A Study to Evaluate the Efficacy, Safety and Tolerability of PDNO Infusion in COVID-19 Patients With Acute Pulmonary Hypertension

Inclusion Criteria: * Ability to understand and willing to sign an ICF * Male and female patients at least 18 years of age * Diagnosed with COVID-19 at admission to the ICU * Diagnosed with echocardiographic signs of pulmonary artery systolic pressure (PASP) \> 40 mmHg Exclusion Criteria: * History of chronic pulmonary hypertension (PH), as judged by the Investigator at screening * Known New York Heart Association (NYHA) Functional Class III or IV symptoms * Left heart failure with ejection fraction (EF) \< 35% * Acute coronary syndrome * Body Mass Index (BMI) \> 45 kg/m\^2 * Estimated glomerular filtration rate (eGFR) \< 30 mL/min * MetHb \> 3% * PCO2 \> 7 * Indication of liver disease, defined by serum levels of either alanine aminotransferase (ALT), aspartate aminotransferase (AST) or alkaline phosphatase (ALP) above 3 x upper limit of normal (ULN) at screening * Haemoglobin \< 80 g/dL * Thrombocytopenia (platelet count \< 80000/mm\^3) * Prothrombin time International ratio (INR) \> 1.4 * Pregnancy, or a positive pregnancy test * Ongoing daily treatment the last 3 days with non-steroidal anti-inflammatory drugs * Known active malignancy within the past 3 years * History of allergy/hypersensitivity to PD or ongoing allergy/hypersensitivity or history of hypersensitivity to drugs with a similar chemical structure or class to PDNO * History of any other clinically significant disease or disorder * Participation in any interventional clinical study