The Role of Lung Ultrasound as an Early Diagnostic Tool for Need of Surfactant Therapy in Preterm Infants with Respiratory Distress Syndrome

The role of chest X-ray in the diagnosis of neonatal respiratory distress syndrome: a systematic review concerning low-resource birth scenarios

BACKGROUND

Access to diagnostic tools like chest radiography (CXR) is challenging in resource-limited areas. Despite reduced reliance on CXR due to the need for quick clinical decisions, its usage remains prevalent in the approach to neonatal respiratory distress syndrome (NRDS).

OBJECTIVES

To assess CXR's role in diagnosing and grading NRDS severity compared to current clinical features and laboratory standards.

METHODS

A review of studies with NRDS diagnostic criteria was conducted across six databases (MEDLINE, EMBASE, BVS, Scopus-Elsevier, Web of Science, Cochrane) up to 3 March 2023. Independent reviewers selected studies, with discrepancies resolved by a senior reviewer. Data were organised into descriptive tables to highlight the use of CXR and clinical indicators of NRDS.

RESULTS

Out of 1,686 studies screened, 23 were selected, involving a total of 2,245 newborns. All selected studies used CXR to diagnose NRDS, and 21 (91%) applied it to assess disease severity. While seven reports (30%) indicated that CXR is irreplaceable by other diagnostic tools for NRDS diagnosis, 10 studies (43%) found that alternative methods surpassed CXR in several respects, such as severity assessment, monitoring progress, predicting the need for surfactant therapy, foreseeing Continuous Positive Airway Pressure failure, anticipating intubation requirements, and aiding in differential diagnosis.

CONCLUSION

CXR remains an important diagnostic tool for NRDS. Despite its continued use in scientific reports, the findings suggest that the study's outcomes may not fully reflect the current global clinical practices, especially in low-resource settings where the early NRDS approach remains a challenge for neonatal survival.Trial registration: PROSPERO number CRD42022336480.

Substantiating and Adopting Lung Ultrasound Scores to Predict Surfactant Need in Preterm Neonates with Respiratory Distress Syndrome within an Institution

OBJECTIVE

 Administering surfactant timely and appropriately is important to minimize lung injury but remains challenging in preterm neonates with respiratory distress syndrome. The published literature supports that lung ultrasound (LUS) score can predict surfactant need. Neonatal LUS scanning specification and parameter setting guidelines have been recently published for standardization. However, variations in scanning protocols and machine settings hinder its clinical implementation widely. This observational study aims to internally validate the suggested LUS protocol in a neonatal intensive care unit to establish a correlation between LUS scores and surfactant need as the first step of integrating LUS in the clinical practice.

STUDY DESIGN

 LUS was performed on 40 eligible preterm neonates within 3 hours after birth or before surfactant administration between May 2020 and March 2021. The neonates were between 27 and 32 weeks' gestational age, and all had respiratory distress. Neonates with known congenital anomalies were excluded. A high-frequency linear probe was used to obtain LUS images from six lung zones which were scored using a 0 to 3 system, yielding a maximum of 18 points. Treating physicians were blinded to the LUS score. Receiver operating characteristic analysis determined the optimal LUS score cut-off for predicting surfactant need.

RESULTS

 Fifteen of the 40 neonates (38%) required higher oxygen fraction and received surfactant. In our cohort, an LUS score ≥10 was identified as the optimal cut-off for predicting surfactant need, with a sensitivity of 80% and specificity of 84%. The area under the curve was 0.8 (p = 0.0003). LUS predicted surfactant need at a median of 3.5 hours earlier than traditional clinical decision (p < 0.0037).

CONCLUSION

 LUS is a helpful adjunct for predicting surfactant need in preterm neonates. This study describes an approach to implement the LUS protocol and score for clinical decision-making in the clinical practice.

KEY POINTS

· LUS is a helpful adjunct for predicting surfactant need in preterm neonates.. · Machine setting variation and probe selection may affect LUS image and score.. · LUS score should be validated at the local unit before clinical implementation..

Lung Ultrasound Score for Prediction of Surfactant Administration in Preterm Infants with Respiratory Failure

OBJECTIVE

We investigated the predictive value of a lung ultrasound score (LUS) for surfactant administration in a United States Level 4 Neonatal Intensive Care Unit.

STUDY DESIGN

Thirty infants born at <37 weeks gestational age with respiratory distress syndrome associated respiratory failure requiring continuous positive airway pressure were included. A LUS was obtained within six hours of life. Surfactant administration in the first five days of life was recorded. Receiver operating characteristic (ROC) analysis for LUS and surfactant administration was performed.

RESULTS

Median completed gestational age was 33 weeks (31-34 weeks interquartile range) and median birth weight was 2.0 kg (1.5-2.3 kg). LUS for predicting an initial surfactant dose had an area under the ROC curve of 0.97. A score > 9 provided 100% sensitivity and 91% specificity for predicting administration of an initial surfactant dose.

CONCLUSION

A LUS > 9 provided excellent sensitivity and specificity for predicting which infants will receive surfactant for associated respiratory failure.

Lung Ultrasound and Ultrasound Score: A Useful Tool in Neonatal Intensive Care Units for the Diagnosis and Therapeutic Management of Newborns With Respiratory Pathology

Pulmonary ultrasound has become a fundamental tool for the early detection and management of major neonatal lung diseases in neonatal intensive care units (NICUs). The advantages of this imaging investigation include its rapid execution and information acquisition, non-invasive nature, early diagnosis establishment, dynamic monitoring, and usefulness in therapeutic management. Regarding therapeutic management, the lung ultrasound (LUS) score is used as a basic tool for indicating surfactant administration. Performing and interpreting pulmonary ultrasounds requires an experienced clinician capable of recognizing anatomical structures, understanding the limitations of the technique, and correlating the obtained data with the patient's clinical picture. A series of diagnostic characteristics of pulmonary ultrasonography for neonatal lung pathologies have been described, making pulmonary ultrasound a useful tool in establishing differential diagnoses. This study evaluates the effectiveness of ultrasonography in determining the severity of lung pathologies in newborns and its impact on therapeutic decision-making, including surfactant administration and continuous positive airway pressure (CPAP) support. Newborns admitted to the NICU with various respiratory conditions underwent LUS scoring. The study analyzed the relationship between LUS scoring and the severity of conditions such as pneumonia, respiratory distress syndrome, meconium aspiration syndrome, transient tachypnea of the newborn, and pneumothorax. The correlation between LUS scoring, surfactant administration, and CPAP requirements was also examined.

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.

Advanced Diagnostics of Respiratory Distress Syndrome in Premature Infants Treated with Surfactant and Budesonide through Computer-Assisted Chest X-ray Analysis

This research addresses the respiratory distress syndrome (RDS) in preterm newborns caused by insufficient surfactant synthesis, which can lead to serious complications, including pneumothorax, pulmonary hypertension, and pulmonary hemorrhage, increasing the risk of a fatal outcome. By analyzing chest radiographs and blood gases, we specifically focus on the significant contributions of these parameters to the diagnosis and analysis of the recovery of patients with RDS. The study involved 32 preterm newborns, and the analysis of gas parameters before and after the administration of surfactants and inhalation corticosteroid therapy revealed statistically significant changes in values of parameters such as FiO2, pH, pCO2, HCO3, and BE (Sig. < 0.05), while the pO2 parameter showed a potential change (Sig. = 0.061). Parallel to this, the research emphasizes the development of a lung segmentation algorithm implemented in the MATLAB programming environment. The key steps of the algorithm include preprocessing, segmentation, and visualization for a more detailed understanding of the recovery dynamics after RDS. These algorithms have achieved promising results, with a global accuracy of 0.93 ± 0.06, precision of 0.81 ± 0.16, and an F-score of 0.82 ± 0.14. These results highlight the potential application of algorithms in the analysis and monitoring of recovery in newborns with RDS, also underscoring the need for further development of software solutions in medicine, particularly in neonatology, to enhance the diagnosis and treatment of preterm newborns with respiratory distress syndrome.

Surfactant therapy guided by tests for lung maturity in preterm infants at risk of respiratory distress syndrome

BACKGROUND

Administration of various exogenous surfactant preparations has been shown to decrease lung injury and pneumothorax and improve survival in very preterm infants with respiratory distress syndrome (RDS). There is no consensus on the threshold for surfactant administration, to allow timely intervention and avoid over-treatment, also considering the invasiveness of the procedure and its cost. Rapid tests for lung maturity, which include the click test, lamellar body counts and stable microbubble test, might guide the identification of those infants needing surfactant administration.

OBJECTIVES

To assess the effects of surfactant treatment guided by rapid tests for surfactant deficiency in preterm infants at risk for or having RDS. Comparison 1: In preterm infants at risk for RDS, does surfactant treatment guided by rapid tests for surfactant deficiency compared to prophylactic surfactant administration to all high-risk infants minimize the need for surfactant treatment and prevent bronchopulmonary dysplasia and mortality? Comparison 2: In preterm infants who require early respiratory support, does surfactant treatment guided by rapid tests for surfactant deficiency compared to surfactant therapy provided to infants with RDS diagnosed on clinical and radiologic criteria minimize the need for surfactant treatment and prevent bronchopulmonary dysplasia and mortality?

SEARCH METHODS

We searched in October 2022 CENTRAL, PubMed, Embase and three additional trial registries. We also screened the reference lists of included studies and related systematic reviews for studies not identified by the database searches.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs evaluating rapid tests after birth for surfactant deficiency in infants at high risk of RDS or requiring respiratory support. We specified two comparisons: 1)surfactant treatment guided by rapid tests for surfactant deficiency versus prophylactic surfactant administration to all high-risk infants in extremely preterm (less than 28 weeks' gestation) and very preterm (28 to 32 weeks' gestation); 2)surfactant treatment guided by rapid tests for surfactant deficiency versus surfactant therapy provided to preterm infants (less than 37 weeks' gestation) with RDS diagnosed on clinical and radiologic criteria.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. We used the fixed-effect model with risk ratio (RR) and risk difference (RD), with their 95% confidence intervals (CIs) for dichotomous data. Our primary outcomes were: neonatal mortality, mortality prior to hospital discharge, bronchopulmonary dysplasia and the composite outcome bronchopulmonary dysplasia or mortality. We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included three RCTs enrolling 562 newborn infants in this review. No studies compared surfactant treatment guided by rapid tests for surfactant deficiency versus prophylactic surfactant administration to all high-risk infants. Comparing surfactant therapy guided by rapid tests for surfactant deficiency versus surfactant therapy provided to infants with RDS diagnosed on clinical and radiologic criteria. No studies reported neonatal mortality. Compared with surfactant therapy provided to infants with RDS diagnosed on clinical and radiologic criteria, the evidence is very uncertain about the effect of surfactant treatment guided by rapid tests for surfactant deficiency on mortality prior to hospital discharge: RR 1.25, 95% CI 0.65 to 2.41, RD 0.01, 95% CI -0.03 to 0.05, 562 participants, 3 studies; I² for RR and RD = 75% and 43%, respectively; very low-certainty evidence. Surfactant treatment guided by rapid tests for surfactant deficiency may result in little to no difference in bronchopulmonary dysplasia: RR 0.90, 95% CI 0.61 to 1.32, RD -0.02, 95% CI -0.08 to 0.04, 562 participants, 3 studies; I² for RR and RD = 0%; low-certainty evidence. No studies reported the composite outcome bronchopulmonary dysplasia or mortality. Surfactant treatment guided by rapid tests for surfactant deficiency may result in little to no difference in surfactant utilization (RR 0.97, 95% CI 0.85 to 1.11, RD -0.02, 95% CI -0.10 to 0.06, 562 participants, 3 studies, I² for RR and RD = 63% and 65%, respectively, low-certainty evidence), and any pneumothorax (RR 0.53, 95% CI 0.15 to 1.92, RD -0.01, 95% CI -0.04 to 0.01, 506 participants, 2 studies, I² for RR and RD = 0%, low-certainty evidence) compared with surfactant therapy provided to infants with RDS diagnosed on clinical and radiologic criteria. No studies reported moderate to severe neurodevelopmental impairment. We identified two large ongoing RCTs.

AUTHORS' CONCLUSIONS

No studies compared surfactant treatment guided by rapid tests for surfactant deficiency to prophylactic surfactant administration to all high-risk infants. Low to very low-certainty evidence from three studies is available on surfactant therapy guided by rapid tests for surfactant deficiency versus surfactant therapy provided to infants with RDS diagnosed on clinical and radiologic criteria. No studies reported neonatal mortality, the composite outcome 'bronchopulmonary dysplasia or mortality', or neurodevelopmental outcomes. Compared with surfactant therapy provided to infants with RDS diagnosed on clinical and radiologic criteria, the evidence is very uncertain about the effect of surfactant treatment guided by rapid tests for surfactant deficiency on mortality prior to hospital discharge. Surfactant treatment guided by rapid tests for surfactant deficiency may result in little to no difference in bronchopulmonary dysplasia, surfactant utilization and any pneumothorax. The findings of the two large ongoing trials identified in this review are likely to have an important impact on establishing the effects of surfactant treatment guided by rapid tests for surfactant deficiency in preterm infants.

Bile Acids Pneumonia: A Respiratory Distress Syndrome in Early-Term Neonates

Intrahepatic cholestasis of pregnancy (ICP) complicates among 0.2-2% of pregnancies and has been associated with adverse perinatal outcomes, including sudden stillbirth, meconium strained fluid, preterm birth, perinatal asphyxia, and transient tachypnea of the newborn. The diagnosis of "bile acids pneumonia" was previously proposed and a causative role of bile acids (BA) was supposed with a possible mechanism of action including surfactant dysfunction, inflammation, and chemical pneumonia. In the last few years, the role of lung ultrasound (LUS) in the diagnosis and management of neonatal respiratory distress syndrome has grown, and LUS scores have been introduced in the literature, as an effective predictor of the need for surfactant treatment among neonates with respiratory distress syndrome. We present four cases of infants born from pregnancies complicated by ICP, who developed respiratory distress syndrome early after birth. Lung ultrasound showed the same pattern for all infants, corresponding to a homogeneous alveolar-interstitial syndrome characterized by a diffuse coalescing B-line pattern (white lung). All infants evaluated require non-invasive respiratory support and in three cases surfactant administration, despite the near-term gestational age, with rapid improvement of respiratory disease and a good clinical outcome.

RDS-NExT workshop: consensus statements for the use of surfactant in preterm neonates with RDS

OBJECTIVE

To provide the best clinical practice guidance for surfactant use in preterm neonates with respiratory distress syndrome (RDS). The RDS-Neonatal Expert Taskforce (RDS-NExT) initiative was intended to add to existing evidence and clinical guidelines, where evidence is lacking, with input from an expert panel.

STUDY DESIGN

An expert panel of healthcare providers specializing in neonatal intensive care was convened and administered a survey questionnaire, followed by 3 virtual workshops. A modified Delphi method was used to obtain consensus around topics in surfactant use in neonatal RDS.

RESULT

Statements focused on establishing RDS diagnosis and indicators for surfactant administration, surfactant administration methods and techniques, and other considerations. After discussion and voting, consensus was achieved on 20 statements.

CONCLUSION

These consensus statements provide practical guidance for surfactant administration in preterm neonates with RDS, with a goal to contribute to improving the care of neonates and providing a stimulus for further investigation to bridge existing knowledge gaps.

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.

Prevention of Chronic Morbidities in Extremely Premature Newborns with LISA-nCPAP Respiratory Therapy and Adjuvant Perinatal Strategies

Less invasive surfactant administration techniques, together with nasal continuous airway pressure (LISA-nCPAP) ventilation, an emerging noninvasive ventilation (NIV) technique in neonatology, are gaining more significance, even in extremely premature newborns (ELBW), under 27 weeks of gestational age. In this review, studies on LISA-nCPAP are compiled with an emphasis on short- and long-term morbidities associated with prematurity. Several perinatal preventative and therapeutic investigations are also discussed in order to start integrated therapies as numerous organ-saving techniques in addition to lung-protective ventilations. Two thirds of immature newborns can start their lives on NIV, and one third of them never need mechanical ventilation. With adjuvant intervention, these ratios are expected to be increased, resulting in better outcomes. Optimized cardiopulmonary transition, especially physiologic cord clamping, could have an additively beneficial effect on patient outcomes gained from NIV. Organ development and angiogenesis are strictly linked not only in the immature lung and retina, but also possibly in the kidney, and optimized interventions using angiogenic growth factors could lead to better morbidity-free survival. Corticosteroids, caffeine, insulin, thyroid hormones, antioxidants, N-acetylcysteine, and, moreover, the immunomodulatory components of mother's milk are also discussed as adjuvant treatments, since immature newborns deserve more complex neonatal interventions.

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.

Neonatal cardiorespiratory imaging-a multimodality state-of-the-art review

Advanced cardiorespiratory imaging of the chest with ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) plays an important role in diagnosing respiratory and cardiac conditions in neonates when radiography and echocardiography alone are not sufficient. This pictorial essay highlights the particularities, clinical indications and technical aspects of applying chest US, cardiac CT and cardiorespiratory MRI techniques specifically to neonates, summarising the first session of the European Society of Paediatric Radiology's cardiothoracic task force.

Prediction of respiratory distress severity and bronchopulmonary dysplasia by lung ultrasounds and transthoracic electrical bioimpedance

This study aims to evaluate whether the assessment of a lung ultrasound score (LUS) by lung ultrasonography and of thoracic fluid contents (TFC) by electrical cardiometry may predict RDS severity and the development of bronchopulmonary dysplasia (BPD) in preterm infants with respiratory distress (RDS). Infants ≤ 34 weeks' gestation admitted with RDS to two neonatal intensive care units were prospectively enrolled in this observational study. A simultaneous evaluation of LUS and TFC was performed during the first 72 h. The predictivity of LUS and TFC towards mechanical ventilation (MV) need after 24 h and BPD development was evaluated using receiver operating characteristic analysis. Sixty-four infants were included. The area under the curve (AUC) for the prediction of MV need was 0.851 (95%CI, 0.776-0.925, p < 0.001) for LUS and 0.793 (95%CI, 0.724-0.862, p < 0.001) for TFC, while an AUC of 0.876 (95%CI, 0.807-0.946, p < 0.001) was obtained for combined LUS and TFC evaluation. LUS and TFC AUC for BPD prediction were 0.769 (95%CI, 0.697-0.842, p < 0.001) and 0.836 (95%CI, 0.778-0.894, p < 0.001), respectively, whereas their combined assessment yielded an AUC of 0.867 (95%CI, 0.814-0.919, p < 0.001). LUS ≥ 11 and TFC ≥ 40 were identified as cut-off values for MV need prediction, whereas LUS ≥ 9 and TFC ≥ 41.4 best predicted BPD development.   Conclusion: A combined evaluation of LUS and TFC by lung ultrasonography and EC during the first 72 h may represent a useful predictive tool towards short- and medium-term pulmonary outcomes in preterm infants with RDS. What is Known: • Lung ultrasonography is largely used in neonatal intensive care and can contribute to RDS diagnosis in preterm infants. • Little is known on the diagnostic and predictive role of TFC, measured by transthoracic electrical bioimpedance, in neonatal RDS. What is New: • Combining lung ultrasonography and TFC evaluation during the first 72 h can improve the prediction of RDS severity and BPD development in preterm infants with RDS and may aid to establish tailored respiratory approaches to improve these outcomes.

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

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

Surfactant Replacement Therapy: What’s the New Future?

Surfactant replacement therapy (SRT) can be lifesaving for preterm babies with respiratory distress because of surfactant deficiency. Attempts have been made over the last two decades to make surfactant administration as smooth and as nontraumatic as possible. Lesser invasive techniques, such as less invasive surfactant administration, minimally invasive surfactant therapy, intrapartum pharyngeal surfactant therapy, and the laryngeal mask airway, are preferred over invasive techniques like intubate surfactant extubation to reduce trauma and peridosing adverse effects. However, at present, aerosolized surfactant (AS) via nebulization remains the only truly noninvasive method of SRT. Many animal and human studies have shown promising results with the use of AS with similar clinical effects to an instilled surfactant with greater safety potential. But still AS has not been adapted to routine neonatal care. There is still scope for studies to further strengthen the role of AS. Also, SRT is a constantly changing field with new innovations revolutionizing and replacing old techniques.

Lung Ultrasound for Predicting the Respiratory Outcome in Patients with Bronchopulmonary Dysplasia

OBJECTIVE

This study aimed to investigate the utility of lung ultrasound (LUS) with whole chest scanning for predicting respiratory outcomes in patients with bronchopulmonary dysplasia (BPD).

STUDY DESIGN

We performed a prospective observational study. Preterm infants of less than 32 weeks' gestational age requiring oxygen therapy at 28 days of life were included. LUS was performed on day 28, at 36 weeks' postmenstrual age, and at the time of discharge. Each lung was divided into three regions by the anterior and posterior axillary lines and received an LUS score of 0 to 3 points; the total score was obtained by adding the six regional scores. The classification of BPD was determined based on the National Institute of Child and Human Development. The outcomes of this study were the development of moderate-to-severe BPD and the need for home oxygen therapy (HOT).

RESULTS

We enrolled 87 patients; 39, 33, and 15 infants had mild, moderate, and severe BPD, respectively. The LUS score correlated with BPD severity and exhibited an improvement trend with time toward the point of discharge. LUS at 28 days of life predicted moderate-to-severe BPD with an area under the curve of 0.95 (95% confidence interval: 0.91-0.99) and HOT with an area under the curve of 0.95 (95% confidence interval: 0.81-1.0).

CONCLUSION

LUS with whole chest scanning is useful for predicting respiratory outcomes in patients with BPD, as well as for understanding BPD severity or clinical improvement trends.

KEY POINTS

· LUS predicts respiratory outcomes in patients with BPD.. · LUS indicates BPD severity.. · LUS can show clinical improvement with time..

Lung ultrasound scores in neonatal clinical practice: A narrative review of the literature

Lung ultrasound (LU) has in recent years increasingly been used as a point-of-care method. Initially, LU was used as a so-called descriptive diagnostic method for neonatal respiratory diseases. Instead, this review article focuses on the use of LU as a "functional" tool using classification of findings in patterns or using semiquantitative scores. We review and describe the evidence that led to the implementation of LU in predicting the need for surfactant replacement therapy in preterm infants and in the identification of newborns at risk of developing bronchopulmonary dysplasia. LU appears to be a very promising method for the future of clinical management of newborns in both acute and chronic phases of pulmonary pathologies related to prematurity. However, further studies are needed to define its role before full implementation.

The Value of Lung Ultrasound Score in Neonatology

Point-of-care lung ultrasound (LUS) is increasingly applied in the neonatal intensive care unit (NICU). Diagnostic applications for LUS in the NICU contain the diagnosis of many common neonatal pulmonary diseases (such as Respiratory distress syndrome, Transient tachypnea of the newborn, Meconium aspiration syndrome, Pneumonia, Pneumothorax, and Pleural effusion) which have been validated. In addition to being employed as a diagnostic tool in the classical sense of the term, recent studies have shown that the number and type of artifacts are associated with lung aeration. Based on this theory, over the last few years, LUS has also been used as a semi-quantitative method or as a "functional" tool. Scores have been proposed to monitor the progress of neonatal lung diseases and to decide whether or not to perform a specific treatment. The semi-quantitative LUS scores (LUSs) have been developed to predict the demand for surfactant therapy, the need of respiratory support and the progress of bronchopulmonary dysplasia. Given their ease of use, accuracy and lack of invasiveness, the use of LUSs is increasing in clinical practice. Therefore, this manuscript will review the application of LUSs in neonatal lung diseases.

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).

Gravity-induced loss of aeration and atelectasis development in the preterm lung: a serial sonographic assessment

OBJECTIVE

To assess the impact of gravity and time on the changes in the distribution patterns of loss of aeration and atelectasis development in very preterm infants.

STUDY DESIGN

Preterm infants less than 32 weeks gestation were included in this prospective, observational study. Infants were assessed via serial lung ultrasound (LUS) score in four lung zones, performed on days 7, 14, 21, and 28 after birth.

RESULT

Eighty-eight patients were enrolled. There was a significant main effect of gravity (P < 0.001) and time (P = 0.01) on the LUS score between gravity-dependent lungs and non-dependent lungs. Moreover, there was a significant main effect of gravity (P = 0.003) on atelectasis development between the lungs.

CONCLUSION

Gravity and time have an impact on the changes in the distribution patterns of gravity-induced lung injuries in preterm infants.

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.

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.

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.

Personalized Medicine for the Management of RDS in Preterm Neonates

Continuous positive airway pressure and surfactant represent the first- and second-line treatment for respiratory distress syndrome in preterm neonates, as European and American guidelines, since 2013 and 2014, respectively, started to recommend surfactant replacement only when continuous positive airway pressure fails. These recommendations, however, are not personalized to the individual physiopathology. Simple clinical algorithms may have improved the diffusion of neonatal care, but complex medical issues can hardly be addressed with simple solutions. The treatment of respiratory distress syndrome is a complex matter and can be only optimized with personalization. We performed a review of tools to individualize the management of respiratory distress syndrome based on physiopathology and actual patients' need, according to precision medicine principles. Advanced oxygenation metrics, lung ultrasound, electrical impedance tomography, and both quantitative and qualitative surfactant assays were examined. When these techniques were investigated with diagnostic accuracy studies, reliability measures have been meta-analysed. Amongst all these tools, quantitative lung ultrasound seems the more developed for the widespread use and has a higher diagnostic accuracy (meta-analytical AUC = 0.952 [95% CI: 0.951-0.953]). Surfactant adsorption (AUC = 0.840 [95% CI: 0.824-0.856]) and stable microbubble test (AUC = 0.800 [95% CI: 0.788-0.812]) also have good reliability, but need further industrial development. We advocate for a more accurate characterization and a personalized approach of respiratory distress syndrome. With the above-described currently available tools, it should be possible to personalize the treatment of respiratory distress syndrome according to physiopathol-ogy.

Roles of Lung Ultrasound Score in the Extubation Failure From Mechanical Ventilation Among Premature Infants With Neonatal Respiratory Distress Syndrome

Objective: To investigate the predictive value of lung ultrasound score (LUS) in the extubation failure from mechanical ventilation (MV) among premature infants with neonatal respiratory distress syndrome (RDS). Methods: The retrospective cohort study was conducted with a total of 314 RDS newborns who received MV support for over 24 h. After extubation from MV, infants were divided into extubation success and extubation failure groups. Extubation failure was defined as re-intubation within 48 h after extubation. Univariate and multivariate logistic regression analyses were used to identify the predictors of the extubation failure. The predictive effectiveness of the combined model and LUS in the extubation failure was assessed by receiver operating characteristic curve, area under curve (AUC), and internal validation. Results: 106 infants failed extubation from MV. The combined model for predicting the extubation failure was performed according to the predictors of gestational age, body length, birth weight, and LUS. The AUC of this combined model was 0.871 (sensitivity: 86.67%, specificity: 74.31%). The AUC of LUS was 0.858 (sensitivity: 84.00%, specificity: 80.69%), and the cutoff value was 18. There was no statistical difference in the predictive power between the combined model and LUS (Z = 0.880, P = 0.379). The internal validation result showed that the AUC of LUS was 0.855. Conclusions: LUS presented a good ability in predicting the extubation failure among RDS newborns after MV.