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.

Main findings: Access to diagnostic tools like chest radiography is challenging in resource-limited areas, yet its usage persists in the management of neonatal respiratory distress syndrome despite a decreased dependency due to the imperative for swift clinical decisions.Added knowledge: Despite its continued significance in scientific literature, the usage of chest radiography as a diagnostic tool for neonatal respiratory distress syndrome may not entirely reflect current global clinical practices, particularly in low-resource settings where early management of neonatal respiratory distress syndrome poses a challenge for neonatal survival.Global health impact for policy and action: The results underscore the necessity of guidelines for the utilisation of chest radiography to minimise unnecessary ionising radiation exposure while ensuring timely access to critical clinical information for appropriate newborn care.

Diagnostic value of bedside lung ultrasound and 12-zone score in the 65 cases of neonatal respiratory distress syndrome and its severity.

OBJECTIVE: To explore the predictive value of bedside lung ultrasound score in the severity of neonatal respiratory distress syndrome (NRDS) and mechanical ventilation and extubation. METHODS: The clinical data of 65 neonates with NRDS and invasive mechanical ventilation diagnosed in the neonatal intensive care unit of our hospital from July 2021 to July 2022 were retrospectively analyzed. 65 neonates were included in the NRDS group, and 40 neonates with other common lung diseases were selected as the other lung disease groups. All neonates underwent lung ultrasound and X-ray examination. The correlation between lung ultrasound scores and arterial blood gas indexes was analyzed by Pearson. The efficacy of successful evacuation of mechanical ventilation was evaluated by lung ultrasound analysis by ROC curve analysis. RESULTS: The positive rates of lung consolidation and white lung in NRDS group were higher than the other lung disease groups (P < 0.05). The positive rates of bronchial inflation sign and double lung points were lower than these in the other lung disease groups (P < 0.05). The ultrasound scores of both lungs, left lung, right lung, bilateral lung and double basal lung in the NRDS group were significantly higher than those in the other lung disease groups (P < 0.05). There was a significant positive correlation between lung ultrasound score and X-ray grade (r = 0.841, P < 0.001). The area under the curve (AUC) of lung ultrasound score for the differential diagnosis of NRDS and common lung diseases was 0.907. The AUC of lung ultrasound score in the differential diagnosis of mild and moderate, and moderate and severe NRDS were 0.914 and 0.933, respectively, which had high clinical value. The lung ultrasound score was positively correlated with the level of PaCO2 (r = 0.254, P = 0.041), and negatively correlated with the levels of SpO2 and PaO2 (r = - 0.459, - 0.362, P = 0.001, 0.003). The AUC of successful mechanical ventilation withdrawal predicted by the pulmonary ultrasound score before extubation was 0.954 (95% CI 0.907-1.000). The predictive value of successful extubation was 10 points of the pulmonary ultrasound score, with a sensitivity of 93.33% and a specificity of 88.00%. CONCLUSION: The bedside lung ultrasound score can intuitively reflect the respiratory status of neonates, which provides clinicians with an important basis for disease evaluation.

Exploring the diagnostic value of ultrasound radiomics for neonatal respiratory distress syndrome.

BACKGROUND: Neonatal respiratory distress syndrome (NRDS) is a prevalent cause of respiratory failure and death among newborns, and prompt diagnosis is imperative. Historically, diagnosis of NRDS relied mostly on typical clinical manifestations, chest X-rays, and CT scans. However, recently, ultrasound has emerged as a valuable and preferred tool for aiding NRDS diagnosis. Nevertheless, evaluating lung ultrasound imagery necessitates rigorous training and may be subject to operator-dependent bias, limiting its widespread use. As a result, it is essential to investigate a new, reliable, and operator-independent diagnostic approach that does not require subjective factors or operator expertise. This article aims to explore the diagnostic potential of ultrasound-based radiomics in differentiating NRDS from other non-NRDS lung disease. METHODS: A total of 150 neonatal lung disease cases were consecutively collected from the department of neonatal intensive care unit of the Quanzhou Maternity and Children's Hospital, Fujian Province, from September 2021 to October 2022. Of these patients, 60 were diagnosed with NRDS, whereas 30 were diagnosed with neonatal pneumonia, meconium aspiration syndrome (MAS), and transient tachypnea (TTN). Two ultrasound images with characteristic manifestations of each lung disease were acquired and divided into training (n = 120) and validation cohorts (n = 30) based on the examination date using an 8:2 ratio. The imaging texture features were extracted using PyRadiomics and, after the screening, machine learning models such as random forest (RF), logistic regression (LR), K-nearest neighbors (KNN), support vector machine (SVM), and multilayer perceptron (MLP) were developed to construct an imaging-based diagnostic model. The diagnostic efficacy of each model was analyzed. Lastly, we randomly selected 282 lung ultrasound images and evaluated the diagnostic efficacy disparities between the optimal model and doctors across differing levels of expertise. RESULTS: Twenty-two imaging-based features with the highest weights were selected to construct a predictive model for neonatal respiratory distress syndrome. All models exhibited favorable diagnostic performances. Analysis of the Youden index demonstrated that the RF model had the highest score in both the training (0.99) and validation (0.90) cohorts. Additionally, the calibration curve indicated that the RF model had the best calibration (P = 0.98). When compared to the diagnostic performance of experienced and junior physicians, the RF model had an area under the curve (AUC) of 0.99; however, the values for experienced and junior physicians were 0.98 and 0.85, respectively. The difference in diagnostic efficacy between the RF model and experienced physicians was not statistically significant (P = 0.24), whereas that between the RF model and junior physicians was statistically significant (P < 0.0001). CONCLUSION: The RF model exhibited excellent diagnostic performance in the analysis of texture features based on ultrasound radiomics for diagnosing NRDS.

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.

Inspiratory-expiratory variation of pleural line thickness in neonates with and without acute respiratory failure.

BACKGROUND: There are relatively few data about the ultrasound evaluation of pleural line in patients with respiratory failure. We measured the pleural line thickness during different phases of the respiratory cycle in neonates with and without acute respiratory failure as we hypothesized that this can significantly change. METHODS: Prospective, observational, cohort study performed in an academic tertiary neonatal intensive care unit recruiting neonates with transient tachypnoea of the neonate (TTN), respiratory distress syndrome (RDS) or neonatal acute respiratory distress syndrome (NARDS). Neonates with no lung disease (NLD) were also recruited as controls. Pleural line thickness was measured with high-frequency ultrasound at end-inspiration and end-expiration by two different raters. RESULTS: Pleural line thickness was slightly but significantly higher at end-expiration (0.53 [0.43-0.63] mm) than at end-inspiration (0.5 [0.4-0.6] mm; p = 0.001) for the whole population. End-inspiratory (NLD: 0.45 [0.38-0.53], TTN: 0.49 [0.43-0.59], RDS: 0.53 [0.41-0.62], NARDS: 0.6 [0.5-0.7] mm) and -expiratory (NLD: 0.47 [0.42-0.56], TTN: 0.48 [0.43-0.61], RDS: 0.53 [0.46-0.65], NARDS: 0.61 [0.54-0.72] mm) thickness were significantly different (overall p = 0.021 for both), between the groups although the absolute differences were small. The inter-rater agreement was optimal (ICC: 0.95 (0.94-0.96)). Coefficient of variation was 2.8% and 2.5% for end-inspiratory and end-expiratory measurements, respectively. These findings provide normative data of pleural line thickness for the most common forms of neonatal acute respiratory failure and are useful to design future studies to investigate possible clinical applications.

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.

Lung ultrasound score for monitoring the withdrawal of extracorporeal membrane oxygenation on neonatal acute respiratory distress syndrome.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is considered an efficient and life-saving treatment for neonatal severe acute respiratory distress syndrome (ARDS). Bedside lung ultrasound (LUS) is an attractive and feasible method for evaluating neonatal ARDS. OBJECTIVE: To evaluate the value of LUS score at veno-arterial (V-A) ECMO withdrawal in neonatal patients with severe acute ARDS. METHODS: A retrospective preliminary study was conducted in our cardiac intensive care unit from June 2021 to June 2022. Eight severe ARDS neonates who received V-A ECMO were enroled in this study. LUS was measured daily during ECMO and when weaning off ECMO. The relationships between the LUS score and ECMO parameters (blood flow and the sweep gas of FiO2) were assessed. RESULTS: (1) There was a significant improvement in LUS score by ECMO treatment. And, various diagnostic signs of lung ultrasound were detected during ECMO, including pulmonary edema (7 neonates) and lung consolidation (4 neonates), followed by pleural effusion (1 neonate) and bilateral white lung (1 neonate). (2) A total of 12 trials for weaning off ECMO were carried out, of which four failed, but all eight neonates finally succeeded in passing the weaning trial. LUS score of 21 or less was defined as a cut-off value for predicting ECMO weaning success. During ECMO treatment, LUS score was positively correlated with ECMO blood flow (r = 0.866, P < 0.05). CONCLUSIONS: LUS can be used to evaluate the various lung diagnostic signs in ARDS neonatal patients during ECMO treatment, and the LUS score under ECMO treatment decreases over time. The reduction in LUS score is associated with lower ECMO blood flow. LUS score is regarded as a predictor of ECMO weaning success.

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.

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.

Effect of preterm chorioamnionitis on lung ultrasound score used to guide surfactant replacement.

OBJECTIVE: Lung ultrasound score (LUS) accurately guides surfactant replacement in preterm neonates with respiratory distress syndrome due to surfactant deficiency. However, surfactant deficiency is not the unique pathobiological feature, as there may be relevant lung inflammation, such as in certain cases of clinical chorioamnionitis (CC). We aim to investigate if CC influences LUS and ultrasound-guided surfactant treatment. DESIGN: Retrospective (2017-2022), large, cohort study targeted to recruit a homogeneous population treated with unchanged respiratory care policy and lung ultrasound protocol. Patients with (CC+: 207) and without (CC-: 205) chorioamnionitis were analyzed with propensity score matching and subsequent additional multivariate adjustments. RESULTS: LUS was identical at unmatched and matched comparisons. Consistently, at least one surfactant dose was given in 98 (47.3%) and 83 (40.5%) neonates in the CC+ and CC- matched cohorts, respectively (p = .210). Multiple doses were needed in 28 (13.5%) and 21 (10.2%) neonates in the CC+ and CC- cohorts, respectively (p = .373). Postnatal age at surfactant dosing was also similar. LUS was higher in patients who were diagnosed with neonatal acute respiratory distress syndrome (NARDS) (CC+ cohort: 10.3 (2.9), CC- cohort: 11.4 (2.6)), than in those without NARDS (CC+ cohort: 6.1 (3.7), CC- cohort: 6.2 (3.9); p < .001, for both). Surfactant use was more frequent in neonates with, than in those without NARDS (p < .001). Multivariate adjustments confirmed NARDS as the variable with greater effect size on LUS. CONCLUSIONS: CC does not influence LUS in preterm neonates, unless inflammation is enough severe to trigger NARDS. The occurrence of NARDS is key factor influencing the LUS.

Sonographic prediction of fetal main pulmonary artery (MPA) Doppler indices of lung maturity and neonatal respiratory distress syndrome (RDS) development.

PURPOSE: The aim of this study is to highlight the predictive role of perinatal fetal main pulmonary artery (MPA) Doppler measurements in neonatal respiratory distress syndrome development. Respiratory distress syndrome (RDS) is one of the lead causes of neonatal respiratory distress as well as neonatal death. Thus, it seems logic to evaluate fetal lung maturity before labour. METHODS: The study is a prospective cohort study performed in tertiary hospital over a period of one-year duration. 70 pregnant ladies between 34 and 38 weeks of gestation were referred for fetal echo, when pregnancy was considered a high risk. A trained radiologist using dedicated ultrasound machine with updated obstetric and fetal echo software performed the fetal echo. Doppler mode and curvilinear probe of 5.7 MHz transducer. Pediatric neonatologist observed the neonatal outcome post-natally. RESULTS: A total of 70 pregnant patients with risk factors underwent fetal echo, 26/70 (37.1%) were diagnosed with RDS conforming to the neonatal criteria. The mean acceleration time/ejection time ratio (At/Et ratio) of the fetal pulmonary artery was significantly reduced in fetuses that subsequently developed RDS than those without RDS. Contrarily, the mean pulsatility index (PI), resistance index (RI), and peak systolic velocity (PSV) of the fetal pulmonary artery were significantly high in fetuses who later developed RDS than in those who did not. CONCLUSION: Fetal MPA Doppler measurements have a major role in anticipating the development of neonatal RDS in preterm and early term neonates.

Feasibility of ultrasound in the diagnosis of neonatal respiratory distress syndrome in preterm infants.

BACKGROUND: The aim of this study was to investigate the feasibility of lung ultrasound in the diagnosis of neonatal respiratory distress syndrome (NRDS) in preterm infants. METHODS: One hundred and nine preterm infants were prospectively recruited. Three ultrasound diagnostic criteria were developed to diagnose preterm infants with NRDS: (A) thickened or not smooth pleural line, part of the lung field shows diffuse 'B-line' sign or alveolar-interstitial syndrome (AIS); (B) thickened or not smooth pleural line, all lung fields show AIS, signifying the 'white lung' sign; (C) thickened or rough pleural line, 'white lung' sign and 'lung consolidation' sign can be observed in any lung field. RESULTS: The sensitivity and negative predictive value of NRDS in preterm infants with diagnostic criteria A were 100%, but the specificity and positive predictive value were 67.95 and 55.36%, respectively. The specificity and positive predictive value of diagnostic criteria B and C were 100%, while the 95% CI of diagnostic criteria B was narrower than diagnostic criteria C. The sensitivity and negative predictive value of diagnostic criteria B were higher than that of diagnostic criteria C. Of the 31 NRDS cases, 15 cases had severe NRDS and the other 16 did not have severe NRDS. CONCLUSION: Thickened or rough pleural line with white lung sign is an important characteristic for the diagnosis of NRDS by lung ultrasound. White lung sign combined with the lung consolidation sign had high diagnostic efficacy when distinguishing severe NRDS from not severe NRDS.

Lung Ultrasound in the Evaluation of Neonatal Respiratory Distress Syndrome.

OBJECTIVE: The purpose of this study is to examine the impact of bedside lung ultrasound (LUS) and LUS scores in the evaluating and grading of neonatal respiratory distress syndrome (NRDS). METHODS: We performed a prospective study on 80 children with suspected NRDS. Infants with a PaO2 -to-FiO2 ratio of <200, 200-300, and >300 mmHg were categorized as the "severe-NRDS group," "mild-NRDS group," and "non-NRDS group," respectively. Left and right lungs were divided into six areas, respectively. For each lung area, a 0- to 3-point score was given. RESULTS: The most common ultrasonic signs of NRDS include bilateral coalescent B-lines, thickened pleural line, and white lung without spared areas. Moreover, different LUS scores among non-NRDS, mild-NRDS, and severe-NRDS groups were identified (6.00 ± 4.033, 25.82 ± 3.778 and 27.90 ± 4.071, respectively; P < .05). When the cutoff value of LUS score was selected as 13 for the differentiation of non-NRDS from NRDS, the sensitivity and specificity were 96.9% and 93.3%, respectively, and the area under the curve (AUC) of receiver operating characteristics (ROC) was 0.938 (95% confidence interval [CI], 0.84-1.00). With a cutoff value of 26.5 for the differentiation between mild- and severe-ARDS, the AUC of ROC curve of the LUS score was 0.707 (95% CI, 0.58-0.83). Similar results were revealed as those with chest X-ray. CONCLUSION: This study showed that LUS and LUS scores complement each other, and are highly reliable and efficient in bedside radiological diagnostic investigations in newborns with NRDS.

Comparison between lung ultrasonography and chest X-ray in the evaluation of neonatal respiratory distress syndrome.

PURPOSE: Respiratory distress syndrome (RDS), also known as hyaline membrane disease, is the most common clinical syndrome encountered among preterm infants, and the complications of the disease account for substantial mortality. Diagnosis of RDS is based on the clinical status of patients in correlation with laboratory parameters and chest X-ray. Lung ultrasound despite its wide use still is not incorporated into diagnostic algorithms. The aim of the study was to evaluate the diagnostic ability of lung ultrasound in diagnosing respiratory distress syndrome as well as in the monitoring of the response to treatment. A secondary aim was to propose a modified ultrasound grading scale. METHODS: The prospective study included 150 neonates with clinical and radiographic signs of neonatal respiratory distress syndrome within the first 24 h of life, with different gestational age (≤ 35 weeks). Lung ultrasound was performed by two radiologists and correlated with a chest X-ray. Two gradation scales (ultrasound and X-ray) were compared and each scale was correlated with the patient's clinical data. RESULTS: In comparison between ultrasound findings and X-ray results showed a statistically significant difference in a favor of ultrasound. Based on the presence of subpleural consolidations, further differentiation of ultrasound profiles were made into subgroups and new ultrasound classification have been proposed. CONCLUSION: Our study showed that lung ultrasound enables the diagnosing of respiratory distress syndrome in premature neonates and also shows a significant correlation with chest X-ray, which is considered as a radiological method of choice for the diagnosis of RDS.

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

OBJECTIVE: To use clinical, lung ultrasound, and gas exchange data to clarify the evolution of lung aeration and function in neonates with respiratory distress syndrome (RDS) and transient tachypnea of the neonate (TTN), the most common types of neonatal respiratory failure. STUDY DESIGN: In this prospective observational cohort study, lung aeration and function were measured with a semiquantitative lung ultrasound score (LUS) and transcutaneous blood gas measurement performed at 1 hour (time point 0), 6 hours (time point 1), 12 hours (time point 2), 24 hours (time point 3) and 72 hours (time point 4) of life. Endogenous surfactant was estimated using lamellar body count (LBC). LUS, oxygenation index (OI), oxygen saturation index (OSI), and transcutaneous pressure of carbon dioxide (PtcCO2) were the primary outcomes. All results were adjusted for gestational age. RESULTS: Sixty-nine neonates were enrolled in the RDS cohort, and 58 neonates were enrolled in the TTN cohort. LUS improved over time (within-subjects, P < .001) but was worse for the RDS cohort than for the TTN cohort at all time points (between-subjects, P < .001). Oxygenation improved over time (within-subjects, P = .011 for OI, P < .001 for OSI) but was worse for the RDS cohort than for the TTN cohort at all time points (between-subjects, P < .001 for OI and OSI). PtcCO2 improved over time (within-subjects, P < .001) and was similar in the RDS and TTN cohorts at all time points. Results were unchanged after adjustment for gestational age. LBC was associated with RDS (ß = -0.2 [95% CI, -0.004 to -0.0001]; P = .037) and LUS (ß = -3 [95% CI, -5.5 to -0.5]; P = .019). CONCLUSIONS: For the first 72 hours of life, the RDS cohort had worse lung aeration and oxygenation compared with the TTN cohort at all time points. CO2 clearance did not differ between the cohorts, whereas both lung aeration and function improved in the first 72 hours of life.

Ultrasound-assessed lung aeration correlates with respiratory system compliance in adults and neonates with acute hypoxemic restrictive respiratory failure: an observational prospective study.

BACKGROUND: Lung ultrasound allows lung aeration to be assessed through dedicated lung ultrasound scores (LUS). Despite LUS have been validated using several techniques, scanty data exist about the relationships between LUS and compliance of the respiratory system (Crs) in restrictive respiratory failure. Aim of this study was to investigate the relationship between LUS and Crs in neonates and adults affected by acute hypoxemic restrictive respiratory failure, as well as the effect of patients' age on this relationship. METHODS: Observational, cross-sectional, international, patho-physiology, bi-center study recruiting invasively ventilated, adults and neonates with acute respiratory distress syndrome (ARDS), neonatal ARDS (NARDS) or respiratory distress syndrome (RDS) due to primary surfactant deficiency. Subjects without lung disease (NLD) and ventilated for extra-pulmonary conditions were recruited as controls. LUS, Crs and resistances (Rrs) of the respiratory system were measured within 1 h from each other. RESULTS: Forty adults and fifty-six neonates were recruited. LUS was higher in ARDS, NARDS and RDS and lower in control subjects (overall p < 0.001), while Crs was lower in ARDS, NARDS and RDS and higher in control subjects (overall p < 0.001), without differences between adults and neonates. LUS and Crs were correlated in adults [r = - 0.86 (95% CI - 0.93; - 0.76), p < 0.001] and neonates [r = - 0.76 (95% CI - 0.85; - 0.62), p < 0.001]. Correlations remained significant among subgroups with different causes of respiratory failure; LUS and Rrs were not correlated. Multivariate analyses confirmed the association between LUS and Crs both in adults [B = - 2.8 (95% CI - 4.9; - 0.6), p = 0.012] and neonates [B = - 0.045 (95% CI - 0.07; - 0.02), p = 0.001]. CONCLUSIONS: Lung aeration and compliance of the respiratory system are significantly and inversely correlated irrespective of patients' age. A restrictive respiratory failure has the same ultrasound appearance and mechanical characteristics in adults and neonates.

The Role and Clinical Value of Optimized Fetal Main Pulmonary Artery Doppler Parameters in the Diagnosis and Prognosis Monitoring of Neonatal Respiratory Distress Syndrome.

Objective: A retrospective study was conducted to explore the role and clinical value of optimized fetal main pulmonary artery Doppler parameters in the diagnosis and prognosis monitoring of neonatal respiratory distress syndrome (NRDS). Methods: Pregnant women admitted to our hospital for delivery from March 2019 to June 2021 were included in the study. There were 372 singleton pregnant women who voluntarily underwent ultrasound and Doppler examinations with informed consent for the study. The AT/ET ratio of the middle segment of the main pulmonary artery, the middle part of the left (or right) pulmonary artery, and the proximal segment of the intrapulmonary artery was measured by ultrasonic Doppler. According to the outcome of the newborn, it was divided into NRDS group (n =90) and non-NRDS group (n =282) to compare the differences of fetal AT/ET ratio at three Doppler sampling locations and the differences of fetal AT/ET ratio in different gestational weeks. Using Pearson's correlation analysis, the correlation among the Doppler parameters of fetal main pulmonary artery, the ratio of AT and AT/ET, gestational weeks, and the efficiency of prenatal prediction of NRDS was evaluated by receiver-operating characteristic (ROC). In addition, the diagnostic efficiency of fetal main pulmonary artery Doppler parameter AT/ET ratio and amniotic fluid method for prenatal prediction of NRDS was compared. Results: Compared with the non-NRDS group, the gestational age, gestational age at delivery, and birth weight in the NRDS group were significantly lower than those in the non-NRDS group. The 1 min Apgar score of newborns was less than 7, and the proportion of newborns transferred to NICU was significantly higher than that in the control group. Compared with non-NRDS group, AT was significantly shortened, AT/ET ratio was significantly decreased, and ET was significantly prolonged in NRDS group. The fetal aortic blood flow parameters AT, ET, and AT/ET ratio in different gestational weeks were significantly different among the three groups. The AT/ET ratio in the middle segment of the aorta in NRDS group was lower than that in non-NRDS group. The ratio of AT/ET was still correlated with the occurrence of postpartum NRDS. The AUC value of NRDS predicted by AT/ET ratio was 0.984. In the combined determination of amniotic fluid Lh and S ratio and PG, the diagnostic accuracy of prenatal prediction of neonatal respiratory distress syndrome was 100.005%, 98.43%, and 95.56%, respectively. The accuracy of fetal aortic AT/ET ratio in prenatal prediction of neonatal respiratory distress syndrome was 100.005%, 95.28%, and 95.57%, respectively. The order of Kappa coefficient from high to low was amniotic fluid PG/L/S ratio, fetal main pulmonary artery blood flow parameter AT/ET ratio, amniotic fluid L/S ratio, OD650, amniotic fluid PG, and foam test. Conclusion: Fetal main pulmonary artery Doppler AT/ET ratio may be a very potential parameter for prenatal noninvasive prediction of NRDS. The fetal main pulmonary artery Doppler flow spectrum may be a very potential alternative to amniocentesis to evaluate FLM.

Early lung ultrasound score to predict noninvasive ventilation needing in neonates from 33 weeks of gestational age: A multicentric study.

OBJECTIVE: To propose an early lung ultrasound (LUS) score for the prediction of the need for respiratory assistance in newborns of gestational age (GA) ≥ 33 weeks presenting respiratory distress. STUDY DESIGN AND SETTING: Multicenter, prospective observational study in third-level neonatal intensive care units. PATIENT SELECTION: Infants with GA ≥ 33 + 0 weeks with respiratory distress within 3 h of life. METHODS: Three LUS for each patient were collected: within 3 h of life (T0), at 4-6 h of life (T1), and at the resolution of symptoms (T2). The primary aim was to assess the validity of the early LUS score in predicting the need for continuous positive airway pressure (CPAP). We also evaluated the validity of the score in predicting the need for surfactant, the scores' trend in our population, and any correlation with the duration of ventilation and oxygen therapy. RESULTS: Sixty-two patients were enrolled in the study. The mean GA was 36 weeks. The receiver operating characteristic analysis for the LUS T0 and T1 yielded area under the curves of 0.91 and 0.82 in predicting the need for CPAP, respectively. LUS score cut off of 6 (sensitivity 84.8%, specificity 86.2%) and 5 (sensitivity 66.7%, specificity 100%) were calculated at T0 and T1, respectively. We found significant correlations between LUS score and respiratory assistance, surfactant administration, and SpO2 /FiO2 ratio. CONCLUSION: An early LUS score is a good noninvasive predictor of the need for respiratory assistance with CPAP and surfactant administration in newborns with GA ≥ 33 weeks.