Quote from nettie01
I'm writing from New Zealand and I just thought I'd run a couple of things past you experienced respiratory nurses... I usually know what to do and what is going on with my patients but today I got a bit out of my depth with a pt in respiratory failure.
She was Very hard to wake up for breakfast - very large lady, on 2litres O2. Oxygen saturations 79 - 80% but artierial blood gas showed ++ CO2 retention so I knew we had to be careful about giving O2 (two litres maximum). I also suspected obstructive sleep apnoea because of her size so I suspected her drowsyness was because of that. After a few minutes of stimulation she sat up and ate breakfast.
The docs came to assess her... another artierial blood gas was their priority after bedside assessment.
At about 10.30 the student nurse told me that the O2 was turned down to one litre but we don't know who turned it down. The registrar was talking about getting her transferred to intensive care and then the consultant physician came to the bedside so check on her (something I rarely see.) It was weird, like I knew that the patient was critical, not because of what I saw with the patient (she was opening her eyes, responding to me, responding to her relative when she arrived, and also complaining of hunger) but because of what the doctors were saying and doing; e.g. "We want her transferred [to higher-tech hospital] with a doctor, rather than with a nurse". I just didn't get how serious her situation was.
I asked the consultant, "Did you turn down the oxygen?" He said, "Yes, and you can take it off completely now."
So I did. A few minutes later her pulse oxymetry was 60% and I panicked a bit. How low can it go? Doesn't the cardiac muscle give out at some point?
So I put the O2 back on to one litre again and went to inform the registrar (our term for the doc that works under the consultant - he's not the junior) of what I'd done, saying that I was a bit out of my depth and could he tell me what he wanted etc.
He rang the consultant who was in the building. The consultant came back and said, "Oxygen definitely off. That's what I said. If she gets too much her breathing will stop." "What about her cardiac muscle?" I said. Apparently that was less of a priority but I simply don't know how safe it is to have O2 sats of 60 - 65%.
Anyway, sure I should read up on respiratory physiology, which in the past I've found quite hard to completely understand; what would you do if you saw 60% sats on someone?
My charge nurse said that a person can "recompensate" once they're breathing room air and that the O2 sats would probably start to climb again.
Thanks for reading thus far; thanks for any comments.
This woman did not have CO2 narcosis.....yet. You were right on to be concerned about this particular patient in this instance.
Just knowing the patient had CO2 retention is not enough information at this point. What was the pH and bicarb on the gases? Blood gases should have been priority and not relying on sats only.
When the pulse ox drops below about 70% it really becomes unreliable. Assuming the pulse ox was accurate, a 65% sat would equal a PO2 in the high 30's to low 40's. Concern for cardiac arrest is legitimate.
I would want to know if this woman had any baseline gases before hand.
From your information, is appears this woman would benefit from bipap or cpap system with face mask. This increases ventilation and drops CO2 levels to a more acceptable level.
This patient also needed a high flow mask (venturi mask if you have this) instead of a nasal cannula in order to exactly control the FIO2. This is beneficial for CO2 retainers, which she was.
She most likely will require intubation and placing on a ventilator.........???
And, the O2 should have NEVER been discontinued.
You were correct with your concerns regarding cardioplumonary arrest.
I think you know your stuff.