WARNING!
As an ICU specialist. I am reading this in utter disbelief at the recommendation for homemade treatments using this method! The treatment of ARDS is done so in a controlled environment, where if something goes dramatically wrong, the equipment & personnel are there to manage it. Nebulised bicarb outside of that environment is dangerous to say the least! It's no better than the advice to use bleach internally to alter the blood pH.
One case study as the article referred to doesn't set a precedent. Please DO NOT follow this advice.
If you do; then I'll see you soon.