O2 Almost killed my patient.

The evidence suggests that the "hypoxic drive" is (as many people have said) of little clinical importance. They have done studies where they took COPD patients, either at high risk of intubation, or in the process of being weaned from the ventilator, and watched what an increase in inspired oxygen did to them.

The answer: not much.

Still, a study in Tasmania suggested harm with oxygen used by EMS. Actually, it showed a huge jump in mortality just from EMS use of high-flow oxygen.

If you want a closer look at these studies, check out COPD: Is EMS Killing Patients with Oxygen? Part 1 and Part 2. As always, informative and somewhat witty.

Spoiler: It's not the oxygen, it's the ventilation. Prehospital CPAP!

Added - jrm818 referred to the Tasmanian study as well. Essential reading for EMS, but should be taken with a toss of salt.
 
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As KellyBracket said: "It's not the oxygen, it's the ventilation. Prehospital CPAP!" To that end, I seem to recall that at times, mixed gas has been used too. CPAP with heliox might just be the ticket at times. That might be a bit expensive to do though, and is probably only truly useful in a certain population... however, it would be highly entertaining to hear people talking like Donald Duck at times...
 
When referring to COPD and hypoxic drive I'm going to try to put this in philosophical terms for those treating COPD pts and are concerned with knocking out their hypoxic drive.

In order to be a CO2 retainer with a true hypoxic drive you will need documentation of such. And that requires ABG's. And they'll have values in the range of (and these are "ish" ranges) pH of 7.3 or higher, PaCO2 > 60, PaO2 60-80 on 1, maybe 2 - 2 1/2 L/min NC, and HCO3 = > 30. These pts will ALWAYS be short of breath. They will have SpO2's of 88% on 1.5 L/min with orders to not let SpO2 get above certain levels. If they have any auscultated breath sounds at all they'll be decreased with wheezes. Little to no lung function left. They'll be pursed lip breathing speaking in broken sentences on a regular day. When they have an acute exacerbation, they won't speak at all to anyone. They're too short of breath and are too focused on breathing. They'll also be looking emaciated. Because chewing food makes them short of breath. These people might also have active DNR's.

To have a hypoxic drive literally means you must be hypoxic and short of breath in order to breathe. We healthy people don't. We have a hypercarbic drive. Our primary stimulus to breathe is when our PaCO2 increases, secondary is hypoxia.

About the only CO2 retainers with a known hypoxic drive that I get nervous with are the pts with Pickwickian Syndrome. These are the pts walking through the grocery store with a room air SpO2 of 75% and not short of breath at all.

Hope this makes sense.
 
This discussion reminds me of a very stubborn patient I had once.

80's year old female c/o trouble breathing. No significant medical history, no COPD, no home O2, no meds. Answers all questions correctly, she is actually very with it, she is having trouble breathing however. 2-3 word dyspnea, tri-podding. Vitals are WNL, O2 Sat is 90 and dropping, with wheezing. I get out the cannula and begin to put it on her, and she FREAKS out! Slapping at me and trying to climb off the gurney. I step back and ask what is wrong, she tells me she is very allergic to o2! I ask again if she has COPD and she says no (paperwork from Dr doesn't mention it either). Any other allergies...nope just oxygen. I tried calling it something else (O2, air, ect) she still refused it. I tried a mask thinking maybe I could "trick" her into thinking it was something else, no luck. I told her I needed to give a Neb, but as soon as she saw the tubing it was a no go. I tried explaning that she could not be allergic as she is breathing it all the time, told her what could happen if she didn't get it, tried changing partners (maybe he could talk her into it). NOTHING worked, she was convienced she was allergic. Very stressful call, but we laugh about it now
 
med109 said:
This discussion reminds me of a very stubborn patient I had once.

80's year old female c/o trouble breathing. No significant medical history, no COPD, no home O2, no meds. Answers all questions correctly, she is actually very with it, she is having trouble breathing however. 2-3 word dyspnea, tri-podding. Vitals are WNL, O2 Sat is 90 and dropping, with wheezing. I get out the cannula and begin to put it on her, and she FREAKS out! Slapping at me and trying to climb off the gurney. I step back and ask what is wrong, she tells me she is very allergic to o2! I ask again if she has COPD and she says no (paperwork from Dr doesn't mention it either). Any other allergies...nope just oxygen. I tried calling it something else (O2, air, ect) she still refused it. I tried a mask thinking maybe I could "trick" her into thinking it was something else, no luck. I told her I needed to give a Neb, but as soon as she saw the tubing it was a no go. I tried explaning that she could not be allergic as she is breathing it all the time, told her what could happen if she didn't get it, tried changing partners (maybe he could talk her into it). NOTHING worked, she was convienced she was allergic. Very stressful call, but we laugh about it now
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People don't have to be smart to be able to make their own medical decisions.
 
@Med109. That's a great example of informed consent (however you want to define "informed") and the patient exercising the right to refuse treatment.
 
NPO said:
The reason I posted this is because I wanted to understand what the nurse's perspective was. I was not concerned about giving 02.
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The nurses' perspective was probably just that he was following written MD orders.

Also, being someone who takes care of elderly COPD patients regularly, he's probably quite used to presentations such as what you describe, and realizes that it doesn't equate to an emergency.

NPO said:
the patient been on my ambulance I would have increased o2 until he was breathing adequately. But seeing as he was still at the facility, and I had other resources available to me (the RT) I chose that route.
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Well, assuming he has a pathology causing his low Sp02, increasing 02 won't cause him to breathe adequately.

It may increase his Sp02, but it won't affect his minute volume (in fact it may reduce it), or do anything to address the cause of his dyspnea.

Robb said:
93% is a fantastic SpO2% for a COPDer.
Sounds like he needed a treatment, which he got, not his FiO2% increased. :)
Click to expand...

Exactly.

Serious complications of high flow rates in a COPD patient are rare, but they are not non-existent.

Usually, what happens is not that the patient stops breathing shortly after you increase the Fi02.

What happens is that they show up to a busy ED with a great Sp02, so they get triaged to a back room and no one pays attention to them for a while because they're busy wrestling with drunks and dealing with patients looking for a Percocet refill. A couple hours later, they find your patient with a Co2 of 90 and a reduced LOC and now he's admitted to the ICU. When all he really needed was some albuterol.


I'm not saying that you did anything wrong at all. As an EMT-B, you did exactly what you were trained to do.

I'm just saying that it wasn't wrong of the nurse to discourage high flow oxygen, as it wasn't going to fix the problem and it just may worsen it.
 
As far as my system is concerned the short term O2 would not kill him although there have been rare cases of it happening in the long term. short term being under 40 MIN or so. As for the MDs order we must follow to the letter if we know for sure the he is an MD and not just an imposter. Although once he is in our care medical control can counter the order.
 
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