Why would respiratory therapist lower supplemental oxygen from 4 liters to two?

If your dad is a COPD patient giving too much oxygen will suppress his body’s need to breathe. Research “the hypoxic response”in COPD. COPD’ers have high carbon monoxide due to the disease. If he gets too much oxygen, the instinct to breathe is suppressed due to an imbalance of oxygen and carbon monoxide.
I am a RN. I tried to keep my patients with COPD on the lowest dose of O2 (2/4 L Nasal cannula). In hospice at this time for your father, 2L will suffice.

My husband is on hospice and has dementia. He can not do anything for himself. Like morphine, other meds for restlessness is for comfort. Oxygen is considered for comfort also. Hospice will provide this if I or we feel it is needed for him. For his comfort. I will not be afraid to have him on oxygen if he needs it and it makes him more comfortable like morphine would. If you feel he needs the 4 L of oxygen keep it there. Checking oxygen saturations is something that is done often by a small clip like device on the finger. God be with you at the difficult time.

I am not a nurse but I think there comes a time that oxygen is not doing any good. I think it has something to do with hemoglobin in the blood. Hemoglobin helps to carry oxygen thru the body. When its low, it can't do this. So no amount of oxygen will help. Alva is a nurse and will correct me if I am wrong.

You can use your search engine to look up "Is too much O2 dangerous" and receive many answers about conditions under which too much O2 is as dangerous as too little. Your question is one to ask the therapist involved or Hospice if they are now involved in care. The latter is very responsive to family questions. No one on Forum can possibly know what is happening now with your Father and his specific case. I sure do sympathize with how overwhelmingly difficult it is to get answers now, and being unable to be with our elders and other family members. I am so sorry for the loss you are facing down. I hope you will find someone who can answer your questions; keep trying to get that person.

My husband who was under hospice care in our home for 22 months, was on 4 liters of oxygen right up until the last couple weeks of his life, when his nurse actually told me that I could actually remove it completely if I wanted to. I wasn't really comfortable doing that, so I agreed to turn it down to 2 liters, with the understanding that if I saw him struggling for air I would turn it back up. And then in his final coupe of days, I did turn his oxygen off, as it was obvious that it wasn't really helping and he was past the point of no return.

You do deserve an explanation though, so keep calling until you get through. God bless you.

bumping up - hopefully one of our medical experts will see this and can help

When my brother was dying in the end of life hospice facility, he didn’t want any oxygen.

The nurse told me that if the oxygen is bothersome they stop giving it to the patient.