\documentclass[10pt]{article}

\usepackage{fullpage}
\usepackage{setspace}
\usepackage{parskip}
\usepackage{titlesec}
\usepackage[section]{placeins}
\usepackage{xcolor}
\usepackage{breakcites}
\usepackage{lineno}
\usepackage{hyphenat}





\PassOptionsToPackage{hyphens}{url}
\usepackage[colorlinks = true,
            linkcolor = blue,
            urlcolor  = blue,
            citecolor = blue,
            anchorcolor = blue]{hyperref}
\usepackage{etoolbox}
\makeatletter
\patchcmd\@combinedblfloats{\box\@outputbox}{\unvbox\@outputbox}{}{%
  \errmessage{\noexpand\@combinedblfloats could not be patched}%
}%
\makeatother


\usepackage{natbib}




\renewenvironment{abstract}
  {{\bfseries\noindent{\abstractname}\par\nobreak}\footnotesize}
  {\bigskip}

\titlespacing{\section}{0pt}{*3}{*1}
\titlespacing{\subsection}{0pt}{*2}{*0.5}
\titlespacing{\subsubsection}{0pt}{*1.5}{0pt}


\usepackage{authblk}


\usepackage{graphicx}
\usepackage[space]{grffile}
\usepackage{latexsym}
\usepackage{textcomp}
\usepackage{longtable}
\usepackage{tabulary}
\usepackage{booktabs,array,multirow}
\usepackage{amsfonts,amsmath,amssymb}
\providecommand\citet{\cite}
\providecommand\citep{\cite}
\providecommand\citealt{\cite}
% You can conditionalize code for latexml or normal latex using this.
\newif\iflatexml\latexmlfalse
\providecommand{\tightlist}{\setlength{\itemsep}{0pt}\setlength{\parskip}{0pt}}%

\AtBeginDocument{\DeclareGraphicsExtensions{.pdf,.PDF,.eps,.EPS,.png,.PNG,.tif,.TIF,.jpg,.JPG,.jpeg,.JPEG}}

\usepackage[utf8]{inputenc}
\usepackage[T2A]{fontenc}
\usepackage[ngerman,polish,english]{babel}



\usepackage{float}








\begin{document}

\title{Lung Ultrasound to Diagnose Infectious Pneumonia of the Newborns: A
Prospective Multicenter Study}



\author[1]{Hai-Ran Ma}%
\author[2]{Bi-Ying Deng}%
\author[1]{Jing Liu}%
\author[3]{Peng Jiang}%
\author[4]{Yan-Lei Xu}%
\author[5]{Xiu-Yun Song}%
\author[6]{Jie Li}%
\author[7]{Li-Han Huang}%
\author[8]{Ling-Yun Bao}%
\author[9]{Rui-Yan Shan}%
\affil[1]{Southern Medical University}%
\affil[2]{Guangdong Medical University}%
\affil[3]{Liaocheng People's Hospital}%
\affil[4]{The First Affiliated Hospital of Zhengzhou University}%
\affil[5]{Children's Hospital of Shanxi}%
\affil[6]{Zaozhuang University}%
\affil[7]{Xiamen University}%
\affil[8]{Kunming University}%
\affil[9]{Qindao University Medical College Affiliated Yantai Yuhuangding Hospital}%


\vspace{-1em}



  
  \date{May 24, 2024}


\begingroup
\let\center\flushleft
\let\endcenter\endflushleft
\maketitle
\endgroup





\selectlanguage{english}
\begin{abstract}
\emph{Background:} Whether Lung ultrasound (LUS) can be used for
pathogenic diagnosis is still controversial. This was conducted to test
the accuracy and reliability of ultrasound in the diagnosis of pneumonia
and to clarify whether ultrasound has diagnostic value for the etiology.
\emph{Methods:} A total of 135 neonatal pneumonia patients with an
identified pathogen and 50 newborns with normal lungs in the newborn
intensive care unit of 10 tertiary hospitals in China were enrolled. The
study ran from November 2020 to December 2021. The infants were divided
into various groups according to pathogens, the time of infection, the
gestational age, the severity of the disease. The distribution of
pleural line abnormalities, pulmonary edema, and pulmonary
consolidation, as well as the incidence of air bronchogram and pleural
effusion based on LUS, were compared between the above groups and
between the pneumonia and healthy control groups. \emph{Results:} There
were significant differences in pulmonary consolidation. The sensitivity
and specificity of the diagnosis of severe pneumonia based on the extent
of pulmonary consolidation were 83.3\% and 85.2\%, respectively. The
area under the receiver operating characteristic curve for the
identification of mild or severe pneumonia based on the distribution of
pulmonary consolidation was 0.776. \emph{Conclusion:} Lung ultrasound
has good performance in differentiating the severity of neonatal
pneumonia, but cannot be used for pathogenic diagnosis.%
\end{abstract}%



\sloppy


Lung Ultrasound to Diagnose Infectious Pneumonia of the Newborns: A
Prospective Multicenter Study

Hai-Ran Ma\textsuperscript{1,2,3}, PhD; Bi-Ying Deng\textsuperscript{5},
MBBS; Jing Liu\textsuperscript{1,2,4}, MD PhD; Peng
Jiang\textsuperscript{6}, MSc; Yan-Lei Xu\textsuperscript{7},MSc;
Xiu-Yun Song\textsuperscript{8}, MSc; Jie Li\textsuperscript{9}, MSc;
Li-Han Huang\textsuperscript{10}, MBBS; Ling-Yun
Bao\textsuperscript{11}, MBBS; Rui-Yan Shan\textsuperscript{12}, PhD.

\begin{enumerate}
\tightlist
\item
  Department of Paediatrics, The Second School of Clinical Medicine,
  Southern Medical University, Guangzhou 510000, China.
\item
  Department of Neonatology and Neonatal Intensive Care Unit, Beijing
  Chao-Yang Hospital, Capital Medical University, Beijing 100000, China.
\item
  Department of Neonatology and Neonatal Intensive Care Unit, Huizhou
  Central People's Hospital, Huizhou 516000, China.
\item
  Department of Neonatology and Neonatal Intensive Care Unit, Beijing
  Chaoyang District Maternal and Child Healthcare Hospital, Beijing
  100000, China.
\item
  Department of Neonatology, The Seventh Medical Center of The PLA
  General Hospital, Beijing 100000, China
\item
  Department of Neonatal Intensive Care Unit, Guangdong Medical
  University Affiliated Dongguan Children's Hospital, Dongguan 523000,
  China.
\item
  Department of Paediatrics, Liaocheng People's Hospital, Liaocheng
  252000, China.
\item
  Department of Neonatology and Neonatal Intensive Care Unit, The First
  Affiliated Hospital of Zhengzhou University, Zhengzhou 450000, China.
\item
  Children`s hospital of Shanxi (Women Health Center of Shanxi), Taiyuan
  030000, China.
\item
  Department of neonatology, Maternity and Child Health Care of
  Zaozhuang 277000, China.
\item
  Department of Neonatology, Women and Children's Hospital, School of
  Medicine, Xiamen University, Xiamen 361000, China.
\item
  Department of Neonatology, Kunming Children's Hospital, Kunming
  650000, China.
\item
  Department of Pediatrics, The Affiliated Yantai Yuhuangding Hospital
  of Qingdao University, Yantai 264000, China.
\end{enumerate}

\emph{*Corresponding Author}

Full name: Jing Liu

Department: Department of Neonatology and NICU, Beijing Chao-Yang
Hospital, Capital Medical University.

Street Name \& Number: No.5, Jingyuan Road.

City, State, Postal code, Country: Shijingshan District, Beijing 100043,
China..

Tel: 086-13301195869

E-mail: liujingbj@live.cn

\par\null

\emph{What's Known on This Subject}

Lung ultrasound has been successfully used to diagnose neonatal
pneumonia, but whether lung ultrasound can be used for pathogenic
diagnosis is still controversial.

\emph{What This Study Adds}

Lung ultrasound has good performance in differentiating the severity of
neonatal pneumonia, but cannot be used for pathogenic diagnosis.

\emph{Background:} Whether Lung ultrasound (LUS) can be used for
pathogenic diagnosis is still controversial. This was conducted to test
the accuracy and reliability of ultrasound in the diagnosis of pneumonia
and to clarify whether ultrasound has diagnostic value for the etiology.

\emph{Methods:} A total of 135 neonatal pneumonia patients with an
identified pathogen and 50 newborns with normal lungs in the newborn
intensive care unit of 10 tertiary hospitals in China were enrolled. The
study ran from November 2020 to December 2021. The infants were divided
into various groups according to pathogens, the time of infection, the
gestational age, the severity of the disease. The distribution of
pleural line abnormalities, pulmonary edema, and pulmonary
consolidation, as well as the incidence of air bronchogram and pleural
effusion based on LUS, were compared between the above groups and
between the pneumonia and healthy control groups.

\emph{Results:} There were significant differences in pulmonary
consolidation. The sensitivity and specificity of the diagnosis of
severe pneumonia based on the extent of pulmonary consolidation were
83.3\% and 85.2\%, respectively. The area under the receiver operating
characteristic curve for the identification of mild or severe pneumonia
based on the distribution of pulmonary consolidation was 0.776.

\emph{Conclusion:} Lung ultrasound has good performance in
differentiating the severity of neonatal pneumonia, but cannot be used
for pathogenic diagnosis.

Key words: Lung ultrasound; Neonatal pneumonia; diagnosis.

Word counts: abstract: 218; text: 3341;

1. Background

Pneumonia is one of the main causes of death in infants and young
children, especially in developing countries\textsuperscript{{[}1,
2{]}}. Pneumonia has the greatest risk of death in the neonatal period,
causing approximately 750,000-1.2 million neonatal deaths each year,
accounting for 10\% of the global child
mortality\textsuperscript{{[}3{]}}. A survey showed that pneumonia was
the leading cause of death in ultralow-birth-weight infants, at
approximately 22.5\%\textsuperscript{{[}4{]}}. As an auxiliary tool,
lung ultrasound (LUS) has been increasingly used in the diagnosis of
pneumonia in recent years and has good diagnostic
performance\textsuperscript{{[}5-9{]}}. It has become an international
consensus method for the diagnosis of neonatal pneumonia
\textsuperscript{{[}10, 11{]}}. Compared with chest X-ray, LUS has the
advantages of no radiation, low cost, convenience, speed, and
accuracy\textsuperscript{{[}12-14{]}} and has a higher diagnostic
efficacy for pneumonia\textsuperscript{{[}15-18{]}}.

The current problems with LUS and pneumonia are as follows: (1) To the
best of our knowledge, the studies on the diagnosis of neonatal
pneumonia using LUS are all small, single-center, retrospective studies,
so large, multicenter, prospective studies are needed. (2) There is
considerable controversy as to whether LUS can differentiate the
etiology of pneumonia. Some studies suggest that LUS imaging can make
pathogenic judgments about bacterial vs. non-bacterial
pneumonia\textsuperscript{{[}19, 20{]}}, but our experience is quite
different. Therefore, we conducted this multicenter prospective study to
try to clarify these problems, thereby contributing to the better
clinical application of LUS.

2. Methods

2.1 Research subjects

This study was a multicenter, prospective, descriptive study. Eighteen
tertiary hospitals in China signed up to participate in this study, but
eight hospitals could not meet the requirements of this study (seven
hospitals provided case collection data that did not meet the
requirements, and the images of one hospital did not meet the
requirements). Neonatal pneumonia patients from the newborn intensive
care unit of the other 10 tertiary hospitals were included in the study.
The study ran from November 2020 to December 2021. Participating
hospitals and personnel had to meet the following requirements: 1) The
ultrasound examination personnel received more than 3-6 months of
professional training at the professional training base for LUS and
passed the assessment. 2) The quality of the provided LUS images was
good enough. 3) The hospital did LUS examinations for more than 1 year.

The inclusion criteria of the study subjects were as follows: 1.
Patients with a confirmed diagnosis of neonatal pneumonia. The
diagnostic criteria were as follows: (1) presence of cough, fever, or
dyspnea; (2) fine, moist rales on auscultation; (3) significantly
increased or decreased white blood cell count, increased neutrophil
concentration or immature/total neutrophil ratio, high erythrocyte
sedimentation rate, or high C-reactive protein level; and (4) patchy,
blurred shadows of uneven density in the lung fields on chest radiograph
or lung consolidations accompanied by air bronchograms or fluid
bronchograms; the pleural line was abnormal and the A-lines disappeared,
while B-lines or alveolar-interstitial syndrome was visible in the
nonconsolidated areas; different degrees of unilateral or bilateral
pleural effusion were visible in some infants on LUS. 2. Patients with
complete LUS examination and related necessary auxiliary examinations
within 1-2 hours after clinical diagnosis of pneumonia. 3. Patients with
clear etiological evidence. The etiological diagnosis came from a
positive result in any of the following tests: 1) blood culture; 2)
sputum culture (the same bacterium more than two times); 3) polymerase
chain reaction; 4) the tuberculosis test (T-spot) was positive and
sputum smears were positive for acid-fast bacilli twice; and 5) gene
sequencing. Exclusion criteria: 1. severe congenital malformations; 2.
chromosomal or genetic diseases; 3. no consent from family members; 4.
incomplete data, or the ultrasound image collection did not meet the
criteria.

The newborns enrolled in the study were still treated according to the
local diagnosis and treatment plan. LUS images of five newborns with
normal lungs were selected from each hospital as the control group,
including at least one preterm infant. 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.
Informed consent was obtained from the baby's guardian before collecting
the data.

2.2 Demographic and clinical data of study subjects

In this study, the general information of the study subjects, such as
gestational age, sex, delivery method, and birth weight, were analyzed.
The time interval between clinical examination and the acquisition of
LUS images was no more than 2 hours. After collection, the study
subjects were divided into groups by different criteria: 1. According to
the pathogen(s) detected, the subjects were divided into the bacterial
infection group, the viral infection group, the atypical pathogen
(mycoplasma or chlamydia) group, the fungal infection group, and the
mixed infection group (with two or more pathogens). After the patient
was discharged from the hospital, the final diagnosis of the pathogen
was made based on the clinical data and the test results. 2. The infants
were divided into the full-term group and the preterm group according to
their gestational age. 3. According to the time of infection, the
newborns were divided into congenital infectious pneumonia (within 48
hours after birth), nosocomial infectious pneumonia (48 hours after
hospitalization), and community-acquired pneumonia. 4. According to the
criteria (adapted from the Pediatric Infectious Diseases
Society--Infectious Diseases Society of America
criteria\textsuperscript{{[}21{]}}) in Table S1, the patients were
divided into the mild pneumonia group and the severe pneumonia group .

2.3 LUS

LUS examinations were performed by physicians who had performed LUS
examinations for more than 1 year. Before the start of the study, three
12-region LUS images were collected from each participating center and
sent to an ultrasound expert for review (J.L). The personnel collecting
the images were further trained until they met the requirements of image
acquisition. Those who eventually could still not meet the requirements
were not included in the multicenter study. The doctor who performed the
LUS examination and the doctor who supervised the patient were different
doctors, and the doctor who performed the LUS was blinded to the results
of the clinical examination and etiological examination. Instrument and
equipment probe selection and operation methods strictly followed
relevant guidelines \textsuperscript{{[}10, 22{]}}. At the time of
examination, the bilateral lungs were divided into 12 regions based on
the anterior axillary line, the posterior axillary line, and the nipple
line. Patients were examined in the decubitus, lateral, and prone
positions using the longitudinal and transverse
approaches\textsuperscript{{[}22{]}}.

For the description of the LUS findings in each of the 12 regions, we
referred to the \emph{Protocol and Guidelines for Point-of-Care Lung
Ultrasound in Diagnosing Neonatal Pulmonary Diseases Based on
International Expert Consensus} \textsuperscript{{[}10{]}}. In this
study, the abnormal LUS signs were as follows: 1. abnormal pleural
lines, including a broken, thickened, blurred, and disappeared pleural
line; 2. pulmonary edema signs, including the B-line, confluent B-line,
alveolar-interstitial synthesis, compact B-line, and white lung; 3.
pulmonary consolidation and air bronchogram; 4. comorbidities such as
pleural effusion and pneumothorax.

According to the 12-region method, the total number and distribution of
pleural line abnormalities, pulmonary edema signs, and pulmonary
consolidation in each subject was counted. For example, if the total
number of regions involved in pulmonary consolidation was 3, it was
recorded as 3. The incidence of air bronchogram and pleural effusion was
analyzed. Then, the incidence and the number of regions in which LUS
images were distributed were compared between different groups. The LUS
images that were distributed in the unilateral or bilateral lungs were
compared between patients with pneumonia caused by different pathogens.
According to the area involved in the pulmonary consolidation, the size
of the pulmonary consolidation was divided into mild pulmonary
consolidation (the consolidation extent was limited to the pleural line,
involving only one intercostal space, see Figure 1), moderate pulmonary
consolidation (the consolidation involved 2-3 intercostal spaces, see
Figure 1), and extensive lung consolidation (involving more than three
intercostal spaces, see Figure 1). The correlation between the number of
areas involved in pulmonary consolidation and the presence of mild or
severe pneumonia was analyzed. The correlation between extensive
pulmonary consolidation and mild and severe pneumonia was analyzed.

3. Statistical analysis

Bacterial pathogens are easy to detect relative to other pathogens and,
based on previous experience, account for approximately 70\% of all
pathogens that can be detected. Assuming that bacterial pneumonia can be
distinguished from other pathogenic pneumonia by lung ultrasound, AUC
values of 0.7--0.79 is a fair test\textsuperscript{{[}23{]}}, and the
lowest value of 0.7 is taken to estimate the sample size. In this case,
considering alpha = 0.05 and beta = 0.10, n=96.

All data were statistically analyzed with SPSS version 25.0 (IBM Inc.,
Chicago, IL, USA). Continuous data were evaluated for normality and
homogeneity of variances by the Kolmogorov--Smirnov test and analysis of
variance, respectively. The data did not satisfy the normal distribution
or the 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 chi-squared test or Fisher's exact test. The specificity
and sensitivity of the extensive lung consolidation for distinguishing
mild and severe pneumonia were calculated based on this test. The
relationship between the number of areas involved in pulmonary
consolidation and mild or severe pneumonia was analyzed using the
receiver operating characteristic curve (ROC), and the Youden index of
the curve was calculated.

We present summary statistics as median (interquartile range {[}IQR{]})
for continuous variables and frequencies (percentages) for categorical
variables. All tests were two-sided, and a p value \textless{}0.05 was
considered a significant difference.

4. Results

4.1 Demographics and general information

A total of 135 cases of neonatal pneumonia with confirmed pathogens were
collected, with a gestational age of 25-42\textsuperscript{+4} weeks,
birth weight of 700-4350 g. Fifty newborns with normal lungs were
enrolled as a control group (Figure 1), with gestational age of
25\textsuperscript{+4} to 41\textsuperscript{+1} weeks, birth weight of
750-4010 g, A comparison of demographic characteristics between two
groups is presented in Table 1. In the pneumonia group, there were 135
patients with abnormal pleural lines, and the involved areas were in
1-12 regions; 126 patients had pulmonary edema signs, which were in 1-12
regions; 135 patients had pulmonary consolidation, which were in 1-12
regions; and there were 37 patients with air bronchogram and 19 patients
with pleural effusion. In the control group, there were no patients with
pleural line abnormalities, pulmonary consolidation, air bronchogram, or
pleural effusion, though six patients had pulmonary edema signs in
regions 1-3. The basic demographic data of children with pneumonia and
healthy newborns were not significantly different, but the distribution
of LUS images was significantly different (Table 2)

4.2 Comparison of lung ultrasound in different groups

Among the 135 children, 72 were infected with bacteria, 20 had mixed
infections, 19 had viral infections, 12 had atypical pathogen
infections, and 12 had fungal infections (Figure 2). There was no
significant difference in the distribution of the LUS images between the
groups after pairwise multiple comparison (Table 2).

The bacterial infection group was divided into the bacillus group (49
cases, Figure 2) and the coccus group (23 cases, Figure 2). There was no
significant difference in LUS images between the two groups (Table 2).

There were 61 patients with community-acquired pneumonia, 37 patients
with congenital pneumonia, and 37 patients with nosocomial pneumonia
(Figure 2). The LUS images were similar between the three groups (Table
2).

There were 69 full-term infants and 66 premature infants (Figure 2). The
differences in LUS manifestations between the two groups were not
significant (Table 2).

There were 108 patients in the severe group (Figure 1, 2) and 27
patients in the mild group (Figure 1). There were no significant
differences in pleural line abnormalities, pulmonary edema signs, or
pleural effusion between the severe group and the mild group, but there
were significant differences in pulmonary consolidation and air
bronchogram between two groups. The ROC curve of pulmonary consolidation
(total number of regions) to distinguish severe and mild pneumonia had
an area under the curve of 0.776. The Youden index was 3.5, the
sensitivity was 77.8\%, and the specificity was 63\% (Table S2). The
sensitivity of LUS images of extensive pulmonary consolidation to
distinguish severe and mild pneumonia was 83.3\%, and the specificity
was 85.2\% (Table 3).

There were 68 patients with bilateral pleural line abnormalities in the
bacterial infection group, 18 patients in the mixed infection group, 16
patients in the viral infection group, 10 patients in the atypical
pathogen infection group, and 12 patients in the fungal infection group.
There were four patients with unilateral pleural line abnormalities in
the bacterial infection group, two in the mixed infection group, three
in the viral infection group, two in the atypical pathogen infection
group, and zero in the fungal infection group. There were 58 patients
with bilateral pulmonary edema signs in the bacterial infection group,
16 in the mixed infection group, 14 in the viral infection group, 10 in
the atypical pathogen infection group, and 10 in the fungal infection
group. There were 11 patients with signs of unilateral pulmonary edema
in the bacterial infection group, two in the mixed infection group,
three in the viral infection group, one in the atypical pathogen
infection group, and one in the fungal infection group. There were 53
patients with bilateral pulmonary consolidation in the bacterial
infection group, 16 in the mixed infection group, 12 in the viral
infection group, nine in the atypical pathogen infection group, and 11
in the fungal infection group. There were 19 patients with unilateral
pulmonary consolidation in the bacterial infection group, four in the
mixed infection group, seven in the viral infection group, three in the
atypical pathogen infection group, and one in the fungal infection
group. There was no significant difference in unilateral or bilateral
distribution between groups based on the pairwise multiple comparison
(Figure S1).

5. Discussion

To the best of our knowledge, this is the first multicenter prospective
ultrasound study of neonatal pneumonia based on the identification of
the pathogen. We compared neonatal pneumonia with different pathogens,
different degrees of infection, different infection times, and different
gestational ages. The results showed that (1) LUS can well diagnose
neonatal pneumonia, but there was no difference in the LUS signs of
neonatal pneumonia between different pathogens, different infection
times, or different gestational ages. (2) The size and extent of the
pulmonary consolidation has a high sensitivity (83.3\%) and specificity
(85.2\%) for the distinction of severe and mild neonatal pneumonia.

With the widespread application of LUS, Tsung et
al.\textsuperscript{{[}24{]}} proposed that pulmonary consolidation
combined with air bronchogram suggested bacterial infectious pneumonia.
In contrast, in the study by \selectlanguage{ngerman}Öktem et al.\textsuperscript{{[}25{]}}, 50
cases (100\%) of viral pneumonia all had pulmonary consolidation
combined with air bronchogram. In the study by Buonsenso et
al.\textsuperscript{{[}19{]}}, among the 76 cases of viral pneumonia and
43 cases of atypical pathogenic pneumonia, 25 (32.9\%) and 26 cases
(60.5\%) were associated with air bronchogram. In this study, the
differences in the incidence of air bronchogram between pneumonia
patients with different pathogens was not significant. Unlike the above
studies based on other auxiliary examinations, this study was based on
the study of the clear etiology and may therefore be more accurate. Air
bronchogram is the presence of air in bronchioles and terminal
bronchioles in pulmonary consolidation .\textsuperscript{{[}26{]}}. It
is only associated with pathological changes at different stages of
disease development\textsuperscript{{[}27{]}}, not a sign of bacterial
or viral infection. For example, the typical LUS manifestations of
neonatal respiratory distress syndrome are pulmonary consolidation and
air bronchogram\textsuperscript{{[}28, 29{]}}.

Some studies suggest that bilateral pulmonary consolidation mostly
occurs in viral pneumonia while unilateral pulmonary consolidation
mostly occurs in bacterial pneumonia\textsuperscript{{[}19, 20{]}}. In
the study by Buonsenso et al.\textsuperscript{{[}19{]}}, bilateral
pulmonary consolidation was found in 0.09\% of bacterial pneumonia,
46.15\% of viral pneumonia, and 31.58\% of atypical pneumonia cases. In
contrast, Malla et al.\textsuperscript{{[}30{]}} found that bilateral
pulmonary consolidation occurred in 35.6\% of bacterial pneumonia cases
and 11.1\% of viral pneumonia cases. The study of coronavirus disease
2019 (COVID-19) by Zieleskiewicz et al.\textsuperscript{{[}31{]}} found
that 17\% of pulmonary consolidation occurred in one of the lungs, and
15\% of pulmonary consolidation occurred in both lungs. The size of
pulmonary consolidation has also been used to distinguish between
bacterial pneumonia and viral pneumonia. Malla et
al.\textsuperscript{{[}30{]}} believed that pulmonary consolidation of
viral pneumonia was \textless{}0.5 cm. Berce et
al.\textsuperscript{{[}20{]}} set the threshold of 2.1 cm of pulmonary
consolidation for the identification of bacterial vs. viral pneumonia.
In a study of bronchitis, Biagi et al.\textsuperscript{{[}32{]}} found
that when pulmonary consolidation was greater than 1 cm, the likelihood
of bacterial bronchitis was high. Buonsenso et
al.\textsuperscript{{[}19{]}} found that 55.22\% of bacterial pneumonia,
35.38\% of viral pneumonia, and 44.74\% of atypical pneumonia had
pulmonary consolidation of 1.5-4 cm. The three cases of COVID-19
reported by Hernández et al.\textsuperscript{{[}33{]}} each had multiple
pulmonary consolidations with diameters ranging from 2 to 24 mm.
According to the above reports, due to differences between subjects, the
location and size of pulmonary consolidation in patients with viral or
bacterial pneumonia are not specific. The extent of pulmonary
consolidation and the total area of the lung involved are only related
to the severity of the disease and are not affected by the etiology of
the infection. This study did not find differences in pleural lines,
pulmonary edema signs, distribution of pulmonary consolidation, or the
involved areas between bacterial infection, atypical pathogen infection,
viral infection, mixed infections, and fungal infections. Pulmonary
consolidation is caused by alveolar exudate\textsuperscript{{[}34{]}}.
Its size depends on the degree of air loss from the
alveoli\textsuperscript{{[}35{]}}. It is only a nonspecific sign of
pneumonia. Pneumonia caused by any etiology or pathogen can result in
pulmonary consolidation. In addition, LUS sometimes has difficulty
measuring the actual size of each pulmonary
consolidation\textsuperscript{{[}36{]}}. Therefore, it is difficult to
distinguish the etiology of neonatal pneumonia from the size and
distribution of pulmonary consolidation.

Through this multicenter, prospective study, we have confirmed that the
degree and extent of pulmonary consolidation in neonatal pneumonia with
different pathogens were only related to the severity of the disease,
and extensive pulmonary consolidation could be used to well distinguish
between severe and mild neonatal pneumonia. The size of pulmonary
consolidation only represents the degree of lung tissue damage by
pneumonia, which is consistent with the pathology of pulmonary
consolidation. The area under the ROC curve correlating the area of
pulmonary consolidation and the severity of pulmonary consolidation was
0.776. When the area of pulmonary consolidation was \selectlanguage{english}[?] 4, the sensitivity
was 77.8\%, and the specificity was 63\%. Bitar et
al.\textsuperscript{{[}37{]}} found that the number of pulmonary
consolidations in pneumonia was correlated with the degree of
PO\textsubscript{2}/F\textsubscript{i}O\textsubscript{2} deterioration,
and the results of this study were similar. Mafort et
al.\textsuperscript{{[}38{]}} believed that pulmonary consolidation was
related to the severity of pneumonia. Kong et
al.\textsuperscript{{[}39{]}} found that pulmonary consolidations were
significantly more numerous in severe pneumonia. However, Alharthy et
al.\textsuperscript{{[}40{]}} found that by the time patients with
severe pneumonia were discharged, the LUS signs of pulmonary
consolidation had been significantly reduced. This evidence indicates
that the imaging manifestations of pulmonary consolidation in pneumonia
can only represent the disease process of neonatal pneumonia, and it is
difficult to distinguish the pathogens of neonatal pneumonia based on
pulmonary consolidation.

The shortcomings of this study are as follows: First, the pathogens were
unevenly distributed, being mainly bacteria, and the sample size of some
pathogens, such as mycoplasma, chlamydia, and fungi, was small. More
experiments containing a larger number of these pathogens are needed to
confirm the above findings. Second, there were more severe pneumonia
patients than mild patients, which may have influenced the specificity
of distinguishing mild from severe pneumonia based on the extent of
pulmonary consolidation. In the future, more mild pneumonia patients
need to be included to confirm the conclusions of this study.

6. Conclusion

LUS is a radiation-free, convenient, efficient auxiliary tool for the
diagnosis of neonatal pneumonia. However, LUS has difficulty
distinguishing neonatal pneumonia with different pathogens, different
gestational ages, and different infection times. The size and extent of
pulmonary consolidation has good performance in judging the severity of
neonatal pneumonia. These LUS features will help clinicians more
accurately manage patients.

Contributors' Statement:

Dr Jing Liu conceptualized and designed the study, drafted the initial
manuscript, obtained funding and take responsibility for the integrity
of the data and the accuracy of the data analysis.Dr Hai-Ran Ma
conceptualized and designed the study, drafted the initial manuscript,
and reviewed and revised the manuscript.Drs Peng Jiang, Yan-Lei Xu,
Xiu-Yun Song, Jie Li, Li-Han Huang, Ling-Yun Bao and Rui-Yan Shan
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.

Funding/Support: This work was supported by a grant from the Social
Development Projects, Beijing Chaoyang District Bureau of Science,
Technology and Information (SYSF1820,CYSF1922) and the Clinical Research
Special Fund of Wu Jieping Medical Foundation (320. 6750. 15072).

Conflict of Interest Disclosures for all authors: The authors have no
conflicts of interest relevant to this article to disclose

Informed Consent Statement: Written informed consent was obtained from
the participants' parents.

Data Availability Statement: Not applicable.

Abbreviation List

AB: air bronchogram

APL: abnormal pleural lines

IQR: interquartile range

LUS: Lung ultrasound

PE: pleural effusion

PES: pulmonary edema signs

PS: pulmonary consolidation

ROC: receiver operating characteristic curve

References

1. Hooven TA, Polin RA. Pneumonia. Seminars in fetal \& neonatal
medicine. 2017;22(4):206-13.

2. Stoll BJ. The global impact of neonatal infection. Clinics in
perinatology. 1997;24(1):1-21.

3. Duke T. Neonatal pneumonia in developing countries. Archives of
disease in childhood Fetal and neonatal edition. 2005;90(3):F211-9.

4. Barton L, Hodgman JE, Pavlova Z. Causes of death in the extremely low
birth weight infant. Pediatrics. 1999;103(2):446-51.

5. Orso D, Ban A, Guglielmo N. Lung ultrasound in diagnosing pneumonia
in childhood: a systematic review and meta-analysis. Journal of
ultrasound. 2018;21(3):183-95.

6. Najgrodzka P, Buda N, Zamojska A, Marciniewicz E,
Lewandowicz-Uszy\selectlanguage{polish}ń\selectlanguage{english}ska A. Lung Ultrasonography in the Diagnosis of
Pneumonia in Children-A Metaanalysis and a Review of Pediatric Lung
Imaging. Ultrasound quarterly. 2019;35(2):157-63.

7. Tsou PY, Chen KP, Wang YH, et al. Diagnostic Accuracy of Lung
Ultrasound Performed by Novice Versus Advanced Sonographers for
Pneumonia in Children: A Systematic Review and Meta-analysis. Academic
emergency medicine : official journal of the Society for Academic
Emergency Medicine. 2019;26(9):1074-88.

8. Kurepa D, Zaghloul N, Watkins L, Liu J. Neonatal lung ultrasound exam
guidelines. Journal of perinatology : official journal of the California
Perinatal Association. 2018;38(1):11-22.

9. Liu J, Ma HR, Fu W. Lung Ultrasound to Diagnose Pneumonia in Neonates
with Fungal Infection. Diagnostics (Basel, Switzerland). 2022;12(8).

10. Liu J, Copetti R, Sorantin E, et al. Protocol and Guidelines for
Point-of-Care Lung Ultrasound in Diagnosing Neonatal Pulmonary Diseases
Based on International Expert Consensus. Journal of visualized
experiments : JoVE. 2019(145).

11. Singh Y, Tissot C, Fraga MV, et al. International evidence-based
guidelines on Point of Care Ultrasound (POCUS) for critically ill
neonates and children issued by the POCUS Working Group of the European
Society of Paediatric and Neonatal Intensive Care (ESPNIC). Critical
care (London, England). 2020;24(1):65.

12. 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. 2018:1-8.

13. Staub LJ, Biscaro RRM, Maurici R. Accuracy and Applications of Lung
Ultrasound to Diagnose Ventilator-Associated Pneumonia: A Systematic
Review. Journal of intensive care medicine. 2018;33(8):447-55.

14. Sharma D, Farahbakhsh N. Role of chest ultrasound in neonatal lung
disease: a review of current evidences. The journal of maternal-fetal \&
neonatal medicine : the official journal of the European Association of
Perinatal Medicine, the Federation of Asia and Oceania Perinatal
Societies, the International Society of Perinatal Obstet.
2019;32(2):310-6.

15. 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.

16. Mart\selectlanguage{ngerman}ínez Redondo J, Comas Rodríguez C, Pujol Salud J, et al. 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).

17. Balk DS, Lee C, Schafer J, et al. Lung ultrasound compared to chest
X-ray for diagnosis of pediatric pneumonia: A meta-analysis. Pediatric
pulmonology. 2018;53(8):1130-9.

18. Reali F, Sferrazza Papa GF, Carlucci P, et al. Can lung ultrasound
replace chest radiography for the diagnosis of pneumonia in hospitalized
children? Respiration; international review of thoracic diseases.
2014;88(2):112-5.

19. Buonsenso D, Musolino A, Ferro V, et al. Role of lung ultrasound for
the etiological diagnosis of acute lower respiratory tract infection
(ALRTI) in children: a prospective study. Journal of ultrasound.
2021:1-13.

20. Berce V, Tomazin M, Gorenjak M, Berce T, Lovren\selectlanguage{polish}č\selectlanguage{english}i\selectlanguage{polish}č \selectlanguage{english}B. The Usefulness
of Lung Ultrasound for the Aetiological Diagnosis of Community-Acquired
Pneumonia in Children. Scientific reports. 2019;9(1):17957.

21. Bradley JS, Byington CL, Shah SS, et al. The management of
community-acquired pneumonia in infants and children older than 3 months
of age: clinical practice guidelines by the Pediatric Infectious
Diseases Society and the Infectious Diseases Society of America.
Clinical infectious diseases : an official publication of the Infectious
Diseases Society of America. 2011;53(7):e25-76.

22. Liu J, Guo G, Kurepa D, et al. Specification and guideline for
technical aspects and scanning parameter settings of neonatal lung
ultrasound examination. The journal of maternal-fetal \& neonatal
medicine : the official journal of the European Association of Perinatal
Medicine, the Federation of Asia and Oceania Perinatal Societies, the
International Society of Perinatal Obstet. 2021:1-15.

23. Carter JV, Pan J, Rai SN, Galandiuk S. ROC-ing along: Evaluation and
interpretation of receiver operating characteristic curves. Surgery.
2016;159(6):1638-45.

24. Tsung JW, Kessler DO, Shah VP. Prospective application of
clinician-performed lung ultrasonography during the 2009 H1N1 influenza
A pandemic: distinguishing viral from bacterial pneumonia. Critical
ultrasound journal. 2012;4(1):16.

25. \selectlanguage{ngerman}Öktem A, Zenciro\selectlanguage{polish}ğ\selectlanguage{english}lu A, \selectlanguage{ngerman}Üner Ç, Aydo\selectlanguage{polish}ğ\selectlanguage{english}an S, Dilli D, Okumu\selectlanguage{polish}ş \selectlanguage{english}N.
Efficiency of Lung Ultrasonography in the Diagnosis and Follow-up of
Viral Pneumonia in Newborn. American journal of perinatology. 2021.

26. Weinberg B, Diakoumakis EE, Kass EG, Seife B, Zvi ZB. The air
bronchogram: sonographic demonstration. AJR American journal of
roentgenology. 1986;147(3):593-5.

27. Buonsenso D, Brancato F, Valentini P, Curatola A, Supino M, Musolino
AM. The Use of Lung Ultrasound to Monitor the Antibiotic Response of
Community-Acquired Pneumonia in Children: A Preliminary Hypothesis.
Journal of ultrasound in medicine : official journal of the American
Institute of Ultrasound in Medicine. 2020;39(4):817-26.

28. Liu J, Wang Y, Fu W, Yang CS, Huang JJ. Diagnosis of neonatal
transient tachypnea and its differentiation from respiratory distress
syndrome using lung ultrasound. Medicine. 2014;93(27):e197.

29. Liu J, Cao HY, Wang HW, Kong XY. The role of lung ultrasound in
diagnosis of respiratory distress syndrome in newborn infants. Iranian
journal of pediatrics. 2014;24(2):147-54.

30. Malla D, Rathi V, Gomber S, Upreti L. Can lung ultrasound
differentiate between bacterial and viral pneumonia in children? Journal
of clinical ultrasound : JCU. 2021;49(2):91-100.

31. Zieleskiewicz L, Markarian T, Lopez A, et al. Comparative study of
lung ultrasound and chest computed tomography scan in the assessment of
severity of confirmed COVID-19 pneumonia. Intensive care medicine.
2020;46(9):1707-13.

32. Biagi C, Pierantoni L, Baldazzi M, et al. Lung ultrasound for the
diagnosis of pneumonia in children with acute bronchiolitis. BMC
pulmonary medicine. 2018;18(1):191.

33. Gregorio-Hern\selectlanguage{ngerman}ández R, Escobar-Izquierdo AB, Cobas-Pazos J,
Martínez-Gimeno A. Point-of-care lung ultrasound in three neonates with
COVID-19. European journal of pediatrics. 2020;179(8):1279-85.

34. Liu XL, Lian R, Tao YK, Gu CD, Zhang GQ. Lung ultrasonography: an
effective way to diagnose community-acquired pneumonia. Emergency
medicine journal : EMJ. 2015;32(6):433-8.

35. Volpicelli G, Elbarbary M, Blaivas M, et al. International
evidence-based recommendations for point-of-care lung ultrasound.
Intensive care medicine. 2012;38(4):577-91.

36. Lichtenstein DA, Lascols N, Mezière G, Gepner A. Ultrasound
diagnosis of alveolar consolidation in the critically ill. Intensive
care medicine. 2004;30(2):276-81.

37. Bitar ZI, Shamsah M, Maadarani O, Bamasood OM, Bitar AZ, Alfoudri H.
Lung Ultrasound and Sonographic Subpleural Consolidation in COVID-19
Pneumonia Correlate with Disease Severity. Critical care research and
practice. 2021;2021:6695033.

38. Mafort TT, Lopes AJ, da Costa CH, et al. Changes in lung ultrasound
of symptomatic healthcare professionals with COVID-19 pneumonia and
their association with clinical findings. Journal of clinical ultrasound
: JCU. 2020;48(9):515-21.

39. Kong S, Wang J, Li Y, et al. Value of Bedside Lung Ultrasound in
Severe and Critical COVID-19 Pneumonia. Respiratory care.
2021;66(6):920-7.

40. Alharthy A, Faqihi F, Abuhamdah M, et al. Prospective Longitudinal
Evaluation of Point-of-Care Lung Ultrasound in Critically Ill Patients
With Severe COVID-19 Pneumonia. Journal of ultrasound in medicine :
official journal of the American Institute of Ultrasound in Medicine.
2021;40(3):443-56.

Table 1. Demographic and Descriptive Information\selectlanguage{english}
\begin{longtable}[]{@{}llll@{}}
\toprule
Variable & Pneumonia (N=135) & control subjects (N=50) & \emph{P}
values\tabularnewline
\midrule
\endhead
Demographic information & & &\tabularnewline
Gestational Age, wk & 37.8(5.6) & 37.1(8.4) & 0.72\tabularnewline
Birth Weight, g & 3(1.7) & 2.7(1.9) & 0.99\tabularnewline
Sex\textsuperscript{b} & & &\tabularnewline
Male & 84(62) & 26(52) & 0.24\tabularnewline
Female & 51(38) & 24(48) &\tabularnewline
Delivery method\textsuperscript{b} & & &\tabularnewline
Cesarean delivery & 58(43) & 26(52) & 0.32\tabularnewline
Vaginal delivery & 77(57) & 24(48) &\tabularnewline
\bottomrule
\end{longtable}

a, Data are presented as median (IQR)

b, Data are presented as No. (\%).

Table2. Comparison of the LUS manifestations in different groups.\selectlanguage{english}
\begin{longtable}[]{@{}llllllll@{}}
\toprule
& median (IQR) & median (IQR) & median (IQR) & & No. (\%) & No. (\%)
&\tabularnewline
\midrule
\endhead
Group & APL & PES & PC & PC & AB & PE & PE\tabularnewline
Pneumonia (N=135) & 8(6) & 7(7) & 4(5) & 4(5) & 37(27) & 19(14) &
19(14)\tabularnewline
Control subjects (N=50) & 0(0) & 0(0) & 0(0) & 0(0) & 0(0) & 0(0) &
0(0)\tabularnewline
\emph{P} values & \textless{}0.001 & \textless{}0.001 & \textless{}0.001
& \textless{}0.001 & \textless{}0.001 & 0.004 & 0.004\tabularnewline
Bacteria (N=72) & 10(6) & 8(8) & 4(5) & 4(5) & 17(22) & 8(10) &
8(10)\tabularnewline
Mixed infections (N=20) & 8(6) & 6(5) & 5(6) & 5(6) & 7(35) & 4(20) &
4(20)\tabularnewline
Viral infections (N=19) & 8(8) & 4(5) & 3(5) & 3(5) & 5(26) & 2(11) &
2(11)\tabularnewline
Atypical pathogen (N=12) & 9(6) & 7(8) & 7(6) & 7(6) & 3(25) & 3(25) &
3(25)\tabularnewline
Fungal infections (N=12) & 8(7) & 8(7) & 5(2) & 5(2) & 5(42) & 2(17) &
2(17)\tabularnewline
\emph{P} values & 0.62 & 0.10 & 0.49 & 0.49 & 0. 64 & 0.55 &
0.55\tabularnewline
bacillary pneumonia(N=49) & 10(6) & 8(7) & 4(4) & 4(4) & 14 (29) & 6
(12) & 6 (12)\tabularnewline
coccal pneumonia(N=23) & 12(7) & 8(8) & 4(5) & 4(5) & 3 (13) & 2 (9) & 2
(9)\tabularnewline
\emph{P} values & 0.82 & 0.89 & 0.50 & 0.50 & 0.23 & \textgreater{}0.99
& \textgreater{}0.99\tabularnewline
community-acquired pneumonia (N=61) & 8(8) & 6(5) & 4(6) & 4(6) & 15(25)
& 12(20) & 12(20)\tabularnewline
Congenital pneumonia(N=37) & 8(6) & 8(5) & 4(3) & 4(3) & 8(22) & 3(8) &
3(8)\tabularnewline
Nosocomial pneumonia(N=37) & 11(6) & 7(8) & 6(4) & 6(4) & 14(38) & 4(11)
& 4(11)\tabularnewline
\emph{P} values & 0.22 & 0.51 & 0.10 & 0.10 & 0.25 & 0. 24 & 0.
24\tabularnewline
Full-term(N=69) & 8(7) & 6(5) & 4(5) & 4(5) & 17(25) & 11(16) &
11(16)\tabularnewline
Preterm(N=66) & 10(6) & 7 (5) & 5(4) & 5(4) & 20(30) & 8(12) &
8(12)\tabularnewline
\emph{P} values & 0.23 & 0.33 & 0.25 & 0.25 & 0.56 & 0.52 &
0.52\tabularnewline
Severe pneumonia(N=108) & 10(6) & 7(7) & 5(4) & 5(4) & 35(32) & 16 (15)
& 16 (15)\tabularnewline
Mild pneumonia(N=27) & 6(8) & 6(5) & 2 (2) & 2 (2) & 2(7) & 3 (11) & 3
(11)\tabularnewline
\emph{P} values & 0.15 & 0.37 & \textless{}0.001 & \textless{}0.001 &
0.01 & 0.76 & 0.76\tabularnewline
\bottomrule
\end{longtable}

Abbreviations: APL, abnormal pleural lines; PES, pulmonary edema signs;
PS, pulmonary consolidation;

AB, air bronchogram; PE, pleural effusion.

Table3. The sensitivity and specificity of LUS images of extensive
pulmonary consolidation to distinguish severe and mild pneumonia\selectlanguage{english}
\begin{longtable}[]{@{}llllll@{}}
\toprule
Extensive pulmonary consolidation & Severe pneumonia & Mild pneumonia &
Total & Sensitivity (a/a+c) & Specificity (d/b+d)\tabularnewline
\midrule
\endhead
Present & 90(a) & 4(b) & 94(a+b) & 83.3\% & 85.2\%\tabularnewline
Not present & 18(c) & 23(d) & 41(c+d) & &\tabularnewline
Total & 108 (a+c) & 27(b+d) & 82(a+b+c+d) & &\tabularnewline
\bottomrule
\end{longtable}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image1/image1}

\end{center}
\end{figure}

Figure1: Lung ultrasound findings of normal lung and pneumonia in
neonates: a. Normal lung b. Mild pulmonary consolidation (mild
pneumonia): the consolidation extent was limited to the pleural line,
involving only one intercostal space; c. Moderate pulmonary
consolidation (mild pneumonia): the consolidation involved 2-3
intercostal spaces. d. Extensive lung consolidation (severe pneumonia):
involving more than three intercostal spaces.\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/image2/image2}

\end{center}
\end{figure}

Figure2: Lung ultrasound findings of severe pneumonia in neonates: a.
Pseudomonas aeruginosa Pneumonia (nosocomial pneumonia); gestational
age, 28 wk plus 3 d; b. Streptococcus pneumonia (congenital pneumonia);
gestational age, 41 wk plus 3 d; c. Pneumonia infected by Staphylococcus
aureus and Escherichia coli (nosocomial pneumonia); gestational age, 28
wk; d. Respiratory syncytial virus pneumonia (community-acquired
pneumonia); gestational age, 40 wk; e. Chlamydia trachomatis pneumonia
(community-acquired pneumonia); gestational age, 38 wk plus 2 d; f.
Candida albicans pneumonia (nosocomial pneumonia) gestational age, 27 wk
plus 6 d.\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/figure1/figure1}

\end{center}
\end{figure}

\textbf{Hosted file}

\verb`Figure S1.docx`  available at \url{https://authorea.com/users/500029/articles/580916-lung-ultrasound-to-diagnose-infectious-pneumonia-of-the-newborns-a-prospective-multicenter-study}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-S1/Figure-S1}

\end{center}
\end{figure}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/figure2/figure2}

\end{center}
\end{figure}

\textbf{Hosted file}

\verb`Table S1.docx`  available at \url{https://authorea.com/users/500029/articles/580916-lung-ultrasound-to-diagnose-infectious-pneumonia-of-the-newborns-a-prospective-multicenter-study}

\textbf{Hosted file}

\verb`Table S2.docx`  available at \url{https://authorea.com/users/500029/articles/580916-lung-ultrasound-to-diagnose-infectious-pneumonia-of-the-newborns-a-prospective-multicenter-study}

\selectlanguage{english}
\FloatBarrier
\end{document}

