Hi HaydenJack, and thanks for sharing your current situation with your mother, here with the community. Although we cannot provide medical advice or diagnostics over the internet (for your own (and mom's) safety), your concern certainly warrant a reply.
As you may be aware, COPD affects all patients differently. Having said that, multiple conditions (as you've said mom has), can make managing her health somewhat complex. As one aspect of care is adjusted, it may have another effect (good or bad), on any of the other coexisting conditions. In the most general of terms, if the medical team has taken her off diuretics, that may be a factor in her oxygenation levels, and something to (re)consider.
I can appreciate the hotline suggesting not to increase the oxygen flow rate to 5 liters and yet, when you do, mom's oxygen saturation does respond. Sometimes, although hotline/phone suggestions can be good, it can also be better to have mom seen by a physician to evaluate your very real concerns for her (oxygen) at this time. Do you feel it would be beneficial or even feasible (you did say she was bedridden), to have mom seen by her doctor at this point?
Your mom is fortunate to have such a compassionate and devoted son, such as you. My heart goes out to you during this very challenging time. Keep up the good work! If there is anything we can do to assist you, please let me or any other moderator / team member know.
Warm regards,
Leon (site moderator COPD.net)