Lung ultrasonography cannot identify the categories of neonatal pneumonia: the Findings From A Prospective Multicenter Study Running Head: LUS cannot identify the categories of pneumonia

Lung ultrasonography cannot identify the categories of neonatal pneumonia: the Findings From A Prospective Multicenter Study Running Head: LUS cannot identify the categories of pneumonia | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Lung ultrasonography cannot identify the categories of neonatal pneumonia: the Findings From A Prospective Multicenter Study Running Head: LUS cannot identify the categories of pneumonia Hai-Ran Ma, Peng Jiang, Rui-Yan Shan, Wei Fu, Jing Liu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8573536/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 21 You are reading this latest preprint version Abstract Background Lung ultrasound (LUS) is widely used in the management of neonatal pneumonia, our previous research has confirmed that LUS cannot identify the etiologies of neonatal pneumonia. However, there is still controversy and confusion regarding whether LUS can differentiate between different types of pneumonia (such as intrauterine infectious pneumonia (IP), ventilator-associated pneumonia (VAP), community-acquired pneumonia (CAP), meconiumaspiration pneumonia (MAP)). Therefore, we have organized this prospective multicenter study to address and answer these remaining questions. Methods A prospective approach was used to collect LUS data on neonatal all kinds of pneumonia from 5 tertiary hospitals in China. The patients were devided into three categories: based on whether there is evidence of infection,ventilator treatment ot the history of meconium aspiration, they are classified as IP and non-IP, VAP and non-VAP, MAP and non-MAP. The major LUS imaging characteristics and complications were compared among groups. Results A total of 235 patients with neonatal pneumonia were included, comprising 195 patients with IP and 40 patients with non-IP. The ultrasound characteristics included pleural line abnormalities in all 235 patients, involving zones 1–12;B-lines in 174 patients, involving zones 1–12;lung consolidation in all 235 patients, involving zones 1–12%; pneumothorax in 4 patients; and pleural effusion in 31 patients.No significant differences in ultrasound characteristics were found between patients with MAP and patients with non-MAP or between patients with-or without VAP.Compared with IP,aspiration pneumonia was associated with a significantly greater incidence of right lung consolidation (100% vs. 89.2%),with no significant differences in other ultrasound signs. Conclusion The results of this study show that the most common ultrasound imaging manifestations of various etiologies of pneumonia in newborns are lung consolidation accompanied by airbronchograms.Differentiating between various types of pneumonia still requires the combination of medical history and relevant laboratory tests. Neonate Pneumonia Lung Ultrasound Figures Figure 1 INTRODUCTION Neonatal pneumonia is one of the most common diseases and is an important cause of death or severe sequelae in newborns. A significant proportion of child deaths due to pneumonia occur in the neonatal period [ 1 ] . Among the 10.8 million child deaths worldwide each year, at least one-third occur within the first 28 days after birth [ 2 ] . Epidemiological surveys have shown a mortality rate of 5% − 20% for neonatal infectious pneumonia, which is particularly severe in developing countries [ 3 – 5 ] . It is reported that hospitalizations due to pneumonia account for 14% of total hospitalizations for newborns [ 5 ] . Therefore, strengthening the research on pneumonia diagnosis techniques is of great significance for improving the prognosis of newborns. Lung ultrasound (LUS) has been increasingly used as an diagnostic tool for neonatal pneumonia over the past decade, offering advantages of no radiation, portability, cost-effectiveness [ 6 – 8 ] , and higher diagnostic efficiency than traditional chest X-rays (CXR) [ 8 – 13 ] . Our previous research has confirmed that LUS cannot identify the etiologies of neonatal pneumonia, thus resolving some long-standing puzzles that have puzzled both clinicians and ultrasound specialists [ 11 , 14 ] . However, there is still controversy and confusion regarding whether LUS can differentiate between different types of pneumonia, such as infectious pneumonia (IP) or noninfectious pneumonia (non-IP), ventilator-associated pneumonia (VAP), community-acquired pneumonia (CAP), meconiumaspiration pneumonia (MAP) or nonmeconiumaspiration pneumonia (non-MAP), etc.. Therefore, we have organized this prospective multicenter study to address and answer these remaining questions. PARTICIPANTS and METHODS Participants This research is a part of our previously large-scale multicenter study that data has not been published yet[11], the research subjects,inclusion and exclusion criteria for the research subjects, research methods, observation indicators, and the qualifications of the participants are all consistent with it, which will not be elaborated on further here [11]. Demographic and Clinical Data In this study, the general information of the study participants, such as gestational age (GA), gender, delivery method, and birth weight, was collected. After data collection, the study participants were divided into groups according to different criteria: (1) pneumonia was classified as “IP” or “non-IP” on the basis of the presence of infection. (2) infectious pneumonia was further subdivided into “VAP” or “non-VAP” on the basis of whether the infection was associated with mechanical ventilation. and (3) aspiration pneumonia was classified as “MAP” or “non-MAP” on the basis of whether the aspirated substance was meconium. LUS examination The division of the lungs, as well as the examination and operation methods of lung ultrasound, are all carried out and implemented in accordance with the published internationally standards [ 15 – 17 ] . In the presented study, abnormal LUS signs were defined as follows: (1) pleural line abnormalities, including a broken, thickened, blurred, and missing pleural line. (2) B-line signs, including a single B-line, confluent B-line, alveolar-interstitial synthesis, compact B-line, and white lung. (3) lung consolidations and air bronchograms; and (4) comorbidities such as pleural effusion and pneumothorax. The total number and distribution of pleural line abnormalities, B-line signs, lung consolidations, pneumothorax and pleural effusion in each participant were determined in accordance with the 12-region method. For example, if the total number of regions involved in lung consolidation was three, it was recorded as three. Then, the number of regions in which LUS images were distributed was compared across the different groups. The distribution and incidence of consolidations were compared between patients with infectious pneumonia‌ and those with noninfectious pneumonia. Statistics analysis All the data were statistically analyzed using SPSS version 25.0 (IBM, Inc.). Continuous data were evaluated for normality and homogeneity of variance by the Kolmogorov‒Smirnov test and analysis of variance, respectively. The data did not follow a normal distribution or homogeneity of variances, so they were compared by the Kruskal‒Wallis H test or the Mann‒Whitney U test. Categorical data were compared by the χ 2 test or Fisher's exact test. Summary statistics are presented as the median (interquartile range) for continuous variables and frequencies (percentages) for categorical variables. All tests were two-sided, and p < 0.05 was considered to indicate a significant difference. RESULTS Demographics and general information A total of 235 patients with neonatal pneumonia were included, with gestational ages ranging from 25 to 42 + 4 weeks and birth weights ranging from 700 g to 4400 g. A total of 105 patients were delivered by cesarean section, and 130 were delivered by vaginally, with 146 males and 89 females. There were 195 patients with infectious pneumonia and 40 with noninfectious pneumonia, 123 patients with non-VAP, 72 patients with VAP, 23 patients with MAP, and 17 patients with non-MAP. Comparison of the LUS findings in different groups Among the 235 patients with neonatal pneumonia, 235 (100%) had abnormal pleural lines, and the number of affected areas ranged from 1 to 12. 174 patients (74.0%) had B-lines, and the number of affected areas ranged from 1 to 12. 235 patients (100%) had lung consolidations, and the number of affected areas ranged from 1 to 12. 4 patients (1.7%) had pneumothorax; and 31 patients (13.2%) had pleural effusion. The characteristics of the LUS images of the patients with various types of pneumonia were similar and included mainly lung consolidations with air bronchograms, abnormal pleural lines, the disappearance of A-lines, and B-line signs such as B-lines or AISs visible in nonconsolidated areas. A small number of cases were complicated with signs of pleural effusion and pneumothorax (Table 1 ). Various types of pneumonia share similar morphological characteristics in terms of lung consolidations. Lung consolidations of different sizes can be found in the same area, with irregular boundaries accompanied by air bronchograms. It is difficult to distinguish different types of pneumonia on the basis of the morphology of lung consolidation (Fig. 1 ). Table 1 Characteristics of LUS findings in patients with various types of pneumonia No. Group PLA B lines LC PT PE IP (N = 195) 195 147 195 3 28 Non-IP (N = 40) 40 27 40 1 3 Non-VAP (N = 123) 123 90 123 3 15 VAP (N = 72) 72 57 72 0 13 MAP (N = 23) 23 15 23 1 2 Non-MAP (N = 17) 17 12 17 0 1 Note: LC, lung consolidation; LUS, lung ultrasound; MAP, meconium aspiration pneumonia; PE, pleural effusion; PLA, pleural line abnormalities; PT, pneumothorax; VAP, ventilator-associated pneumonia. There was no significant difference in the LUS findings between patients with VAP and patients with non-VAP or between patients with MAP patients and patients with non-MAP (Table 2 ). Among the patients with infectious pneumonia, 147 had bilateral lung consolidation, and 47 had unilateral lung consolidation (21 on the left and 27 on the right); 125 had bilateral B-lines, and 22 had unilateral lung consolidations (9 on the left and 13 on the right); 176 had bilateral pleural line abnormalities, and 19 had unilateral pleural line abnormalities (9 on the left and 10 on the right). Among the patients with noninfectious pneumonia, 34 had bilateral lung consolidations and 6 had unilateral lung consolidations (all on the right), 25 had bilateral B-line signs and 2 had unilateral B-line signs (all on the left), and 38 had bilateral pleural line abnormalities and 2 had unilateral pleural line abnormalities (1 on the left and 1 on the right). Lesions associated with infectious pneumonia and noninfectious aspiration pneumonia were slightly more common in the right lung, and there was no significant difference in the distribution of pleural line abnormalities or B-line signs between the bilateral lungs. The incidence of right lung consolidation in patients with aspiration pneumonia (100%) was significantly greater than that in patients with infectious pneumonia (89.2%), whereas there was no significant difference in the incidence of left lung consolidation (Table 3 ). Table 2 Comparison of LUS findings in different pneumonia groups Median (IQR) Group PLA B lines LC PT PE IP (N = 195) 8(8) 4(7) 4(5) 0(0) 0(0) Non-IP (N = 40) 12(5) 4(12) 5(7) 0(0) 0(0) p -Values 0.22 0.98 0.30 0.30 0.63 Non-VAP (N = 123) 8(8) 4(8) 4(6) 0(0) 0(0) VAP (N = 72) 9(8) 4(10) 4(6) 0(0) 0(0) p -Values 0.20 0.22 0.96 0.18 0.16 MAP (N = 23) 12(7) 2(12) 4(7) 0(0) 0(0) Non-MAP (N = 17) 8(4) 8(12) 6(6) 0(0) 0(0) p -Values 0.84 0.32 0.37 0.78 0.42 Note: IQR, interquartile range; LC, lung consolidation; LUS, lung ultrasound; MAP, meconium aspiration pneumonia; PE, pleural effusion; PLA, pleural line abnormalities; PT, pneumothorax; VAP, ventilator-associated pneumonia. Table 3 Comparison of lung consolidation between patients with infectious pneumonia and those with noninfectious pneumonia PLA No. (%) B line No. (%) LC No. (%) Group Left Right Left Right Left Right IP(N = 195) 185(94.9) 186(95.4) 134(68.7) 138(70.8) 168(86.2) 174(89.2) Non-IP(N = 40) 39(97.5) 39(97.5) 27(67.5) 25(62.5) 34(85.0) 40(100) p -Values 0.70 1.00 0.88 0.30 0.85 0.03 Abbreviations: LC, lung consolidation; LUS, lung ultrasound; PLA, pleural line abnormality. DISCUSSION The results of this study revealed that: (1) the main LUS manifestations of neonatal pneumonia are as follows: lung consolidations with air bronchograms, irregular boundaries of the consolidation areas, and abnormal pleural lines, and most pneumonia patients present B-line signs such as B-lines or AIS in nonconsolidated areas. A few cases are complicated with pleural effusion and pneumothorax signs. (2) Different types of neonatal pneumonia have similar manifestations on LUS. The incidence of consolidations in the right lung in patients with aspiration pneumonia is slightly greater than that in patients with infectious pneumonia. In this study, there was no difference in LUS findings between patients with neonatal infectious pneumonia and patients with noninfectious aspiration pneumonia. At present, many clinical studies have confirmed that the characteristics of LUS findings in patients with neonatal or childhood infectious pneumonia are mainly pulmonary consolidations with air bronchograms, B-lines, and abnormal pleural lines and are sometimes accompanied by pleural effusion and pneumothorax [ 11 , 17 – 19 ] , which is consistent with the present study. To our knowledge, comparative studies on LUS characteristics between neonatal infectious pneumonia and noninfectious pneumonia have not yet been reported. However, the main characteristics of chest radiography in children with aspiration pneumonia are diffuse ground‒glass opacities, interstitial thickening, or dense consolidations [ 20 – 21 ] . These characteristics are the same as the chest radiograph features of neonatal infectious pneumonia. The chest radiograph manifestations of aspiration pneumonia in adults are similar to those of infectious pneumonia, which also supports this point from another perspective. [ 22 – 23 ] Aspiration pneumonia is a common emergency in newborns. Aspiration pneumonia can be classified into chemical pneumonia, oropharyngeal secretion aspiration pneumonia, and inert substance aspiration pneumonia according to the nature of the inhaled substance [ 24 ] . The main characteristics of aspiration pneumonia on LUS are lung consolidations, B-line signs, and pleural line abnormalities, which are occasionally accompanied by pneumothorax and pleural effusion [ 25 – 26 ] . In aspiration pneumonia, meconium aspiration syndrome caused by MAP has been widely studied. The LUS manifestations of MAP include lung consolidations, B-line signs, and pleural line abnormalities, and some cases involve pneumothorax and pleural effusion [ 15 , 27 – 28 ] . Research on the LUS characteristics of other types of aspiration pneumonia is limited. In the study by Regiroli G et al., the LUS manifestations of bile aspiration pneumonia were consistent with those described above [ 29 ] . Wu H et al. compared the radiographic features of X-ray chest films between patients with gastric content aspiration pneumonia and those with other types of pneumonia. The results revealed that the positive rates of lesions in the right lung lobe for patients with gastric content aspiration pneumonia and those with other types of pneumonia were 84.3% and 69.5%, respectively, whereas the positive rates of lesions in the left lung lobe were 69.5% and 68.5%, respectively [ 30 ] . In this study, the incidence of right-sided lung consolidations in patients with aspiration pneumonia was 100%, whereas that in patients with infectious pneumonia was 89.2%, which is similar to the findings of Wu H et al. Although patients with aspiration pneumonia presented a slightly higher incidence of right-sided lung consolidation than patients with infectious pneumonia did, given the high incidence of both types and the similar morphology of lung consolidations, there is no clinical possibility of distinguishing between them on the basis of these findings. Hugosson CO et al. reported that the chest radiograph and CT imaging features of lipid aspiration pneumonia in infants mainly presented as lung consolidation [ 31 ] ; this finding is consistent with the major CT imaging manifestations of other types of pneumonia. The above research results indicate that the LUS findings of different types of aspiration pneumonia are similar and are characterized by lung consolidation as the main manifestation, which is in accordance with the results of this study. The characteristics of pulmonary lesions in patients with infectious pneumonia are related to pathogens. The main pathogens of VAP include Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, respiratory syncytial virus, adenovirus, mycoplasma, and fungal infections. This is similar to the pathogen spectrum of other infectious pneumonias, such as congenital pneumonia and community-acquired pneumonia [ 3 , 32 ] . Therefore, the LUS characteristics of the two types of pneumonia are similar. There have been numerous studies on LUS characteristics in patients with VAP, and the ultrasonic signs of VAP are consistent with classic pneumonia manifestations, mainly including lung consolidations with air bronchograms, pleural line abnormalities, B-line signs, and occasionally pleural effusion and pneumothorax [12–13,33−34] , which is consistent with the conclusions of this study. The LUS findings of patients with VAP revealed new signs of lung consolidation on the basis of preexisting pneumonia manifestations [ 35 – 36 ] . This study confirms that these additional lung consolidations do not make the LUS manifestations of VAP different from those of other types of pneumonia. This multicenter, prospective study confirmed that the signs detected by LUS in patients with noninfectious pneumonia are consistent with those detected in patients with infectious pneumonia and that there are no differences in LUS manifestations among different types of neonatal pneumonia. Their most prominent feature is irregularly bordered lung consolidations with air bronchograms. Lung consolidation cannot be used to distinguish between different types of pneumonia but is related only to the severity of pneumonia [ 11 , 37 – 38 ] . In clinical practice, LUS may need to be combined with other diagnostic tools and clinical symptoms to diagnose various types of pneumonia. There are several limitations of this study. First, the sample size of patients with noninfectious aspiration pneumonia was small, and a larger sample size is needed in the future to confirm the conclusions of this study. Second, this study only compared the characteristics of LUS in the early stage of pneumonia but did not compare the ultrasound characteristics throughout the entire course of pneumonia. More studies are needed in the future to explore whether the ultrasound images of patients in the middle and late stages of different types of neonatal pneumonia have independent characteristics. Conclusion The results of this study show that the most common ultrasound imaging manifestations of various etiologies of pneumonia in newborns are lung consolidation accompanied by airbronchograms. There is no specificity in the ultrasound characteristics among different etiologies of pneumonia. Although aspiration pneumonia is more likely to occur in the right lung, this fact alone is not sufficient to distinguish between aspiration pneumonia and non-aspiration pneumonia. Differentiating between various types of pneumonia still requires the combination of medical history and relevant laboratory tests. Abbreviations LUS: Lung ultrasound; CXR: chest X-rays; IP: infectious pneumonia; non-IP: noninfectious pneumonia; VAP: ventilator-associated pneumonia; CAP: community-acquired pneumonia;MAP: meconiumaspiration pneumonia; non-MAP: nonmeconiumaspiration pneumonia; GA: gestational age Declarations Human Ethics :This study was approved by the Ethics Committee of Maternal and Child Health Care Hospital, Chaoyang District, Beijing (No. 2011-LC-Ped-01), and the participating hospitals. Consent to Participate declarations : Informed consent was obtained from the guardians of the newborns before the data were collected. Author contributions: Jing Liu conceptualized and designed the study, drafted the initial manuscript, obtained funding and takes responsibility for the integrity of the data and the accuracy of the data analysis. Hai-Ran Ma conceptualized and designed the study, undertook the statistical analysis, drafted the initial manuscript, and reviewed and revised the manuscript. Peng Jiang, Rui-Yan Shan, and Wei Fu designed the study, collected data, carried out the initial analyses, and reviewed and revised the manuscript. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work. All authors contributed equally to this work and should be considered co-first authors. Funding or research support: This study was supported by the Foundation of the Social Development Projects,Beijing Chaoyang District Bureau of Science, Technology and Information (CYSF1922) and the Clinical Research Special Fund of Wu Jieping Medical Foundation (320. 6750.2024-03-32). Conflict of interest : The authors declare no conflict of interest. Availability of Supporting Data: The dataset used and analyzed are available from the corresponding author upon reasonable request. Clinical trial number : not applicable. References Duke T. Neonatal pneumonia in developing countries. Archives of disease in childhood. Fetal and neonatal edition, 2005; 90 (3): F211-219. Black RE, Morris SS, Bryce J. Where and why are 10 million children dying every year? Lancet,2003;361 (9376):2226–2234. Hooven TA, Polin RA. Pneumonia. Seminars in fetal & neonatal medicine, 2017; 22 (4):206–213. Stoll BJ. The global impact of neonatal infection. Clinics in perinatology,1997; 24 (1): 1–21. Yang L,Ying Z,Yu X, Man L. Prevalence and risk factors of neonatal pneumonia in China: A longitudinal clinical study. Biomedical Research, 2018; 29 (1): 57–60. Liu J, Liu F, Liu Y, Wang HW, Feng ZC. Lung ultrasonography for the diagnosis of severe pneumonia of the newborn. Chest, 2014;146 (2):483–488. Raimondi F,Yousef N, Migliaro F, Capasso L, De Luca D. Point-of-care lung ultrasound in neonatology: classification into descriptive and functional applications. Pediatric research, 2021; 90 (3):524–531. Sharma D, Farahbakhsh N. Role of chest ultrasound in neonatal lung disease: a review of current evidences. The journal of maternal-fetal & neonatal medicine, 2019;32 (2):310–316. Ye X, Xiao H, Chen B, Zhang S. Accuracy of Lung Ultrasonography versus Chest Radiography for the Diagnosis of Adult Community-Acquired Pneumonia: Review of the Literature and Meta-Analysis. PloS one, 2015;10 (6): e0130066. Martínez Redondo J, Comas Rodríguez C, Pujol Salud J, Crespo Pons M, García Serrano C, Ortega Bravo M, Palacín Peruga J M. Higher Accuracy of Lung Ultrasound over Chest X-ray for Early Diagnosis of COVID-19 Pneumonia. International journal of environmental research and public health, 2021; 18 (7):3481. doi: 10.3390/ijerph18073481 . Ma HR,Deng BY, Liu J, Jiang P, Xu YL, Song XY, Li J, Huang LH, Bao LY, Shan RY, Fu W. Lung ultrasound to diagnose infectious pneumonia of newborns: A prospective multicenter study. Pediatric pulmonology, 2023; 58 (1): 122–129. Tusor N, De Cunto A, Basma Y, Klein J L, Meau-Petit V. Ventilator-associated pneumonia in neonates: the role of point of care lung ultrasound. European journal of pediatrics, 2021; 180 (1):137–146. Jiang P, Wei J. The Application of Pulmonary Ultrasound in Neonatal Ventilator-Associated Pneumonia. Frontiers in pediatrics, 2022;10:882056. Liu J. Lung Ultrasonography Cannot Identify the Etiology of Pediatric Pneumonia. Archivos de Bronconeumología, 2024; 60(7):445–447. https://doi.org/10.1016/j.arbres.2024.02.016 Liu J, Copetti R, Sorantin E, Lovrenski J, Rodriguez-Fanjul J, Kurepa D, Feng X, Cattaross L, Zhang H, Hwang M, et al. Protocol and Guidelines for Point-of-Care Lung Ultrasound in Diagnosing Neonatal Pulmonary Diseases Based on International Expert Consensus. JoVE, 2019; 145:e58990,doi: 10.3791/58990 Liu J, Guo G, Kurepa D, Volpicelli G, Sorantin E, Lovrenski J, Alonso-Ojembarrena A, Hsieh KS, Lodha A, Yeh T F, et al. Specification and guideline for technical aspects and scanning parameter settings of neonatal lung ultrasound examination. The journal of maternal-fetal & neonatal medicine, 2022; 35(5): 1003–1016. Liu J, Ma HR,Fu W. Lung Ultrasound to Diagnose Pneumonia in Neonates with Fungal Infection. Diagnostics, 2022; 12 (8):1776. Guitart C,Rodríguez-Fanjul J, Bobillo-Perez S, Carrasco JL, Inarejos Clemente EJ, Cambra FJ, Balaguer M, Jordan I. An algorithm combining procalcitonin and lung ultrasound improves the diagnosis of bacterial pneumonia in critically ill children: The PROLUSP study, a randomized clinical trial. Pediatric pulmonology, 2022;57 (3):711–723. Öktem A, Zenciroğlu A, Üner Ç, Aydoğan S, Dilli D, Okumuş N. Efficiency of Lung Ultrasonography in the Diagnosis and Follow-up of Viral Pneumonia in Newborn. American journal of perinatology, 2023;40 (4):432–437. Lee KH, Kim WS, Cheon JE, Seo J B, Kim IO, Yeon KM. Squalene aspiration pneumonia in children: radiographic and CT findings as the first clue to diagnosis. Pediatric radiology, 2005; 35 (6):619–623. Streck HL, Goldman JL, Lee BR, Sheets JM, Wirtz AL. Evaluation of the Treatment of Aspiration Pneumonia in Hospitalized Children. Journal of the Pediatric Infectious Diseases Society, 2022;11 (3):102–107. Sharma S, Maycher B, Eschun G. Radiological imaging in pneumonia: recent innovations. Current opinion in pulmonary medicine,2007;13 (3):159–169. Katz DS, Leung AN. Radiology of pneumonia. Clinics in chest medicine, 1999;20 (3):549–562. Karim RM, Momin IA, Lalani II, Merchant SS, Sewani AA, Hassan BS, Mahmood N. Aspiration pneumonia in pediatric age group: etiology, predisposing factors and clinical outcome. JPMA. The Journal of the Pakistan Medical Association, 1999; 49 (4): 105–108. Buonsenso D, De Rose C, Morello R, Lazzareschi I, Valentini P. Aspiration pneumonia in children with neurological disorders: a new indication for lung ultrasound? A case series. Journal of ultrasound, 2022; 25 (2): 325–331. Fernandes Rodrigues N, Giraud L, Bolen G, Fastrès A, Clercx C, Boysen S, Billen F, Gommeren K. Comparison of lung ultrasound, chest radiographs, C-reactive protein, and clinical findings in dogs treated for aspiration pneumonia. Journal of veterinary internal medicine, 2022; 36 (2):743–752. Piastra M, Yousef N, Brat R, Manzoni P, Mokhtari M, De Luca D. Lung ultrasound findings in meconium aspiration syndrome. Early human development, 2014, 90(Suppl 2): S41-S43. Liu J, Cao HY, Fu W. Lung ultrasonography to diagnose meconium aspiration syndrome of the newborn. The Journal of international medical research,2016;44 (6):1534–1542. Regiroli G, La Malfa G, Loi B, Vivanti A, Centorrino R, De Luca D. Ultrasound-assessed lung aeration, oxygenation and respiratory care in neonatal bile acid pneumonia: A nested case-control study. Acta paediatrica,2023; 112 (9):1898–1904. Wu H, Zhao X. Pulmonary aspiration only increases the risk of right-sided pneumonia in children: comparison of salivagrams and chest radiographs. Nuclear medicine communications, 2018; 39 (6):505–510. Hugosson CO, Riff EJ, Moore CC, Akhtar M, Tufenkeji HT. Lipoid pneumonia in infants: a radiological-pathological study. Pediatric radiology, 1991;21 (3):193–197. Nissen MD. Congenital and neonatal pneumonia. Paediatric respiratory reviews, 2007; 8 (3):195–203. Ibrahim M, Omran A, Ibrahim M, Bioumy N, El-Sharkawy S. Lung Ultrasound in Early Diagnosis of Neonatal Ventilator Associated Pneumonia before Any Radiographic or Laboratory Changes. Case reports in pediatrics,2016;2016: 4168592. Liu J, Qiu RX. Lung Ultrasound Monitoring of Legionella Ventilator-Associated Pneumonia in an Extremely Low-Birth- Weight Infant. Diagnostics,2022;12 (9):2253. Bouhemad B,Dransart-Rayé O, Mojoli F, Mongodi S. Lung ultrasound for diagnosis and monitoring of ventilator-associated pneumonia. Annals of translational medicine, 2018; 6 (21): 418. Pradhan S, Shrestha PS, Shrestha GS, Marhatta MN. Clinical impact of lung ultrasound monitoring for diagnosis of ventilator associated pneumonia: A diagnostic randomized controlled trial. Journal of critical care 2020;58(1): 65–71. Mafort TT, Lopes AJ, da Costa CH, da Cal MS, Lopes MC, da Silva BRA, Faria LF, Faria AC. Costa W, Salles REB, et al. Changes in lung ultrasound of symptomatic healthcare professionals with COVID-19 pneumonia and their association with clinical findings. Journal of clinical ultrasound, 2020; 48 (9):515–521. Kong S, Wang J, Li Y, Tian Y, Yu C, Zhang D, Li H, Zhang L, Pang X, Xie M. Value of Bedside Lung Ultrasound in Severe and Critical COVID-19 Pneumonia. Respiratory care, 2021; 66 (6):920–927. Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8573536","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":578113923,"identity":"30beae88-5165-473b-9a03-ab9d7f904a14","order_by":0,"name":"Hai-Ran Ma","email":"","orcid":"","institution":"Department of Neonatology and Neonatal Intensive Care Unit, Huizhou Central People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Hai-Ran","middleName":"","lastName":"Ma","suffix":""},{"id":578113924,"identity":"ca596975-daec-438e-8a3e-d20fddb47f8d","order_by":1,"name":"Peng Jiang","email":"","orcid":"","institution":"Department of Neonatology and NICU, Beijing Obstetrics and Gynecology Hospital, Capital Medical University. Beijing Maternal and Child Health Care Hospital","correspondingAuthor":false,"prefix":"","firstName":"Peng","middleName":"","lastName":"Jiang","suffix":""},{"id":578113926,"identity":"64a78444-f42c-4909-ab94-8863bb548eea","order_by":2,"name":"Rui-Yan Shan","email":"","orcid":"","institution":"Department of Neonatology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University","correspondingAuthor":false,"prefix":"","firstName":"Rui-Yan","middleName":"","lastName":"Shan","suffix":""},{"id":578113927,"identity":"f7976d3b-97af-4812-94ec-06b00b6cd65b","order_by":3,"name":"Wei Fu","email":"","orcid":"","institution":"Department of Neonatology and NICU, Beijing Chaoyang District Maternal and Child Health Care Hospital","correspondingAuthor":false,"prefix":"","firstName":"Wei","middleName":"","lastName":"Fu","suffix":""},{"id":578113929,"identity":"b21038c2-f9a4-4664-b5f5-77d96066a845","order_by":4,"name":"Jing Liu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAyUlEQVRIie3OPwrCMBTH8V8p1KXYtVuvkEwuHia5QCl0caglRWiXHsDiJZxEt5RAXXoIe4M6uoj1D67JKJjvEgLvw3uAzfaDzV2AMIA51UZII+J9Sd2aks/LEHJhdpg380kyHNex2wyF8leIFvrDfEJ4f06dHRfK70FPumVvUna8mEjblGBEGpOmncjdnGS82DpCXoUR8ZKJyNSpuZBjF9K9jgSBOtBbmce0Umpk2TLSbnkuIoACFa9PqJ+fci9Ajsho1maz2f6yBykLQyM65OYBAAAAAElFTkSuQmCC","orcid":"","institution":"Department of Neonatology and NICU, Beijing Obstetrics and Gynecology Hospital, Capital Medical University. Beijing Maternal and Child Health Care Hospital","correspondingAuthor":true,"prefix":"","firstName":"Jing","middleName":"","lastName":"Liu","suffix":""}],"badges":[],"createdAt":"2026-01-11 12:38:41","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8573536/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8573536/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":101205839,"identity":"ee205ba4-1dfc-4234-8675-59eeb6017eb6","added_by":"auto","created_at":"2026-01-27 09:50:22","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":110144,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscrips.docx","url":"https://assets-eu.researchsquare.com/files/rs-8573536/v1/36bad309f7915ee8deffaf04.docx"},{"id":101205043,"identity":"b70b7552-baba-4108-b6e8-3b5c49c77351","added_by":"auto","created_at":"2026-01-27 09:45:45","extension":"tiff","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":8295670,"visible":true,"origin":"","legend":"","description":"","filename":"Figure1.tiff","url":"https://assets-eu.researchsquare.com/files/rs-8573536/v1/05fa3049a11f0491149be509.tiff"},{"id":101074050,"identity":"7fd4407b-9671-4519-8700-0aa255a0e306","added_by":"auto","created_at":"2026-01-25 10:19:20","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":66383,"visible":true,"origin":"","legend":"","description":"","filename":"Tables.docx","url":"https://assets-eu.researchsquare.com/files/rs-8573536/v1/4d544352d0c61c86f85bd7df.docx"},{"id":101074048,"identity":"7056421d-b240-4e6d-ad3f-95235a0ef1a2","added_by":"auto","created_at":"2026-01-25 10:19:20","extension":"json","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":7645,"visible":true,"origin":"","legend":"","description":"","filename":"52ad5f6dc2dd4db59fc4fc8089ec5440.json","url":"https://assets-eu.researchsquare.com/files/rs-8573536/v1/f0b009d5157b9d2148f86179.json"},{"id":101205708,"identity":"12a669e6-53e4-4b3f-92bb-f1fcb8a82b3d","added_by":"auto","created_at":"2026-01-27 09:50:10","extension":"xml","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":98011,"visible":true,"origin":"","legend":"","description":"","filename":"52ad5f6dc2dd4db59fc4fc8089ec54401enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-8573536/v1/e11f0f313881aebf1e1d9a50.xml"},{"id":101074051,"identity":"ae2890fd-d75a-486a-9a05-c1efa7d37ae9","added_by":"auto","created_at":"2026-01-25 10:19:20","extension":"tiff","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":8295670,"visible":true,"origin":"","legend":"","description":"","filename":"Figure1.tiff","url":"https://assets-eu.researchsquare.com/files/rs-8573536/v1/200db3cb13a0d75b5995ed76.tiff"},{"id":101074045,"identity":"c563de98-a623-43a4-ab48-fb3a8ba9506c","added_by":"auto","created_at":"2026-01-25 10:19:20","extension":"png","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":166044,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineFigure1.png","url":"https://assets-eu.researchsquare.com/files/rs-8573536/v1/5ff17c360408d1fbc81d4ce0.png"},{"id":101204885,"identity":"23cfa08e-f21a-4be6-bd3d-6dde2a0228ac","added_by":"auto","created_at":"2026-01-27 09:44:56","extension":"xml","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":97029,"visible":true,"origin":"","legend":"","description":"","filename":"52ad5f6dc2dd4db59fc4fc8089ec54401structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-8573536/v1/52769c85c3a27a371b953561.xml"},{"id":101074044,"identity":"f62c551c-65f8-4c45-bd49-18a958f9aa23","added_by":"auto","created_at":"2026-01-25 10:19:20","extension":"html","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":107477,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8573536/v1/c82b38d43286c3d5cf871bbd.html"},{"id":101074043,"identity":"5fc905c1-ca56-46d5-9906-69c5edc87b10","added_by":"auto","created_at":"2026-01-25 10:19:20","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1440004,"visible":true,"origin":"","legend":"\u003cp\u003eLUS findings of normal lung and different types of pneumonia in newborns.\u003c/p\u003e\n\u003cp\u003eA: Normal lung. B:Congenital IP. C: VAP. D: CAP. E: MAP. F: Milk aspiration pneumonia. It can be seen that we cannot distinguish the types of pneumonia based on ultrasound images.\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-8573536/v1/b70dc222be6dd250b03d48c3.png"},{"id":101208064,"identity":"425f22d7-9295-4d13-9a92-22fca19cde87","added_by":"auto","created_at":"2026-01-27 10:09:04","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2283310,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8573536/v1/ae184831-fcd3-4f1e-845b-e76754465366.pdf"},{"id":101074041,"identity":"8fd58de2-3000-41ca-a135-3b2e0ea19fb7","added_by":"auto","created_at":"2026-01-25 10:19:20","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":66383,"visible":true,"origin":"","legend":"","description":"","filename":"Tables.docx","url":"https://assets-eu.researchsquare.com/files/rs-8573536/v1/2258d1b9c9679fd4b82185f0.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Lung ultrasonography cannot identify the categories of neonatal pneumonia: the Findings From A Prospective Multicenter Study Running Head: LUS cannot identify the categories of pneumonia","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eNeonatal pneumonia is one of the most common diseases and is an important cause of death or severe sequelae in newborns. A significant proportion of child deaths due to pneumonia occur in the neonatal period \u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e. Among the 10.8\u0026nbsp;million child deaths worldwide each year, at least one-third occur within the first 28 days after birth \u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e. Epidemiological surveys have shown a mortality rate of 5% \u0026minus;\u0026thinsp;20% for neonatal infectious pneumonia, which is particularly severe in developing countries \u003csup\u003e[\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e. It is reported that hospitalizations due to pneumonia account for 14% of total hospitalizations for newborns \u003csup\u003e[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e. Therefore, strengthening the research on pneumonia diagnosis techniques is of great significance for improving the prognosis of newborns. Lung ultrasound (LUS) has been increasingly used as an diagnostic tool for neonatal pneumonia over the past decade, offering advantages of no radiation, portability, cost-effectiveness \u003csup\u003e[\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e, and higher diagnostic efficiency than traditional chest X-rays (CXR) \u003csup\u003e[\u003cspan additionalcitationids=\"CR9 CR10 CR11 CR12\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e. Our previous research has confirmed that LUS cannot identify the etiologies of neonatal pneumonia, thus resolving some long-standing puzzles that have puzzled both clinicians and ultrasound specialists \u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]\u003c/sup\u003e. However, there is still controversy and confusion regarding whether LUS can differentiate between different types of pneumonia, such as infectious pneumonia (IP) or noninfectious pneumonia (non-IP), ventilator-associated pneumonia (VAP), community-acquired pneumonia (CAP), meconiumaspiration pneumonia (MAP) or nonmeconiumaspiration pneumonia (non-MAP), etc.. Therefore, we have organized this prospective multicenter study to address and answer these remaining questions.\u003c/p\u003e "},{"header":"PARTICIPANTS and METHODS","content":"\n\u003ch3\u003eParticipants\u003c/h3\u003e\n\u003cp\u003eThis research is a part of our previously large-scale multicenter study that data has not been published yet[11], the research subjects,inclusion and exclusion criteria for the research subjects, research methods, observation indicators, and the qualifications of the participants are all consistent with it, which will not be elaborated on further here [11].\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eDemographic and Clinical Data\u003c/h2\u003e \u003cp\u003eIn this study, the general information of the study participants, such as gestational age (GA), gender, delivery method, and birth weight, was collected. After data collection, the study participants were divided into groups according to different criteria: (1) pneumonia was classified as \u0026ldquo;IP\u0026rdquo; or \u0026ldquo;non-IP\u0026rdquo; on the basis of the presence of infection. (2) infectious pneumonia was further subdivided into \u0026ldquo;VAP\u0026rdquo; or \u0026ldquo;non-VAP\u0026rdquo; on the basis of whether the infection was associated with mechanical ventilation. and (3) aspiration pneumonia was classified as \u0026ldquo;MAP\u0026rdquo; or \u0026ldquo;non-MAP\u0026rdquo; on the basis of whether the aspirated substance was meconium.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eLUS examination\u003c/h3\u003e\n\u003cp\u003eThe division of the lungs, as well as the examination and operation methods of lung ultrasound, are all carried out and implemented in accordance with the published internationally standards \u003csup\u003e[\u003cspan additionalcitationids=\"CR16\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e. In the presented study, abnormal LUS signs were defined as follows: (1) pleural line abnormalities, including a broken, thickened, blurred, and missing pleural line. (2) B-line signs, including a single B-line, confluent B-line, alveolar-interstitial synthesis, compact B-line, and white lung. (3) lung consolidations and air bronchograms; and (4) comorbidities such as pleural effusion and pneumothorax.\u003c/p\u003e \u003cp\u003eThe total number and distribution of pleural line abnormalities, B-line signs, lung consolidations, pneumothorax and pleural effusion in each participant were determined in accordance with the 12-region method. For example, if the total number of regions involved in lung consolidation was three, it was recorded as three. Then, the number of regions in which LUS images were distributed was compared across the different groups. The distribution and incidence of consolidations were compared between patients with infectious pneumonia\u0026zwnj; and those with noninfectious pneumonia.\u003c/p\u003e\n\u003ch3\u003eStatistics analysis\u003c/h3\u003e\n\u003cp\u003eAll the data were statistically analyzed using SPSS version 25.0 (IBM, Inc.). Continuous data were evaluated for normality and homogeneity of variance by the Kolmogorov‒Smirnov test and analysis of variance, respectively. The data did not follow a normal distribution or homogeneity of variances, so they were compared by the Kruskal‒Wallis H test or the Mann‒Whitney U test. Categorical data were compared by the χ\u003csup\u003e2\u003c/sup\u003e test or Fisher's exact test. Summary statistics are presented as the median (interquartile range) for continuous variables and frequencies (percentages) for categorical variables. All tests were two-sided, and \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered to indicate a significant difference.\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eDemographics and general information\u003c/h2\u003e \u003cp\u003eA total of 235 patients with neonatal pneumonia were included, with gestational ages ranging from 25 to 42\u0026thinsp;+\u0026thinsp;4 weeks and birth weights ranging from 700 g to 4400 g. A total of 105 patients were delivered by cesarean section, and 130 were delivered by vaginally, with 146 males and 89 females. There were 195 patients with infectious pneumonia and 40 with noninfectious pneumonia, 123 patients with non-VAP, 72 patients with VAP, 23 patients with MAP, and 17 patients with non-MAP.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eComparison of the LUS findings in different groups\u003c/h2\u003e \u003cp\u003eAmong the 235 patients with neonatal pneumonia, 235 (100%) had abnormal pleural lines, and the number of affected areas ranged from 1 to 12. 174 patients (74.0%) had B-lines, and the number of affected areas ranged from 1 to 12. 235 patients (100%) had lung consolidations, and the number of affected areas ranged from 1 to 12. 4 patients (1.7%) had pneumothorax; and 31 patients (13.2%) had pleural effusion. The characteristics of the LUS images of the patients with various types of pneumonia were similar and included mainly lung consolidations with air bronchograms, abnormal pleural lines, the disappearance of A-lines, and B-line signs such as B-lines or AISs visible in nonconsolidated areas. A small number of cases were complicated with signs of pleural effusion and pneumothorax (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Various types of pneumonia share similar morphological characteristics in terms of lung consolidations. Lung consolidations of different sizes can be found in the same area, with irregular boundaries accompanied by air bronchograms. It is difficult to distinguish different types of pneumonia on the basis of the morphology of lung consolidation (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCharacteristics of LUS findings in patients with various types of pneumonia\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e \u003cp\u003eNo.\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePLA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eB lines\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ePE\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIP (N\u0026thinsp;=\u0026thinsp;195)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e195\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e147\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e195\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon-IP (N\u0026thinsp;=\u0026thinsp;40)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon-VAP (N\u0026thinsp;=\u0026thinsp;123)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e123\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e123\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVAP (N\u0026thinsp;=\u0026thinsp;72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMAP (N\u0026thinsp;=\u0026thinsp;23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon-MAP (N\u0026thinsp;=\u0026thinsp;17)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eNote: LC, lung consolidation; LUS, lung ultrasound; MAP, meconium aspiration pneumonia; PE, pleural effusion; PLA, pleural line abnormalities; PT, pneumothorax; VAP, ventilator-associated pneumonia.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThere was no significant difference in the LUS findings between patients with VAP and patients with non-VAP or between patients with MAP patients and patients with non-MAP (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Among the patients with infectious pneumonia, 147 had bilateral lung consolidation, and 47 had unilateral lung consolidation (21 on the left and 27 on the right); 125 had bilateral B-lines, and 22 had unilateral lung consolidations (9 on the left and 13 on the right); 176 had bilateral pleural line abnormalities, and 19 had unilateral pleural line abnormalities (9 on the left and 10 on the right). Among the patients with noninfectious pneumonia, 34 had bilateral lung consolidations and 6 had unilateral lung consolidations (all on the right), 25 had bilateral B-line signs and 2 had unilateral B-line signs (all on the left), and 38 had bilateral pleural line abnormalities and 2 had unilateral pleural line abnormalities (1 on the left and 1 on the right). Lesions associated with infectious pneumonia and noninfectious aspiration pneumonia were slightly more common in the right lung, and there was no significant difference in the distribution of pleural line abnormalities or B-line signs between the bilateral lungs. The incidence of right lung consolidation in patients with aspiration pneumonia (100%) was significantly greater than that in patients with infectious pneumonia (89.2%), whereas there was no significant difference in the incidence of left lung consolidation (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of LUS findings in different pneumonia groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e \u003cp\u003eMedian (IQR)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePLA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eB lines\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ePE\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIP (N\u0026thinsp;=\u0026thinsp;195)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8(8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4(7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4(5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0(0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0(0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon-IP (N\u0026thinsp;=\u0026thinsp;40)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12(5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4(12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5(7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0(0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0(0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-Values\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.63\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon-VAP (N\u0026thinsp;=\u0026thinsp;123)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8(8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4(8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4(6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0(0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0(0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVAP (N\u0026thinsp;=\u0026thinsp;72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9(8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4(10)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4(6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0(0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0(0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-Values\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.16\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMAP (N\u0026thinsp;=\u0026thinsp;23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12(7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2(12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4(7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0(0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0(0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon-MAP (N\u0026thinsp;=\u0026thinsp;17)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8(4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8(12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6(6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0(0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0(0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-Values\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.42\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eNote: IQR, interquartile range; LC, lung consolidation; LUS, lung ultrasound; MAP, meconium aspiration pneumonia; PE, pleural effusion; PLA, pleural line abnormalities; PT, pneumothorax; VAP, ventilator-associated pneumonia.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of lung consolidation between patients with infectious pneumonia and those with noninfectious pneumonia\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePLA\u003c/p\u003e \u003cp\u003eNo. (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eB line\u003c/p\u003e \u003cp\u003eNo. (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLC\u003c/p\u003e \u003cp\u003eNo. (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLeft\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLeft\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eRight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLeft\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eRight\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIP(N\u0026thinsp;=\u0026thinsp;195)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e185(94.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e186(95.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e134(68.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e138(70.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e168(86.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e174(89.2)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon-IP(N\u0026thinsp;=\u0026thinsp;40)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e39(97.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e39(97.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27(67.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e25(62.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e34(85.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e40(100)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-Values\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.03\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003eAbbreviations: LC, lung consolidation; LUS, lung ultrasound; PLA, pleural line abnormality.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThe results of this study revealed that: (1) the main LUS manifestations of neonatal pneumonia are as follows: lung consolidations with air bronchograms, irregular boundaries of the consolidation areas, and abnormal pleural lines, and most pneumonia patients present B-line signs such as B-lines or AIS in nonconsolidated areas. A few cases are complicated with pleural effusion and pneumothorax signs. (2) Different types of neonatal pneumonia have similar manifestations on LUS. The incidence of consolidations in the right lung in patients with aspiration pneumonia is slightly greater than that in patients with infectious pneumonia.\u003c/p\u003e \u003cp\u003eIn this study, there was no difference in LUS findings between patients with neonatal infectious pneumonia and patients with noninfectious aspiration pneumonia. At present, many clinical studies have confirmed that the characteristics of LUS findings in patients with neonatal or childhood infectious pneumonia are mainly pulmonary consolidations with air bronchograms, B-lines, and abnormal pleural lines and are sometimes accompanied by pleural effusion and pneumothorax \u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan additionalcitationids=\"CR18\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/sup\u003e, which is consistent with the present study. To our knowledge, comparative studies on LUS characteristics between neonatal infectious pneumonia and noninfectious pneumonia have not yet been reported. However, the main characteristics of chest radiography in children with aspiration pneumonia are diffuse ground‒glass opacities, interstitial thickening, or dense consolidations \u003csup\u003e[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/sup\u003e. These characteristics are the same as the chest radiograph features of neonatal infectious pneumonia. The chest radiograph manifestations of aspiration pneumonia in adults are similar to those of infectious pneumonia, which also supports this point from another perspective. \u003csup\u003e[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eAspiration pneumonia is a common emergency in newborns. Aspiration pneumonia can be classified into chemical pneumonia, oropharyngeal secretion aspiration pneumonia, and inert substance aspiration pneumonia according to the nature of the inhaled substance \u003csup\u003e[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/sup\u003e. The main characteristics of aspiration pneumonia on LUS are lung consolidations, B-line signs, and pleural line abnormalities, which are occasionally accompanied by pneumothorax and pleural effusion \u003csup\u003e[\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/sup\u003e. In aspiration pneumonia, meconium aspiration syndrome caused by MAP has been widely studied. The LUS manifestations of MAP include lung consolidations, B-line signs, and pleural line abnormalities, and some cases involve pneumothorax and pleural effusion \u003csup\u003e[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]\u003c/sup\u003e. Research on the LUS characteristics of other types of aspiration pneumonia is limited. In the study by Regiroli G et al., the LUS manifestations of bile aspiration pneumonia were consistent with those described above \u003csup\u003e[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]\u003c/sup\u003e. Wu H et al. compared the radiographic features of X-ray chest films between patients with gastric content aspiration pneumonia and those with other types of pneumonia. The results revealed that the positive rates of lesions in the right lung lobe for patients with gastric content aspiration pneumonia and those with other types of pneumonia were 84.3% and 69.5%, respectively, whereas the positive rates of lesions in the left lung lobe were 69.5% and 68.5%, respectively \u003csup\u003e[\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]\u003c/sup\u003e. In this study, the incidence of right-sided lung consolidations in patients with aspiration pneumonia was 100%, whereas that in patients with infectious pneumonia was 89.2%, which is similar to the findings of Wu H et al. Although patients with aspiration pneumonia presented a slightly higher incidence of right-sided lung consolidation than patients with infectious pneumonia did, given the high incidence of both types and the similar morphology of lung consolidations, there is no clinical possibility of distinguishing between them on the basis of these findings. Hugosson CO et al. reported that the chest radiograph and CT imaging features of lipid aspiration pneumonia in infants mainly presented as lung consolidation\u003csup\u003e[\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]\u003c/sup\u003e; this finding is consistent with the major CT imaging manifestations of other types of pneumonia. The above research results indicate that the LUS findings of different types of aspiration pneumonia are similar and are characterized by lung consolidation as the main manifestation, which is in accordance with the results of this study.\u003c/p\u003e \u003cp\u003eThe characteristics of pulmonary lesions in patients with infectious pneumonia are related to pathogens. The main pathogens of VAP include Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, respiratory syncytial virus, adenovirus, mycoplasma, and fungal infections. This is similar to the pathogen spectrum of other infectious pneumonias, such as congenital pneumonia and community-acquired pneumonia \u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]\u003c/sup\u003e. Therefore, the LUS characteristics of the two types of pneumonia are similar. There have been numerous studies on LUS characteristics in patients with VAP, and the ultrasonic signs of VAP are consistent with classic pneumonia manifestations, mainly including lung consolidations with air bronchograms, pleural line abnormalities, B-line signs, and occasionally pleural effusion and pneumothorax \u003csup\u003e[12\u0026ndash;13,33\u0026minus;34]\u003c/sup\u003e, which is consistent with the conclusions of this study. The LUS findings of patients with VAP revealed new signs of lung consolidation on the basis of preexisting pneumonia manifestations\u003csup\u003e[\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]\u003c/sup\u003e. This study confirms that these additional lung consolidations do not make the LUS manifestations of VAP different from those of other types of pneumonia.\u003c/p\u003e \u003cp\u003eThis multicenter, prospective study confirmed that the signs detected by LUS in patients with noninfectious pneumonia are consistent with those detected in patients with infectious pneumonia and that there are no differences in LUS manifestations among different types of neonatal pneumonia. Their most prominent feature is irregularly bordered lung consolidations with air bronchograms. Lung consolidation cannot be used to distinguish between different types of pneumonia but is related only to the severity of pneumonia \u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]\u003c/sup\u003e. In clinical practice, LUS may need to be combined with other diagnostic tools and clinical symptoms to diagnose various types of pneumonia.\u003c/p\u003e \u003cp\u003eThere are several limitations of this study. First, the sample size of patients with noninfectious aspiration pneumonia was small, and a larger sample size is needed in the future to confirm the conclusions of this study. Second, this study only compared the characteristics of LUS in the early stage of pneumonia but did not compare the ultrasound characteristics throughout the entire course of pneumonia. More studies are needed in the future to explore whether the ultrasound images of patients in the middle and late stages of different types of neonatal pneumonia have independent characteristics.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe results of this study show that the most common ultrasound imaging manifestations of various etiologies of pneumonia in newborns are lung consolidation accompanied by airbronchograms. There is no specificity in the ultrasound characteristics among different etiologies of pneumonia. Although aspiration pneumonia is more likely to occur in the right lung, this fact alone is not sufficient to distinguish between aspiration pneumonia and non-aspiration pneumonia. Differentiating between various types of pneumonia still requires the combination of medical history and relevant laboratory tests.\u003c/p\u003e "},{"header":"Abbreviations","content":"\u003cp\u003eLUS: Lung ultrasound; CXR: chest X-rays; IP: infectious pneumonia; non-IP: noninfectious pneumonia; VAP: ventilator-associated pneumonia; CAP: community-acquired pneumonia;MAP: meconiumaspiration pneumonia; non-MAP: nonmeconiumaspiration pneumonia; GA: gestational age\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eHuman Ethics\u003c/strong\u003e:This study was approved by the Ethics Committee of Maternal and Child Health Care Hospital, Chaoyang District, Beijing (No. 2011-LC-Ped-01), and the participating hospitals.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Participate declarations\u003c/strong\u003e:\u0026nbsp;Informed consent was obtained from the guardians of the newborns before the data were collected.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions:\u0026nbsp;\u003c/strong\u003eJing Liu conceptualized and designed the study, drafted the initial manuscript, obtained funding and takes responsibility for the integrity of the data and the accuracy of the data analysis. Hai-Ran Ma conceptualized and designed the study, undertook the statistical analysis, drafted the initial manuscript, and reviewed and revised the manuscript. Peng Jiang, Rui-Yan Shan, and Wei Fu designed the study, collected data, carried out the initial analyses, and reviewed and revised the manuscript. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work. All authors contributed equally to this work and should be considered co-first authors.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding or research support:\u0026nbsp;\u003c/strong\u003eThis study was supported by the Foundation of the Social Development Projects,Beijing Chaoyang District Bureau of Science, Technology and Information (CYSF1922) and the Clinical Research Special Fund of Wu Jieping Medical Foundation (320. 6750.2024-03-32).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e: The authors declare no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of Supporting Data:\u0026nbsp;\u003c/strong\u003eThe dataset used and analyzed are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial number\u003c/strong\u003e: not applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eDuke T. Neonatal pneumonia in developing countries. Archives of disease in childhood. Fetal and neonatal edition, 2005; 90 (3): F211-219.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBlack RE, Morris SS, Bryce J. Where and why are 10 million children dying every year? Lancet,2003;361 (9376):2226\u0026ndash;2234.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHooven TA, Polin RA. Pneumonia. Seminars in fetal \u0026amp; neonatal medicine, 2017; 22 (4):206\u0026ndash;213.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStoll BJ. The global impact of neonatal infection. Clinics in perinatology,1997; 24 (1): 1\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYang L,Ying Z,Yu X, Man L. Prevalence and risk factors of neonatal pneumonia in China: A longitudinal clinical study. Biomedical Research, 2018; 29 (1): 57\u0026ndash;60.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu J, Liu F, Liu Y, Wang HW, Feng ZC. Lung ultrasonography for the diagnosis of severe pneumonia of the newborn. Chest, 2014;146 (2):483\u0026ndash;488.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRaimondi F,Yousef N, Migliaro F, Capasso L, De Luca D. Point-of-care lung ultrasound in neonatology: classification into descriptive and functional applications. Pediatric research, 2021; 90 (3):524\u0026ndash;531.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSharma D, Farahbakhsh N. Role of chest ultrasound in neonatal lung disease: a review of current evidences. The journal of maternal-fetal \u0026amp; neonatal medicine, 2019;32 (2):310\u0026ndash;316.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYe X, Xiao H, Chen B, Zhang S. Accuracy of Lung Ultrasonography versus Chest Radiography for the Diagnosis of Adult Community-Acquired Pneumonia: Review of the Literature and Meta-Analysis. PloS one, 2015;10 (6): e0130066.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMart\u0026iacute;nez Redondo J, Comas Rodr\u0026iacute;guez C, Pujol Salud J, Crespo Pons M, Garc\u0026iacute;a Serrano C, Ortega Bravo M, Palac\u0026iacute;n Peruga J M. Higher Accuracy of Lung Ultrasound over Chest X-ray for Early Diagnosis of COVID-19 Pneumonia. International journal of environmental research and public health, 2021; 18 (7):3481. doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/ijerph18073481\u003c/span\u003e\u003cspan address=\"10.3390/ijerph18073481\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMa HR,Deng BY, Liu J, Jiang P, Xu YL, Song XY, Li J, Huang LH, Bao LY, Shan RY, Fu W. Lung ultrasound to diagnose infectious pneumonia of newborns: A prospective multicenter study. Pediatric pulmonology, 2023; 58 (1): 122\u0026ndash;129.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTusor N, De Cunto A, Basma Y, Klein J L, Meau-Petit V. Ventilator-associated pneumonia in neonates: the role of point of care lung ultrasound. European journal of pediatrics, 2021; 180 (1):137\u0026ndash;146.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJiang P, Wei J. The Application of Pulmonary Ultrasound in Neonatal Ventilator-Associated Pneumonia. Frontiers in pediatrics, 2022;10:882056.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu J. Lung Ultrasonography Cannot Identify the Etiology of Pediatric Pneumonia. Archivos de Bronconeumolog\u0026iacute;a, 2024; 60(7):445\u0026ndash;447. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.arbres.2024.02.016\u003c/span\u003e\u003cspan address=\"10.1016/j.arbres.2024.02.016\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu J, Copetti R, Sorantin E, Lovrenski J, Rodriguez-Fanjul J, Kurepa D, Feng X, Cattaross L, Zhang H, Hwang M, et al. Protocol and Guidelines for Point-of-Care Lung Ultrasound in Diagnosing Neonatal Pulmonary Diseases Based on International Expert Consensus. JoVE, 2019; 145:e58990,doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3791/58990\u003c/span\u003e\u003cspan address=\"10.3791/58990\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu J, Guo G, Kurepa D, Volpicelli G, Sorantin E, Lovrenski J, Alonso-Ojembarrena A, Hsieh KS, Lodha A, Yeh T F, et al. Specification and guideline for technical aspects and scanning parameter settings of neonatal lung ultrasound examination. The journal of maternal-fetal \u0026amp; neonatal medicine, 2022; 35(5): 1003\u0026ndash;1016.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu J, Ma HR,Fu W. Lung Ultrasound to Diagnose Pneumonia in Neonates with Fungal Infection. Diagnostics, 2022; 12 (8):1776.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuitart C,Rodr\u0026iacute;guez-Fanjul J, Bobillo-Perez S, Carrasco JL, Inarejos Clemente EJ, Cambra FJ, Balaguer M, Jordan I. An algorithm combining procalcitonin and lung ultrasound improves the diagnosis of bacterial pneumonia in critically ill children: The PROLUSP study, a randomized clinical trial. Pediatric pulmonology, 2022;57 (3):711\u0026ndash;723.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003e\u0026Ouml;ktem A, Zenciroğlu A, \u0026Uuml;ner \u0026Ccedil;, Aydoğan S, Dilli D, Okumuş N. Efficiency of Lung Ultrasonography in the Diagnosis and Follow-up of Viral Pneumonia in Newborn. American journal of perinatology, 2023;40 (4):432\u0026ndash;437.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee KH, Kim WS, Cheon JE, Seo J B, Kim IO, Yeon KM. Squalene aspiration pneumonia in children: radiographic and CT findings as the first clue to diagnosis. Pediatric radiology, 2005; 35 (6):619\u0026ndash;623.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStreck HL, Goldman JL, Lee BR, Sheets JM, Wirtz AL. Evaluation of the Treatment of Aspiration Pneumonia in Hospitalized Children. Journal of the Pediatric Infectious Diseases Society, 2022;11 (3):102\u0026ndash;107.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSharma S, Maycher B, Eschun G. Radiological imaging in pneumonia: recent innovations. Current opinion in pulmonary medicine,2007;13 (3):159\u0026ndash;169.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKatz DS, Leung AN. Radiology of pneumonia. Clinics in chest medicine, 1999;20 (3):549\u0026ndash;562.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKarim RM, Momin IA, Lalani II, Merchant SS, Sewani AA, Hassan BS, Mahmood N. Aspiration pneumonia in pediatric age group: etiology, predisposing factors and clinical outcome. JPMA. The Journal of the Pakistan Medical Association, 1999; 49 (4): 105\u0026ndash;108.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBuonsenso D, De Rose C, Morello R, Lazzareschi I, Valentini P. Aspiration pneumonia in children with neurological disorders: a new indication for lung ultrasound? A case series. Journal of ultrasound, 2022; 25 (2): 325\u0026ndash;331.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFernandes Rodrigues N, Giraud L, Bolen G, Fastr\u0026egrave;s A, Clercx C, Boysen S, Billen F, Gommeren K. Comparison of lung ultrasound, chest radiographs, C-reactive protein, and clinical findings in dogs treated for aspiration pneumonia. Journal of veterinary internal medicine, 2022; 36 (2):743\u0026ndash;752.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePiastra M, Yousef N, Brat R, Manzoni P, Mokhtari M, De Luca D. Lung ultrasound findings in meconium aspiration syndrome. Early human development, 2014, 90(Suppl 2): S41-S43.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu J, Cao HY, Fu W. Lung ultrasonography to diagnose meconium aspiration syndrome of the newborn. The Journal of international medical research,2016;44 (6):1534\u0026ndash;1542.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRegiroli G, La Malfa G, Loi B, Vivanti A, Centorrino R, De Luca D. Ultrasound-assessed lung aeration, oxygenation and respiratory care in neonatal bile acid pneumonia: A nested case-control study. Acta paediatrica,2023; 112 (9):1898\u0026ndash;1904.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWu H, Zhao X. Pulmonary aspiration only increases the risk of right-sided pneumonia in children: comparison of salivagrams and chest radiographs. Nuclear medicine communications, 2018; 39 (6):505\u0026ndash;510.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHugosson CO, Riff EJ, Moore CC, Akhtar M, Tufenkeji HT. Lipoid pneumonia in infants: a radiological-pathological study. Pediatric radiology, 1991;21 (3):193\u0026ndash;197.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNissen MD. Congenital and neonatal pneumonia. Paediatric respiratory reviews, 2007; 8 (3):195\u0026ndash;203.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIbrahim M, Omran A, Ibrahim M, Bioumy N, El-Sharkawy S. Lung Ultrasound in Early Diagnosis of Neonatal Ventilator Associated Pneumonia before Any Radiographic or Laboratory Changes. Case reports in pediatrics,2016;2016: 4168592.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu J, Qiu RX. Lung Ultrasound Monitoring of Legionella Ventilator-Associated Pneumonia in an Extremely Low-Birth- Weight Infant. Diagnostics,2022;12 (9):2253.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBouhemad B,Dransart-Ray\u0026eacute; O, Mojoli F, Mongodi S. Lung ultrasound for diagnosis and monitoring of ventilator-associated pneumonia. Annals of translational medicine, 2018; 6 (21): 418.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePradhan S, Shrestha PS, Shrestha GS, Marhatta MN. Clinical impact of lung ultrasound monitoring for diagnosis of ventilator associated pneumonia: A diagnostic randomized controlled trial. Journal of critical care 2020;58(1): 65\u0026ndash;71.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMafort TT, Lopes AJ, da Costa CH, da Cal MS, Lopes MC, da Silva BRA, Faria LF, Faria AC. Costa W, Salles REB, et al. Changes in lung ultrasound of symptomatic healthcare professionals with COVID-19 pneumonia and their association with clinical findings. Journal of clinical ultrasound, 2020; 48 (9):515\u0026ndash;521.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKong S, Wang J, Li Y, Tian Y, Yu C, Zhang D, Li H, Zhang L, Pang X, Xie M. Value of Bedside Lung Ultrasound in Severe and Critical COVID-19 Pneumonia. Respiratory care, 2021; 66 (6):920\u0026ndash;927.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"european-journal-of-medical-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ejmr","sideBox":"Learn more about [European Journal of Medical Research](http://eurjmedres.biomedcentral.com)","snPcode":"40001","submissionUrl":"https://submission.nature.com/new-submission/40001/3","title":"European Journal of Medical Research","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Neonate, Pneumonia, Lung Ultrasound","lastPublishedDoi":"10.21203/rs.3.rs-8573536/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8573536/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eLung ultrasound (LUS) is widely used in the management of neonatal pneumonia, our previous research has confirmed that LUS cannot identify the etiologies of neonatal pneumonia. However, there is still controversy and confusion regarding whether LUS can differentiate between different types of pneumonia (such as intrauterine infectious pneumonia (IP), ventilator-associated pneumonia (VAP), community-acquired pneumonia (CAP), meconiumaspiration pneumonia (MAP)). Therefore, we have organized this prospective multicenter study to address and answer these remaining questions.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eA prospective approach was used to collect LUS data on neonatal all kinds of pneumonia from 5 tertiary hospitals in China. The patients were devided into three categories: based on whether there is evidence of infection,ventilator treatment ot the history of meconium aspiration, they are classified as IP and non-IP, VAP and non-VAP, MAP and non-MAP. The major LUS imaging characteristics and complications were compared among groups.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eA total of 235 patients with neonatal pneumonia were included, comprising 195 patients with IP and 40 patients with non-IP. The ultrasound characteristics included pleural line abnormalities in all 235 patients, involving zones 1\u0026ndash;12;B-lines in 174 patients, involving zones 1\u0026ndash;12;lung consolidation in all 235 patients, involving zones 1\u0026ndash;12%; pneumothorax in 4 patients; and pleural effusion in 31 patients.No significant differences in ultrasound characteristics were found between patients with MAP and patients with non-MAP or between patients with-or without VAP.Compared with IP,aspiration pneumonia was associated with a significantly greater incidence of right lung consolidation (100% vs. 89.2%),with no significant differences in other ultrasound signs.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eThe results of this study show that the most common ultrasound imaging manifestations of various etiologies of pneumonia in newborns are lung consolidation accompanied by airbronchograms.Differentiating between various types of pneumonia still requires the combination of medical history and relevant laboratory tests.\u003c/p\u003e","manuscriptTitle":"Lung ultrasonography cannot identify the categories of neonatal pneumonia: the Findings From A Prospective Multicenter Study Running Head: LUS cannot identify the categories of pneumonia","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-25 10:19:15","doi":"10.21203/rs.3.rs-8573536/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision 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