUS, oxygen saturation to Fio₂ ratio, Fio₂, and Silverman score for surfactant administration were evaluated using receiver operating characteristic curves. The simultaneous prognostic values of LUS and oxygen saturation to Fio₂ ratio for surfactant administration, adjusting for gestational age (GA), were analyzed through a logistic regression model.

RESULTS

Two hundred forty infants were enrolled. One hundred eight received at least one dose of surfactant. LUS predicted the first surfactant administration with an area under the receiver operating characteristic curve (AUC) of 0.86 (95% CI, 0.81-0.91), cut off of 9, sensitivity of 0.79 (95% CI, 0.70-0.86), specificity of 0.83 (95% CI, 0.76-0.89), positive predictive value of 0.79 (95% CI, 0.71-0.87), negative predictive value of 0.82 (95% CI, 0.75-0.89), positive likelihood ratio of 4.65 (95% CI, 3.14-6.89), and negative likelihood ratio of 0.26 (95% CI, 0.18-0.37). No significant difference was shown among different GA groups: 25 to 27 weeks' GA (AUC, 0.91; 95% CI, 0.84-0.99), 28 to 30 weeks' GA (AUC, 0.81; 95% CI, 0.72-0.91), and 31 to 33 weeks' GA (AUC, 0.88; 95% CI, 0.79-0.95), respectively. LUS declined significantly within 24 h in infants receiving one surfactant dose. When comparing Fio₂, oxygen saturation to Fio₂ ratio, LUS, and Silverman scores as criteria for surfactant administration, only the latter showed a significantly poorer performance. The combination of oxygen saturation to Fio₂ ratio and LUS showed the highest predictive power, with an AUC of 0.93 (95% CI, 0.89-0.97), regardless of the GA interval.

INTERPRETATION

LUS is a reliable criterion to administer the first surfactant dose regardless of GA. Its association with oxygen saturation to Fio₂ ratio significantly improves the prediction power for surfactant need.

Evaluation of Different Types of Natural Surfactants by Lung Ultrasound in Respiratory Distress Syndrome

OBJECTIVE

This study aimed to compare the lung ultrasonography (LUS) scores after two different natural surfactant administration as a parameter reflecting lung inflation.

STUDY DESIGN

Preterm infants of 32 gestational weeks and below who were diagnosed with respiratory distress syndrome (RDS) were randomly assigned to be administered either poractant alfa or beractant, prospectively. Serial LUS scans were obtained by an experienced neonatologist in a standardized manner before and after (2 and 6 hours) surfactant administration. The LUS scans were evaluated by protocols based on scores and lung profiles.

RESULTS

Thirty-seven infants received poractant alfa and 36 received beractant. The baseline characteristics and presurfactant LUS scores were similar in groups. The scores were significantly decreased after surfactant administration in both groups (2 hours, p = < 0.001; 6 hours, p = < 0.001). LUS scores in poractant group were significantly lower than beractant group when compared at each time point. At the end of 6 hours, the number of infants with the normal profile was significantly higher in the poractant group (∼65%) than the beractant group (22%).

CONCLUSION

LUS is beneficial for evaluating lung aeration after surfactant treatment in preterm infants with RDS. A better lung aeration can be achieved in the early period with the use of poractant alfa.

Modern pulmonary imaging of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a complex and serious cardiopulmonary morbidity in infants who are born preterm. Despite advances in clinical care, BPD remains a significant source of morbidity and mortality, due in large part to the increased survival of extremely preterm infants. There are few strong early prognostic indicators of BPD or its later outcomes, and evidence for the usage and timing of various interventions is minimal. As a result, clinical management is often imprecise. In this review, we highlight cutting-edge methods and findings from recent pulmonary imaging research that have high translational value. Further, we discuss the potential role that various radiological modalities may play in early risk stratification for development of BPD and in guiding treatment strategies of BPD when employed in varying severities and time-points throughout the neonatal disease course.

Lung Ultrasound Score Progress in Neonatal Respiratory Distress Syndrome

BACKGROUND AND OBJECTIVES

The utility of a lung ultrasound score (LUS) has been described in the early phases of neonatal respiratory distress syndrome (RDS). We investigated lung ultrasound as a tool to monitor respiratory status in preterm neonates throughout the course of RDS.

METHODS

Preterm neonates, stratified in 3 gestational age cohorts (25-27, 28-30, and 31-33 weeks), underwent lung ultrasound at weekly intervals from birth. Clinical data, respiratory support variables, and major complications (sepsis, patent ductus arteriosus, pneumothorax, and persistent pulmonary hypertension of the neonate) were also recorded.

RESULTS

We enrolled 240 infants in total. The 3 gestational age intervals had significantly different LUS patterns. There was a significant correlation between LUS and the ratio of oxygen saturation to inspired oxygen throughout the admission, increasing with gestational age (b = -0.002 [P < .001] at 25-27 weeks; b = -0.006 [P < .001] at 28-30 weeks; b = -0.012 [P < .001] at 31-33 weeks). Infants with complications had a higher LUS already at birth (12 interquartile range 13-8 vs 8 interquartile range 12-4 control group; P = .001). In infants 25 to 30 weeks' gestation, the LUS at 7 days of life predicted bronchopulmonary dysplasia with an area under the curve of 0.82 (95% confidence interval 0.71 to 93).

CONCLUSIONS

In preterm neonates affected by RDS, the LUS trajectory is gestational age dependent, significantly correlates with the oxygenation status, and predicts bronchopulmonary dysplasia. In this population, LUS is a useful, bedside, noninvasive tool to monitor the respiratory status.

The Predictive Value of Lung Ultrasound Scores in Developing Bronchopulmonary Dysplasia: A Prospective Multicenter Diagnostic Accuracy Study

BACKGROUND

Different lung ultrasound (LUS) scanning protocols have been used, and the results in terms of diagnostic accuracy are heterogeneous.

RESEARCH QUESTIONS

What is the diagnostic accuracy of the LUS score to predict moderate to severe bronchopulmonary dysplasia (msBPD)? Does scanning of posterior lung fields improve the diagnostic accuracy?

STUDY DESIGN AND METHODS

This was a multicenter prospective, observational study in six centers. Two LUS aeration scores, one involving only anterolateral lung fields and the other adding the posterior fields were obtained at birth, on the third day of life (DOL), on the seventh DOL, on the 14th DOL, and on the 21st DOL. The diagnostic accuracy of both scores to predict msBPD was assessed at each time point.

RESULTS

Eight hundred thirty-two LUS examinations in 298 infants were included. Both LUS score using anterolateral and posterior fields and LUS score using only anterolateral fields showed a similar moderate diagnostic accuracy to predict msBPD on the third DOL (area under the receiver operating characteristic curve [AUC] 95% CI, 0.68-0.85 vs 0.68-0.85; P = .97), seventh DOL (AUC 95% CI, 0.74-0.85 vs 0.74-0.84; P = .26), and 21st DOL (AUC 95% CI, 0.72-0.86 vs 0.74-0.88; P = .17). The LUS score using anterolateral and posterior fields was slightly more accurate at 14th DOL (AUC 95% CI, 0.69-0.83 vs 0.66-0.80; P = .01). A cutoff of 8 points in the LUS score using only anterolateral fields on the seventh DOL provided a sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of 70%, 79%, 3.3, and 0.38, respectively, to predict msBPD. Adding gestational age (GA) and sex improved the discriminative value without significant differences compared with a predictive model based on multiple clinical variables: AUC 95% CI, 0.77-0.88 vs 0.80-0.91 (P = .52).

INTERPRETATION

The LUS score is able to predict msBPD from the third DOL with a moderate diagnostic accuracy. Scanning posterior lung fields slightly improved diagnostic accuracy only at the 14th DOL. Adding GA and sex improves the diagnostic accuracy of the LUS scores. The LUS score is useful to stratify BPD risk early after birth.

Respiratory distress syndrome in preterm neonates in the era of precision medicine: A modern critical care-based approach

Respiratory distress syndrome (RDS) was recognized to be caused by primary surfactant deficiency almost 70 years ago and continuous positive airway pressure was introduced approximately 50 years ago. Since then, there have been many developments in neonatology; we know many things but others are still controversial. The more we know, the more questions arise. However, this review aims to indicate what is more needed to understand and how should be the modern approach to RDS in the era of precision medicine. The review is divided between new concepts and new tools. We will explain the interaction between steroids, CPAP and surfactant, as well as the surfactant catabolism and the diagnosis of NARDS; lung ultrasound and new tools to optimize CPAP will also be covered. How these concepts are integrated in the author's personal experience is also illustrated.

Modified lung ultrasound score predicts ventilation requirements in neonatal respiratory distress syndrome

Background

We propose a modified lung ultrasound (LUS) score in neonates with respiratory distress syndrome (RDS), which includes posterior instead of lateral lung fields, and a 5-grade rating scale instead of a 4-grade rating scale. The purpose of this study was to evaluate the reproducibility of the rating scale and its correlation with blood oxygenation and to assess the ability of early post-birth scans to predict the mode of respiratory support on day of life 3 (DOL 3). As a secondary objective, the weight of posterior scans in the overall LUS score was assessed.

Methods

We analyzed 619 serial lung scans performed in 70 preterm infants < 32 weeks gestation and birth weight < 1500 g. Assessments were performed within 24 h of birth (LUS₀) and on days 2, 3, 5, 7, 10, 14, 21 and 28. LUS scores were correlated with oxygen saturation over fraction of inspired oxygen (S/F) and mode of respiratory support. Interrater agreement was determined with the intraclass correlation coefficient (ICC) and Cronbach’s alpha. Probabilities of the need for various respiratory support modes on DOL 3 were assessed with ordinal logistic regression. Least square (ls) means of the posterior and anterior pulmonary field scores were compared.

Results

The LUS score correlated significantly with S/F (Spearman rho = −0.635; p < 0.0001) and had excellent interrater agreement (ICC = 0.94, 95% CI 0.93–0.95; Cronbach’s alpha = 0.99). Significant predictors of ventilation requirements on DOL 3 were LUS₀ (p < 0.016) and birth weight (BW) (p < 0.001). In the ROC analysis, LUS₀ had high reliability in prognosing invasive ventilation on DOL 3 (AUC = 0.845 (95% DeLong CI: 0.738–0.951; p < 0.001)). Invasive ventilation was the most likely mode of respiratory support for LUS₀ scores: ≥7 (in infants with BW 900 g), ≥ 10 (in infants with BW 1050 g) and ≥ 15 (in infants with BW 1280 g). Posterior fields exhibited significantly higher average scores than anterior fields. Respective ls means (confidence levels) were 4.0 (3.8–4.1) vs. 2.2 (2.0–2.4); p < 0.001.

Conclusions

Post-birth LUS predicts ventilation requirements on DOL 3. Scores of posterior pulmonary fields have a predominant weight in the overall LUS score.

Surfactant use in late preterm infants: a survey among Belgian neonatologists

Specific recommendations on surfactant administration in late preterm (LPT) infants with pulmonary disease are lacking. We performed an online-based, nationwide survey amongst all (n = 102) Belgian neonatologists to identify the use of surfactant in LPT infants suffering from several respiratory pathologies. The survey used clearly defined clinical cases and resulted in a 86% response rate. Neonatologists adhere to the 200 mg/kg initial surfactant dosing scheme. Surfactant is widely used in respiratory distress syndrome (70.1%), but there is less unanimity on its use in meconium aspiration syndrome (58.0%), transient tachypnoea of the newborn (30.6%), congenital pneumonia (27.2%) and congenital diaphragmatic hernia (8.6%). Respondents adhere to the European guideline of a timely referral to a newborn intensive care unit (non-invasive ventilation and FiO₂ > 0.30 at 12 h of age), in order to minimise the risk of deterioration.Conclusion: We demonstrate a wide variety in the use of surfactant within LPT infants. The majority of Belgian neonatologists therefore urge for an investment in multi-centre trials on surfactant administration in LPT infants, in order to create an evidence-based practice as well as to reduce the strain on health care budgets.Trial registration: https://clinicaltrials.gov What is Known: • Any late preterm (LPT) infant with respiratory distress needs a timely referral to a neonatal intensive care unit in case of non-invasive ventilation and FiO₂ > 0.30 at 12 h of life, in order to minimise the risk of acute deterioration as well as chronic lung disease. • Any modest increase in morbidity in the sizeable group of LPT infants exerts a significant strain on health care budgets. What is New: • We report the attitudes and opinions of Belgian neonatologists about the use of surfactant in LPT infants suffering from several respiratory diseases. • Our survey demonstrates a significant variability in practice between neonatologists during treatment of respiratory pathologies in LPT infants. This highlights an urgent need for univocal therapeutic lines.