Introduction
The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)
was found to induce an increased incidence of
thrombosis1, 2 and strokes3 in
adults. They developed a recognizable coagulopathy, characterized by
increased thrombin generation, decreased fibrinolysis, elevated D-dimers
and a prolonged prothrombin time (PT), which was found to be a strong
predictor of mortality, with pulmonary microthrombi contributing
significantly4. Anticoagulation has been shown to
decrease this mortality5.
Rannucci et al 6 reported baseline viscoelastic
testing (using the Quantra Hemostasis analyzer system) obtained 2-5 days
after admission to the ICU demonstrating increased clot strength,
fibrinogen contribution to clot strength and elevated fibrinogen and
D-dimer levels in 16 patients. After escalating thromboprophylaxis,
there was a significant time-related decrease in fibrinogen, D-dimer
levels and clot strength without significant thromboembolic events.
Spieza et al 7 used another viscoelastic tool,
Rotational Thromboelastometry (ROTEM), in acutely ill hospitalized
SARS-CoV-2 patients and demonstrated elevated fibrinogen and D-dimers (p
< 0.0001) and higher maximum clot firmness (MCF) in all ROTEM
parameters in patients compared to controls (p< 0.0001).
Children develop thromboembolic complications in the face of
catheter-related, genetic, anatomical and disease-related predisposing
factors. Elevated fibrinogen and D-dimer levels are observed in various
conditions in children such as infections and autoimmune diseases,
including SARS-CoV-2. However, the prevalence of thromboembolic
complications in children with SARS-CoV-2 infection has not been well
documented, and there are no pediatric-specific thromboprophylaxis
guidelines. Major hematology organizations, including the American
Society of Hematology (ASH)8 and the International
Society of Thrombosis Haemostasis (ISTH)9 have
published recommendations for anticoagulation of hospitalized
symptomatic adults with SARS-CoV-2, which have been largely extrapolated
to the pediatric population. A recent report by Loi et al10 has made some diagnostic and therapeutic
anticoagulation recommendations based on risk stratification of a single
institutional experience. However, there remains a need in this
population for laboratory-based risk-assessment tools to guide clinical
decision making on the use of anticoagulant prophylaxis.
In an effort to explore the utility of viscoelastic testing in children
with SARS-CoV-2, we added ROTEM (a viscoelasticity-based tool available
for clinical use at our institution) to routine coagulation testing in
children admitted with SARS-CoV-2. The objective of this analysis was to
determine if standard coagulation tests and ROTEM testing could be
obtained in children admitted with SARS-CoV-2 infection to assess its
feasibility in determining thrombosis risk. And, if so, were changes in
clot strength in children during an acute SARS-CoV-2 infection
comparable to that seen in adults. We report our experience in this
retrospective analysis of a case series of 8 children with SARS-CoV-2
infection.