Children and young adults hospitalized for severe COVID‐19 exhibit thrombotic coagulopathy

Abstract

We report the clinical and laboratory coagulation characteristics of 27 pediatric and young adult patients (2 months to 21 years) treated for symptomatic COVID-19 at a children's hospital in the Bronx, New York, between March 1 and May 31, 2020. D-Dimer was > 0.5 µg/mL (upper limit of normal) in 25 (93%) patients at admission; 11 (41%) developed peak D-dimer > 5 µg/mL during admission. Seven (26%) patients developed venous thromboembolism: three with deep vein thrombosis and four with pulmonary embolism. Requirement of increased ventilatory support was a risk factor for thrombosis (P = 0.006). Three of eight (38%) patients on prophylactic anticoagulation developed thrombosis; however, no patients developed VTE on low-molecularweight heparin prophylaxis titrated to anti-Xa level. Manifestation of COVID-19 disease was severe or critical in 16 (59%) patients. Four (15%) patients died of COVID-19 complications: all had comorbidities. Elevated D-dimer and increased VTE rate were observed in this young cohort, particularly in those with severe respiratory complications, suggesting thrombotic coagulopathy. More data are needed to guide thromboprophylaxis in this age group.

How we approach thrombosis risk in children with COVID‐19 infection and MIS‐C

“…In this article, we discuss specific clinical vignettes to illustrate approaches to assessing thrombosis risk and decision making regarding thromboprophylaxis in children with COVID-19. Our goal is to use these cases to highlight challenging issues that are not addressed in detail within the consensus guidelines, 23 which are listed in Table 1 Key considerations in our proposed approaches are framed upon severity of COVID-19, 4 current knowledge about the risk factors of thrombosis in children with and without COVID-19, 3,19 current throm-boprophylaxis practices among children without COVID-19, 24 and current practices in adults with COVID-19 22 (Figure 1). We acknowledge that we have focused primarily on VTE prevention and in many situations, there is insufficient evidence to recommend a treatment strategy.…”

“…3 A recent study reported a 7% rate of VTE in those hospitalized with COVID-19 and respiratory symptoms 3 and another study demonstrated a significant risk VTE in those needing high ventilatory support (≥5 L/min oxygen, high-flow nasal cannula, non-rebreather mask, or intubation). 19 This patient has at least three additional risk factors for VTE besides oxygen requirement: a pneumonia, 3 underlying comorbid condition with chronic inflammation, and Hispanic race, 2,3 increasing thrombotic risk. Based on the consensus guidelines, 23 he would meet criteria for thromboprophylaxis.…”

“…39 One pediatric report showed elevation of D-dimer more than five times ULN increased odds of VTE. 19 While D-dimer is not specific for COVID-19, based on adult experience, elevation of D-dimer has been incorporated into pediatric guidelines for risk assessment. 23,40 Recent report from Italy suggested that elevated D-dimer in children was more pronounced with MIS-C and did not predict disease severity in acute infection.…”

“…23,40 Recent report from Italy suggested that elevated D-dimer in children was more pronounced with MIS-C and did not predict disease severity in acute infection. 40 Based on available data, 19,23 we consider elevation of D-dimer (greater than or equal to five times ULN) as an additional thrombotic risk that should be incorporated into the overall risk assessment in children. This child had a D-dimer seven times the ULN along with clinical risk factors for VTE, and thromboprophylaxis was recommended.…”

“…8,[11][12][13][14][15][16] Bleeding is not common and the thrombotic spectrum of CAC ranges from pulmonary embolism (PE), deep venous thrombosis (DVT), thrombotic microangiopathy (TMA), and arterial events including stroke. 9,10,17,18 Thrombotic complications have also been reported in children with COVID-19, 7,19,20 but much less is known about its prevalence and risk factors. Anticoagulation therapy has shown to reduce mortality in hospitalized adult patients.…”