Because hyperactive platelets explain 'heparin resistance' in severe COVID-19, when the blood of a patient on anticoagulants still clots in vessels, often in spite of bleeding elsewhere.
The things we are discussing about 5-HT2 antagonists and plasma serotonin, about attempting to halt progression in the early severe stage, are relevant *during* these events.
Rates of PTSD following survival from severe COVID-19 exceed 30%, ditto anxiety and depression.
The ventilator settings required to keep these patients alive tend to permit blood CO2 levels to rise somewhat, in avoiding excessive mechanical damage to the lungs.
This has been repeatedly demonstrated to cause severe anxiety and promote PTSD.