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

Neonatal lung diseases: lung ultrasound or chest x-ray

Chest X-ray (CXR) examination is a well-recognized imaging modality in the diagnosis of neonatal lung diseases. On the other hand, lung ultrasound (LUS) has been an emerging and increasingly studied modality. However, the role of LUS as well as its potential to replace CXRs in the detection of neonatal lung diseases has been debated. We combine the present research progress and our own clinical experience to elaborate on various aspects of the potential routine use of lung ultrasound in neonatal intensive care units. We conclude that both LUS and CXR have a number of advantages and disadvantages. They should serve as complementary diagnostic methods in providing accurate, timely, and reliable information.

Lung Ultrasound Score Progress in Neonatal Respiratory Distress Syndrome

BACKGROUND AND OBJECTIVES

The utility of a lung ultrasound score (LUS) has been described in the early phases of neonatal respiratory distress syndrome (RDS). We investigated lung ultrasound as a tool to monitor respiratory status in preterm neonates throughout the course of RDS.

METHODS

Preterm neonates, stratified in 3 gestational age cohorts (25-27, 28-30, and 31-33 weeks), underwent lung ultrasound at weekly intervals from birth. Clinical data, respiratory support variables, and major complications (sepsis, patent ductus arteriosus, pneumothorax, and persistent pulmonary hypertension of the neonate) were also recorded.

RESULTS

We enrolled 240 infants in total. The 3 gestational age intervals had significantly different LUS patterns. There was a significant correlation between LUS and the ratio of oxygen saturation to inspired oxygen throughout the admission, increasing with gestational age (b = -0.002 [P < .001] at 25-27 weeks; b = -0.006 [P < .001] at 28-30 weeks; b = -0.012 [P < .001] at 31-33 weeks). Infants with complications had a higher LUS already at birth (12 interquartile range 13-8 vs 8 interquartile range 12-4 control group; P = .001). In infants 25 to 30 weeks' gestation, the LUS at 7 days of life predicted bronchopulmonary dysplasia with an area under the curve of 0.82 (95% confidence interval 0.71 to 93).

CONCLUSIONS

In preterm neonates affected by RDS, the LUS trajectory is gestational age dependent, significantly correlates with the oxygenation status, and predicts bronchopulmonary dysplasia. In this population, LUS is a useful, bedside, noninvasive tool to monitor the respiratory status.

Modified lung ultrasound score predicts ventilation requirements in neonatal respiratory distress syndrome

Background

We propose a modified lung ultrasound (LUS) score in neonates with respiratory distress syndrome (RDS), which includes posterior instead of lateral lung fields, and a 5-grade rating scale instead of a 4-grade rating scale. The purpose of this study was to evaluate the reproducibility of the rating scale and its correlation with blood oxygenation and to assess the ability of early post-birth scans to predict the mode of respiratory support on day of life 3 (DOL 3). As a secondary objective, the weight of posterior scans in the overall LUS score was assessed.

Methods

We analyzed 619 serial lung scans performed in 70 preterm infants < 32 weeks gestation and birth weight < 1500 g. Assessments were performed within 24 h of birth (LUS₀) and on days 2, 3, 5, 7, 10, 14, 21 and 28. LUS scores were correlated with oxygen saturation over fraction of inspired oxygen (S/F) and mode of respiratory support. Interrater agreement was determined with the intraclass correlation coefficient (ICC) and Cronbach’s alpha. Probabilities of the need for various respiratory support modes on DOL 3 were assessed with ordinal logistic regression. Least square (ls) means of the posterior and anterior pulmonary field scores were compared.

Results

The LUS score correlated significantly with S/F (Spearman rho = −0.635; p < 0.0001) and had excellent interrater agreement (ICC = 0.94, 95% CI 0.93–0.95; Cronbach’s alpha = 0.99). Significant predictors of ventilation requirements on DOL 3 were LUS₀ (p < 0.016) and birth weight (BW) (p < 0.001). In the ROC analysis, LUS₀ had high reliability in prognosing invasive ventilation on DOL 3 (AUC = 0.845 (95% DeLong CI: 0.738–0.951; p < 0.001)). Invasive ventilation was the most likely mode of respiratory support for LUS₀ scores: ≥7 (in infants with BW 900 g), ≥ 10 (in infants with BW 1050 g) and ≥ 15 (in infants with BW 1280 g). Posterior fields exhibited significantly higher average scores than anterior fields. Respective ls means (confidence levels) were 4.0 (3.8–4.1) vs. 2.2 (2.0–2.4); p < 0.001.

Conclusions

Post-birth LUS predicts ventilation requirements on DOL 3. Scores of posterior pulmonary fields have a predominant weight in the overall LUS score.

Ultrasound for Endotracheal Tube Tip Position in Term and Preterm Infants

BACKGROUND AND OBJECTIVE

Placing an endotracheal tube (ETT) in neonates is challenging and currently requires timely radiographic confirmation of correct tip placement. The objective was to establish the reliability of ultrasound (US) for assessing ETT position in the neonatal intensive care unit (NICU), time needed to do so, and patients' tolerance.

METHODS

A prospective study on 71 newborns admitted to our NICU whose ETT placement was evaluated with US (ETT-echo) and confirmed on chest X-rays (CXR). Data were collected by 3 operators (2 neonatologists and a resident in pediatrics). The right pulmonary artery (RPA) was used as a landmark for US. The distance between the tip of the ETT and the upper margin of the RPA was measured using US and compared with the distance between the tube's tip and the carina on the CXR.

RESULTS

Seventy-one intubated newborns were included in the study (n = 34 < 1,000 g, n = 18 1,000-2,000 g, n = 19 > 2,000 g). Statistical analysis (Bland-Altman plot and Lin's concordance correlation coefficient) showed an excellent consistency between ETT positions identified on US and chest X-ray. The 2 measures (ETT-echo and CXR) were extremely concordant both in the whole sample and in the subgroups. Minimal changes in patients' vital signs were infrequently observed during US, confirming the tolerability of ETT-echo. The mean time to perform US was 3.2 min (range 1-13).

CONCLUSIONS

ETT-echo seems to be a rapid, tolerable, and highly reliable method worth further investigating for future routine use in neonatology with a view to reducing radiation exposure.

Lung ultrasound features predict admission to the neonatal intensive care unit in infants with transient neonatal tachypnoea or respiratory distress syndrome born by caesarean section

We aimed to evaluate the reliability of lung ultrasound (LU) to predict admission to the neonatal intensive care unit (NICU) for transient neonatal tachypnoea or respiratory distress syndrome in infants born by caesarean section (CS). A prospective, observational, single-centre study was performed in the delivery room and NICU of Sant'Orsola-Malpighi Hospital in Bologna, Italy. Term and late-preterm infants born by CS were included. LU was performed at 30' and 4 h after birth. LU appearance was graded according to a previously validated three-point scoring system (3P-LUS: type-1, white lung; type-2, black/white lung; type-3, normal lung). Full LUS was also calculated. One hundred infants were enrolled, and seven were admitted to the NICU. The 5 infants with bilateral type-1 lung at birth were all admitted to the NICU. Infants with type-2 and/or type-3 lung were unlikely to be admitted to the NICU. Mean full-LUS was 17 in infants admitted to the NICU, and 8 in infants not admitted. In two separate binary logistic regression models, both the 3P- and the full LUS proved to be independently associated with NICU admission (OR [95% CI] 0.001 [0.000-0.058], P = .001, and 2.890 [1.472-5.672], P = .002, respectively). The ROC analysis for the 3P-LUS yielded an AUC of 0.942 (95%CI, 0.876-0.979; P<.001), while ROC analysis for the full LUS yielded an AUC of 0.978 (95%CI, 0.926-0.997; P<.001). The AUCs for the two LU scores were not significantly different (p = .261).Conclusion: the 3P-LUS performed 30 min after birth proved to be a reliable tool to identify, among term and late preterm infants born to CS, those who will require NICU admission for transient neonatal tachypnoea or respiratory distress syndrome. What is known • Lung ultrasound (LU) has become an attractive diagnostic tool in neonatal settings, and guidelines on point-of-care LU in the neonatal intensive care unit (NICU) have been recently issued. • LU is currently used for diagnosing several neonatal respiratory morbidities and has been also proposed for predicting further intervention, such as NICU admission, need for surfactant treatment or mechanical ventilation in preterm infants. What is new • LU performed 30' after birth and evaluated through a simple three-point scoring system represents a reliable tool to identify, among term and late preterm infants born to caesarean section, those with transient neonatal tachypnoea or respiratory distress syndrome who will require NICU admission. • LU performed in the neonatal period confirms its potential role in ameliorating routine neonatal clinical management.

Introduction of point-of-care neonatal lung ultrasound in a developing country

Despite neonatal lung ultrasound (LU) being diffused worldwide, its introduction in limited-resource areas has not been formally investigated. We conceived a project to introduce it in a level 3 NICU of a developing country and verify if, after a short protocolized training, clinicians may efficaciously use LU. Inter-rater agreement between ultrasound trainees and trainers was analyzed within both the local test and the diffusion phases of the project. High inter-rater agreements were found between expert trainers and the two neonatologists who were trained in a skilled European center (Cohen's Kappa, 0.951; 95%CI, 0.882-0.999), as well as between the two and the second round of locally trained colleagues (Cohen's Kappa, 0.896; 95%CI, 0.797-0.996). Moreover, a high agreement was found between the clinical respiratory diagnosis (used as the "gold standard") and the LU diagnosis given by the first two trainees (intraclass correlation, 0.992; 95%CI, 0.987-0.996) and the locally trained physicians (intraclass correlation, 0.97; 95%CI, 0.95-0.98). A final survey demonstrated that the project was perceived as efficacious and that LU was going to be integrated into routine clinical practice.Conclusions: А short LU training provided sufficient proficiency and allowed the LU introduction in clinical practice in the neonatal intensive care unit in a developing country.What is Known:• Lung ultrasound is a promising technique for evaluating neonatal respiratory distress at least in high-income countries. Previous studies revealed high specificity and sensitivity in diagnosing specific neonatal disorders.• An important barrier to the more extensive use of lung ultrasound in neonatal critical care is a lack of efficient and suitable training solutions.What is New:• Descriptive LU performed by neonatologist in a developing country after a short formal training is feasible with good quality.• A short formal LU training program provided good proficiency and allowed a correct descriptive diagnosis in a neonatal unit in a developing country.

Surfactant-secreted phospholipase A2interplay and respiratory outcome in preterm neonates

Secreted phospholipase A2hydrolyzes surfactant phospholipids and is crucial for the inflammatory cascade; preterm neonates are treated with exogenous surfactant, but the interaction between surfactant and phospholipase is unknown. We hypothesize that this interplay is complex and the enzyme plays a relevant role in neonates needing surfactant replacement. We aimed to: 1) identify phospholipases A2isoforms expressed in preterm lung; 2) study the enzyme role on surfactant retreatment and function and the effect of exogenous surfactant on the enzyme system; and 3) verify whether phospholipase A2is linked to respiratory outcomes. In bronchoalveolar lavages of preterm neonates, we measured enzyme activity (alone or with inhibitors), enzyme subtypes, surfactant protein-A, and inflammatory mediators. Surfactant function and phospholipid profile were also tested. Urea ratio was used to obtain epithelial lining fluid concentrations. Follow-up data were prospectively collected. Subtype-IIA is the main phospholipase isoform in preterm lung, although subtype-IB may be significantly expressed. Neonates needing surfactant retreatment have higher enzyme activity ( P = 0.021) and inflammatory mediators ( P always ≤ 0.001) and lower amounts of phospholipids ( P always < 0.05). Enzyme activity was inversely correlated to surfactant adsorption (ρ = −0.6; P = 0.008; adjusted P = 0.009), total phospholipids (ρ = −0.475; P = 0.05), and phosphatidylcholine (ρ = −0.622; P = 0.017). Exogenous surfactant significantly reduced global phospholipase activity ( P < 0.001) and subtype-IIA ( P = 0.005) and increased dioleoylphosphatidylglycerol ( P < 0.001) and surfactant adsorption ( P < 0.001). Enzyme activity correlated with duration of ventilation (ρ = 0.679, P = 0.005; adjusted P = 0.04) and respiratory morbidity score at 12 mo postnatal age (τ-b = 0.349, P = 0.037; adjusted P = 0.043) but was not associated with mortality, bronchopulmonary dysplasia, or other long-term respiratory outcomes.

Lung ultrasound in the neonatal intensive care unit: Review of the literature and future perspectives

Lung ultrasound (LU) has been increasingly used as a point-of-care method in recent years. LU has numerous advantages compared to traditional imaging tools such as chest X-ray (radiography) (CXR): it is faster and portable, does not use ionizing radiation, is performed by the same physician who cares for the patient, and can be repeated to follow the progress of the disease and the response to treatment. There is a large body of evidence that LU has an excellent diagnostic effectiveness compared to CXR, not only in adults and children, but also in neonates. This review article describes how to perform LU, how to interpret findings, and how to use LU to diagnose and differentiate common neonatal pulmonary diseases. Strengths but also limits of the technique are highlighted. Finally, we describe the recent revolutionary role of LU. The development of scoring methods in neonates with respiratory distress syndrome allowed to quantify the severity of the disease and to assist the physician in the clinical management and follow-up.

Defining information needs in neonatal resuscitation with work domain analysis

OBJECTIVE

To gain a deeper understanding of the information requirements of clinicians conducting neonatal resuscitation in the first 10 min after birth.

BACKGROUND

During the resuscitation of a newborn infant in the first minutes after birth, clinicians must monitor crucial physiological adjustments that are relatively unobservable, unpredictable, and highly variable. Clinicians' access to information regarding the physiological status of the infant is also crucial to determining which interventions are most appropriate. To design displays to support clinicians during newborn resuscitation, we must first carefully consider the information requirements.

METHODS

We conducted a work domain analysis (WDA) for the neonatal transition in the first 10 min after birth. We split the work domain into two 'subdomains'; the physiology of the neonatal transition, and the clinical resources supporting the neonatal transition. A WDA can reveal information requirements that are not yet supported by resources.

RESULTS

The physiological WDA acted as a conceptual tool to model the exact processes and functions that clinicians must monitor and potentially support during the neonatal transition. Importantly, the clinical resources WDA revealed several capabilities and limitations of the physical objects in the work domain-ultimately revealing which physiological functions currently have no existing sensor to provide clinicians with information regarding their status.

CONCLUSION

We propose two potential approaches to improving the clinician's information environment: (1) developing new sensors for the information we lack, and (2) employing principles of ecological interface design to present currently available information to the clinician in a more effective way.

Neonatal lung ultrasonography to evaluate need for surfactant or mechanical ventilation: a systematic review and meta-analysis

CONTEXT

Lung ultrasonography (LUS) is increasingly used to identify various neonatal respiratory disorders. There is emerging evidence that it can identify infants with significant lung disease who need surfactant treatment or mechanical ventilation.

OBJECTIVE

To systematically review the accuracy of LUS in determining the need for surfactant treatment or mechanical ventilation in infants with respiratory distress treated with nasal continuous positive airway pressure (NCPAP).

METHODS

Database search include EMBASE, Medline, CINAHL and Cochrane central from inception until 17 October 2018. Included is diagnostic accuracy studies reporting LUS evaluating surfactant therapy/mechanical ventilation. Two authors extracted data independently and assessed quality. Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to determine the methodological quality.

RESULTS

Six studies involving 485 infants included in the review. Three studies used LUS score, two used type 1 lung profile, and one used high-risk LUS to evaluate the outcome. The pooled sensitivity and specificity at LUS score cut-off >5-6 was 88% (95% CI 80% to 93%) and 82% (95% CI 74% to 89%), respectively. Infants with LUS score >5-6 were at significantly increased risk of surfactant treatment compared with infants with LUS score <5-6 (relative risk=7.51; 95% CI 4.16 to 13.58; two studies; participants=189; I²=0%). The diagnostic accuracy of type 1 lung profile was better in younger preterm infants (sensitivity 88.9%, specificity 100%) compared with late preterm and term infants (sensitivity 100%, specificity 28%).

CONCLUSIONS

LUS, particularly LUS score, can be used accurately to determine the need for surfactant replacement treatment or mechanical ventilation in infants with respiratory distress treated with NCPAP support. The accuracy is better in younger preterm infants compared with late preterm and term infants.

PROSPERO REGISTRATION NUMBER

CRD42018115135.

Neonatal lung ultrasonography score after surfactant in preterm infants: A prospective observational study

OBJECTIVE

To assess changes in neonatal lung ultrasonography score (nLUS) after surfactant administration in preterm infants with respiratory distress syndrome (RDS).

WORKING HYPOTHESIS

The reduction of nLUS score before (nLUSpre), 2 hours (nLUS2h), and 12 hours (nLUS12h) after surfactant administration to identify patients who will not need a second treatment.

STUDY DESIGN AND SETTING

Prospective observational study in the tertiary neonatal intensive care unit.

PATIENTS SELECTION

Forty-six preterm neonates with RDS of 32 weeks median gestational age (IQR 30-33) and mean birth weight of 1650 ± 715 g.

METHODOLOGY

Lung ultrasonography was performed before, 2 hours, and 12 hours after surfactant administration in preterm infants with RDS needing surfactant treatment. Resulting nLUS was analyzed.

RESULTS

The Wilcoxon signed-rank test demonstrated an nLUS lowering after 2 hours (P < .001) and 12 hours (P < .001) from surfactant administration. Sixteen newborns required surfactant retreatment with median gestational age of 32 weeks (IQR 29-33) and mean birth weight of 1519 ± 506 g.The receiver operating characteristic analysis for the nLUS2h yielded an area under the curve of 0.80 (95% confidence interval, 0.76-0.85; P < .001). A nLUS2h ≥7 showed a sensitivity of 94% and a specificity of 60% for needing a second treatment with surfactant.

CONCLUSIONS

In preterm infants with RDS requiring surfactant treatment, nLUS evaluated 2 hours after surfactant administration can be used to identify patients who will not need a second treatment.

Point-of-care lung ultrasound in three neonates with COVID-19

Since March 2020, the world is involved in the COVID-19 pandemic, a disease caused by a novel virus called SARS-CoV-2. Some authors have described the ultrasonographic findings of COVID-19 pneumonia in adults and children, but data on neonates are lacking. Our objective was to describe the ultrasonographic lung pattern on newborns with SARS-CoV-2 infection during the COVID-19 pandemic. Newborns who tested positive for SARS-CoV-2 PCR in respiratory samples and were evaluated with point-of-care lung ultrasound (LU) from March to April 2020 were included. LU was performed bedside by a single investigator at the time of diagnosis and every 48 h during the first week following diagnosis. Six areas were studied. Three neonates were included. Infants' comorbidities included meconium aspiration syndrome, bronchopulmonary dysplasia, and Hirschsprung's disease. One required mechanical ventilation. No deaths occurred. LU showed B-lines, consolidation, and spared areas. No pneumothorax or pleural effusion was observedConclusions: LU could be of value when managing COVID-19 neonates. We describe the findings of lung ultrasound monitoring during the first week following diagnosis in three neonates with SARS-CoV-2 infection. What is known: • Lung ultrasound (LU) is a useful tool in COVID-19 management in adults. To date, no report on LU and neonates with SARS-CoV-2 infection has been published. What is new: • This study adds evidence about LU findings in neonates with SARS-CoV-2 infection.

Lung ultrasound in preterm infants with respiratory distress: experience in a neonatal intensive care unit

Lung ultrasound (LUS) has been described as a useful tool in early prognosis of several respiratory diseases of the newborn, especially preterm infant newborns (PTNB) with respiratory distress syndrome (RDS), but still, it is not a standard of care in many neonatal units. We have conducted a descriptive, prospective study in a tertiary neonatal unit during 1 year. PTNB less than 35 weeks with respiratory distress at birth on non-invasive ventilation were recruited. A LUS was performed in the first 12 h of life and scored from 6 to 18 points (6 areas, 1 to 3 points each). They were followed until discharge. Main outcomes: need for surfactant treatment. Sixty-four preterm infants, median gestational age 29 weeks. Median LUS score in surfactant group was significantly higher than in no surfactant group (p < 0.0001). LUS ROC curve for surfactant treatment shows AUC 0.97 (IC 95% 0.92-1). LUS Odds ratio for surfactant treatment 3.17 (IC 95% 1.36-7.35).Conclusion: Early high LUS score correlates with surfactant necessity in preterm infants with respiratory distress at birth.What is Known:• Lung ultrasound (LUS) is a useful tool in determining prognosis of preterm infants with respiratory distress at birth.What is New:• This study adds evidence about LUS and preterm infants with respiratory distress, early predicting surfactant need and mechanical ventilation.

Echography-Guided Surfactant Therapy to Improve Timeliness of Surfactant Replacement: A Quality Improvement Project

OBJECTIVE

To improve time of surfactant administration with a surfactant replacement protocol based on semiquantitative lung ultrasound score (LUS) thresholds.

STUDY DESIGN

Quality improvement (QI), prospective, before-after, pilot study. In a 6-month period surfactant replacement was based only on inspired oxygen fraction (FiO₂) thresholds. In the second 6-month period, surfactant was given when either the FiO₂ or LUS exceeded the limits. The main QI measures were the proportion of neonates receiving surfactant within the first 3 hours of life and maximal FiO₂ reached before surfactant replacement. Secondary QI measures were the duration of respiratory support and ventilator-free days. Data were also collected for 1 year after the study to verify sustainability.

RESULTS

Echography-guided Surfactant THERapy (ESTHER) increased the proportion of neonates receiving surfactant within the first 3 hours of life (71.4%-90%; P < .0001) and reduced the maximal FiO₂ reached before surfactant replacement (0.33 [0.26-0.5]) vs 0.4 [0.4-0.55]; P = .005). The global need for surfactant did not significantly change. ESTHER also resulted in a significant decrease in duration of invasive ventilation and ventilator-free days.

CONCLUSIONS

ESTHER improved the timeliness of surfactant administration and secondary QI indicators related to surfactant replacement.

Continuous positive airway pressure (CPAP) vs noninvasive positive pressure ventilation (NIPPV) vs noninvasive high frequency oscillation ventilation (NHFOV) as post-extubation support in preterm neonates: protocol for an assessor-blinded, multicenter, randomized controlled trial

BACKGROUND

Various noninvasive respiratory support modalities are available in neonatal critical care in order to minimize invasive ventilation. Continuous positive airway pressure (CPAP) is the more commonly used but noninvasive positive pressure ventilation (NIPPV) seems more efficacious in the early post-extubation phase, although it is not clear if NIPPV may influence longterm outcomes. A recently introduced alternative is noninvasive high frequency oscillatory ventilation (NHFOV) which might be especially useful in babies needing high constant distending pressure. Preterm neonates may receive these respiratory supports for several weeks. Nonetheless, no data are available for the longterm use of NIPPV and NHFOV; few data exist on NHFOV and clinical outcomes, although its safety and suitability are reported in a number of preliminary short-term studies.

METHODS

We designed an assessor-blinded, multicenter, three-arms, parallel, pragmatic, randomized, controlled trial with a superiority design, investigating the use of CPAP vs NIPPV vs NHFOV during the whole stay in neonatal intensive care units in China. Since safety data will also be analyzed it may be considered a phase II/III trial. Moreover, subgroup analyses will be performed on patients according to prespecified criteria based on physiopathology traits: these subgroup analyses should be considered preliminary. At least 1440 neonates are supposed to be enrolled. The trial has been designed with the collaboration of international colleagues expert in NHFOV, who will also perform an interim analysis at the about 50% of the enrolment.

DISCUSSION

The study is applying the best trial methodology to neonatal ventilation, a field where it is often difficult to do so for practical reasons. Nonetheless, ours is also a physiology-driven trial, since interventions are applied based on physiological perspective, in order to use ventilatory techniques at their best. The pragmatic design will increase generalizability of our results but subgroup analyses according to predefined physiopathological criteria are also previewed trying to have some advantages of an explanatory design. Since not all clinicians are well versed in all respiratory techniques, the training is pivotal. We intend to apply particular care to train the participating units: a specific 3-month period and several means have been dedicated to this end.

TRIAL REGISTRATION

NCT03181958 (registered on June 9, 2017).

Estimation of early life endogenous surfactant pool and CPAP failure in preterm neonates with RDS

Background

It is not known if the endogenous surfactant pool available early in life is associated with the RDS clinical course in preterm neonates treated with CPAP. We aim to clarify the clinical factors affecting surfactant pool in preterm neonates and study its association with CPAP failure.

Methods

Prospective, pragmatic, blind, cohort study. Gastric aspirates were obtained (within the first 6 h of life and before the first feeding) from 125 preterm neonates with RDS. Surfactant pool was measured by postnatal automated lamellar body count based on impedancemetry, without any pre-analytical treatment. A formal respiratory care protocol based on European guidelines was applied. Clinical data and perinatal risk factors influencing RDS severity or lamellar body count were real-time recorded. Investigators performing lamellar body count were blind to the clinical data and LBC was not used in clinical practice.

Results

Multivariate analysis showed gestational age to be the only factor significantly associated with lamellar body count (standardized β:0.233;p = 0.023). Lamellar body count was significantly higher in neonates with CPAP success (43.500 [23.750–93.750]bodies/μL), than in those failing CPAP (20.500 [12.250–49.750] bodies/μL;p = 0.0003).LBC had a moderate reliability to detect CPAP failure (AUC: 0.703 (0.615–0.781);p < 0.0001; best cut-off: ≤30,000 bodies/μL). Upon adjustment for possible confounders, neither lamellar body count, nor its interaction factor with gestational age resulted associated with CPAP failure.

Conclusions

Early postnatal lamellar body count on gastric aspirates in CPAP-treated preterm neonates with RDS is significantly influenced only by gestational age. Lamellar bodies are not associated with CPAP failure. Thus, the endogenous surfactant pool available early in life only has a moderate reliability to predict CPAP failure.

Lung ultrasound findings in congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) occurs in approximately 1 in 2500 to 5000 infants. The use of lung ultrasound (LUS) for its diagnosis has been reported in only two case reports. The aim of this study was to report the LUS pattern of CDH in a case series of infants with respiratory distress. This case series was part of a cohort enrolled in a larger prospective observational study. LUS was performed at the point-of-care during the first 24 h of life of the neonates and its operation time was measured. Seven cases (six left and one right CDH) were diagnosed. We found that the pattern of LUS for CDH diagnosis includes (1) partial absence of the hyperechoic line representing the normal diaphragmatic profile, (2) partial absence of the pleural line in the affected hemithorax, (3) absence of A lines in the affected area, (4) presence of multi-layered area with hyperechoic contents in motion (normal gut), and (5) possible presence of parenchymatous organs inside the thorax (i.e., liver or spleen).Conclusion: A description of LUS pattern in infants with CDH is provided. LUS at the point-of-care may allow the prompt diagnosis of CDH and this is particularly useful in cases of missed prenatal diagnosis. What is Known: • Congenital diaphragmatic hernia occurs in approximately 1 in 2500 to 5000 infants but the use of lung ultrasound for its diagnosis has been reported in only two case reports. What is New: • Research provided a description of lung ultrasound pattern in infants with congenital diaphragmatic hernia. • Lung ultrasound at the point-of-care may allow a prompt diagnosis of congenital diaphragmatic hernia, particularly useful in cases of missed prenatal diagnosis.