INTRODUCTION
Acute bronchiolitis (AB) is a lower respiratory tract infection that
affects approximately 20% of all children, resulting in hospitalization
for 2-3% of them under 12 months of age. Mortality from AB occurs
predominantly in developing countries. In developed countries it is
associated with various complex chronic conditions and sociodemographic
risk factors.
AB classically presents with increased respiratory effort and wheezing,
often accompanied by systemic manifestations such as fever or apnea, a
common symptom in neonates. a common disease is of 14-21 days with peak
symptoms at days 3-5. guidelines recommend avoiding laboratory or
radiographic evaluations. Nonetheless, these are often performed in
various clinical settings.
The most common viral pathogen associated with bronchiolitis is
Respiratory Syncytial Virus (RSV), which accounts for 50-80% of cases,
and is associated with more severe disease. Co-infections with other
viruses are seen in up to 30% of cases. Secondary bacterial infections,
such as AOM, Pneumonia, and UTI (37-74%, up to 32%, 1-7%
respectively) (7,9) have been reported in hospitalized patients.
(7,9–11). Respiratory failure requiring invasive or non-invasive
ventilation occurs in 3-19% of hospitalized children, usually in PICU
settings.
C-reactive protein (CRP), an acute phase reactant which is synthesized
in the liver, acts as a mediator between the innate and acquired immune
systems. Peaking 48-72 hours after the onset of an inflammatory
response, it is a common clinical tool for diagnosis and monitoring of
inflammatory responses. Only a few studies have examined the relevance
of CRP in RSV bronchiolitis. These studies identified a correlation
between higher CRP levels and an increased risk of severe disease
particularly in cases of radiologically confirmed pneumonia, or the
diagnosis of sepsis in PICU settings.
In this study, our objective is to investigate the correlation between
CRP levels on admission and the severity of RSV bronchiolitis, as well
as any related complications in hospitalized children. Additionally, we
aim to propose specific cutoff values for CRP levels that are indicative
of different severity outcomes, such as the incidence of secondary
infections, prolonged length of stay in the hospital (LOS), and the need
for PICU admission.