Use of lung ultrasound in detection of complications of 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.

Lung Ultrasound in Neonatal Respiratory Distress Syndrome: A Narrative Review of the Last 10 Years

Neonatal respiratory distress syndrome (RDS) is a common and potentially life-threatening condition in preterm infants, primarily due to surfactant deficiency. Early and accurate diagnosis is critical to guide timely interventions such as surfactant administration and respiratory support. Traditionally, chest X-rays have been used for diagnosis, but lung ultrasound (LUS) has gained prominence due to its non-invasive, radiation-free, and bedside applicability. Compared to chest X-rays and CT scans, LUS demonstrates superior sensitivity and specificity in diagnosing RDS, particularly in identifying surfactant need and predicting CPAP failure. Additionally, LUS offers real-time imaging without radiation exposure, an advantage over other modalities. However, its broader adoption is limited by challenges in standardizing training, ensuring diagnostic reproducibility, and validating scoring systems, especially in resource-limited settings. This narrative review aims to evaluate the role of LUS in the diagnosis and management of neonatal RDS over the past decade, focusing on its clinical utility, scoring systems, and emerging applications. We reviewed the literature from 2013 to 2023, focusing on studies evaluating LUS' diagnostic accuracy, scoring systems, and its potential role in guiding surfactant therapy and predicting CPAP failure. Despite its benefits, addressing the variability in operator expertise and integrating artificial intelligence to enhance usability are crucial for ensuring LUS' efficacy across diverse clinical environments. Future research should prioritize standardizing training and scoring protocols to facilitate wider implementation and optimize neonatal respiratory care outcomes.

Progress in the Application of Lung Ultrasound for the Evaluation of Neonates with Respiratory Distress Syndrome

Neonatal respiratory distress syndrome (NRDS) is a common critical disease in neonates. Early diagnosis and timely treatment are crucial. Historically, X-ray imaging was the primary method for diagnosing NRDS. However, this method carries radiation exposure risks, making it unsuitable for dynamic lung condition monitoring. In addition, neonates who are critically ill require bedside imaging, but diagnostic delays are often unavoidable due to equipment transportation and positioning limitations. These challenges have been resolved with the introduction of lung ultrasound (LUS) in neonatal intensive care. The diagnostic efficacy and specificity of LUS for NRDS is superior to that of X-ray. The non-invasive, dynamic, and real-time benefits of LUS also allow for real-time monitoring of lung changes throughout treatment for NRDS, yielding important insights for guiding therapy. In this paper, we examine the ultrasonographic characteristics of NRDS and the recent progress in the application of ultrasound in the diagnosis and treatment of NRDS while aiming to promote wider adoption of this method.

Feasibility of Endotracheal Extubation Evaluation Form in Predicting Successful Extubation in Neonatal Intensive Care Units: A Retrospective Study

Given the limited availability of evidence-based methods for assessing the timing of extubation in intubated preterm infants, we aimed to standardize the extubation protocol in this single-center, retrospective study. To accomplish this, we established an extubation evaluation form to assess the suitability of extubation in preterm infants. The form comprises six indicators: improved clinical condition, spontaneous breath rate ≥ 30 breaths per minute, peak inspiratory pressure (PIP) ≤ 15 cmH₂O, fraction of inspired oxygen (FiO₂) ≤ 30%, blood pH ≥ 7.2, and mixed venous carbon dioxide tension (PvCO₂) < 70 mmHg. Each positive answer is given one point, indicating a maximum of six points. We enrolled 41 intubated preterm infants (gestational age < 32 weeks, birth weight < 1500 g) who were receiving mechanical ventilation support for over 24 h. Among them, 35 were successfully extubated, and 6 were not. After completing the extubation evaluation form and adjusting for birth weight and postextubation device, we observed that the total score of the form was significantly associated with successful extubation; the higher the score, the greater the chance of successful extubation. Thus, we infer that the extubation evaluation form may provide a more objective standard for extubation assessment in preterm infants.

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

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

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).

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

OBJECTIVE

This study aimed to determine the accuracy of neonatal lung ultrasound (LUS) in predicting the need for surfactant therapy compared with chest X-ray (CXR) in preterm infants.

STUDY DESIGN

A prospective double-blind study was conducted in infants with a gestational age <34 weeks with respiratory distress syndrome (RDS) by evaluation with LUS and CXR on admission.

RESULTS

Among 45 preterm infants, the median (interquartile range [IQR]) LUS score was 4 (2-8) in the mild RDS group, whereas it was 10 (IQR: 9-12) in the severe RDS group (p < 0.01). The LUS score showed a significant correlation with the need for total surfactant doses (ρ = 0.855; 95% confidence interval [CI]: 0.801-0.902; p < 0.001). A cut-off LUS score of four predicted the need for surfactant with 96% sensitivity and 100% specificity (area under the curve [AUC]: 1.00; 95% CI: 0.97-1.00; p < 0.01). LUS scores predicted continuous positive airway pressure (CPAP) failure accurately (AUC: 0.804; 95% CI: 0.673-0.935; p = 0.001). A significant correlation was observed between LUS scores and positive end-expiratory pressure levels (ρ = 0.782; p < 0.001). During the study period, the CXR number per infant with RDS decreased significantly when compared with preceding months (p < 0.001). The LUS score in the first day of life did not predict the development of bronchopulmonary dysplasia (AUC: 0.274; 95% CI: 0.053-0.495; p = 0.065).

CONCLUSION

The LUS score in preterm infants accurately predicts the severity of RDS, the need for surfactant and CPAP failure. The routine use of LUS can decrease the frequency of CXRs in the neonatal intensive care units.

KEY POINTS

· LUS is a nonhazardous bedside technique.. · LUS predicts the need for surfactant in preterm infants.. · LUS predicts the severity of RDS better than CXR..

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

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

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.

Tools to assess lung aeration in neonates with respiratory distress syndrome

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

Can lung ultrasound assist in the decision of weaning mechanically ventilated neonates?

Background

Mechanical ventilation is widely used in neonates presenting with respiratory distress; however, it is not without complications. Early weaning of neonates is vital however the process of extubation is difficult to determine precisely. The use of lung ultrasound in neonates is recently accepted as a reliable tool in the assessment of several lung conditions. The aim of this study was to assess the use of lung ultrasound score as a quantitative method to assist in the decision of weaning mechanically ventilated neonates.

Results

The study was conducted on 40 neonates admitted to the NICU with different causes of respiratory distress needing respiratory support by mechanical ventilation. Lung ultrasound was performed using a linear superficial probe at least three times, at admission, before switching mechanical ventilation mode and before weaning. The initial lung ultrasound score for all patients was between 9 and 36 (mean 25 ± 6.97, median 26) with the 11 patients initiated on Sync. Intermittent ventilation (SIMV) showing significantly lower scores than those initiated on assist/control ventilation (ACV). Patients successfully switched from ACV to SIMV showed significantly lower scores than those who failed. Patients successfully weaned from SIMV showed significantly lower scores than those who failed. ROC analysis showed a cut-off score of ≤ 14 had 85% sensitivity and 100% specificity for a successful switch between ACV to SIMV. It also showed that a score ≤ 6 had 87.5% sensitivity and 100% specificity for successful extubation.

Conclusion

The use of quantitative lung ultrasound scores in assessment of mechanically ventilated neonates shows a great potential in aiding the process of weaning.

Lung ultrasound in the diagnosis of neonatal respiratory failure prior to patient transport

PURPOSE

Lung ultrasound (LUS) at the point-of-care is a new method that is increasingly used in neonatology. The aim of this study was to determine the utility of the addition of LUS prior to the interhospital transport of neonates with respiratory failure.

METHODS

LUS was performed on 50 newborns with respiratory failure prior to transport to a tertiary neonatal intensive care unit. We analyzed the performance of LUS for diagnosing the cause of respiratory failure, the concordance between LUS, chest X-ray (CXR) and final clinical diagnosis, and the impact of LUS on clinical decision making before transport.

RESULTS

LUS sensitivity for the diagnosis of respiratory distress syndrome was 91.3% (95%CI: 70.5-98.5%), and specificity was 92.6% (95%CI: 74.2-98.7%), whereas sensitivity and specificity of CXR were 69.6% (95%CI: 47.0-85.9%) and 81.5% (95%CI: 61.2-92.9%), respectively. For the recognition of pneumothorax (PTX) LUS had a sensitivity of 83.3% (95%CI: 36.5-99.1%) and a specificity of 100% (95%CI: 89.9-100%). For CXR, sensitivity was 16.7% (95%CI: 0.01-63.5%) and specificity was 97.7% (95%CI: 86.4-99.9%). The agreement between LUS and CXR in diagnosing the cause of respiratory failure was substantial (κ of 0.57 [95%CI: 0.40-0.74]) and the agreement between LUS and the final clinical diagnosis was very good (κ of 0.86 [95%CI: 0.74-0.98]). In 42% of the patients, a LUS examination prior to transport indicated the need for endotracheal tube repositioning or PTX decompression.

CONCLUSION

LUS may be a reliable imaging technique for differentiating the causes of respiratory failure before neonatal transport. Use of LUS may optimize the care of infants during transport.

Diagnostic value of lung ultrasound in evaluating the severity of neonatal respiratory distress syndrome

BACKGROUND

It is still unclear whether lung ultrasound (LUS) can be used to evaluate the severity of neonatal respiratory distress syndrome (NRDS).

OBJECTIVE

To evaluate the role of LUS in assessing NRDS.

METHODS

From January 2017 to January 2018, newborns with suspected NRDS were enrolled. The LUS score and lung consolidation areas were determined. The receiver operative curve (ROC) was used to analyze the LUS score and lung consolidation to predict NRDS severity.

RESULTS

Neonates with NRDS had higher LUS scores than those with non-NRDS (23.6 ± 3.6 vs. 16.2 ± 1.8, P < 0.05). Among neonates with NRDS, the LUS scores increased with NRDS severity (18.0 ± 2.7 vs. 24.0 ± 1.7 vs. 27.0 ± 1.7, all P < 0.05). There were almost no consolidation areas in non-NRDS, while 1.9 ± 1.7 consolidation areas were observed in the NRDS group (P < 0.05). The number of consolidation areas also increased with NRDS severity (0 vs. 1.5 ± 0.8 vs. 4.1 ± 1.3, all P < 0.05). The LUS score for NRDS vs. non-NRDS showed 80.2% sensitivity and 100% specificity using a cut-off of 21.5 (Area under the ROC curve, AUC = 0.938; P < 0.001). The LUS score for severe vs. mild/moderate NRDS showed 73.1% sensitivity and 95.7% specificity using a cut-off of 25.5 (AUC = 0.944; P < 0.001). The LUS score for predicting mechanical ventilation showed 81.3% sensitivity and 88.8% specificity using a cut-off of 25.5 (AUC = 0.912; P < 0.001). The AUCs of consolidation areas were similar to those of LUS score (all P > 0.05).

CONCLUSION

The LUS score and consolidation areas can discriminate NRDS from non-NRDS and the different grades of NRDS, and predict the application of mechanical ventilation.

Chest ultrasound for the diagnosis of paediatric pulmonary diseases: a systematic review and meta-analysis of diagnostic test accuracy

BACKGROUND

Chest ultrasound is an emerging imaging modality, for several paediatric pulmonary diseases.

SOURCES OF DATA

MEDLINE and EMBASE (1946-47 to 10 March 2017) were searched to collect evidence on the diagnostic accuracy of chest ultrasound, compared to other imaging modalities, for the diagnosis of paediatric pulmonary diseases.

AREAS OF AGREEMENT

Eighteen pneumonia studies, comprising 2031 children, were included for meta-analysis; the summary estimate sensitivity was 95.0% (95%CI: 90.7-97.3%) and specificity was 96.1% (95%CI: 89.1-98.7%).

AREAS OF CONTROVERSY

Other pulmonary diseases also yielded high sensitivity and specificity, but a meta-analysis could not be conducted due to a limited number of studies includable, and their heterogeneity.

GROWING POINTS

Chest ultrasound should be considered as a first-line imaging modality for children with suspected pneumonia.

AREAS TIMELY FOR DEVELOPING RESEARCH

Further research should focus on the diagnostic accuracy of chest ultrasound for the diagnosis of paediatric pulmonary diseases, other than pneumonia, comparing against a valid gold standard.

[Usefulness of early lung ultrasound in acute mild-moderate acute bronchiolitis. A pilot study]

OBJECTIVE

To determine the correlation between the findings seen in early lung ultrasound with the clinical severity scales, and its association with the subsequent progression of the mild-moderate acute bronchiolitis (AB).

PATIENTS AND METHODS

An observational prospective study conducted on infants with mild-moderate BA, using lung ultrasound in the first 24hours of hospital care. The lung involvement was graded (range 0-50 points) based on an ultrasound score (ScECO) and 2routinely used clinical scales: the modified Wood Downes Ferres (WDFM), and the Hospital Sant Joan de Deu (HSJD). The relationship between the ScECO and the subsequent clinical progression (admission to the Paediatric Intensive Care Unit (PICU), days in hospital, and days of oxygen therapy), was also determined.

RESULTS

The study included a total of 59 patients, with a median age of 90 days (IQR: 30-270 days). The median ScECO score was 6 points (2-8) in the patients that did not require hospital admission, with 9 points (5-13.7) admitted to the ward, and 17 (14.5-18) in the patients who needed to be transferred from the ward to the PICU (P=.001). The ScECO had a moderate lineal association with the WDFM scale (rho=0.504, P<.001) and the HSJD (rho=0.518; P<.001). The ScECO was associated with admission to PICU [OR 2.5 (95% CI: 1.1-5.9); P=.035], longer hospital stay [1.2 days 95% CI: 0.55-1.86); P=.001] and duration of oxygen therapy [0.87 days (95% CI: 0.26-1.48); P=.006].

CONCLUSIONS

There is a moderate correlation between early lung ultrasound findings with the severity of the AB evaluated by the clinical scales, as well as some relationship with the clinical progression.

Neonatal lung ultrasound exam guidelines

Point-of-care ultrasound (POC-US) is increasingly used especially in emergency and critical-care medicine. It is focused, quick and does not expose patients to ionizing radiation. It encompasses all organ systems and has well-defined indications. Lung ultrasound (LUS) represents one of the most exciting applications in the field of POC-US. It is particularly important to emphasize the role of LUS in neonatology due to the specific pathology inherent in lung immaturity as well as in the particular sensitivity of neonates to repeated radiation exposure. One of the main barriers to the more extensive use of the ultrasound technology is a lack of efficient and attractive training solutions followed by the structured quality-check assurance. In an effort to help bridge this gap, based on the most current literature, we developed creative and intuitive neonatal LUS algorithms. We hope they can serve as a clinical imaging guidelines and a valuable complement to the history and physical exam.

Role of chest ultrasound in neonatal lung disease: a review of current evidences

Among the common causes of neonatal admission to NICU, respiratory distress is one of the important causes. The neonatal respiratory distress is end result of various pulmonary and non-pulmonary causes. Differentiation of pulmonary causes of respiratory distress is important for the neonatologist as treatment differs with different etiologies. Conventionally, chest X-ray and sometimes CT scan have been used to identify the etiology of respiratory distress but these modalities have several limitations which make their use in NICU doubtful. In recent decades, there has been use of lung ultrasound (LUS) to identify and differentiate the etiologies of respiratory distress. The current available evidence show that LUS has good sensitivity and specificity to identify all the common causes of neonatal distress like respiratory distress syndrome, transient tachypnea of newborn, pneumothorax, and pneumonia. This review will cover the various uses of LUS in neonatal care with current available evidence.

Neonatal respiratory distress syndrome: Chest X-ray or lung ultrasound? A systematic review

BACKGROUND AND AIM

Neonatal respiratory distress syndrome is a leading cause of morbidity in preterm new-born babies (<37 weeks gestation age). The current diagnostic reference standard includes clinical testing and chest radiography with associated exposure to ionising radiation. The aim of this review was to compare the diagnostic accuracy of lung ultrasound against the reference standard in symptomatic neonates of ≤42 weeks gestation age.

METHODS

A systematic search of literature published between 1990 and 2016 identified 803 potentially relevant studies. Six studies met the review inclusion criteria and were retrieved for analysis. Quality assessment was performed before data extraction and meta-analysis.

RESULTS

Four prospective cohort studies and two case control studies included 480 neonates. All studies were of moderate methodological quality although heterogeneity was evident across the studies. The pooled sensitivity and specificity of lung ultrasound were 97% (95% confidence interval [CI] 94-99%) and 91% (CI: 86-95%) respectively. False positive diagnoses were made in 16 cases due to pneumonia (n = 8), transient tachypnoea (n = 3), pneumothorax (n = 1) and meconium aspiration syndrome (n = 1); the diagnoses of the remaining three false positive results were not specified. False negatives diagnoses occurred in nine cases, only two were specified as air-leak syndromes.

CONCLUSIONS

Lung ultrasound was highly sensitive for the detection of neonatal respiratory distress syndrome although there is potential to miss co-morbid air-leak syndromes. Further research into lung ultrasound diagnostic accuracy for neonatal air-leak syndrome and economic modelling for service integration is required before lung ultrasound can replace chest radiography as the imaging component of the reference standard.

Lung Ultrasound in Early Diagnosis of Neonatal Ventilator Associated Pneumonia before Any Radiographic or Laboratory Changes

Neonatal pneumonia is reported to be the primary cause of neonatal respiratory failure and one of the common causes of neonatal hospitalization and death in developing countries. Chest X-ray was considered the gold standard for diagnosis of neonatal pneumonia. Lung ultrasonography has been described as a valuable noninvasive tool for the diagnosis of many neonatal pulmonary diseases. We report a case of ventilation associated neonatal pneumonia with very early diagnosis using lung ultrasound before any significant radiographic changes in chest X-ray or laboratory findings suggestive of infection.

Lung Ultrasound for Diagnosing Pneumothorax in the Critically Ill Neonate

OBJECTIVES

To evaluate the accuracy of lung ultrasound for the diagnosis of pneumothorax in the sudden decompensating patient.

STUDY DESIGN

In an international, prospective study, sudden decompensation was defined as a prolonged significant desaturation (oxygen saturation <65% for more than 40 seconds) and bradycardia or sudden increase of oxygen requirement by at least 50% in less than 10 minutes with a final fraction of inspired oxygen ≥0.7 to keep stable saturations. All eligible patients had an ultrasound scan before undergoing a chest radiograph, which was the reference standard.

RESULTS

Forty-two infants (birth weight = 1531 ± 812 g; gestational age = 31 ± 3.5 weeks) were enrolled in 6 centers; pneumothorax was detected in 26 (62%). Lung ultrasound accuracy in diagnosing pneumothorax was as follows: sensitivity 100%, specificity 100%, positive predictive value 100%, and negative predictive value 100%. Clinical evaluation of pneumothorax showed sensitivity 84%, specificity 56%, positive predictive value 76%, and negative predictive value 69%. After sudden decompensation, a lung ultrasound scan was performed in an average time of 5.3 ± 5.6 minutes vs 19 ± 11.7 minutes required for a chest radiography. Emergency drainage was performed after an ultrasound scan but before radiography in 9 cases.

CONCLUSIONS

Lung ultrasound shows high accuracy in detecting pneumothorax in the critical infant, outperforming clinical evaluation and reducing time to imaging diagnosis and drainage.