Lung ultrasound for early surfactant treatment: Development and validation of a predictive model

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.

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.

Predictors of CPAP failure after less-invasive surfactant administration in preterm infants

Introduction

Less-invasive surfactant administration (LISA) is associated with better respiratory outcomes in preterm infants with respiratory distress syndrome. However, mechanical ventilation (MV) shortly after the LISA procedure has been related to lower survival. This study aimed to analyze the trends and main predictors of continuous positive airway pressure (CPAP) failure after LISA.

Material and methods

Preterm infants born between 230 and 336 weeks gestational age (GA) in two level III neonatal units who received surfactant were included (2017-2022). Demographic data, lung ultrasound (LUS) scores, the saturation/fraction of inspired oxygen (SF) ratio, technique, time to surfactant administration, and the main neonatal outcomes were collected.

Results

Over the study period, 289 inborn preterm infants received surfactant, 174 with the LISA method (60.2%). Patients who received surfactant after intubation in the delivery room (n = 56) were more immature and exhibited worse outcomes. Patients who received surfactant via an endotracheal tube in the neonatal intensive care unit (n = 59) had higher LUS scores and a lower SF ratio than those treated with LISA. The LISA method was associated with less death or bronchopulmonary dysplasia (BPD), with an adjusted odds ratio (aOR) = 0.37 [95% confidence interval (CI), 0.18-0.74, p = 0.006]. CPAP failure after LISA (defined as the need for intubation and MV in the first 72 h of life) occurred in 38 patients (21.8%), inversely proportional to GA (38.7% at 23-26 weeks, 26.3% at 27-30 weeks, and 7.9% at 30-33 weeks (p < 0.001). CPAP failure after LISA was significantly related to death, with an aOR = 12.0 (95% CI, 3.0-47.8, p < 0.001), and moderate to severe BPD, with an aOR = 2.9 (95% CI, 1.1-8.0, p = 0.035), when adjusting for GA. The best predictors of CPAP failure after LISA were GA, intrauterine growth restriction, temperature at admission, the SF ratio, and the LUS score, with a Nagelkerke's R 2 = 0.458 (p < 0.001). The predictive model showed an area under the curve = 0.84 (95% CI, 0.75-0.93, p < 0.001).

Conclusions

CPAP failure after LISA is still common in extremely preterm infants, leading to an increase in death or disability. Clinicians must acknowledge the main risk factors of CPAP failure to choose wisely the right patient and the best technique. LUS and the SF ratio at admission can be useful when making these decisions.

Lung ultrasound for the sick child: less harm and more information than a radiograph

In the realm of emergency medicine, the swift adoption of lung ultrasound (LU) has extended from the adult population to encompass pediatric and neonatal intensivists. LU stands out as a bedside, replicable, and cost-effective modality, distinct in its avoidance of ionizing radiations, a departure from conventional chest radiography. Recent years have witnessed a seamless adaptation of experiences gained in the adult setting to the neonatal and pediatric contexts, underscoring the versatility of bedside Point of care ultrasound (POCUS). This adaptability has proven reliable in diagnosing common pathologies and executing therapeutic interventions, including chest drainage, and central and peripheral vascular cannulation. The surge in POCUS utilization among neonatologists and pediatric intensivists is notable, spanning economically advanced Western nations with sophisticated, high-cost intensive care facilities and extending to low-income countries. Within the neonatal and pediatric population, POCUS has become integral for diagnosing and monitoring respiratory infections and chronic and acute lung pathologies. This, in turn, contributes to a reduction in radiation exposure during critical periods of growth, thereby mitigating oncological risks. Collaboration among various national and international societies has led to the formulation of guidelines addressing both the clinical application and regulatory aspects of operator training. Nevertheless, unified guidelines specific to the pediatric and neonatal population remain lacking, in contrast to the well-established protocols for adults. The initial application of POCUS in neonatal and pediatric settings centered on goal-directed echocardiography. Pivotal developments include expert statements in 2011, the UK consensus statement on echocardiography by neonatologists, and European training recommendations. The Australian Clinician Performed Ultrasound (CPU) program has played a crucial role, providing a robust academic curriculum tailored for training neonatologists in cerebral and cardiac assessment. Notably, the European Society for Paediatric and Neonatal Intensive Care (ESPNIC) recently disseminated evidence-based guidelines through an international panel, delineating the use and applications of POCUS in the pediatric setting. These guidelines are pertinent to any professional tending to critically ill children in routine or emergency scenarios. In light of the burgeoning literature, this paper will succinctly elucidate the methodology of performing an LU scan and underscore its primary indications in the neonatal and pediatric patient cohort. The focal points of this review comprise as follows: (1) methodology for conducting a lung ultrasound scan, (2) key ultrasonographic features characterizing a healthy lung, and (3) the functional approach: Lung Ultrasound Score in the child and the neonate.  Conclusion: the aim of this review is to discuss the following key points: 1. How to perform a lung ultrasound scan 2. Main ultrasonographic features of the healthy lung 3. The functional approach: Lung Ultrasound Score in the child and the neonate What is Known: • Lung Ultrasound (LUS) is applied in pediatric and neonatal age for the diagnosis of pneumothorax, consolidation, and pleural effusion. • Recently, LUS has been introduced into clinical practice as a bedside diagnostic method for monitoring surfactant use in NARDS and lung recruitment in PARDS. What is New: • Lung Ultrasound (LUS) has proven to be useful in confirming diagnoses of pneumothorax, consolidation, and pleural effusion. • Furthermore, it has demonstrated effectiveness in monitoring the response to surfactant therapy in neonates, in staging the severity of bronchiolitis, and in PARDS.

A Retrospective Analysis of Ultrasonic Diagnosis of Neonatal Respiratory Distress Syndrome

ABSTRACT

The aim of the study was to investigate ultrasound's diagnostic capabilities for infant respiratory distress syndrome. Retrospective analysis was performed on the clinical information of 96 newborns with respiratory distress syndrome who were treated at our hospital between July 2015 and October 2017. The patients were split into the mild group (n = 55) and the severe group based on the findings of the chest x-ray examinations (n = 41). All neonates underwent an ultrasound examination at baseline, 12 hours after treatment and 24 hours after treatment of pulmonary surfactant (PS). Between the 2 groups, ultrasonographic characteristics and imaging scores were compared between infants with and without PS treatment. When compared with the severe group, the ultrasound score in the mild group was lower ( P < 0.05). Before treatment, there was no statistically significant difference in ultrasound score between the PS treatment group and the non-PS treatment group ( P > 0.05). At each time point after treatment, the ultrasonography score of the non-PS treatment group was greater than that of the PS treatment group ( P < 0.05). Neonatal respiratory distress syndrome severity may be accurately assessed using ultrasound technology. Furthermore, the results of ultrasonography examinations may serve as a significant marker for assessing and measuring the severity of newborn respiratory distress syndrome.

Surfactant status assessment and personalized therapy for surfactant deficiency or dysfunction

Surfactant is a pivotal neonatal drug used both for respiratory distress syndrome due to surfactant deficiency and for more complex surfactant dysfunctions (such as in case of neonatal acute respiratory distress syndrome). Despite its importance, indications for surfactant therapy are often based on oversimplified criteria. Lung biology and modern monitoring provide several diagnostic tools to assess the patient surfactant status and they can be used for a personalized surfactant therapy. This is desirable to improve the efficacy of surfactant treatment and reduce associated costs and side effects. In this review we will discuss these diagnostic tools from a pathophysiological and multi-disciplinary perspective, focusing on the quantitative or qualitative surfactant assays, lung mechanics or aeration measurements, and gas exchange metrics. Their biological and technical characteristics are described with practical information for clinicians. Finally, available evidence-based data are reviewed, and the diagnostic accuracy of the different tools is compared. Lung ultrasound seems the most suitable tool for assessing the surfactant status, while some other promising tests require further research and/or development.

External Validation of a Multivariate Model for Targeted Surfactant Replacement

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

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.

Accuracy of lung and diaphragm ultrasound in predicting successful extubation in extremely preterm infants: A prospective observational study

OBJECTIVE

Chest ultrasound has emerged as a promising tool in predicting extubation readiness in adults and children, yet its utility in preterm infants is lacking. Our aim was to assess the utility of lung ultrasound severity score (LUSS) and diaphragmatic function in predicting extubation readiness in extremely preterm infants.

STUDY DESIGN

In this prospective cohort study, preterm infants < 28 weeks gestational age (GA) who received invasive mechanical ventilation for ≥12 h were enrolled. Chest ultrasound was performed before extubation. The primary outcome was lung ultrasound accuracy for predicting successful extubation at 3 days. Descriptive statistics and logistic regression were done using SPSS version 22.

RESULTS

We enrolled 45 infants, of whom 36 (80%) were successfully extubated. GA and postmenstrual age (PMA) at extubation were significantly higher in the successful group. The LUSS was significantly lower in the successful group compared to failed group (11.9 ± 3.2 vs. 19.1 ± 3.1 p < 0.001). The two groups had no statistically significant difference in diaphragmatic excursion or diaphragmatic thickness fraction. Logistic regression analysis controlling for GA and PMA at extubation showed LUSS was an independent predictor for successful extubation (odd ratio 0.46, 95% confidence interval [0.23-0.9], p = 0.02). The area under the receiver operating characteristic curve was 0.95 (p ˂ 0.001) for LUSS, and a cut-off value of ≥15 had 95% sensitivity and 85% specificity in detecting extubation failure.

CONCLUSION

In extremely preterm infants, lung ultrasound has good accuracy for predicting successful extubation. However, diaphragmatic measurements were not reliable predictors.

Lung ultrasound to evaluate lung recruitment in neonates with respiratory distress (RELUS study)

BACKGROUND

Lung ultrasound (LUS) is a bedside tool useful to diagnose neonatal respiratory disease and to guide surfactant therapy. LUS scores have emerged as useful tool for newborn respiratory distress but is unknown if respiratory support settings may influence it. The aim of the study was to evaluate the feasibility of LUS scores evaluating lung recruitment in term newborns with respiratory distress when noninvasive respiratory it is increased.

MATERIAL AND METHODS

Prospective study in a tertiary neonatal intensive care unit. Inclusion criteria were term neonates with respiratory distress requiring noninvasive respiratory support with nasal continuous positive airway pressure (nCPAP) within first 6 h of life with an LUS score higher than 8 were enrolled. LUS was performed three times. First LUS (LUS-1) was done in patients in nCPAP (Fabian Device) (Acutronic) (pressure of 6 cmH₂ O). Afterwards patients were placed in duo positive airway pressure (12/6 cmH₂ O), a second LUS (LUS-2) was performed immediately and a third (LUS-3) was done 2 h later on the same respiratory support. The primary outcome was to compare LUS scores in the different timelines. Second outcomes were to evaluate the level of respiratory distress and oxygenation were evaluated with SpO₂ /fraction of inspired oxygen (FiO₂ ) ratio (S/F ratio), FiO₂  ratio, respiratory rate, and blood gas analysis which were analyzed during the LUS-1 and the LUS-3. To evaluate newborn discomfort, patients were evaluated with Crying Requires oxygen Increased vital signs Expression Sleep (CRIES) scale.

RESULTS

Forty neonates were enrolled. Fifty percent were female (n = 20), median gestational age was 38 + 4 (interquartile range [IQR]: 37 + 5-39 + 4) with a median weight of 3155 g (IQR: 2637-3532). Duration of non invasive ventilation support was 72 h (IQR: 54-96). None of the patients required surfactant therapy or mechanical ventilation. LUS scores were no different between LUS-1 9 (IQR: 8.3-10) and LUS-2 9 (IQR: 8.3-10) (p = 0.675) but there were differences between LUS-1 and LUS-3 7 (IQR: 6.3-8.5) (p = 0.036). There was an improvement in the oxygen parameters, respiratory rate, and CO₂ between LUS-1 and LUS-3 (p < 0.001). There were no changes in the CRIES scale.

CONCLUSIONS

There is an improvement in clinical and laboratory parameters after the increasing of respiratory support in newborns with noninvasive ventilation. We observe a correlation with an improvement in the assessment of lung aeration were evaluated with LUS score.

Lung Ultrasound for the Diagnosis and Management of Neonatal Respiratory Distress Syndrome: A Minireview

Lung ultrasound (LUS) is useful for diagnosis of respiratory distress syndrome in neonates. Recently, it has been proved to play an important role in the management of neonatal respiratory distress syndrome (RDS). It is feasible to grade RDS and select therapeutic modalities accordingly by LUS. The treatment also should be adjusted with the change in ultrasound images. In conclusion, LUS is valuable for the diagnosis and management of neonatal respiratory distress syndrome.

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).

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.

Indications for and Risks of Noninvasive Respiratory Support

Within the last decades, therapeutic advances have significantly improved the survival of extremely preterm infants. In contrast, the incidence of major neonatal morbidities, including bronchopulmonary dysplasia, has not declined. Given the well-established relationship between exposure to invasive mechanical ventilation and neonatal lung injury, neonatologists have sought for effective strategies of noninvasive respiratory support in high-risk infants. Continuous positive airway pressure has replaced invasive mechanical ventilation for the initial stabilization and the treatment of respiratory distress syndrome. Today, noninvasive respiratory support has been adopted even in the tiniest babies with the highest risk of lung injury. Moreover, different modes of noninvasive respiratory support supplemented by a number of adjunctive measures and rescue strategies have entered clinical practice with the goal of preventing intubation or reintubation. However, does this unquestionably important paradigm shift to strategies focused on noninvasive support lull us into a false sense of security? Can we do better in (i) identifying those very immature preterm infants best equipped for noninvasive stabilization, can we improve (ii) determinants of failure of noninvasive respiratory support in the individual infant and underlying etiology, and can we enhance (iii) success of noninvasive respiratory support and (iv) better prevent ultimate harm to the developing lung? With increased survival of infants at the highest risk of developing lung injury and an unchanging burden of bronchopulmonary dysplasia, we should question indiscriminate use of noninvasive respiratory support and address the above issues.

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.

Lung Ultrasound in Bronchopulmonary Dysplasia: Patterns and Predictors in Very Preterm Infants

INTRODUCTION

Lung ultrasound (LUS) is useful for respiratory management in very preterm infants (VPI), but little is known about the echographic patterns in bronchopulmonary dysplasia (BPD), the relation between the image findings, and the severity of the disease and its long-term outcomes. We aimed to describe LUS patterns in BPD and analyze the accuracy of LUS to predict the need for respiratory support at 36 weeks postmenstrual age (PMA) in VPI.

METHODS

Preterm infants ≤30.6 weeks of gestational age were recruited. LUS was performed at admission, at 7th, and 28th day of life (DOL) with a standardized protocol (6 zones: anterior, lateral, and posterior fields). Clinical data, respiratory outcomes, and image findings were recorded.

RESULTS

Eighty-nine patients were studied. Infants with BPD had significantly higher LUS score at admission, at 7th, and 28th DOL. Patients with BPD exhibited more consolidations and pleural line abnormalities at 7th and 28th DOL than those without BPD (p < 0.001), regardless of the definition used for BPD. LUS at 7th DOL predicted NICHD 2001-BPD with R2 = 0.522; AUC = 0.87 (0.79-0.94), p < 0.001, and Jensen 2019-BPD with R2 = 0.315 (AUC = 0.80 [0.70-0.90], p < 0.001). A model including mechanical ventilation >5 days, oxygen therapy for 7 days and LUS score at 7th DOL accurately predicted the need for respiratory support at 36 weeks PMA (R2 = 0.655, p < 0.001) with an AUC = 0.90 (0.84-0.97), p < 0.001.

CONCLUSION

LUS score, pleural line abnormalities, and consolidations can be useful to diagnose BPD in VPI and to predict its severity after the first week of life.