Case Description
A 15-year-old male was referred to our emergency department with a
four-day history of gradually progressive pain and swelling of the right
lower limb, in the absence of any recent history of injury. A magnetic
resonance imaging (MRI) of the hip, undertaken previously in outpatient
setting following orthopedic referral, demonstrated a thrombus in the
external iliac vein (Fig. 1A and 1B). The patient also reported
gastrointestinal symptoms two weeks earlier, i.e., diarrhea and
vomiting, along with low-grade fever of 37.3oC,
lasting for two days. Regarding his medical history, he was on
anastrozole, an aromatase inhibitor (AI), over the last two years, as
prescribed by his physician for short stature.
On admission, the adolescent had body mass index (BMI) of 25.2
kg/m2. He presented fever of 38.9oC
and exhibited pain in the right hip with limited mobility of the joint
and edema of the right knee. Triplex ultrasound of the right lower
extremity depicted an extended DVT, from the external iliac vein down to
the great saphenous and popliteal vein. Further laboratory
investigations were undertaken, including SARS-CoV-2 RT-PCR on
nasopharyngeal sample. Initial management consisted of combined
antibiotic therapy with intravenous (IV) ceftriaxone and teicoplanin and
anticoagulation treatment with subcutaneous low molecular weight heparin
(LMWH) i.e., tinzaparin in a therapeutic dose of 175 IU/kg/d.
Within the first hour, he developed hypotension with low diastolic blood
pressure (25 mmHg), not responding to IV fluids, tachycardia (125
beats/min) and reduced urine output. Saturation of oxygen dropped to
94%, few hours later. Computed tomography pulmonary angiogram (CTPA)
demonstrated embolus in the left pulmonary artery (Fig. 1C and 1D),
whereas the SARS-CoV-2 RT-PCR revealed high viral
load.4
The patient was urgently transferred to the COVID-19 pediatric intensive
care unit where IV dexamethasone 0.15 mg/kg (max 6 mg/d) was added to
his treatment plan. Oxygen supply was maintained to 2-3 L/min without
further need of intubation or mechanical ventilation. Subcutaneous
tinzaparin was continued and a single dose of IV antithrombin
concentrate was administered due to low levels, resulting in immediate
response to 125%. Systematic thrombolysis was not required. High
temperature subsided 24 hours later, oxygen was weaned off and
antibiotic treatment was discontinued following negative blood cultures.
The patient stepped down to the COVID-19 pediatric ward after 72 hours
where he gradually improved. A total of ten days of IV dexamethasone was
completed and LMWH was substituted by oral warfarin, after completion of
three weeks. He was discharged on day 34, on warfarin 5 mg/d for 6
months. Therapy with anastrozole was ceased. Duration of anticoagulation
treatment will be further guided by clinical outcome and laboratory
profile, including hereditary thrombophilia and antiphospholipid
antibodies testing. Laboratory parameters, regularly evaluated, are
summarized in Table 1.