Nonrebreather vs high-flow (vapotherm)

[what, ASN]

Hello all,

I have been long curious about something. I’ve been working as a PCU-covid night nurse in a small hospital in AZ. I had a patient pass away, bless her soul, sometime before the spike of cases in Arizona and I was still learning about things then like plan of care, etc.

A night before she passed away, pt was already on a nonrebreather, and somewhat tachypneic. Saturation would mainly be on the 85s, and rarely on the low 90s. But it got worse, went to the 70s then to the 60s and with her HR increasing. She was DNR/DNI. I received a bunch of orders, meds, breathing tx. I remember bringing up to the doctor about possibly switching to high-flow, because I’ve taken care of other patients that were placed on high flow in the covid unit. The doctor did not consider it, I remember him saying something like, it wouldn’t be beneficial with the patient satting the way she does, in the 60s.

The next night I took care of the patient, she was on comfort care only. Can’t remember her medical history so I can’t provide that, sorry. But what I have been curious knowing about is if anyone can explain the possible reasoning behind the doctor’s choice of nonrebreather vs high flow? Is it because patient is DNR/DNI? What qualifies/disqualifies a patient from using high-flow? I am not an expert about nonrebreather and high flow but if anyone who has more experience with these that can share their knowledge I would greatly appreciate it.