Gene expression in sepsis and sterile sirs in pediatric patients after cardiac surgery

Because of the high risk of infection and endocarditis in patients after
cardiac surgery,
there is a low threshold for starting antibiotics when infection is suspected,
or changing the CVC when catheter related infection is suspected.
Systemic Inflammatory Response Syndrome (SIRS) appears similar clinically,
irrespective if it is caused by an infectious (sepsis) or non-infectious
(sterile SIRS) etiology.
In pediatric patients after cardiac surgery there is a low threshold for the
use of antibiotics when infection is suspected. However, in a lot of cases no
causative microorganism can be demonstrated. Probably, the symptoms are
reflecting SIRS, which can for example, be the result of using cardiopulmonary
bypass during the procedure.
Often unnecessary antibiotics will be started. Extensive use of antibiotics
might cause adverse effects such as bacterial resistance and infections with
candida or aspergillus species.
Every seven days, the central venous catheter is electively changed, although
in literature there is no evidence found for this routine. In case of
suspected (blood stream) infection, often the CVC will be replaced, which can
lead to mechanical or other omplications, and also another vessel might be
sacrificed due to obstruction.
Despite the similar phenotypic expression, genotypic expression may differ in
case of different etiologies causing SIRS. This hypothesis is verified by
several studies in critical ill adults with all kinds of underlying diseases.
Besides the arguments mentioned above, differentiation between sepsis and
sterile SIRS is important considering the fact that the mortality of sepsis is
much higher than that of uninfected SIRS.
One study showed a unique pattern of gene expression in the neonatal myocardium
of neonates after cardiac surgery for right heart obstructive lesions. However
it*s not clear whether this is age dependent, or reflecting underlying
disease.
In several other publications (in adults), gene expression profiles after
cardiopulmonary bypass and cardioplegic arrest were described.

To differentiate between gene expression in sepsis and sterile sirs.

This is an observational explorative study that will be conducted at the
operating room (OR) and pediatric intensive care unit (PICU) at LUMC, Leiden,
the Netherlands.
20 patients will be enrolled in the study, undergoing cardiac surgery with
bypass for congenital heart defects.
Residual blood from arterial samples will be collected on the OR ( moment of
study entry), immediate after admittance on the PICU, 12, 24 and 48 hours
later. Taking blood samples at these timepoints is routine patient practice.
Genetic expression will be analyzed, in order to investigate if there is a
differencein expression in patients with SIRS or Sepsis.
The diagnosis of Sepsis and SIRS are based on the clinical criteria as defined
by the Members of the International consensus conference on pediatric sepsis.

not applicable