2.2. Study Population
pulmonary embolism, hypertension, insufficiency, interstitial pneumonia
PULMONARY EMBOLISM, PCT, SARS-COV-2 INFECTION, INTERSTITIAL PNEUMONIA, HYPERTENSION
Adult patients with severe COVID-19 and PAH who met the following inclusion and exclusion criteria were recruited to the study.Inclusion criteria:SARS-CoV-2 infection (confirmed with a positive reverse transcription polymerase chain reaction (RT PCR test));Bilateral interstitial pneumonia confirmed with a computed tomography (CT) scan;Arterial partial pressure of oxygen (PaOPulmonary hypertension (PH) ≥ 40 mmHg based on Doppler ultrasonography;Informed consent of the patient or their legal representative to participate in the study.Exclusion criteria:Circulatory instability with 80 mmHg < systolic blood pressure < 180 mmHg;High risk of pulmonary embolism (PE) as defined by ESC Guidelines [Clinically significant active bleeding;Kidney insufficiency with creatinine clearance (Cockcroft-Gault formula) < 30 mL/min;Severe liver failure;Retinitis pigmentosa;Hypersensitivity to sildenafil or enoxaparin sodium;Pregnancy or breastfeeding;Participation in other clinical trials.All patients participating in the study received the standard treatment for severe COVID-19 according to the local protocol:methylprednisolone 0.5 mg/kg daily orally;enoxaparin 60 anti-Xa IU/kg once daily if D-dimer < 5 µg/mL, or 100 anti-Xa IU/kg once daily if D-dimer levels ≥ 5 µg/mL;antibiotics in the presence of pathogenic bacterial flora in sputum, urine, or blood;an infusion volume calculated to ensure zero or slightly negative daily fluid balance;oxygen therapy with or without non-invasive ventilation to maintain respiratory index PaOintubation and pressure-controlled mechanical ventilation if PaOstandard treatment of comorbidities.Patients were randomly assigned to one of two groups:Group 1 (treatment group, S)—sildenafil (Superviga, Zdorovye, Ukraine) was administered orally at a dose of 0.25 mg/kg three times a day for seven days after enrolment;Group 2 (control group, C)—placebo was administered in a double-blind manner.The following parameters were measured in all patients one day before the start of the treatment and seven days after the start of the treatment: complete blood count, arterial blood gases, C-reactive protein (CRP), procalcitonin (PCT), fibrinogen, D-dimer, Il-6, and ferritin. Doppler measurement of pulmonary artery pressure (PAP) was also performed.