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(Figs. 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. With regards to his medical history, he was under anastrozole, an aromatase inhibitor (AI), over the last two years, as prescribed by his physician for short stature.
The adolescent was overweight with body mass index (BMI) of 25.2 kg/m2. On admission, he had body temperature 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 body weight once daily.
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. (Figs. 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/day) 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 subcutaneous tinzaparin was substituted by oral warfarin, after completion of three weeks. Anastrozole was discontinued. He was discharged34 days after admission under warfarin 5 mg once daily. Hemostatic parameters and SARS-CoV-2 RT-PCR were regularly evaluated during hospital stay and post discharge, as summarized in Table 1. Genetic testing for hereditary thrombophilia has been scheduled after the acute phase of thrombosis.