Pray that he does not get pneumonia. These little critters wreak havoc on the lungs and are very difficult to overcome. However, God is greater than Covid..
If his oxygen sats are low and he’s on a ventilator, he has pneumonia.
To prevent more lung damage, corticosteroids are used, IV or nebulized inhalation.
Inhaled nitric (not nitrous) oxide can be used to reduce pulmonary hypertension.
Try to get off ventilator and on mask cpap which is less damaging to lungs.