Lung ultrasound accuracy in respiratory distress syndrome and transient tachypnea of the newborn

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.

Implementation of a standardized lung ultrasound protocol for respiratory distress in a neonatal intensive care unit: an observational study

OBJECTIVE

To assess the feasibility of implementing a simple point-of-care lung ultrasound (LU) evaluation and reporting protocol in a neonatal intensive care unit (NICU) and its effect on patient management.

STUDY DESIGN

Retrospective observational study of LU examinations performed in a level III NICU. Each examination was performed according to a standardized protocol. An independent radiologist-assessed chest X-ray (CXR) was used to compare the LU diagnosis. The impact on patient management was also evaluated.

RESULT

A total of 206 LU studies in 158 neonates were reviewed. There was significant agreement between LU and CXR diagnoses (84.95%, 95% CI 80.07-89.83%). LU affected patient management in 87.8% of the cases (95% CI 83.33-92.28%).

CONCLUSION

Implementation of a simplified, sign-based protocol for LU in the NICU is feasible. LU is not inferior to CXR studies and supports patient management as an imaging modality.

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.

Lung ultrasound detects regional aeration inhomogeneity in ventilated preterm lambs

BACKGROUND

Inhomogeneous lung aeration is a significant contributor to preterm lung injury. EIT detects inhomogeneous aeration in the research setting. Whether LUS detects inhomogeneous aeration is unknown. The aim was to determine whether LUS detects regional inhomogeneity identified by EIT in preterm lambs.

METHODS

LUS and EIT were simultaneously performed on mechanically ventilated preterm lambs. LUS images from non-dependent and dependent regions were acquired and reported using a validated scoring system and computer-assisted quantitative LUS greyscale analysis (Q-LUSMGV). Regional inhomogeneity was calculated by observed over predicted aeration ratio from the EIT reconstructive model. LUS scores and Q-LUSMGV were compared with EIT aeration ratios using one-way ANOVA.

RESULTS

LUS was performed in 32 lambs (~125d gestation, 128 images). LUS scores were greater in upper anterior (non-dependent) compared to lower lateral (dependent) regions of the left (3.4 vs 2.9, p = 0.1) and right (3.4 vs 2.7, p < 0.0087). The left and right upper regions also had greater LUS scores compared to right lower (3.4 vs 2.7, p < 0.0087) and left lower (3.7 vs 2.9, p = 0.1). Q-LUSMGV yielded similar results. All LUS findings corresponded with EIT regional differences.

CONCLUSION

LUS may have potential in measuring regional aeration, which should be further explored in human studies.

IMPACT

Inhomogeneous lung aeration is an important contributor to preterm lung injury, however, tools detecting inhomogeneous aeration at the bedside are limited. Currently, the only tool clinically available to detect this is electrical impedance tomography (EIT), however, its use is largely limited to research. Lung ultrasound (LUS) may play a role in monitoring lung aeration in preterm infants, however, whether it detects inhomogeneous lung aeration is unknown. Visual LUS scores and mean greyscale image analysis using computer assisted quantitative LUS (Q-LUSMGV) detects regional lung aeration differences when compared to EIT. This suggests LUS reliably detects aeration inhomogeneity warranting further investigation in human trials.

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.

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.

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.

Lung ultrasound in neonates - An underused tool

Point of care lung ultrasound (USG) can help in the diagnosis and management of critically sick neonates. It is based on seven simple principles that are comprehensive enough to diagnose all major lung pathologies. A compact small machine and a micro-convex or linear probe are the basic requirements to perform lung USG. In contrast to traditional USG principles, USG of the lung is based on artefacts. Some of the terminologies that are used to characterize normal lung include the pleural line, A-line, bat sign, lung sliding and seashore sign. Air/fluid mixture in varying ratios helps in diagnosis of normal lung, pneumothorax, interstitial syndrome (transient tachypnoea of newborn, respiratory distress syndrome, bronchopulmonary dysplasia), lung consolidation and pleural effusion.

Lung ultrasound score as a predictor of ventilator use in preterm infants with dyspnea within 24 h after dhospitalization

BACKGROUND

Selecting the correct ventilation strategy is crucial for the survival of preterm infants with dyspnea in NICU. Lung ultrasound score (LUSsc) is a potential predictor for respiratory support patterns in preterm infants.

METHODS

We prospectively included 857 preterm infants. LUS was performed in the first 2 h after admission, and LUSsc was determined by two specialist sonographers. Participants were divided into two categories according to gestational age (<32⁺⁰ weeks and 32⁺⁰-36⁺⁶ weeks) and randomly divided into a training set and a validation set. There were two main outcomes: invasive and non-invasive respiratory support. In the training set, clinical factors were analyzed to find the best cut-off value of LUSsc, and consistency was verified in the verification set. The choice of invasive respiratory support was based on neonatal mechanical ventilation strategies.

RESULTS

Preterm infants with invasive respiratory support had a higher LUSsc, greater use of Pulmonary Surfactant（PS）, and lower Oxygenation Index（OI）、birth weight than those with non-invasive support. In the <32⁺⁰ weeks group, the area under the curve (AUC) for the receiver operating characteristic curve plotted with 2-h LUSsc was 0.749 (95% CI: 0.689-0.809), the cut-off point of LUSsc was 8, and the sensitivity and specificity were 74.0% and 68.3%, respectively. In the 32⁺⁰-36⁺⁶ weeks group, the AUC was 0.863 (95% CI: 0.811-0.911), with a cut-off point of 7. Sensitivity and specificity were 75.3% and 0.836%, respectively. In the validation set, using the actual clinical respiratory support selection results for verification, the validation results showed for the <32⁺⁰ weeks group (Kappa value 0.660, P < 0.05, McNemar test P > 0.05) for preterm 32⁺⁰-36⁺⁶ weeks (Kappa value 0.779, P < 0.05, McNemar test P > 0.05).

CONCLUSION

The LUSsc showed good reliability in predicting respiratory support mode for preterm infants with dyspnea. Registered at ClinicalTrials.gov (identifier: chiCTR1900023869).

Lung Ultrasound Role in Diagnosis of Neonatal Respiratory Disorders: A Prospective Cross-Sectional Study

Lung ultrasound (LUS) has become one of the most exciting applications in neonatal point-of-care ultrasound (POCUS), yet still lacks routine clinical use. This study assesses the utility of LUS for neonatal respiratory disorders (NRDs) diagnosis and follow-up compared to chest X-ray (CXR). A prospective cross-sectional study was conducted on 100 neonates having NRDs with a gestational age ≥28 weeks, excluding those having multiple congenital anomalies, chromosomal aberrations, hydrops fetalis and/or heart failure. CXR and LUS were done on admission for diagnosis and were repeated after 7 days, or if needed earlier within the 7 days. The diagnosis of NRDs by CXR and LUS on admission and after 7 days was comparable (p > 0.05). LUS diagnosis sensitivity and specificity for respiratory distress syndrome, pneumonia, meconium aspiration syndrome, pneumothorax and pulmonary atelectasis were 94.7/100%, 97.5/95%, 92.3/100%, 90.9/98.9% and 100/97.8%, respectively. The total agreement between LUS and CXR was 98.5% with 95% CI (0.88 to 0.92). LUS and CXR had considerable agreement in the diagnosis of NRDs. Being a reliable bedside modality of diagnosis and safer than CXR, LUS may be considered an alternative method for the diagnosis of neonates with NRDs.

Unnecessary radiation exposure during diagnostic radiography in infants in a neonatal intensive care unit: a retrospective cohort study

Unnecessary radiation exposure (URE) during radiographic examination is an issue among infants in neonatal intensive care units (NICUs). The causes of URE have not been fully explored. This study investigated the incidence and identified the causes of URE in infants during diagnostic radiography in a NICU. This was a retrospective cohort study. We retrieved and analysed requests and radiographs taken at a tertiary NICU between September and November 2018. URE was defined as the rate of discordance between requests and images taken (DisBRI) and unnecessary radiation exposure in irrelevant regions (UREIR) during radiography. We compared the rates of URE between very low-birth-weight (VLBW, birth weight < 1500 g) infants and non-VLBW infants. A total of 306 radiographs from 88 infants were taken. The means ± standard deviations (SDs) of gestational age and birth weight were 35.7 ± 3.6 weeks and 2471 ± 816 g, respectively. Each infant underwent an average of 3.5 radiographs. The DisBRI rate was 1.3% and was mostly related to poor adherence to requests. The UREIR rates in thoraco-abdominal babygrams were 89.6% for the head, 14.8% for the elbows and 18.4% for the knee and were mainly related to improper positioning of and collimation in infants while performing radiography. The UREIR rates for the head, knee and ankle were higher in VLBW infants than in non-VLBW infants (94.6% vs. 85.6%, 27.0% vs. 11.5% and 5.4% vs. 0.7%, respectively, p < 0.05).

CONCLUSIONS

URE during diagnostic radiography is common in sick infants and is mainly related to improper positioning and collimation during examinations. Adherence to protocols when performing radiographic examination or using ultrasonography may be a solution to reduce URE in infants in NICUs.

WHAT IS KNOWN

• The risk of unnecessary radiation exposure (URE) during radiography has been a common and important issue in sick infants in neonatal intensive care units (NICUs). • The new point-of-care ultrasound (POCUS) technique decreases the need for chest films and prevents radiation exposure in neonates.

WHAT IS NEW

• In the NICU, URE is still a common issue in critically ill infants during radiographic examinations. The causes of URE during diagnostic radiography are mainly due to improper positioning and collimation during examinations. • The incidence of URE in irrelevant regions is higher in very low-birth-weight (VLBW) infants than in non-VLBW infants.

Neonatal POCUS: Embracing our modern day "stethoscope"

The dramatic technologic advancements seen in ultrasound have accelerated the growth of point-of-care ultrasound (POCUS) in medicine. Neonatology has lagged behind other pediatric and adult specialties in incorporating POCUS into clinical practice despite there being numerous applications in cardiac and non-cardiac arenas. Widely available training programs are aiding in improving this situation but significantly more structure and orchestration for neonatal POCUS dissemination will be needed to fully actualize the potential for POCUS to augment its widespread clinical application.

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.

Surfactant therapy in late preterm and term neonates with respiratory distress syndrome: a systematic review and meta-analysis

BACKGROUND

There are no evidence-based recommendations for surfactant use in late preterm (LPT) and term infants with respiratory distress syndrome (RDS).

OBJECTIVE

To investigate the safety and efficacy of surfactant in LPT and term infants with RDS.

METHODS

Systematic review, meta-analysis and evidence grading.

INTERVENTIONS

Surfactant therapy versus standard of care.

MAIN OUTCOME MEASURES

Mortality and requirement for invasive mechanical ventilation (IMV).

RESULTS

Of the 7970 titles and abstracts screened, 17 studies (16 observational studies and 1 randomised controlled trial (RCT)) were included. Of the LPT and term neonates with RDS, 46% (95% CI 40% to 51%) were treated with surfactant. We found moderate certainty of evidence (CoE) from observational studies evaluating infants supported with non-invasive respiratory support (NRS) or IMV that surfactant use may be associated with a decreased risk of mortality (OR 0.45, 95% CI 0.32 to 0.64). Very low CoE from observational trials in which surfactant was administered at FiO₂ >0.30-0.40 to infants on Continuous Positive Airway Pressure (CPAP) indicated that surfactant did not decrease the risk of IMV (OR 1.20, 95% CI 0.40 to 3.56). Very low to low CoE from the RCT and observational trials showed that surfactant use was associated with a significant decrease in risk of air leak, persistent pulmonary hypertension of the newborn (PPHN), duration of IMV, NRS and hospital stay.

CONCLUSIONS

Current evidence base on surfactant therapy in LPT and term infants with RDS indicates a potentially decreased risk of mortality, air leak, PPHN and duration of respiratory support. In view of the low to very low CoE and widely varying thresholds for deciding on surfactant replacement in the included studies, further trials are needed.

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..

Tools for assessing lung fluid in neonates with respiratory distress

Background

Transient tachypnea of the newborn (TTN), as a common cause of neonatal respiratory distress, needs to be distinguished from respiratory distress syndrome (RDS). Various modalities such as lung ultrasonography, cytokine analysis, and electrical cardiometry for the evaluation of lung fluid can be helpful for the exact diagnosis, however, clinical diagnosis has been applied mainly. This study aimed to evaluate the usefulness of the various tools for the diagnosis of TTN and RDS in neonates.

Methods

This study evaluated 22 late-preterm and term infants admitted to the neonatal intensive care unit of Gangnam Severance Hospital because of respiratory distress. Total 9 neonates were diagnosed with TTN and 13 had RDS. In addition to chest radiography, the LUS score was calculated by a neonatologist using the portable ultrasound device. Cytokines in the bronchoalveolar lavage fluid supernatant were measured. Thoracic fluid content was measured using an electrical cardiometry device.

Results

We enrolled 22 patients with median gestational age, 37.1 weeks, and birth weight 3100 g. There is no difference in patient characteristics between RDS and TTN group. Lung ultrasound score was significantly higher in RDS than TTN (11 vs 6, p = 0.001). Score 0 is shown in all infants with TTN. Score 1 is shown as significantly more in RDS than TTN. Between the TTN and RDS groups, there were significant differences in the changes of thoracic fluid content (2 vs − 1.5, p < 0.001), IL-1β levels (2.5 vs 11.3, p = 0.02), and TNF-α levels (20.1 vs 11.2, p = 0.04).

Conclusion

We found lung ultrasound and electrical cardiometry to be reliable diagnostic tools for assessing infants with respiratory distress among late-preterm and term infants. Further studies with a large number of patients are needed to confirm their clinical usefulness.

A modified lung ultrasound score to evaluate short-term clinical outcomes of bronchopulmonary dysplasia

Background

Lung ultrasound (LUS) is a useful tool for assessing the severity of lung disease, without radiation exposure. However, there is little data on the practicality of LUS in assessing the severity of bronchopulmonary dysplasia (BPD) and evaluating short-term clinical outcomes. We adapted a LUS score to evaluate BPD severity and assess the reliability of mLUS score correlated with short-term clinical outcomes.

Methods

Prospective diagnostic accuracy study was designed to enroll preterm infants with gestational age < 34 weeks. Lung ultrasonography was performed at 36 weeks postmenstrual age. The diagnostic and predictive values of new modified lung ultrasound (mLUS) scores based on eight standard sections were compared with classic lung ultrasound (cLUS) scores.

Results

A total of 128 infants were enrolled in this cohort, including 30 without BPD; 31 with mild BPD; 23 with moderate BPD and 44 with severe BPD. The mLUS score was significantly correlated with the short-term clinical outcomes, superior to cLUS score. The mLUS score well correlated with moderate and severe BPD (AUC = 0.813, 95% CI 0.739–0.888) and severe BPD (AUC = 0.801, 95% CI 0.728–0.875), which were superior to cLUS score. The ROC analysis of mLUS score to evaluate the other short-term outcomes also showed significant superiority to cLUS score. The optimal cutoff points for mLUS score were 14 for moderate and severe BPD and 16 for severe BPD.

Conclusions

The mLUS score correlates significantly with short-term clinical outcomes and well evaluates these outcomes in preterm infants.

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.

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).

Lung Ultrasound for Prediction of Bronchopulmonary Dysplasia in Extreme Preterm Neonates: A Prospective Diagnostic Cohort Study

OBJECTIVES

To evaluate the diagnostic and predictive ability of lung ultrasound at 3 time points in the first 2 weeks after birth for predicting bronchopulmonary dysplasia (BPD) among infants <29 weeks of gestational age.

STUDY DESIGN

This was a prospective, diagnostic cohort study. Lung ultrasound was performed on days 3, 7, and 14 after birth and lung ultrasound scores (LUS) were calculated in blinded fashion. Diagnostic test characteristics and area under receiver operating characteristic (AUROC) curves were calculated.

RESULTS

A total of 152 infants were enrolled with mean (SD) gestational age of 25.8 (1.5) weeks gestation. Of them, 87 (57%) infants were diagnosed with BPD. The LUS were significantly higher in infants diagnosed with BPD compared with those without BPD at all scan time points (P < .01). The score of >10 at all 3 time points had higher sensitivity (0.89, 0.89, and 0.77), specificity (0.87, 0.90, and 0.92), and corresponding clinically important positive and negative likelihood ratios. The AUROC for LUS at the 3 time points were 0.96, 0.97, and 0.95 on day 3, 7, and 14, respectively. Compared with the model using clinical characteristics, LUS alone had higher AUROC (P < .05 for all 3 time points).

CONCLUSIONS

In this cohort, LUS in the first 2 weeks after birth had a very high predictive value for the diagnosis of BPD among infants of <29 weeks of gestation.

TRIAL REGISTRATION

ClinicalTrials.govNCT04756297.

Lung Ultrasound in Pediatrics and Neonatology: An Update

The potential role of ultrasound for the diagnosis of pulmonary diseases is a recent field of research, because, traditionally, lungs have been considered unsuitable for ultrasonography for the high presence of air and thoracic cage that prevent a clear evaluation of the organ. The peculiar anatomy of the pediatric chest favors the use of lung ultrasound (LUS) for the diagnosis of respiratory conditions through the interpretation of artefacts generated at the pleural surface, correlating them to disease-specific patterns. Recent studies demonstrate that LUS can be a valid alternative to chest X-rays for the diagnosis of pulmonary diseases, especially in children to avoid excessive exposure to ionizing radiations. This review focuses on the description of normal and abnormal findings during LUS of the most common pediatric pathologies. Current literature demonstrates usefulness of LUS that may become a fundamental tool for the whole spectrum of lung pathologies to guide both diagnostic and therapeutic decisions.

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.

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.

Lung ultrasound (LUS) and surfactant treatment: looking for the best predictive moment

OBJECTIVE

Assess the earliest time of LUS to guide surfactant therapy.

STUDY DESIGN

In this observational study (ClinicalTrials.gov Identifier NCT04544514), LUS was performed within 30 min and repeated at 1, 2, 4, and 6 h on preterm babies. White lung appearance was defined as type 1 group, whereas prevalence of lines B as type 2 and lines A as type 3. Ultrasound and radiographic findings were also compared to determine surfactant need.

RESULTS

Among 71 patients, 41 received surfactant therapy. In the first evaluation, 37 of them have been defined as type 1, whereas 4 of them have been as type 2 group. Type 3 group did not receive surfactant. Type 1 findings were superior to predict surfactant need and the predictive value was 100% at 2 h.

CONCLUSION

Even early LUS assessment at the first 20-30 min  was more significant to predict surfactant need than x-ray. Presence of white lung appearance for 2 h indicates an absolute surfactant need.

Ultrasound performed shortly after birth can predict the respiratory support needs of late preterm and term infants: A diagnostic accuracy study

BACKGROUND

Late preterm and term infants may develop respiratory issues with severe outcomes. Early identification of these diseases shortly after infants' birth can improve their management. Lung ultrasound (LUS) has been used to diagnose neonatal respiratory diseases. However, few LUS methods have been reported to predict the need for respiratory support, the basis of infant respiratory diseases management.

METHODS

We conducted a prospective diagnostic accuracy study following the Standards for the Reporting of Diagnostic Accuracy Studies guidelines at a tertiary academic hospital between 2019 and 2020. A total of 310 late preterm and term infants with mild respiratory symptoms were enrolled. The LUS assessment was performed for each participant at one of the following times: 0.5, 1.0, 2.0, or 4.0 h after birth. Predictive reliability was tested by receiver operating characteristic curve analysis. The main outcome was the need for any respiratory support determined according to international guidelines.

RESULTS

Seventy-four infants needed respiratory support, and 236 were healthy according to a 3-day follow-up confirmation. Six LUS imaging patterns were found. Two "high-risk" patterns were strongly correlated with respiratory support needs (area under the curve [AUC] = 0.95; 95% confidence interval [CI]: 0.92-0.98, p < .001). The optimal cut-off value for "high-risk" patterns was 2 (sensitivity = 87.8% and specificity = 91.1%). The predictive value of LUS was greater than that of a symptom-based method (the Acute Care of at-Risk Newborns assessment score) (AUCs' p < .01).

CONCLUSIONS

LUS can be used to predict the need for respiratory support in late preterm and term infants and is more reliable than tools based on respiratory symptoms.

Application of ultrasound-based radiomics technology in fetal-lung-texture analysis in pregnancies complicated by gestational diabetes and/or pre-eclampsia

OBJECTIVES

To analyze and compare, using ultrasound-based radiomics technology, fetal-lung texture in pregnancies affected by gestational diabetes mellitus (GDM) and/or pre-eclampsia (PE) and in normal pregnancies, overall and at different gestational ages.

METHODS

In this retrospective study, 430 high-throughput features per fetal-lung image were extracted from 548 fetal-lung ultrasound images (obtained at the level of the four-chamber view of the heart) in 548 pregnant women who delivered between July 2018 and August 2019 at the Obstetrics and Gynecology Hospital of Fudan University. Images had been obtained during ultrasound examinations between 28 and 41 weeks of gestation. The data were divided randomly into training set (80% of fetal-lung images) and independent test set (20% of images), and 20% of the images in the training set were then selected as the validation set. A standard machine-learning model based on ultrasound-based radiomics technology was created using features of fetal-lung texture extracted from the images, and a regression model was used to evaluate the relationship between lung-texture features, GDM and/or PE and gestational age.

RESULTS

Of the 548 pregnancies included, 108 were affected by GDM alone, 71 by PE alone and 25 by both GDM and PE, and 344 were normal. The overall performance of the GDM and PE prediction model was superior to that of the gestational-age prediction model, with an area under the receiver-operating-characteristics curve of 0.95-0.99, sensitivity of 78.8-97.1% in the validation set and 74.5-91.3% in the independent test set, specificity of 79.8-94.3% in the validation set and 75.7-88.4% in the independent test set and accuracy of 81.0-95.3% in the validation set and 80.6-86.4% in the independent test set.

CONCLUSIONS

Using ultrasound-based radiomics technology, fetal lungs from pregnancies grouped according to whether they were affected by GDM and/or PE could be distinguished from each other and from fetal lungs of normal pregnancies, and lungs from pregnancies at different gestational ages could be distinguished. These findings support further research to explore the use of this non-invasive technology to predict neonatal respiratory complications in women with PE, GDM or their combination. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Lung Ultrasound for the Diagnosis of Neonatal Respiratory Distress Syndrome: A Meta-analysis

Supplemental digital content is available in the text.

Chest radiography is the primary imaging modality used for the assessment of neonatal respiratory distress syndrome (NRDS) in newborns. However, excessively exposing a growing neonate to harmful ionizing radiation may have long-term consequences. Some studies have shown that lung ultrasound (LUS) is helpful in the diagnosis of NRDS. A comprehensive search was carried out using PubMed, Embase, and the Cochrane Library to identify studies in which newborns with clinically suspected NRDS were assessed by LUS. Two investigators independently screened the literature and extracted the data. Any discrepancies were resolved via discussion with the senior author. Study quality was assessed by the Quality Assessment of Diagnostic Accuracy Studies 2 tool, and pooled sensitivity and specificity of various LUS findings for diagnosing NRDS were determined. Summary receiver operating characteristic curve was used to assess the overall performance of LUS. Ten studies with a total of 887 neonates were included in this meta-analysis. There was significant heterogeneity across the included studies. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio for the diagnosis of NRDS using LUS were 0.92 (95% confidence interval [CI], 0.89–0.94), 0.95 (95% CI, 0.93–0.97), 20.23 (95% CI, 8.54–47.92), 0.07 (95% CI, 0.03–0.14), and 455.30 (95% CI, 153.01–1354.79), respectively. Furthermore, the summary receiver operating characteristic area under the curve was calculated to be 0.9888. The main LUS characteristics of NRDS include bilateral white lung, pleural line abnormalities, and lung consolidation. In summary, LUS is a highly valuable diagnostic technology that complements chest radiography in the diagnosis and follow-up monitoring of NRDS.

Neonatal lung diseases: lung ultrasound or chest x-ray

Chest X-ray (CXR) examination is a well-recognized imaging modality in the diagnosis of neonatal lung diseases. On the other hand, lung ultrasound (LUS) has been an emerging and increasingly studied modality. However, the role of LUS as well as its potential to replace CXRs in the detection of neonatal lung diseases has been debated. We combine the present research progress and our own clinical experience to elaborate on various aspects of the potential routine use of lung ultrasound in neonatal intensive care units. We conclude that both LUS and CXR have a number of advantages and disadvantages. They should serve as complementary diagnostic methods in providing accurate, timely, and reliable information.

Diagnostic performance of lung ultrasound for transient tachypnea of the newborn: A meta-analysis

Several recent studies demonstrated that lung ultrasound could achieve desired diagnostic accuracy for transient tachypnea of the neonate (TTN). However, the diagnostic performance of lung ultrasound for TTN has not been systematically studied to date. This meta-analysis aimed to investigate the performance of lung ultrasound in diagnosing TTN. The relevant literature was searched in PubMed, Medline, the Cochrane Library, and Embase databases without any restriction in terms of language and time until January 31, 2021. Studies that assessed the diagnostic performance of lung ultrasound for TTN were included. Seven studies with 1514 participants were summarized. The lung ultrasound provided more accurate performance for diagnosing TTN with pooled sensitivity and specificity of 0.67 [95% confidence interval (CI) = 0.63–0.71] and 0.97 (95% CI = 0.95–0.98), respectively. A higher summarized area under the summary receiver operating characteristic curve was observed as 0.9906. Lower sensitivity and area under the curve (AUC) of B-lines for TTN were observed as 0.330 (95% CI = 0.27–0.38) and 0.5000, respectively. Lung ultrasound provided highly accurate AUC, sensitivity, and specificity in detecting TTN. Large-scale studies are warranted in the future to confirm these results.

Novel predictor markers for early differentiation between transient tachypnea of newborn and respiratory distress syndrome in neonates

Neonatal Respiratory Distress Syndrome (RDS) and Transient Tachypnea of newborn (TTN) are common similar neonatal respiratory diseases. Study the early predictor markers in differentiation between TTN and RDS in neonates. A prospective case control study which was done in Neonatal Intensive Care Unit (NICU) of Tanta University Hospital (TUH) from September 2016 to March 2018. Three groups of neonates were included in the study: RDS group (45 neonates), TTN group (45 neonates), and control group (45 healthy neonates). There were statistically significant difference (SSD) between our studied three groups as regard serum Malondialdehyde (MDA), Superoxide dismutase SOD, Lactate dehydrogenase (LDH), and blood PH and P-values were 0.001* for these comparative parameters. The ROC curve of RDS cases revealed that the serum MDA Cut off, sensitivity and specificity were 1.87 mmol/L, 98%, 96%, respectively which had the highest sensitivity and specificity followed by the serum SOD then the serum LDH and lastly the blood PH while in TTN cases, the serum MDA Cut off, sensitivity and specificity were 0.74 mmol/L, 96%, 93%, respectively then the serum SOD then the serum LDH and lastly the blood PH. Serum MDA, SOD, LDH, and PH had a beneficial role as early predictors in differentiation between TTN and RDS in neonates.

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.

Point-of-care lung ultrasound in neonatology: classification into descriptive and functional applications

Lung ultrasound (LUS) is the latest amongst imaging techniques: it is a radiation-free, inexpensive, point-of-care tool that the clinician can use at the bedside. This review summarises the rapidly growing scientific evidence on LUS in neonatology, dividing it into descriptive and functional applications. We report the description of the main ultrasound features of neonatal respiratory disorders and functional applications of LUS aiming to help a clinical decision (such as surfactant administration, chest drainage etc). Amongst the functional applications, we propose SAFE (Sonographic Algorithm for liFe threatening Emergencies) as a standardised protocol for emergency functional LUS in critical neonates. SAFE has been funded by a specific grant issued by the European Society for Paediatric Research. Future potential development of LUS in neonatology might be linked to its quantitative evaluation: we also discuss available data and research directions using computer-aided diagnostic techniques. Finally, tools and opportunities to teach LUS and expand the research network are briefly presented.

Prospective investigation of serial ultrasound for transient tachypnea of the newborn

BACKGROUND

Transient tachypnea of the newborn (TTN), which is diagnosed using typical clinical course and radiographic findings, is the most common cause of respiratory distress in late-preterm and term neonates. Lung ultrasound (LUS) is increasingly used to identify TTN according to the distinct characteristics of the disease. However, few studies have reported the application of LUS to monitor the clinical evolution of TTN. Using serial LUS, this prospective study assessed and monitored TTN severity.

METHODS

From November 2018 to October 2019, neonates ≥34 weeks of gestation admitted to the newborn center of Chang Gung Memorial Hospital were enrolled. Neonates diagnosed with TTN and requiring respiratory support comprised the TTN group (n = 29), whereas those without respiratory disease served as the control group (n = 23). LUS was performed and scored in both groups within 4 h of admission and followed up at 24 and 48 h.

RESULTS

A total of 65 infants were screened for enrollment and 13 were excluded. Most of the enrollees in both groups exhibited a peak LUS score on the first day, which then gradually declined thereafter. In comparison with the control group, the LUS score of the TTN group was higher on day 1 and day 2, and it had a significantly greater decrease from day 1 to day 2. In the TTN group, LUS scores moderately correlated with respiratory severity scores.

CONCLUSION

We conducted a serial and quantitative LUS investigation in late-preterm and term infants with TTN. The LUS score mirrored the respiratory status relatively well, and it can help to monitor the clinical course of TTN, in the case of either resolution or deterioration.

Ventilator-associated pneumonia in neonates: the role of point of care lung ultrasound

No consensus exists regarding the definition of ventilator-associated pneumonia (VAP) in neonates and reliability of chest X-ray (CXR) is low. Lung ultrasound (LU) is a potential alternative diagnostic tool. The aim was to define characteristics of VAP in our patient population and propose a multiparameter score, incorporating LU, for VAP diagnosis. Between March 25, 2018, and May 25, 2019, infants with VAP were identified. Clinical, laboratory and microbiology data were collected. CXRs and LU scans were reviewed. A multiparameter VAP score, including LU, was calculated on Day 1 and Day 3 for infants with VAP and for a control group and compared with CXR. VAP incidence was 10.47 episodes/1000 ventilator days. LU and CXR were available for 31 episodes in 21 infants with VAP, and for six episodes in five patients without VAP. On Day 1, a VAP score of > 4, and on Day 3 a score of > 5 showed sensitivity of 0.94, and area under the curve of 0.91 and 0.97, respectively. AUC for clinical information only was 0.88 and for clinical and CXR 0.85.Conclusion: The multiparameter VAP score including LU could be useful in diagnosing VAP in neonates with underlying lung pathology. What is Known: • Ventilator associated pneumonia (VAP) is common in infants on the neonatal unit and is associated with increased use of antibiotics, prolonged ventilation and higher incidence of chronic lung disease. • Commonly used definitions of VAP are difficult to apply in neonates and interpretation of chest X-ray is challenging with poor inter-rater agreement in patients with underlying chronic lung disease. What is New: • The multiparameter VAP score combining clinical, microbiology and lung ultrasound (LU) data is predictive for VAP diagnosis in preterm infants with chronic lung disease. • LU findings of VAP in neonates showed high inter-rater agreement and included consolidated lung areas, dynamic bronchograms and pleural effusion.

Ultrasound for Endotracheal Tube Tip Position in Term and Preterm Infants

BACKGROUND AND OBJECTIVE

Placing an endotracheal tube (ETT) in neonates is challenging and currently requires timely radiographic confirmation of correct tip placement. The objective was to establish the reliability of ultrasound (US) for assessing ETT position in the neonatal intensive care unit (NICU), time needed to do so, and patients' tolerance.

METHODS

A prospective study on 71 newborns admitted to our NICU whose ETT placement was evaluated with US (ETT-echo) and confirmed on chest X-rays (CXR). Data were collected by 3 operators (2 neonatologists and a resident in pediatrics). The right pulmonary artery (RPA) was used as a landmark for US. The distance between the tip of the ETT and the upper margin of the RPA was measured using US and compared with the distance between the tube's tip and the carina on the CXR.

RESULTS

Seventy-one intubated newborns were included in the study (n = 34 < 1,000 g, n = 18 1,000-2,000 g, n = 19 > 2,000 g). Statistical analysis (Bland-Altman plot and Lin's concordance correlation coefficient) showed an excellent consistency between ETT positions identified on US and chest X-ray. The 2 measures (ETT-echo and CXR) were extremely concordant both in the whole sample and in the subgroups. Minimal changes in patients' vital signs were infrequently observed during US, confirming the tolerability of ETT-echo. The mean time to perform US was 3.2 min (range 1-13).

CONCLUSIONS

ETT-echo seems to be a rapid, tolerable, and highly reliable method worth further investigating for future routine use in neonatology with a view to reducing radiation exposure.

Lung ultrasound score and diuretics in preterm infants born before 32 weeks: A pilot study

OBJECTIVE

To describe if weekly determined lung ultrasound (LU) scores in preterm infants born before 32 weeks (PTB32W) change with diuretic therapy.

DESIGN

We included infants who received diuretics and compared LU scores according to their evolution on respiratory support (RS) before and after diuretics.

RESULTS

We included 18 PTB32W divided into two groups. Both groups were similar in terms of median gestational age: 26 weeks (interquartile range [IQR]: 25-28) in the responders' group and 27 weeks (IQR: 24-28) in the other. They differed, however, in the median number of days on invasive mechanical ventilation: 27 (IQR: 11-43) versus 76 (IQR: 35-117), p = .03; in addition to the number of infants with moderate-severe bronchopulmonary dysplasia: 3 (33%) versus 8 (89%), p = .025. The responders' group showed lower LU scores 2 days after diuretics, with a median LU score of 6 (IQR: 3-12) versus 14 (IQR: 12-17) in the nonresponders group, p = .03; 1 week after (3 [IQR: 0-10] versus 12 [12-12], p = .04); and 3 weeks after (5 [IQR: 3-6] versus 12 [10-15], p = .01). RS also decreased at the same time: 7 out of 9 (78%) were extubated in the responders' group, and 1 out of 9 (11%) in the nonresponders group, p = .02, and these differences remained throughout the entire follow-up.

CONCLUSIONS

There is a group of PTB32W patients whose LU score improves after diuretics. This change appears only in those patients that can be weaned off from RS, and at the same period of time as the administration of diuretics.

Pleural line thickness reference values for preterm and term newborns

BACKGROUND

In lung ultrasound (LUS), the pleural line is an artifact whose thickness depends on the underlying lung pathology. To date there are no published studies on normal values of pleural line thickness (PLT) in newborns.

OBJECTIVE

The aim of our study is to describe normal PLT values in term newborn (TN) and preterm newborn (PTN).

METHODS

We recruited eupneic TN and PTN, under 34 weeks of gestation, on their first 24 hours of life. Newborns presenting any respiratory distress since birth were excluded. LUS was performed in four areas: upper anterior, lower anterior, lateral and posterior. At each location, we measured PLT and values where compared. Intraobserver and interobserver agreement were assessed using the intraclass correlation coefficient (ICC), and the kappa coefficient.

RESULTS

We included 23 TN with a median birth weight of 3365 g (interquartile range [IQR] 3100-3575 g) and a median gestational age of 39 weeks (IQR, 38-40 weeks). In the PTN group, 23 patients were included with a median birth weight of 1350 g (IQR, 1150-1590 g) and a median gestational age of 31 weeks (IQR, 30-32 weeks). Median PLT values were less than 1 mm, and there were no significant differences between groups at any locations, with the exception of the left lower anterior field (0.79 mm [IQR, 0.72-0.89 mm] vs 0.68 mm [IQR, 0.62-0.72 mm]). Intraobserver agreement was high: consistency ICC 0.77 (95% confidence interval [CI], 0.32-0.92) and absolute ICC 0.78 (95% CI, 0.34-0.93). Interobserver agreement was high for the definition of thin pleural line as less than 1 mm.

CONCLUSIONS

TN and asymptomatic PTN have similar PLT values. Overall, PLT in healthy newborns should be less than 1 mm.

Introduction of point-of-care neonatal lung ultrasound in a developing country

Despite neonatal lung ultrasound (LU) being diffused worldwide, its introduction in limited-resource areas has not been formally investigated. We conceived a project to introduce it in a level 3 NICU of a developing country and verify if, after a short protocolized training, clinicians may efficaciously use LU. Inter-rater agreement between ultrasound trainees and trainers was analyzed within both the local test and the diffusion phases of the project. High inter-rater agreements were found between expert trainers and the two neonatologists who were trained in a skilled European center (Cohen's Kappa, 0.951; 95%CI, 0.882-0.999), as well as between the two and the second round of locally trained colleagues (Cohen's Kappa, 0.896; 95%CI, 0.797-0.996). Moreover, a high agreement was found between the clinical respiratory diagnosis (used as the "gold standard") and the LU diagnosis given by the first two trainees (intraclass correlation, 0.992; 95%CI, 0.987-0.996) and the locally trained physicians (intraclass correlation, 0.97; 95%CI, 0.95-0.98). A final survey demonstrated that the project was perceived as efficacious and that LU was going to be integrated into routine clinical practice.Conclusions: А short LU training provided sufficient proficiency and allowed the LU introduction in clinical practice in the neonatal intensive care unit in a developing country.What is Known:• Lung ultrasound is a promising technique for evaluating neonatal respiratory distress at least in high-income countries. Previous studies revealed high specificity and sensitivity in diagnosing specific neonatal disorders.• An important barrier to the more extensive use of lung ultrasound in neonatal critical care is a lack of efficient and suitable training solutions.What is New:• Descriptive LU performed by neonatologist in a developing country after a short formal training is feasible with good quality.• A short formal LU training program provided good proficiency and allowed a correct descriptive diagnosis in a neonatal unit in a developing country.

Lung ultrasound in the neonatal intensive care unit: Review of the literature and future perspectives

Lung ultrasound (LU) has been increasingly used as a point-of-care method in recent years. LU has numerous advantages compared to traditional imaging tools such as chest X-ray (radiography) (CXR): it is faster and portable, does not use ionizing radiation, is performed by the same physician who cares for the patient, and can be repeated to follow the progress of the disease and the response to treatment. There is a large body of evidence that LU has an excellent diagnostic effectiveness compared to CXR, not only in adults and children, but also in neonates. This review article describes how to perform LU, how to interpret findings, and how to use LU to diagnose and differentiate common neonatal pulmonary diseases. Strengths but also limits of the technique are highlighted. Finally, we describe the recent revolutionary role of LU. The development of scoring methods in neonates with respiratory distress syndrome allowed to quantify the severity of the disease and to assist the physician in the clinical management and follow-up.

Point-of-care ultrasound in the neonatal ICU

PURPOSE OF REVIEW

Point-of-care ultrasound (POCUS) is an emerging clinical tool in the neonatal intensive care unit (NICU). Recent literature describing the use of POCUS for various applications in the NICU has garnered increased interest among neonatologists.

RECENT FINDINGS

Diagnostic applications for POCUS in the NICU include the evaluation and serial monitoring of common pulmonary diseases, hemodynamic instability, patent ductus arteriosus (PDA), persistent pulmonary hypertension of the newborn (PPHN), necrotizing enterocolitis (NEC), and intraventricular hemorrhage (IVH), among others. Procedural applications include vascular access, endotracheal intubation, lumbar puncture, and fluid drainage.

SUMMARY

Experience with POCUS in the NICU is growing. Current evidence supports the use of POCUS for a number of diagnostic and procedural applications. As use of this tool increases, there is an urgent need to develop formal training requirements specific to neonatology, as well as evidence-based guidelines to standardize use across centers.

Tools to assess lung aeration in neonates with respiratory distress syndrome

AIM

Respiratory distress syndrome is a common condition among preterm neonates, and assessing lung aeration assists in diagnosing the disease and helping to guide and monitor treatment. We aimed to identify and analyse the tools available to assess lung aeration in neonates with respiratory distress syndrome.

METHODS

A systematic review and narrative synthesis of studies published between January 1, 2004, and August 26, 2019, were performed using the OVID Medline, PubMed, Embase and Scopus databases.

RESULTS

A total of 53 relevant papers were retrieved for the narrative synthesis. The main tools used to assess lung aeration were respiratory function monitoring, capnography, chest X-rays, lung ultrasound, electrical impedance tomography and respiratory inductive plethysmography. This paper discusses the evidence to support the use of these tools, including their advantages and disadvantages, and explores the future of lung aeration assessments within neonatal intensive care units.

CONCLUSION

There are currently several promising tools available to assess lung aeration in neonates with respiratory distress syndrome, but they all have their limitations. These tools need to be refined to facilitate convenient and accurate assessments of lung aeration in neonates with respiratory distress syndrome.

Pediatric lung ultrasound - pros and potentials

Lung ultrasound (US) cannot be considered a new diagnostic imaging technique anymore, with some articles dating back 50 years. The question that hovers over it recently is why it is still not widely accepted, like chest radiography. So, have we wasted a lot of time without using lung US, or are we wasting our time using lung US? The main goals of this article are to underline all the advantages, potentials and reasons to use lung US in everyday clinical practice, but also to address the main concerns linked to this imaging tool. From the standpoint of an experienced pediatric radiologist from a tertiary health care children's hospital who has been performing this examination for more than 10 years on a daily basis, this article also addresses the most common applications of lung US, such as detection of pneumonia and neonatal lung diseases.

Lung ultrasound in pediatric radiology - cons

In the 1990s, intensivists suggested a new type of sonography: lung ultrasound, based on artefacts that receive information even from physical acoustic phenomena not directly convertible into images of the human body. They compared the artefacts from the lung zones with no acoustic window with various computed tomography (CT) patterns. They used and still use US as a tool to evaluate patients bedside, i.e. monitoring of lung recruitment. They included Lung ultrasound in what was termed POCUS (Point-of-Care Ultrasound). Lung ultrasound has been progressively extended to paediatrics in general. The most appealing novelty has been the diagnosis of pneumothorax. Lung ultrasound was developed as a support tool for critical patients. Extrapolation with mass diffusion, in the absence of appropriate training, has led to misunderstandings and dangerous therapeutic diagnostic drifts.

International evidence-based guidelines on Point of Care Ultrasound (POCUS) for critically ill neonates and children issued by the POCUS Working Group of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC)

BACKGROUND

Point-of-care ultrasound (POCUS) is nowadays an essential tool in critical care. Its role seems more important in neonates and children where other monitoring techniques may be unavailable. POCUS Working Group of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC) aimed to provide evidence-based clinical guidelines for the use of POCUS in critically ill neonates and children.

METHODS

Creation of an international Euro-American panel of paediatric and neonatal intensivists expert in POCUS and systematic review of relevant literature. A literature search was performed, and the level of evidence was assessed according to a GRADE method. Recommendations were developed through discussions managed following a Quaker-based consensus technique and evaluating appropriateness using a modified blind RAND/UCLA voting method. AGREE statement was followed to prepare this document.

RESULTS

Panellists agreed on 39 out of 41 recommendations for the use of cardiac, lung, vascular, cerebral and abdominal POCUS in critically ill neonates and children. Recommendations were mostly (28 out of 39) based on moderate quality of evidence (B and C).

CONCLUSIONS

Evidence-based guidelines for the use of POCUS in critically ill neonates and children are now available. They will be useful to optimise the use of POCUS, training programs and further research, which are urgently needed given the weak quality of evidence available.

Neonatal lung ultrasonography score after surfactant in preterm infants: A prospective observational study

OBJECTIVE

To assess changes in neonatal lung ultrasonography score (nLUS) after surfactant administration in preterm infants with respiratory distress syndrome (RDS).

WORKING HYPOTHESIS

The reduction of nLUS score before (nLUSpre), 2 hours (nLUS2h), and 12 hours (nLUS12h) after surfactant administration to identify patients who will not need a second treatment.

STUDY DESIGN AND SETTING

Prospective observational study in the tertiary neonatal intensive care unit.

PATIENTS SELECTION

Forty-six preterm neonates with RDS of 32 weeks median gestational age (IQR 30-33) and mean birth weight of 1650 ± 715 g.

METHODOLOGY

Lung ultrasonography was performed before, 2 hours, and 12 hours after surfactant administration in preterm infants with RDS needing surfactant treatment. Resulting nLUS was analyzed.

RESULTS

The Wilcoxon signed-rank test demonstrated an nLUS lowering after 2 hours (P < .001) and 12 hours (P < .001) from surfactant administration. Sixteen newborns required surfactant retreatment with median gestational age of 32 weeks (IQR 29-33) and mean birth weight of 1519 ± 506 g.The receiver operating characteristic analysis for the nLUS2h yielded an area under the curve of 0.80 (95% confidence interval, 0.76-0.85; P < .001). A nLUS2h ≥7 showed a sensitivity of 94% and a specificity of 60% for needing a second treatment with surfactant.

CONCLUSIONS

In preterm infants with RDS requiring surfactant treatment, nLUS evaluated 2 hours after surfactant administration can be used to identify patients who will not need a second treatment.

Predictors and Outcomes of Early Intubation in Infants Born at 28-36 Weeks of Gestation Receiving Noninvasive Respiratory Support

OBJECTIVE

To identify predictors and outcomes of early intubation in preterm infants with respiratory distress, and predictors of need for brief respiratory support (≤1 day).

STUDY DESIGN

Secondary analysis of data from a randomized trial comparing nasal high-flow with continuous positive airway pressure as primary respiratory support in preterm infants born at 28-36 weeks of gestation. Intubation was assessed within 72 hours of randomization.

RESULTS

There were 564 included infants with a mean (SD) gestational age of 32.0 (2.2) weeks and birth weight 1744 (589) g; 76 infants (13.5%) received early intubation. On multivariable analysis, lower gestational age and higher pre-randomization fraction of inspired oxygen (FiO₂) predicted intubation. A test based on gestational age of <30 weeks and an FiO₂ of ≥0.30 produced a likelihood ratio of 9.1. Intubation was associated with prolonged duration of respiratory support and supplemental oxygen, with pneumothorax and nasal trauma, and in infants born at <32 weeks of gestational, with bronchopulmonary dysplasia and patent ductus arteriosus requiring treatment. Greater gestational age and lower FiO₂ predicted the need for ≤1 day of respiratory support. A test based on a gestational age of ≥34 weeks and an FiO₂ of 0.21 produced a likelihood ratio of 4.7.

CONCLUSIONS

In preterm infants 28-36 week of gestation receiving primary noninvasive respiratory support, lower gestational age, and higher FiO₂ predicted need for intubation within 72 hours. Intubation was associated with adverse respiratory outcomes. Greater gestational age and lower FiO₂ predicted need for ≤1 day of respiratory support. It may be reasonable to defer the use of respiratory support in more mature infants with low FiO₂ requirements. TRIAL REGISTRATION AUSTRALIAN NEW ZEALAND CLINICAL TRIALS REGISTRY: ACTRN12613000303741.