INTRODUCTION AND STUDY AIM
In the last years, Lung Ultrasound (LUS) has gained a primary role in
the diagnosis and management of pleuropulmonary disorders, also in
pediatric practice.1-3
LUS is a non-invasive, non-ionizing radiation tool and a rapid,
affordable, point-of-care imaging modality that allow both real-time
diagnosis and follow-up of respiratory diseases.1-3LUS results are immediately available to the clinician, especially in
emergency conditions who can therefore immediately orient himself
towards a diagnosis so that a quick therapeutic decision can be made.
Several studies performed in the pediatric population have shown that
LUS may be better than chest radiography in the diagnosis of
community-acquired pneumonia1-3, can define the
etiology of pneumonia3,4 and many studies have
described and validated LUS pattern or score (based mainly on vertical
artifacts and subpleural consolidations) in neonatal respiratory
disorders5 and bronchiolitis6 but
also the normal LUS pattern in healthy
infants. 2
The latter and other categories of patients are united by having in
common the presence of sonographic interstitial syndrome (SIS): the
presence of multiple or focal, patched or diffuse vertical artifacts
(B-lines) fanning out from the lung wall
interface. 7 It is in fact a lung ultrasound
picture common to various respiratory diseases. 2,6,8
However, to define the nature and possible origin of SIS, not having
many pediatric studies on interpretation of LUS vertical artifacts
available, especially as regards the differentiation between cardiogenic
pulmonary edema or no inflammatory pulmonary congestion and pulmonary
edema of inflammatory origin or fibrosis, up to now it was necessary to
refer to the studies performed on adults, having always in mind the
knowledge of the patient’s clinical background.7-10
In particular, according to studies performed on physical models and in
adult patients7-10, the B lines or vertical artifacts,
in the absence of an analysis of their appearance, cannot easily
differentiate the cause. Soldati et al.7,8,10 have
shown that the B lines are heterogeneous entities in terms of
aggregation and visual structure, the nature of which is linked to the
superficial histological characteristics of their wavelength. Vertical
artifacts generated by a fibrotic or inflammatory lung have a different
appearance from those generated by cardiogenic edema.
Furthermore, several studies performed on the adult
population11-13 have shown that LUS now plays a
leading role in the work-up of adult patients with suspected cardiogenic
pulmonary edema. In fact, the approach that has the best performance is
the one that combines chest X-ray and the determination of the pro-BNP
level with the early use of LUS.13 Recent studies and
systemic reviews11,12 have shown that LUS is highly
sensitive and specific (with a greater sensitivity and specificity than
chest x-ray) in early identification of cardiogenic pulmonary edema and
in its differentiation from primary pulmonary pathologies in dyspneic
geriatric patients (through the evaluation of the B
lines). 7-13
In addition, other studies have shown that the level of pro-BNP is not
only related to pulmonary edema from heart
failure.15-17 In fact, the increase in the value of
NT-pro-BNP, with consequent different degree of pulmonary congestion,
may also be present in the course of other diseases such as the systemic
inflammatory syndrome and / or sepsis also in the absence of organic or
functional damage to the myocardium.16,17
In the pediatric population, on the other hand, in order to interpret
the nature of the SIS picture caused by cardio-pulmonary interactions
and not by primary pulmonary pathologies, up to now we have referred to
the aforementioned preclinical and clinical studies performed on the
adult population. 7-13 In particular, in the
pediatric population a study has never yet been performed which aims to
define the lung ultrasound pattern in acutely ill children (with heart
disease and / or with systemic inflammatory syndrome or sepsis) with a
high pro-BNP level.
Starting from all these assumptions we performed this prospective
observational study aiming to define the LUS pattern in these categories
of acutely ill pediatric patients without primary lung diseases and with
high pro-BNP level.