Does oxygen supplementation in case of pneumonia cause effects other than possibly preventing hypoxemia?

Question

I've been reading about oxygen supplementation and have a question about the effects of oxygen supplementation in case of pneumonia.

Patients with aspiration pneumonitis or pneumonia may progress to acute lung injury and acute respiratory distress symptom (ALI/ARDS), which is characterized by hypoxemia and respiratory failure. - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5564131/

Oxygen supplementation is one way to help patients who cannot breathe adequately on their own. - https://www.cochrane.org/CD006607/ARI_the-effectiveness-of-oxygen-for-adult-patients-with-pneumonia

Normal arterial oxygen is approximately 75 to 100 millimeters of mercury (mm Hg). Values under 60 mm Hg usually indicate the need for supplemental oxygen. - https://www.mayoclinic.org/symptoms/hypoxemia/basics/definition/sym-20050930

Supplementary oxygen is routinely administered to patients, even those with adequate oxygen saturations, in the belief that it increases oxygen delivery. But oxygen delivery depends not just on arterial oxygen content but also on perfusion. - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3218982/

Does oxygen supplementation in case of pneumonia cause (positive or negative) effects other than possibly preventing hypoxemia?

Answer 1

Hyperoxygenation causes vasoconstriction and increased systemic vascular resistance. This can be good in some circumstances and bad in others. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3672526/

Overall there is poor evidence for supplimental oxygen in patients with pneumonia. Cochrane found that: "Non-invasive ventilation can reduce the risk of death in the ICU, endotracheal intubation, shorten ICU stay and length of intubation." But admitted there was very little evidence.

https://www.cochrane.org/CD006607/ARI_the-effectiveness-of-oxygen-for-adult-patients-with-pneumonia