Lung ultrasound is increasingly used in emergency departments, medical wards, and critical care units-adult, pediatric, and neonatal. In vitro and in vivo studies show that the number and type of artifacts visualized change with lung density. This has led to the idea of a quantitative lung ultrasound approach, opening up new prospects for use not only as a diagnostic but also as a monitoring tool. Consequently, the multiple scoring systems proposed in the last few years have different technical approaches and specific clinical indications, adaptable for more or less time-dependent patients. However, multiple scoring systems may generate confusion among physicians aiming at introducing lung ultrasound in their clinical practice. This review describes the various lung ultrasound scoring systems and aims to clarify their use in different settings, focusing on technical aspects, validation with reference techniques, and clinical applications.

Quantitative Lung Ultrasound: Technical Aspects and Clinical Applications

Aim: Neonatal respiratory distress syndrome (NRDS) is one of the most common and severe diseases in neonatal intensive care units worldwide. Increasing evidence suggests that lung ultrasound (LUS) may be a reliable diagnostic tool for neonatal respiratory distress syndrome. The aim of study was to evaluate the diagnostic accuracy of LUS for NRDS with a systematic review and meta-analysis. Material and methods: We searched for articles in EMBASE, PubMed and Cochrane Central from inception until 17 August 2019. The selected studies were diagnostic accuracy studies that reported the utility of LUS in the diagnosis of NRDS. Two researchers independently extracted data and assessed quality using the QUADAS-2 tool. Then, we created a bivariate mixed effects model to calculate the sensitivity and specificity of LUS in diagnosing NRDS. A summary receiver operator characteristic (SROC) curve was constructed to summarize the performance characteristics of LUS. Results: Nine studies involving 703 infants were included in the review. LUS had a pooled sensitivity of 0.99 (CI: 0.92-1.00) and a specificity of 0.95 (CI: 0.87-0.98). The areas under the curve for LUS was 0.99 (0.98-1.0). Meta-regression revealed that LUS had a significant diagnostic accuracy for NRDS. Conclusion: LUS is a promising method that is easily carried out, inexpensive, nonionizing and repeatable and can be performed at the bedside. Current evidence supports LUS as a useful imaging alternative for the diagnosis of NRDS.

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Diagnostic value of lung ultrasound for neonatal respiratory distress syndrome: a meta-analysis and systematic review.

Respiratory infection diseases are among the major causes of morbidity and mortality in children. Diagnosis is focused on clinical presentation, yet signs and symptoms are not specific and there is a need for new non-radiating diagnostic tools. Among these, lung ultrasound (LUS) has recently been included in point-of-care protocols showing interesting results. In comparison to other imaging techniques, such as chest X-ray and computed tomography, ultrasonography does not use ionizing radiations. Therefore, it is particularly suitable for clinical follow-up of paediatric patients. LUS requires only 5-10 min and allows physicians to make quick decisions about the patient's management. Nowadays, LUS has become an early diagnostic tool to detect pneumonia during the COVID-19 pandemic. In this narrative review, we show the most recent scientific literature about advantages and limits of LUS performance in children. Furthermore, we discuss the major paediatric indications separately, with a paragraph fully dedicated to COVID-19. Finally, we mention potential future perspectives about LUS application in paediatric respiratory diseases.

Usefulness of Lung Ultrasound in Paediatric Respiratory Diseases.

https://www.mdpi.com/2227-9032/9/8/1015/pdf

Lung Ultrasound in Pediatrics and Neonatology: An Update.

Abstract The aim was to reflect on the unexpected finding of persistent pulmonary hypertension of the neonate (PPHN) and pulmonary hypertension in infants born within the Dutch STRIDER trial, its definition and possible pathophysiological mechanisms. The trial randomly assigned pregnant women with severe early-onset fetal growth restriction to sildenafil 25 mg three times a day versus placebo. Sildenafil use did not reduce perinatal mortality and morbidity, but did result in a higher rate of neonatal pulmonary hypertension (PH). The current paper reflects on the used definition, prevalence, and possible pathophysiology of the data on pulmonary hypertension. Twenty infants were diagnosed with pulmonary hypertension (12% of 163 live born infants). Of these, 16 infants had PPHN shortly after birth, and four had pulmonary hypertension associated with sepsis or bronchopulmonary dysplasia. Four infants with PPHN in the early neonatal period subsequently developed pulmonary hypertension associated with bronchopulmonary dysplasia in later life. Infants with pulmonary hypertension were at lower gestational age at delivery, had a lower birth weight and a higher rate of neonatal co-morbidity. The infants in the sildenafil group showed a significant increase in pulmonary hypertension compared to the placebo group (relative risk 3.67; 95% confidence interval 1.28 to 10.51, P = 0.02). Conclusion: Pulmonary hypertension occurred more frequent among infants of mothers allocated to antenatal sildenafil compared with placebo. A possible pathophysiological mechanism could be a “rebound” vasoconstriction after cessation of sildenafil. Additional studies and data are necessary to understand the mechanism of action. What is Known: • In the Dutch STRIDER trial, persistent pulmonary hypertension in the neonate (PPHN) was more frequent among infants after antenatal sildenafil exposure versus placebo. What is New: • The current analysis focuses on the distinction between PPHN and pulmonary hypertension associated with sepsis or bronchopulmonary dysplasia and on timing of diagnosis and aims to identify the infants at risk for developing pulmonary hypertension. • The diagnosis pulmonary hypertension is complex, especially in infants born after severe early-onset fetal growth restriction. The research field could benefit from an unambiguous consensus definition and standardized screening in infants at risk is proposed. 

/pdf/neonatal-pulmonary-hypertension-after-severe-early-onset-5wl4irtz.pdf

Neonatal pulmonary hypertension after severe early-onset fetal growth restriction: post hoc reflections on the Dutch STRIDER study

During the pandemic caused by the novel coronavirus (COVID-19), lung ultrasound has been used to diagnose and monitor respiratory condition. The aim of the study was to describe lung ultrasound findings in children with a COVID-19 infection. Patients younger than 18 years old and positive for COVID-19, admitted to pediatric tertiary referral hospital were included. They were divided into two groups depending on the presence of respiratory symptoms. Lung ultrasound results were categorized into four degrees according to Soldati et al. score (J Ultrasound Med 39:1–7, 2020) and it was also described the presence and type of consolidation. Sixteen patients were recruited. The median age was 11 years old (IQR 2.8–12). Four children (25%) required admission to the intensive care unit. Six patients (37.5%) presented with respiratory symptoms. Most of them showed S.score of 2 and subpleural consolidations were observed in four cases (66.6%). Ten patients (62.5%) presented with non-respiratory symptoms, lung ultrasound showed S.score from 0 to 2. Three (30%) were diagnosed of multisystem inflammatory syndrome and lung ultrasounds showed S.score of 2 with bilateral pleural effusion. Conclusions: Children with COVID-19 and respiratory symptoms mostly showed a S.score of 2 and 3 with subpleural consolidations, upon the lung ultrasound assessment.

/pdf/lung-ultrasound-findings-in-pediatric-patients-with-covid-19-27b943t42p.pdf

Lung ultrasound findings in pediatric patients with COVID-19.

Introduction Persistent pulmonary hypertension of the newborn (PPHN) is a neonatal syndrome associated with significant morbidity and mortality that is caused by the failure of postnatal drop in pulmonary vascular resistance. In extreme cases, patients may require extracorporeal membrane oxygenation therapy (ECMO). The aim of this study was to explore lung ultrasound (LUS) patterns in newborns with PPHN requiring ECMO. Patients and methods From January 2014 to January 2018, LUS was performed on patients with PPHN admitted for ECMO treatment. PPHN diagnosis was based on clinical and echocardiographic findings. LUS was performed before patients underwent ECMO cannulation. An underlying diagnosis was made taking into account the patient's complete medical history, excluding LUS information. A blinded physician, unaware of the patient's clinical condition, analyzed the stored ultrasound images. Results were then compared with chest x-ray (CXR) diagnoses. Results Seventeen patients were recruited; 12 were male (70.6%). The median gestational age was 38.7 weeks, with 13 term newborns (76.5%). Twelve were cannulated for VA ECMO, with a median ECMO run of 111.2 h. Six patients (35%) survived. Patients with alveolar capillary dysplasia with misaligned pulmonary veins, fetal ductus arteriosus constriction, or sepsis had normal LUS patterns (A-lines with lung sliding). LUS showed a better sensitivity (88.9%) and specificity (85%) than CXR (55.6 and 77.5%, respectively) in identifying patients with nonparenchymal lung disease. Conclusions LUS can provide essential information to help diagnose the underlying cause of PPHN in an earlier and more effective way than CXR. LUS is suitable for routine utilization in the intensive care unit.

Mónica Girona

Papers

Lung ultrasound findings in pediatric patients with COVID-19.

Lung Ultrasound to Assess the Etiology of Persistent Pulmonary Hypertension of the Newborn (LUPPHYN Study): A Pilot Study.